The project of the heat exchanger for cooling compressed air with water used in penicillin production
MINISTRY
OF EDUCATION AND SCIENCE, YOUTH AND SPORTS OF UKRAINE National Aviation
University Department of Biotechnology
Course
work (Explanatory Note) Discipline "Processes and apparatus for
biotechnological production "
Theme:
The project of the heat exchanger for cooling compressed air with water used in
penicillin production
Kyiv
2013
TASKS for the course work of the
student
. Theme: The project of the heat
exchanger for cooling compressed air with water used in penicillin production
. Deadline student completed the
work: "24" April 2013 3. Output to: Calculate a shell-and-tube heat
exchanger for cooling 1050 m3/h (in standard conditions) of air from 140 oC to
31oC with water. The pressure of the air is p=0,35 MPa. The cooling water,
which gives a deposit of scale, has a temperature of 16 oC.
. Content of explanatory note (list
of issues to be developed): theoretical part contains a description of the
design of heat exchangers and producing penicillin by technical methods.portion
contains calculations and tube heat exchanger for cooling water.
5. Calendar plan:
№
п/п
|
Stage
|
Deadline
|
Evaluation
of the performance
|
1
|
Preparation of the course work plan
|
14.02.2013
|
performed
|
2
|
Retrieval
of Information
|
15.02.13-03.03.13
|
performed
|
3
|
Preparation of the theoretical part
|
04.03.13-04.04.13
|
performed
|
4
|
Preparation of the computation and analytical
part
|
05.04.13-07.04.13
|
performed
|
5
|
Additions
and Changes
|
08.04.13-15.04.13
|
performed
|
6
|
Defence of the course work
|
24.04.13
|
performed
|
. Date of assignment:__________ Kuznetsova
O.O.____________ Kohut K.G.
Summary
Explanatory note to the course work
"The project of the heat exchanger for cooling compressed air with water
used in penicillin production":of the study - heat exchanger.of research -
heat exchanger.- to examine and analyze the design of heat exchanger.methods -
analysis, a systematic approach of observation., Selecting, antibiotics,
penicillin, CALCULATION.
Introduction
An antibacterial is an agent that
inhibits bacterial growth or kills bacteria. The term is often used
synonymously with the term antibiotics. Today, however, with increased
knowledge of the causative agents of various infectious diseases, antibiotic(s)
has come to denote a broader range of antimicrobial compounds, including
anti-fungal and other compounds. [2]term antibiotic was first used in 1942 by
Selman Waksman and his collaborators in journal articles to describe any
substance produced by a microorganism that is antagonistic to the growth of
other microorganisms in high dilution. This definition excluded substances that
kill bacteria, but are not produced by microorganisms (such as gastric juices
and hydrogen peroxide). It also excluded synthetic antibacterial compounds such
as the sulfonamides. Many antibacterial compounds are relatively small
molecules with a molecular weight of less than 2000 atomic mass
units.[2]advances in medicinal chemistry, most of today's antibacterials
chemically are semisynthetic modifications of various natural compounds. These
include, for example, the beta-lactam antibacterials, which include the
penicillins (produced by fungi in the genus Penicillium), the cephalosporins,
and the carbapenems. Compounds that are still isolated from living organisms
are the aminoglycosides, whereas other antibacterials-for example, the
sulfonamides, the quinolones, and the oxazolidinones-are produced solely by
chemical synthesis. In accordance with this, many antibacterial compounds are
classified on the basis of chemical/biosynthetic origin into natural,
semisynthetic, and synthetic. Another classification system is based on
biological activity; in this classification, antibacterials are divided into
two broad groups according to their biological effect on microorganisms:
bactericidal agents kill bacteria, and bacteriostatic agents slow down or stall
bacterial growth. [4]the susceptibility of Staphylococcus aureus to antibiotics
by the Kirby-Bauer disk diffusion method - antibiotics diffuse from
antibiotic-containing disks and inhibit growth of S. aureus, resulting in a
zone of inhibition.[2]successful outcome of antimicrobial therapy with
antibacterial compounds depends on several factors. These include host defense
mechanisms, the location of infection, and the pharmacokinetic and
pharmacodynamic properties of the antibacterial. A bactericidal activity of
antibacterials may depend on the bacterial growth phase, and it often requires
ongoing metabolic activity and division of bacterial cells. These findings are
based on laboratory studies, and in clinical settings have also been shown to
eliminate bacterial infection. Since the activity of antibacterials depends
frequently on its concentration, in vitro characterization of antibacterial
activity commonly includes the determination of the minimum inhibitory
concentration and minimum bactericidal concentration of an antibacterial. To
predict clinical outcome, the antimicrobial activity of an antibacterial is
usually combined with its pharmacokinetic profile, and several pharmacological
parameters are used as markers of drug efficacy.[4]
General characteristics of
antibiotics
The term "antibiotic" was
proposed in 1942 by SA Waksman to describe substances produced by
microorganisms and have antimicrobial activity. Subsequently, many researchers
have offered their own language, putting in them sometimes too limited content
or excessively expanding this concept.[1], under the understanding
chemotherapeutic antibiotic substances derived from microorganisms or other
natural sources, and their semi-synthetic analogs and derivatives that have the
ability to selectively suppress the patient's body of pathogens and (or) delay
the development of cancer. [2]are of natural origin produced by different
groups of microorganisms (mostly actinomycetes, rarely bacteria), lower plants
(yeast, algae, fungi, higher fungi), plants and animals. [1]example, the genera
Micrococcus, Streptococcus, Diplococcus, Chromobacterium, Escherichia. Bacteria
of the genus Bacillus form gramicidin, subtilin polymyxins. [1], which are
formed by microorganisms belonging to several Actinomycetales, - streptomycin,
tetracycline, novobiocin, actinomycin, etc., which are formed by imperfect
fungi: penicillin - Penic. Chrysogenum; griseofulvin - Penic. Griseofulnum;
trihotsetin - Tricholecium roseum., which are formed by fungi, belonging to the
classes of basidiomycetes and ascomycetes: termofillin, lenzitin, hetomin.,
algae and lower plants are capable of forming acid and usnic hlorellin, higher
plants - almitsin, rafanin.are of animal origin: lysozyme ekmolin, krutsin,
interferon.[2]of antibiotics. By the nature of the impact of antibiotics on
bacterial cell can be divided into three groups:
Bacteriostatic (bacteria are alive
but unable to reproduce)- Bactericide (bacteria were sacrificed, but still
physically present in the medium)
Bacteriolytic (death to the
bacteria, and bacterial cell walls are destroyed).On the mechanism of
biological action of antibiotics are divided into:
. Antibiotics that inhibit the
synthesis of the bacterial wall (penicillins, cephalosporins, bacitracin,
vancomycin).
