Semisynthetic and synthetic antibiotics

Semisynthetic and synthetic antibiotics

Anotation

words: Antibiotics, medicine, E.coli, β-lactam antibiotics, penicillin, cephalosporin, macrolides, fluoroquinolone, sulfonamide, tetracycline, aminoglycoside, antibiotic resistance, Streptomyces violatus.

In biotechnology, biologically active substances describes the beneficial or adverse effects of a drug <#"821820.files/image001.jpg">

growth of S. violatus and the production of antibiotic in a starch-nitrate medium were monitored over a period of 14 days (Fig. 1). The antibiotic production by S. violatus occurred in a growth-phase dependent manner and the highest antibiotic yield was obtained in the late exponential phase and the stationary phase, indicating that it is mainly a product of secondary metabolism. Similar results were observed for streptomycin production in batch cultures of S. griseus [29] when grown in a mineral medium and for the production of candicidin in liquid grown cultures of S. Griseus.The results also showed that S. violatus produced a blue pigment associated with the antibiotic appearance in the culture. It was noticed that a direct tight relationship occurred between the antibiotic production and the intensity of the blue colour formed in the culture (r=0.95). These results may suggest the production of a pigmented antibiotic in S. violatus cultures. The production of the blue-pigmented antibiotic actinorhodin and its physiology are known in S. coelicolor cultures.

1. Effect of different incubation periods on the production of antibiotic by Streptomyces violatus.

2.2.1 Influence of some cultivation factors on the production of antibioticof antibiotic production in batch cultures of S. violatus was carried out. This strain was able to grow in all the tested carbon sources (Table 2). However, maximum antibiotic production was obtained in cultures supplemented with glycerol as a sole carbon source followed by cultures containing starch. Cultures containing fructose, maltose, xylose or cellulose did not yield any detectable amounts of the antibiotic. The results also showed that the increase of glycerol level in the culture from 10g/l to 12.5 g/l led to 1.32-fold increase in antibiotic production (Fig 2). The utilisation of glycerol and starch by S. violatus for growth and production of the antibiotic indicates the presence of an active uptake system for these substrates. Glycerol was also found to be used as a sole carbon source by other Streptomyces species.

2. Effect of glycerol concentration on the production of antibiotic byStreptomyces violatus at different incubation periods: a) 4 days, b) 7 days and c) 10 days.

2 - Effect of different carbon sources on the production of antibiotic by S. violatus.

.2.2 Influence of nitrogen source results revealed that the level of antibiotic production may be greatly influenced by the nature, type and concentration of the nitrogen source supplied in the culture medoium (Table 3). Similar observations have been reported by many investigators. The highest antibiotic production was obtained in cultures of S. Violatus containing sodium nitrate or potassium nitrate as a nitrogen source, followed by cultures containing peptone, alanine, monosodium glutamate or phenylalanine. However, cultures containing asparagine or ammonium citrate did not yield any antibiotic activity and showed lowest growth. The results also showed that the concentration of NaNO3 (Fig. 3) greatly influenced the production of the antibiotic by S. violatus cultures, while the maximum antibiotic yield was obtained in cultures suplemented with 2.5 g/l NaNO3. These results are in partial agreement with those of other investigators. A negative effect of asparagine on the production of cephamycin C was also observed on cultures of S. cattleya, S. latamdurans and Cephalosporium acremonium.

Figure 3. Effect of sodium nitrate (NaNO 3) concentration on the production of antibiotic by Streptomyces violatus at different incubation periods: a) 4 days, b) 7 days and c) 10 days.

3 - Effect of different nitrogen sources on the production of antibiotic by S. violatus.

2.2.3 Influence of potassium phosphate and magnesium sulphate salts is a major factor in the synthesis of a wide range of antibiotics. However, an excessive amount of inorganic phosphate suppresses the production of antibiotics such as tetracycline, actinomycin and candicidin (Kishimoto et al. 1996). The results of the present work (Fig 4) showed that KH2PO4 was not favourable for the production of antibiotic by S. violatus, while K2HPO4 at a concentration of 1g/l yieldes an inhibition zone of 22 mm, equivalent to an antibiotic concentration of 128 µg/ml. It was also observed that addition of a mixture of both phosphate salts (KH2PO4 and K2HPO4) showed the most positive effect on the production of antibiotic by S. violatus. The antibiotic concentration reached its maximum value (245µg/ml) when using a phosphate salt mixture of 1g/l, showing a 1.9-fold and 6.1-fold increase when compared to the highest values obtained when K2HPO4 and KH2PO4 were individually supplied to the medium, respectively. These results are in agreement with those reported by other investigators. The results also showed that addition of 0.5g/l magnesium sulphate to the culture medium was optimal for the production of a maximum yield of antibiotic by S. violatus (Fig 5). At this MgSO4.7H2O concentration, the antibiotic yield was 4.2-fold than that in cultures devoid of magnesium sulphate. The importance of magnesium sulphate for antibiotic production by other Streptomyces species has been reported by several investigators . The effects of magnesium availability are presumably due to requirements of this cation for protein synthesis, and its depletion may restrict enzyme synthesis and activity.