. Antibiotics disrupt the
cytoplasmic membrane (polypeptides, polyenes, gramicidin).
. Antibiotics destroy the ribosomal
subunit and inhibiting protein synthesis (tetracyclines, hlormitsetiny,
aminoglycosides, macrolides).
. Antibiotics that selectively
inhibit the synthesis of nucleic acids:
Inhibitors of RNA (actinomycin,
griseofulvin, kanamycin, neomycin, novobiocin, etc.);
Inhibitors of DNA synthesis (bruneomitsin,
sarkomitsin).Antibiotics have a selective effect, only active against
microorganisms while maintaining the viability of the host cells and do not act
at all, but in some genera and species of microorganisms. Since selectivity is
closely related to the concept of the breadth of the spectrum of activity of
antibiotics. Traditionally, the spectrum antimicrobial effects of antibiotics
are divided into narrow-spectrum drugs and broad:
. Narrow spectrum antibiotics are
only a certain type of bacteria. These include penicillin, oxacillin,
erythromycin.
. Antibiotic with a broad spectrum
of activity are effective in killing not only Gram-positive and Gram-negative
bacteria, but also spirochetes leptospira, rickettsia, large viruses (trachoma,
psittacosis, and others). These include tetracyclines (tetracycline,
oxytetracycline, chlortetracycline, glitsiklin, methacycline, morfotsiklin,
doxycycline), and chloramphenicol.values of the biological activity of
antibiotics is usually produced in units contained in 1 ml (U / ml) or 1 mg (U
/ mg). One unit of antibiotic activity take the minimum number of antibiotic
that can suppress or delay the development of the growth of the standard strain
of test organisms in a given volume of medium. [1]of antibiotics. Antibiotics
are the most numerous group of drugs. They are used to prevent and treat
inflammation caused by bacterial microflora. Now there are hundreds of drugs
that selectively act on various disease. Scope of antibiotics - is rapidly
progressing infection or bacterial infection of vital organs, which the immune
system can not handle myself. Antibiotics are essential for the development of
acute disease - angina and pneumonia, as well as in infectious inflammation,
which is localized in closed cavities (otitis media, sinusitis, osteomyelitis,
abscess, cellulitis). Currently, the company is actively working to find a new
generation of antibiotics that are effective in the treatment of viral diseases
and cancer.are used in agriculture, mainly as medical drugs in livestock,
poultry farming, beekeeping and plant, and some antibiotic substances - as
growth promoters of animals.antibiotics have been successfully used in the food
and canning industry in the preservation of perishable goods (fresh fish, meat,
cheese, various vegetables).[2]
Peculiarities of antibiotics
The process of getting an antibiotic
includes the following main stages:
. receive appropriate strain -
producer antibiotic suitable for industrial production;
. biosynthesis of antibiotics;
. isolation and purification of the
antibiotic;
. concentration, stabilization of
antibiotic and the finished product.first task of finding producers of
antibiotics - their separation from natural sources. Biosynthesis of
antibiotics - the hereditary characteristics of an organism, which is
manifested in the fact that each species (strain) is capable of forming one or
more well-defined and strictly specific to his antibiotic substances.potential
form during the life of antibiotics is associated with conditions of cultivation
of organisms. In some conditions, the body forms an antibiotic, in other
circumstances the same body, with good growth will not have the ability to
synthesize an antibiotic substance. Education antibiotics will only occur
during the development of an organism in a specific environment and under
specific environmental conditions. By changing the culture conditions can be
more or less out of antibiotic, or to create the conditions in which no
antibiotic will be formed. It is also possible by changing the culture
conditions of the producer to achieve a preferential biosynthesis of
antibiotics, provided education studied organism several antibiotic substances
or to obtain new forms of antibiotics, but only within the limits of those
compounds that can be synthesized by this organism.[3]the most important
factors that influence the expression of antibiotic properties of
microorganisms, are part of the environment, its active acidity, redox
conditions, cultivation temperature, joint cultivation of two or more
micro-organisms and other factors.for culturing microorganisms. Natural
(complex) environment consisting of natural compounds and have an indefinite
chemical composition (of green plants, animal tissue, malt, yeast, fruit,
vegetables, manure, soil, etc.), contain all the components needed for growth
and development most types of microorganisms. The following environments:
Meat medium, composed simultaneously
with beef extract and peptone are sodium chloride, potassium phosphate,
sometimes glucose or sucrose, is typically used in laboratories.
Potato medium with glucose and
peptone, often used in the laboratory for the cultivation of many species of
actinomycetes and bacteria;
Protection from corn extract, soy
flour, bards and other substances, which include ammonium sulfate, calcium
carbonate, calcium phosphate, glucose, sucrose, lactose or other carbohydrates
and other compounds, from successfully used in industry, because are cheap and
offer good growth of microorganisms with a high yield of antibiotics.[1]the
natural environment do not provide strict quantitative data to study the
physiological and biochemical characteristics of the organism, used synthetic
media that is selected for individual producers individually.sources are
organic acids, alcohols, carbohydrates, a combination of carbon-containing
compounds. With the industrial production of antibiotics as carbon sources is
often used potato starch, corn meal, or other plant materials.sources have a
great influence on the formation of antibiotic substances by microorganisms.
Usually in the media for the cultivation of microorganisms are a source of
nitrate nitrogen (less nitrous acid), ammonium salts of organic and inorganic
acids, amino acids, proteins and their hydrolysates., the most favorable for
microorganisms is the ratio C / N = 20. But for the antibiotic, this ratio is
not always optimal. Therefore, for each producer must select the appropriate
ratio of carbon and nitrogen.of mineral nutrients are phosphorus, sulfur and
other macro-and micronutrients. [1]producers of antibiotics in relation to the
concentration of phosphorus in the environment can be divided into three
groups:- Highly sensitive producers, for which the optimal concentration of
phosphorus in the medium is less than 0.01% (producers nystatin, tetracycline
florimitsina, vancomycin);- Producers of high sensitivity, for which the
optimal concentration of phosphorus is 0,010-0,015% (producers of streptomycin,
erythromycin, cycloserine, neomycin);- Insensitive producers, for which the
optimal concentration of phosphorus is 0,018-0,020% (producers of novobiocin,
gramicidin, oleandomitsina).Sulfur is part of some antibiotics, produced
mushrooms (penicillin, cephalosporin, gliotoksin, etc.), bacteria (bacitracin,
subtilin, lowlands) and actinomycetes (ehinomitsiny, a group of thiostrepton).
Usually, the source of sulfur in the environment are sulfates. However, the
biosynthesis of penicillin, the best source of sulfur for the producer is
sodium thiosulfate.addition, for the biosynthesis of antibiotics are needed and
some trace elements. Thus, the producer albomitsina S. subtropicus forms
antibiotic with significant concentrations of iron in the medium. Iron is
necessary for the formation of chloramphenicol and other antibiotics.[3]
The influence of pH. Many bacterial
organisms that synthesize antibiotics, better developed at a pH of about 7.0,
although some, such as lactic streptococci producing lowlands develop better in
the medium at pH = 5,5 ÷ 6,0.Most actinomycetes
grow well under the initial pH values ranging from 6.7 to 7.8, in
most cases, the viability of actinomycetes at a pH below 4.0-4.5 suppressed.. For
most bacterial organisms temperature optimum in the range of 30-37 ° C. For a
producer of gramicidin with optimum temperature for growth and biosynthesis is
40 ° C.are usually cultivated at 26-30 ° C, although some species can develop
as Streptomyces at low (0 to 18 ° C) and elevated (55-60 ° C) temperatures.most
filamentous fungi optimum temperature is 25-28 ° C.. Most producers of
antibiotics studied are aerobes. For the biosynthesis of many antibiotics
(penicillin, streptomycin, etc.), the maximum accumulation occurs when the
degree of aeration, equal to one in which a certain amount of protection for 1
min purged the same volume of air.[2]the development of antibiotic producer in
industrial conditions the body's need for oxygen varies with the stage of
development, the culture fluid viscosity and other factors. At certain stages
of the situation may arise related to anoxia producer. In these circumstances,
additional measures should be taken, such as increasing the concentration of
the oxidant addition of hydrogen peroxide.most promising method of
micro-organisms - producers of antibiotics found submerged culture method using
batch processes. In the deep cultural development of the organism and
antibiotic synthesis takes place in two phases.the first phase of development
of culture, or as it is sometimes called, tropofaze (phase balanced growth of
the microorganism), there is an intense accumulation of biomass producer
associated with the rapid consumption of the main components of the medium-and
high-oxygen absorption.the second phase of development, called idiofazoy (phase
unbalanced growth of microorganism), biomass accumulation slowed or even
reduced. During this period the products of metabolism of the microorganism is
only partially used for the construction of cellular material, they are mainly
directed to the biosynthesis of the antibiotic. Usually, the maximum production
of antibiotic in the medium occurs after the maximum biomass accumulation. A
detailed description of the process by the example of the production of
penicillin is given in the following chapter. [1]
Production of penicillin
Penicillin was discovered in 1929 by
Alexander Fleming, and was isolated in crystalline form in 1940. Found that
penicillin has antimicrobial activity against certain gram-positive bacteria
(stafillococci, streptococci, diplococci and some others) and virtually
inactive against Gram-negative species and yeast.to form penicillin is common
among many of fungi belonging to the genera Penicillium and Aspergillus. However,
this property is more characteristic of Penicillium notatum-chrysogenum. First
isolated from natural substrates strains as the most active producers of
penicillin produced not more than 20 units (12 micrograms) antibiotic for 1 ml
of the culture fluid. As a result of extensive research on the selection of new
active producing strains of penicillin obtained various strains of Penicillium
chrysogenum, which, in contrast to the original strains are highly productive
and are used in industry. At present, the industrial environment are cultural
liquids containing more than 15,000 units of penicillin / ml, and some strains
are able to synthesize an antibiotic in an amount up to 25 thousand units /
ml.the name "penicillin" combined a large group of substances that
are N-acyl derivatives of the heterocyclic amino acids. Of natural penicillins
are used penicillin and penicillin. [1]
Statement of the process
Preparation of inoculumsof seed
comprises the following steps:
) the cultivation of seed mycelium
1st generation devices in a small container (inoculator);
) the cultivation of seed mycelium
2nd generation in large-capacity vehicles.culture used to inoculate inoculator
is grown on millet in glass vials, dried and stored in this form at room
temperature. Seeding produces dry spores of 2-3 bottles.basis for the
cultivation of the producer of penicillin in sowing machines in preparation of
inoculum is the rapid acquisition of large mass of mycelium that can provide
for reseeding the fermenter intensive growth and high yield of the antibiotic.