4. Effect of different (a) KH2PO4 and (b) K2HPO4 concentrations on the production of antibiotic by Streptomyces violatus.

results also showed that addition of 0.5g/l magnesium sulphate to the culture medium was optimal for the production of a maximum yield of antibiotic by S. violatus (Fig 5). At this MgSO4.7H2O concentration, the antibiotic yield was 4.2-fold than that in cultures devoid of magnesium sulphate. The importance of magnesium sulphate for antibiotic production by other Streptomyces species has been reported by several investigators. The effects of magnesium availability are presumably due to requirements of this cation for protein synthesis, and its depletion may restrict enzyme synthesis and activity (Aasen et al. 1992; mNatsume et al. 1994).

5. Effect of (MgSO4 .7H2O) concentration on the production of antibiotic by Streptomyces violatus.

.2.4 Influence of trace elements results given in Table 4 showed that iron and manganese could play an important role in the promotion of antibiotic production, the highest dry weight (3.8 mg/ml) was also recorded for manganese. A slight increase in the antibiotic concentration was recorded for Cu, whereas Zn addition lowered the antibiotic concentration compared to the control. The highest antibiotic concentration was achieved in the presence of all elements in the culture medium, yielding a 2.1-fold increase compared to the control reported on the importance of ferrous ions for the growth and antibiotic production by Streptoverticillium rimofaciens. Mansour et al.[30]showed that manganese ions enhanced growth and granaticin production in S. violaceolatus.

Table 4 - The role of trace elements on the production of antibiotic by S. violatus.

3. Protection of workers and life safety

In modern conditions of development of production of a problem in the field of industrial and ecological safety tend to an aggravation. Relevance of a problem of safety of the person and environment is especially sharply shown directly at the enterprises when carrying out technological processes. On trebitel of medicines are interested in receiving qualitative and safe preparations. The workers who are carrying out technological process have to have optimum working conditions.

The main gas emissions in the atmosphere of the enterprises for production of antibiotics containing harmful substances include, except air emissions of all-exchange and local ventilation, technological air emissions at biosynthesis of antibiotics, emissions of boiler and some other auxiliary productions. Various ways of cleaning provide catching about 60% of the harmful substances departing from all sources of pollution.harmful substances consist generally of carbon monoxide (77,4%), sulphurous gas (15,2%) and nitrogen oxides (7,4%).of organic solvents making 24,3% of total amount of the thrown-out substances (tab. 3) belong to liquid and gaseous products, specific to production of antibiotics.Besides, at air emissions there is a number of impurity of vapors of various substances making 0,4% of total amount of the liquid and gaseous products released into the atmosphere. Among them chloride hydrogen, vapors of hydrochloric acid, formaldehyde and prevails.substances, nonspecific for production of antibiotics, in emissions are caught by gas-and-dust cleaning installations for 90%, gaseous emissions of boiler rooms dissipate by means of high pipes. Specific to production of antibiotics firm substances from air emissions for 92,5%, organic solvents - for 10%, 5,4% of the volume of air emissions at biosynthesis of antibiotics are neutralized.

In rooms of storage of finished goods, collecting condensate, preliminary processing of barrels, pump station of reverse water supply, the foreman, the supervising foreman the all-exchange supply and exhaust ventilation is provided. Supply of stitched air and removal of the exhaust is carried out from the top zone, for rooms of packaging of ointment - from the lower zone. In the stitched P-1 installation external air is cleared of dust in the filter 3 classes, warmed up in the superficial heat exchanger and moistened during the cold period of year, during the warm period - is only cleared of dust.

 Thus, this system of ventilation of air is effective since provides necessary parameters of air for technological process, favorable microclimatic conditions, deletes harmful substances from air of a working zone.

4. Ecological conservation

Ecological factors influencing the effects of antibiotic production were explored experimentally and theoretically. A spatially structured model was used to model the dynamics of antibiotic-producing and nonproducing bacteria in which growth of the nonproducers was reduced by neighbouring antibiotic producers. Various factors affecting spatial interactions between the bacteria were examined for their impact on antibiotic producers. Spatial clustering had a positive impact on the effect of antibiotic production, as measured by the decline in growth of the nonproducing strain, while increasing the initial density of the nonproducing strain had a negative impact. Experiments examined the growth of antibiotic-producing Streptomyces species and a nonproducing, antibiotic-sensitive strain of Bacillus subtilis that were coinoculated on surface media. There was an effect of the Streptomyces on Bacillus growth in some experiments but not in others. In light of the predictions from the model, unintentional clustering of cells is a more likely explanation for this finding than different initial Bacillus densities. The importance of spatial structure seen in this study is consistent with a terrestrial rather than an aquatic distribution of antibiotic-producing bacteria, and may have implications in the search for novel antibiotics.