To fulfill this task producer must grow in media rich digestible nutrients in
good aeration at optimum temperature for growth of the microorganism. [1]an
easily assimilated carbon acts glucose, sucrose, etc. As a second source of
carbon used in small amounts of lactose, whose presence in the environment for
growing seed mycelium desirable for the following reasons: its consumption does
not start immediately, but after a period of adaptation (addiction), during
which the formation of an enzyme that breaks down lactose. Sowing mycelium
grown on a medium containing lactose, has a high enzymatic activity against
lactose and faster to use it, which has a positive effect on the course of
fermentation.need of the fungus is easily satisfied in nitrogen mineral
nitrogen - ammonium or nitrate. In addition to inorganic nitrogen in the crop
of media used in the industry, is an organic nitrogen-rich plant material such
as corn steep liquor. Vegetable materials is characterized not only by the
presence of organic nitrogen, it contains an additional carbon, which is part
of amino acids, peptides, proteins, and trace minerals, vitamins and growth
substances.addition to the carbon and nitrogen for the growth of a
microorganism requires phosphorus, sulfur, magnesium, potassium and trace
elements - manganese, zinc, iron, copper. Most of the known cultivated media
contains almost all of the above elements, but in different proportions. Table
1 shows an example of the medium used for growing seeds.
Substance
|
%
|
Corn
extract
|
2
(dry weight)
|
Glucose
|
2
|
Lactose
|
0,5
|
Ammonium
nitrate
|
0,125
|
Monobasic
potassium phosphate
|
0,2
|
Magnesium
sulphate
|
0,025
|
Sodium
sulphate
|
0,05
|
Chalk
|
0,5
|
Growing seed mycelium continues
36-50 hours to produce biomass of medium thickness. Mycelium grown in
inoculator, transferred to 10% by volume in the seed sets, which were cultured
for 12-18 hours, and then transferred to large fermenters in an amount of
15-20%. The process of growing plants for the mycelium of the 1st and 2nd
generation is carried out at a temperature of 24-26 °.- producers of penicillin
are common aerobes and require for their growth and development, the
availability of oxygen. To obtain high-yielding seed mycelium along with
optimal nutrient and is necessary to ensure an adequate supply of the fungus.
In the process of growing plants for the production of penicillin mycelium
performed with continuous stirring and uninterrupted supply of air into the
apparatus in an amount of 1.2-1.5 air to 1 volume of medium per minute. [4]of
inoculum - one of the most important operations in the cycle biotechnological
method for producing antibiotics. The number and quality of seeds depends on
the development of culture in the fermenter, and antibiotic biosynthesis.
PRODUCER usually grown on rich composition of natural environments, capable to
provide the highest physiological activity of microorganisms.of inoculum -
multistep process (Figure 1).
Fig. 1 - Scheme of multi-cooking
seed A - growing in vials B - growing in flasks on rocking: 1 - conserved
starting material, 2 - spore generation on beveled agar in vitro, 3 - II spore
generation on solid medium; 3a and 3b - I and III generation on liquid medium
in the flask, 4 - fermenter prior 5 - fermenter inokulation 6 - primary
fermenter
previously grown on agar medium in
vitro (1, 2), then make a tube hanging in flasks with liquid nutrient medium,
spend two generations by deep cultivation on rocking for two to three days for
each generation (3a and 3b). With the second generation culture flask makes
planting in a small (10 liter) inokulyator 4, then a well-developed culture is
transferred to a larger inokulyator 5 (100 - 500 l), which also makes planting
in the main fermenter 6. For planting in the main fermentor using 5 to 10%
inoculum (inoculum) [2].
Fermentation
Fermentation is a major step in the
production of penicillin, which forms the desired product. In industry, the
method of submerged fermentation, in which the culture of the microorganism is
grown in a nutrient medium, filling its entire volume. Different strains of the
need for power supplies varies. Therefore, the composition of matter is not
constant and universal for all producers that make penicillin, and changes with
the emergence of new strains.fermentation medium should be designed in such a
way as to develop a culture, consuming nutrients and extracting metabolites,
she created the necessary conditions and the transition from the growth phase
to the phase of the mycelium. It is desirable that the second phase was longer
and the process of fermentation stopped before autolysis.this, as for growing
seed to the simultaneous presence in the environment is easy carbohydrate.
Carbohydrate provides rapid growth and the formation of abundant biomass
carbohydrate creates conditions favorable for the biosynthesis of the
antibiotic.the industrial biosynthesis of penicillin as the most common
carbohydrate was glucose or hydrological. Carbohydrate is lactose. Lactose is
the only carbohydrate that provides a full course of phase. High yield
antibiotic receive only when the medium of lactose as the main source of
carbohydrate. Lactose is in the culture medium during the process of
fermentation, so the mycelium provided sugar, biomass for formation of penicіllins
slowly growing, and the accumulation of the antibiotic is maximized. [4]composition
of the fermentation medium is organic and mineral nitrogen. An excellent source
of organic nitrogen is corn steep liquor, but it can be successfully replaced
by wheat extract, various cake, soy flour, gluten and other vegetable raw
materials rich in nitrogen.of mineral nitrogen are usually the ammonium
nitrate, ammonium sulphate and other salts. The assimilation of ammonium fungus
released anions of these salts, acids, which contribute to some
acidification.extremely important role in the metabolism of the cells is
phosphorus, which is essential not only for normal growth and development of
the fungus, but also for the process of biosynthesis of penicillin. For the
formation of penicillin required much higher concentration of phosphorus in the
environment than for the growth of the fungus.component of the fermentation
medium is sulfur, which is part of the essential amino acids and enzymes.
Sulfur is necessary also because it is part of the penicillin molecule. In the
culture medium is introduced in the form of sulfur salts of sulfuric acid and
hyposulphate.the other elements necessary for the normal functioning of the
fungus and the formation of the antibiotic, it should be noted potassium,
magnesium, zinc, iron, manganese and copper.[2]optimum concentration of the
precursor in the medium is established, depending on the efficiency of its use
for the biosynthesis of penicillin to the strain.main indicator, the end of
fermentation, are the complete disappearance of carbohydrates in the culture
medium and the cessation of antibiotic biosynthesis. The fermentation process
is carried out in a production environment at a temperature of 26 ± 10C and
usually lasts 120-125 hours.intensity of the biosynthesis of penicillin depends
on the amount of mycelium formed during fermentation. Much more biomass forms
of penicillin, so the content of carbohydrates, nitrogen, phosphorus, and
sulfur in the environment must be sufficiently high to ensure maximum education
mycelium. However, most of the biomass does not guarantee a high yield of the
antibiotic. The fungus is not only necessary to ensure enough nutrients, but
necessary amount of oxygen. Mushroom nutrition and aeration are two sides of
the same process - the more nutrients in the environment, the more oxygen is
required for oxidation. On the other hand, increasing the concentration of
nutrients in the environment leads to increased biomass for respiration which
requires a proportionately larger amount of oxygen. The composition of the
culture medium and aeration interdependent. The maximum number of penicillin
can be obtained only in products with a high concentration of the components in
an adequate supply of dissolved oxygen culture [1].the biosynthesis of
penicillin is most favorable pH neutral. To maintain a certain level of culture
fluid pH should adjust it with the automatic addition of acid or alkali or by
establishing the proper ratio of the components of the medium. In synthetic
media as pH regulators are most often used organic acids in complex
environments - chalk. To obtain the maximum yield of penicillin main components
of the environment must be a member of a well-defined in the ratios and
concentrations. Part of some media, used in the production of penicillin is
given in Table 2.
Table 2 - Composition of media used
for penicillin medium components
Components
|
Medium
|
|
Corn
|
Oilcake
|
Fat
|
Corn
extract
|
2,0
- 3,0
|
-
|
2,0
- 3,0
|
Oilcake
|
-
|
2,0
- 4,0
|
-
|
Lactose
|
5,0
|
5,0
|
1,0
|
Glucose
|
1,5
|
1,5
|
1,5
|
Vegetable
oil
|
0,5
- 0,1
|
0,5
- 0,1
|
2,5
- 3,5
|
Ammonium
nitrate
|
0,4
|
0,4
|
0,4
|
Glauber`s
salt
|
0,05
|
0,05
|
0,05
|
Potassium
phosphate monobasic
|
0,4
|
0,4
|
0,4
|
Magnesium
sulphate
|
0,025
|
0,025
|
0,025
|
Hyposulphate
|
0,2
|
0,2
|
0,2
|
0,5
- 1,0
|
0,5
- 1,0
|
0,5
- 1,0
|
Precursor
|
0,3
- 0,4
|
0,3
- 0,4
|
0,3
- 0,4
|
An important condition for the
success of the biosynthesis of penicillin is a strict aseptic conditions, as
the penetration of foreign microorganisms can dramatically reduce the output of
the antibiotic. Many common microorganisms capable of producing penicillase
enzyme that breaks down penicillin. Contact with even a small number of
bacteria capable of producing penicillase, leads to complete inactivation of
penicillin, because what should emphasize sterile culture media, air and
auxiliary materials.need to ensure the conditions for sterile process
technology ties units each collector system load growth media, transfer of
inoculum inoculators in fermenters imposes greater demands on the level of
automation of these processes.[2]general scheme of antibiotics to the point of
extraction and chemical treatment is shown in Fig. 2.
Fig. 2 - Scheme of antibiotics: I -
making seed; II - inokulyatory for increasing seed; III - sterilizer
environment for large fermenters; IV - setting for the biosynthesis of
antibiotics and - sterilization medium in flasks, b - cooling and seeding crops
producer in the flask; in - growth of culture in resting g - growth of culture
in rocking and e - inokulyator with a sterile environment, e - inokulyator with
the environment, sown crop producer, is - fermenter
The first stage of the process -
growing standard colony strains mold Penicillium chrysogenum - made in
inokulyator on nutrient medium where the process is ~ 30 hours. The prepared
inoculum transferred to sowing machine volume is ~ 10 times more volume inokulyatora.
In sowing machine is also sterilized nutrient medium. The process of growth
here goes ~ 15 - 20 hours, and then seed fed to fermentation in larger reactors
- fermenter volume of 100 m3. Fermentation process lasts ~ 70 hours at 23 - 24
° C, pH 6 - 6.5 and intensive aeration (1 units. Air volume for 1 min at 1 m.