 Over the last 40 years, there has been a steady supply of novel, useful antibiotics produced by microbes isolated from soil and other natural environments. The increased efficiency of screening procedures in the last decade has played a major part in maintaining this supply. However, the selection and sampling of natural environments are still essentially random processes. The main reasons for this are an almost total lack of knowledge of the significance of antibiotics in nature, deficiencies in the taxonomy of antibiotic-producing microbes and its application, and lack of information about the distribution and ecology of known or potential antibiotic producers. The origins of these problems are discussed and some possible solutions are suggested.

 A new perspective on the topic of antibiotic resistance is beginning to emerge based on a broader evolutionary and ecological understanding rather than from the traditional boundaries of clinical research of antibiotic-resistant bacterial pathogens. Phylogenetic insights into the evolution and diversity of several antibiotic resistance genes suggest that at least some of these genes have a long evolutionary history of diversification that began well before the ‘antibiotic era’. Besides, there is no indication that lateral gene transfer from antibiotic-producing bacteria has played any significant role in shaping the pool of antibiotic resistance genes in clinically relevant and commensal bacteria. Most likely, the primary antibiotic resistance gene pool originated and diversified within the environmental bacterial communities, from which the genes were mobilized and penetrated into taxonomically and ecologically distant bacterial populations, including pathogens. Dissemination and penetration of antibiotic resistance genes from antibiotic producers were less significant and essentially limited to other high G+C bacteria.

Conclusion

 Antibiotics are biotechnological products that inhibit bacterial growth or kill bacteria. They are naturally produced by microorganisms, such as fungi, to attain an advantage over bacterial populations <https://www.boundless.com/definition/population/>. Antibiotics are produced on a large scale by cultivating and manipulating fungal cells. Many antibacterial compounds are classified on the basis of their chemical or biosynthetic origin into natural, semisynthetic, and synthetic. Another classification system is based on biological activity. In this classification, antibiotics are divided into two broad groups according to their biological effect on microorganisms: bactericidal <https://www.boundless.com/definition/bactericidal/> agents kill bacteria, and bacteriostatic <https://www.boundless.com/definition/bacteriostatic/> agents slow down or stall bacterial growth. of some locally isolated actinomycetes for the production of antibiotic(s). A survey of four locally isolated Streptomyces strains for antibiotic production was carried out in static and shaken cultures. It was generally observed that the growth and antibacterial activity obtained in static cultutres were higher than shaken cultures. Streptomyces astreogriseus showed the longest incubation time (12 days) needed to obtain maximum antibacterial activity, while Streptomyces violatus showed a relatively short time (7-days) and produced the highest activity among the tested strains. Streptomyces violatus [30] was also characterised by its broader antibacterial activity, because it affected the growth of all the tested bacteria, showing a stronger activity on S. aureus and B. subtilis. Accordingly, S. violatus was selected for further investigation.Antibiotics are produced industrially by a process of fermentation, where the source microorganism is grown in large containers (100,000-150,000 liters or more) containing a liquid growth medium. Oxygen concentration, temperature, pH <http://www.chemeurope.com/en/encyclopedia/PH.html>and nutrient <http://www.chemeurope.com/en/encyclopedia/Nutrient.html> levels must be optimal, and are closely monitored and adjusted if necessary.

The effectiveness of individual antibiotics varies with the location of the infection, the ability of the antibiotic to reach the site of infection, and the ability of the microbe to inactivate or excrete the antibiotic. Some anti-bacterial antibiotics destroy bacteria (bactericidal), whereas others prevent bacteria from multiplying (bacteriostatic).Oral antibiotics are simply ingested, while intravenous <http://www.bionity.com/en/encyclopedia/Intravenous.html> antibiotics are used in more serious cases, such as deep-seated systemic infections <http://www.bionity.com/en/encyclopedia/Systemic_infection.html>. Antibiotics may also sometimes be administered topically, as with eye drops or ointments.the last few years, three new classes of antibiotics have been brought into clinical use. This follows a 40-year hiatus in discovering new classes of antibiotic compounds. These new antibiotics are of the following three classes: cyclic lipopeptides (daptomycin), glycylcyclines (tigecycline), and oxazolidinones (linezolid). Tigecycline is a broad-spectrum antibiotic, while the two others are used for gram-positive infections. These developments show promise as a means to counteract the growing bacterial resistance to existing antibiotics.