Environment volume) [2].To stabilize the reaction medium using chalk. When the
number reaches a maximum penicillin fermentation ceased. Dynamics of mycelium
penicillin biosynthesis and consumption of lactose from the environment shown
in Fig. 6.Rice. 6. Dynamics of the biosynthesis of penicillin mycelium
formation and assimilation of lactose: X - dry mycelium (mg/100 g), P -
concentration of penicillin (1000 units. / Ml), S - lactose concentration (mg /
ml) .first phase - the growth of mycelium, antibiotic yield is low. Always
present in corn extract producer of lactic acid consumed at maximum speed,
lactose consumed slowly. Oxygen consumption - high. Growing nitrogen
metabolism, resulting in an environment appears ammonia and dramatically
increasing pH.during the first phase should be 30 ° C, pH during the growth of
the fungus should be below 7.0.The second phase - the maximum penicillin
formation is due to the rapid consumption of lactose and ammonium nitrogen. pH
remains virtually unchanged, a slight increase in the mass of mycelium, oxygen
consumption decreases. Temperatures during the second phase should be 20 °
C.third phase - reducing the concentration of antibiotics in the environment in
connection with the beginning of autolysis of mycelium and release as a result
of this process, ammonia, accompanied by an increase in pH.[5]
Filtering
to separate the mycelium from the
culture medium used vacuum drum filters are continuous. Filtering begin before
autolysis of mycelium, because the filtering Autolyzed culture mycelium does
not form a film on the surface of the filter drum and sticks in the form of
individual thin lumps that do not depart in the zone of "stripping"
of the filter, and they have to be removed manually. The duration of filtration
is increased by 2 - 3 times, the yield drops sharply filtrate, and the filtrate
is very turbid.must carefully observe the conditions that prevent the
destruction of penicillin during filtration - native solution cooled to 4-6 ° C
and systematic (every boot) filter processing, communications and collections
antiseptics, such as chloramine. The filter should also systematically
sterilized with saturated steam.[1]treatment of native solution.solution (culture
filtrate) is a more or less turbid, colored yellow-brown or greenish-brown
liquid. The pH of the medium, depending on the strain of the producer, the
medium composition and the duration of the fermentation process typically
ranges from 6.2 to 8.2.A very important characteristic of the native solution
is the content of proteins, determined by precipitation with trichloroacetic
acid, or other appropriate means.several methods pretreatment native solution
to free from contaminating proteins: precipitation polyvalent metal salts (for
example, A13 + Fe3 + or Zn2 +), coagulation tannin, thermal coagulation at
60-75 ° C and pH 5.5 - 6.0, the deposition impurities cationic detergents such
as quaternary ammonium compounds. Application of these methods results in a
loss of antibiotic. Usually as a result of coagulation and subsequent
filtration or separation is lost between 5 and 15%) of penicillin. In this
case, coagulation with metal salts can remove up to 50% of total proteins [4].
Extraction and purification of
penicillin
solution contains 3-6% solids. On
minerals account for 30-40% of total solids, 15 to 30% for penicillin, and the
rest is a complex mixture of organic substances, including proteins,
polypeptides, low molecular nitrogen compounds, carbohydrates, and various
organic acids, depending on the strain of the producer, a certain amount of
pigment. To isolate penicillin from this complex mixture can use methods based
on adsorption, extraction or precipitation.industry, the extraction of the
active substance from the native solution is based on the extraction of
water-immiscible solvent in suppressing the dissociation of the carboxyl group
of penicillin. In thinner than penicillin, passes most of the organic acids.
Chemical pollution, most of the nitrogen compounds and other organic substances
remain in the aqueous phase, so that the purity of the product by extraction
increased by 4-6 times.solvents used for the extraction of penicillin, must
meet the following basic requirements:
) low solubility in water;
) the lack of interaction with
penicillin;
) low vapor pressure at the
temperature of 5-30 ° C;
) the possibility of regeneration at
a temperature of 120 - 140 °;
) low cost.acidic pH, penicillin is
unstable, so the extraction of penicillin in the organic solvent is necessary
to strictly control the pH, keeping it in the 1.9-2.0 range, extraction is
carried out in the shortest possible time, the cooling fluid.the extraction of
penicillin from the native form of the solution is very persistent due to the
presence of the native solution of surface-active substances. Usually used for
this purpose anionic detergents, for example sulfonated fatty or naphthenic
acid. Usually the choice of detergent is determined by its availability and
economic considerations. For the separation of the emulsion in the extractors,
separators, usually enough to add to the native solution of 0.05-0.1%
detergent.extraction step of penicillin native solution using either
multi-extractors separators "Luvesta" and "Russia" or the two-stage
scheme of extraction (contacting a native solution acidified with butyl acetate
in a special mixer and separation of emulsions such as centrifugal separators
Sage-3). The use of efficient centrifugal extractors, separators (with a
capacity of 4000-5000 liters / hour), providing at least two stages of
extraction in one car and a good phase separation, minimizes the residence time
of penicillin in acidic aqueous medium and, therefore, increases the yield of
the antibiotic. The use of two-stage scheme for the extraction of penicillin
from the native solution, of course, is undesirable not only because of the
longer residence time of penicillin in adverse conditions, in this case, but
also due to the fact that the use of separators Sage-3 (whose performance is in
the range 800 - 1000 l / h) does not always provide a fairly complete phase
separation. This entails a deterioration of butyl acetate extract (pollution
native solution) and an increase in loss of butyl acetate with used native
solution. Phase relationship during Butyl extraction of penicillin from the
native solution is 1,0:0,3-0,45, temperature 4-3 ° C.the extraction of
penicillin from Butyl native solution is extracted penicillin from butyl
acetate extract of an aqueous solution of sodium bicarbonate or buffer at pH
6,6-7,2. At this stage it is also used multistage extraction machine or use a
two-stage countercurrent extraction with separation of emulsion separators with
attitude solvent-aqueous phase 1.0:0,35. The output buffer for Butyl and extractions
is about 90-92%.For further purification of penicillin re-extracted from the
organic solvent extract buffer (usually butyl acetate or chloroform) at pH 2.0.
The process is similar to butyl acetate extraction from native solution. This
stage of technology is made also with the use of multi-stage extraction
machines or takes the form of a two-stage countercurrent extraction phase
separation on separators. The yield is about 86% of the penicillin contained in
the native solution.whole extraction process of extraction and chemical
treatment of penicillin carried out by a continuous scheme [5].
Isolation of crystalline salts
of penicillin
most reliable methods that provide a
good quality of crystalline penicillin, penicillin is the allocation of butyl
acetate extract in the form of a concentrated aqueous solution of the potassium
salt followed by evaporation of water with butanol under vacuum, resulting in
the crystallization of the potassium salt of butyl alcohol.process has the
following technological sequence:
. Butyl acetate extract of
dehydration by cooling to -16-18 ° C, followed by filtration of ice. Removal of
pigment pollution treatment and activated carbon filtration is cold
druk-filter.
. The concentrate of the potassium
salt of benzylpenicillin extraction 0,56-0,6 N sodium hydroxide.
. Sterilizing filtration of
concentrate of potassium salt and evaporation under vacuum with butyl alcohol
(2.5 volume) at 16-26 ° and a residual pressure of 5-10 mm Hg. Art. Volume
bottoms should be no more than 60-80% of the loaded concentrate. Adding butanol
to concentrate by evaporation under vacuum, due to the fact that the butanol
with water forms a mixture boiling at a lower temperature than the boiling
point of water. Distillation of water held in relatively mild conditions,
resulting in the possibility of inactivation of penicillin decreases. After
removal of the water and most of the butanol benzylpenicillin potassium salt
crystallizes.
. Filtering the precipitate of the
potassium salt of benzylpenicillin on the centrifuge and filter cake washing
anhydrous butyl alcohol.
. Granulation and drying a paste of
potassium chloride in a vacuum oven at a temperature of 75-80 ° and a residual
pressure of 10-20 mm Hg. Art. This yields the potassium salt of penicillin as a
white fine crystalline powder with an activity of penicillin content about 95%
and a yield of 70% of the antibiotic in the native solution.most important
requirement for a dry powder obtainable penicillin, is its complete sterility.
Heat treatment of the drug is not enough. Sterility can be achieved only during
the final stages of the process in a strictly aseptic conditions, precluding
the possibility of product contamination by micro-organisms and their spores.
Therefore, starting from the sterile filtration of concentrate and butanol, all
operations are conducted in an isolated clean room and sterile equipment. To
ensure aseptic conditions are of all necessary sanitary and technical
measures.regeneration, butyl acetate and butanol, used in the process of
separation and chemical treatment, penicillin, washed with alkali to remove
impurities acids [3].
Calculation of a shell-and-tube
heat exchanger
a shell-and-tube heat exchanger for
cooling of V=1050 m3/h (in standard conditions) of air from 140 oC to 31oC with
water. The pressure of the air is p=0,35 mPa. The cooling water, which gives a
deposit of scale, has a temperature of 16 oC. Solution. We assume that the
water in the heat exchanger becomes heated to 35 oC. The temperature scheme of
the heat exchanger with counter flow is (hot fluid - air; cold fluid -
water):=140 oC; tho=31 oC;=35 oC; tci=16 oC.temperature difference:greater
temperature difference - Δgr=
thi - tco=140 - 35=105 oC;smaller temperature difference - Δsm=
tho - tci=31 - 16=15 oC.mean logarithmic temperature drop:
The mean temperature of the water
is:
mean temperature of the air:
amount of heat transferred from the
air to the water is:
ρair - the density
of air in standard conditions (t=0 oC, p=101325 Pa); cair - the mean specific
heat of air.find the density of air in standard condition from Table 1: ρair=1,293
kg/m3.mean specific heat of air is about cair=1000 J/(kg∙K).the values to
the latest formula we obtain:
specific heat of water at twat=15 oC
from Table 2 is cwat=4190 J/(kg∙K).mass flow rate of the water is:
We determine approximately the
required surface area of the shell-and-tube heat exchanger. Since scale may be
deposited on the surface of the tubes at the side of the water being heated and
this greatly hinders the transfer of heat. It is necessary to provide for the
possibility of cleaning the heat exchanger. For this reason, the water should
flow through the tubes, whose internal surface in a shell-and-tube heat
exchanger is easily accessible for cleaning.increase the coefficient of heat
transfer of the air (it is much lower than that for water), we adopt the design
of the heat exchanger with cross flow of the air around the tubes, i.e. with
baffles on the shell side.adopt approximately an overall heat transfer
coefficient U=60 W/(m2∙K). Hence the required
heat exchange surface area is:
to the data of Table 3, we adopt a single-pass
shell-and-tube heat exchanger (with the nearest heat transfer area - 14,8 m2)
with a shell diameter of 400 mm, and with 121 tubes 1,5 m long. The diameter of
the tubes is 25x2 mm (the inner diameter di=0,021 m; the outer diameter
do=0,025 m; the width of a tube - δ=0,002
m) and their pitch (the distance between their axes) is 32 mm.perform more
accurate calculations of the heat exchange surface area. We assume that the
Reynolds number for air is Reair=20000 and calculate the overall heat transfer
coefficient for a triangular pitch of the tubes (Prair -is the Prandtl number
at a temperature tair; from Table 1). We have:
thermal conductivity of air from
Table 1 for tair=71,65 oC is about kair=0,03 W/(m∙K). Hence, the
convective heat transfer coefficient for air is:
determine the conditions of flow of
the water in the tubes.velocity of the water is:
dynamic viscosity of water at
twat=25,5 oC from Table 2 is μwat
=902∙10-6 Pa∙s. The Reynolds number is:
have a laminar flow. To find the
convective heat transfer coefficient for water, we must calculate the product
(taking the value of Prandtl number from Table at a temperature twat):
the than
we can use the formula:
μwall - is the
dynamic viscosity of water at the wall temperature, from Table 2 (assume, that
the mean temperature of the wall is twall=(twat+tair)/2).