References

1 Běhal V. Bioactive products from Streptomyces. Adv Appl Microbiol 2000;47:113-156.

2Omura S, Sasaki Y, Iwari Y and Takeshima H. Staurosporine, a potentially important gift from a microorganism. J Antibiot 1995;48:535-548.

 Běhal V. Nontraditional microbial bioactive metabolites. Folia Microbiol 2001;46: (6) 000-000, (in press).

 4 Umezawa K, Aoyagi T, Suda T, Hamada M and Takeuchi T. Bestatin, an inhibitor of aminopeptidase B, produced by actinomycetes. J Antibiot 1976;30:170-173.

 Bennett JW and Bentley R. What is a name?-Microbial secondary metabolites. Adv Appl Microbiol 1989;35:1-28.

 6 Lipman F. Attempts to map a prcoess evolution of peptide biosynthesis. Science 1971;173:875-884.

 7 Laland SG and Zimmer T-L. Bioactive peptides produced by microorganisms. Essay Biochem 1973;9:31-57.

 Billich A and Zocher R. Enzymatic synthesie of cyclosporine A. J Biol Chem 1987;262:17258-17259.

 10 Běhal V and Hunter IS. In: Vining LC and Stuttard C (eds) Genetics and Biochemistry of Antibiotics Production. Butterworth-Heinemann, Boston, 1995;359-384.

 11 Kleinkauf H von Doehren H In: Kleinkauf H., von Doehren H, Dornauer H and Nasemann G (eds) Regulation of Secondary Metabolite Formation, VCH Verlagsgesselshaft, Weinheim, 1986:173-207.

 12 Roland I, Froyshov O and Laland G. A rapid method for the preparation of three enzymes of bacitracin synthetase essentialy free from other proteins. FEBS Lett 1977;84:22-24.

 13 Ishihara HM, Hara N and Iwabuchi T. Molecular cloning and expression in Escherichia coli of Bacillus licheniformis bacitracin synthetase gene 2 gene. J Bacteriol 1989;171: 1705-1711.

 14 von Doehren H. In: Vining LC and Stuttard C (eds) Genetics and Biochemistry of Antibiotic Production, Butterworth-Heinemann, Boston, 1995;129-171.

 15 Martin JF and Liras P. Beta-lactams. Adv Biochem Eng 1989;39:153-187.

 Jensen SE and Demain AL. In: Vining LC and Stuttard C (eds) Genetics and Biochemistry of Antibiotics Production, Butterworth-Heinemann, Boston, 1995;239-268.

 17 Newton GGF and Abraham EP. Isolation of cephalosporin C, penicillin-like antibiotic containing D-α-aminoadipic acid. Biochem J 1956;62:651-658.

 18 Martin JF. Α-aminoadipyl-cysteinyl-valine santhetases in β-lactam producing organisms. J Antibiot 2000;53:1008-1021.

 19 Abraham EP. In: Kleinkauf H, von Doehren H, Dornauer H and Nesemann G (eds) Regulation of secondary metabolite formation. VCH Verlagegesselshaft, Weinheim, 1986;115-132.

 20 Parenti F and Cavalleri B. Proposal to name the vancomycin-ristoceti like glycopeptides as dalbaheptides. J Antibiot 1989;42:1882-1883.

 21 Williams DH, Stone MJ, Mortishire-Smith RJ and Hauck PR. Molecular recognition by secondary metabolites. Biochem Pharmacol 1990;40:27-34.

 22 Bentley R and Bennett JW. Constructinc polyketides: From Collie to combinatorial biosynthesis. Ann Rev Microbiol 1999;53:411-446.

 23 Hopwood DA and Sherman DH. Molecular genetic of polyketides and its comparison to fatty acid biosynthesis. Ann Rev Genet 1990;14:37-66.

 24 Dimroth P, Walter H and Lynen F. Biosynthesis von 6-methylsalicylsaure. Eur J Biochem 1970;13:98-110.

 25 Dimroth P, Ringelmann E and Lynen F. 6-methylsalicylic acid from Penicillium patulum. Eur J Biochem 1976;68: 591-596.

 26 Aasen IM, Folkvord K & Levine DW (1992) Development of a process for large- scale chromatographic purification of an alginate lyase from Klebsiella pneumoniae. Journal of Applied Microbiology and Biotechnology 37: 55-60.

27 Bibb M (1996) The regulation of antibiotic Production in Streptomyces coelicolor A3(2). Microbiology 142: 1335-1344.

28 Bystrykh LV, Fernander-Moreno M A, Herrema J K, Malportida F, Hopwood D A & Dijkhuizen L (1996) Production of actinorhodin-related blue pigments by Streptomyces coelicolor A3(2). Journal of Bacteriology 178: 2238-2244.

30 Said WY (2001) Production of antibiotics by immobilized Streptomyces strains. Ph.D. Thesis, Faculty of Science, Alexandria University, Egypt. 1995;48:535-548.