We have that So,
we use the formula:
Nuwat=5,17*1,04=5,38
, the corresponding value of
convective heat transfer coefficient:
kwat - the thermal conductance of
water at a temperature twat (Table 2 ).overall heat transfer coefficient is:
required heat transfer area:
adopt the heat exchanger with
greater surface area - 18 m2 from Table 3 (with the length of - 2 m; the inner
diameter of shell - 400 mm; number of tubes - 121; the diameter of the tubes -
25x2 mm)
Table 3 - The thermal properties of
air (p=760 mm Hg)
Temperature
t,
oC
|
Density,
ρ,
kg/m3
|
Specific heat, c, J/(kg∙K)
|
Thermal conductivity, λ,
W/(m∙K)
|
Prandtl
number Pr
|
0
|
1,293
|
1004,8
|
0,0245
|
13,28∙10-6
|
0,707
|
10
|
1,247
|
1004,8
|
0,0252
|
14,16∙10-6
|
0,705
|
20
|
1,205
|
1004,8
|
0,026
|
15,06∙10-6
|
0,703
|
30
|
1,165
|
1004,8
|
0,0268
|
16,00∙10-6
|
0,701
|
40
|
1,128
|
1004,8
|
0,0276
|
16,96∙10-6
|
0,699
|
50
|
1,093
|
1004,8
|
0,0284
|
17,95∙10-6
|
0,698
|
60
|
1,060
|
1004,8
|
0,0291
|
18,97∙10-6
|
0,696
|
70
|
1,029
|
1009
|
0,0297
|
20,02∙10-6
|
0,694
|
80
|
1,00
|
1009
|
0,0306
|
21,09∙10-6
|
0,692
|
90
|
0,972
|
1009
|
0,0314
|
22,10∙10-6
|
0,690
|
100
|
0,946
|
1009
|
0,0322
|
23,13∙10-6
|
0,688
|
120
|
0,898
|
1009
|
25,45∙10-6
|
0,686
|
140
|
0,854
|
1013,2
|
0,0349
|
27,80∙10-6
|
0,684
|
160
|
0,815
|
1017,4
|
0,0364
|
30,09∙10-6
|
0,682
|
penicillin fermentation
purification salt
Table 4 - The thermal properties of
water (on saturation line)
Temperature
t,
oC
|
Density,
ρ,
kg/m3
|
Specific heat, c, J/(kg∙K)
|
Thermal conductivity, λ,
W/(m∙K)
|
Dymamic viscosity μ,
Pa∙s
|
Prandtl
number Pr
|
0
|
999,9
|
4230
|
0,551
|
1790∙10-6
|
13,67
|
10
|
999,7
|
4190
|
0,574
|
1310∙10-6
|
9,52
|
20
|
998,2
|
4190
|
0,599
|
1000∙10-6
|
7,02
|
30
|
995,7
|
4180
|
0,618
|
804∙10-6
|
5,42
|
40
|
992,2
|
4180
|
0,638
|
657∙10-6
|
4,31
|
50
|
988,1
|
4180
|
0,648
|
549∙10-6
|
3,54
|
Table 5 - Basic characteristics of
shell-and tube heat exchangers with tubes having a diameter of 25x2 mm. Tube
pitch is 32 mm
Conclusion
, industrial production process
benzylpenicillin passes the following stages:
. Selection of high-producer strain.
. Preparation of inoculum and
nutrient medium.
. Phase biosynthesis.
. Phase pretreatment culture fluid.
. Phase extraction and purification
of the antibiotic.
. Phase obtain the finished product.
. QA benzylpenicillin.manufacture
benzylpenicillin pay special attention to the inclusion in the culture medium
of precursor substances, ie compounds that producer will use for the synthesis
of benzylpenicillin. These include phenylacetic acid, phenylacetamido,
fenoksyotstova acid.In modern conditions of production shall take measures to
minimize the cost of drugs through the intensification of all stages of the
manufacturing process and, above all, increasing the efficiency of the first
stage - the biosynthesis of antibiotic substances.do this:) the introduction of
the most high strains-producers of antibiotics;) the establishment and
maintenance of favorable conditions for the development of antibiotic producers
at a relatively cheap media;) extensive use of mathematical methods of
planning, the development of the body and electronic computers for optimization
and simulation conditions for its cultivation, ensuring maximum yield
antibiotic;) the use of modern equipment at all stages of the process with
automated systems that control the basic parameters of the organism and stages
of the biosynthesis of the antibiotic.
Reference
2. Тимощенко
Л.В., Чубик М.В. Основы микробиологии и биотехнологии: Учебное пособие. -
Томск: Изд-во Томского политехнического университета, 2009. - 194 с.
. Елинов
Н.П. Химическая микробиология: Учеб для студентов химикотехнол., технол.,
фармац., и др. ин-тов, аспирантов и практ. работников. - М.: Высш. шк., 1989. -
448 с.
. Бекер
М.Е. Введение в биотехнологию. Пер. с латышского. - М.: издательство «Пищевая
промышленность», 1978. - 228 с.
. Елинов
Н.П. Общие закономерности строения и развития микробов-продуцентов биологически
активных веществ. - М., 1977. - 288 с/