Screening of Novel Receptor‐Active Compounds of Microbial Origin

and, Haruo Tanaka; Ōmura, Satoshi

doi:10.1002/9783527620999.ch3g

Cited by 3 publications

(3 citation statements)

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“…Secondary metabolites are primarily aimed at discovering novel secondary metabolites, which can counteract resistance from pathogens and circumvent side effects that are typically associated with most indispensable therapeutic drugs (Bapela et al, 2008). About 70% of all known drugs have been isolated from Actinomycetes bacteria of which 75% and 65% are used in medicine and agriculture, respectively (Tanaka and Omura, 1993). Industrial development practice includes natural selection, mutation and protoplast fusion (Smith, 1986).…”

Section: Introductionmentioning

confidence: 99%

Screening Of Antibiotic Producing Actinomycetes From The Sediments Of Undisturbed Forest Areas And Its Hyper Activity After Mutation

2016

IJACEBS

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Abstract-Wide and uncontrolled usage of antibiotics has made the pathogens to become resistant to currently used antibiotics. There is an urgent need for development of a new drug or a highly active molecule for controlling antibiotic resistant strains. In this study 32 strains of Actinomycetes were isolated and subjected to primary screening by giant colony method against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Aeromonas hydrophilia. The secondary screening was carried out by fermentation process. Antibacterial activity was evaluated by well plate method. The extract of isolates was subjected to well plate method against pathogenic bacteria. B. subtilis and E. coli were highly inhibited by AK1 isolate. Other isolates showed limited inhibition of bacteria. The AK1 isolate was mutated by UV irradiation. The mutants differed from the wild parent in reduced growth rates, changes in the shape and size of the colony, sporulation level, antibiotic activity and variation in the color of the mycelium. The zone of inhibition was higher with Actinomycetes AK1 inoculated plates. The secondary metabolite production was enhanced by UV mutagenesis when compared to wild type. Actinomycetes may produce different molecule that can inhibit different types of pathogens, however efforts like strain development can be done to produce new bioactive components against multidrug resistant bacteria.

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Section: Introductionmentioning

confidence: 99%

Screening Of Antibiotic Producing Actinomycetes From The Sediments Of Undisturbed Forest Areas And Its Hyper Activity After Mutation

2016

IJACEBS

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“…being the largest members of Actinomycetes has been revered for its metabolic potential and are storehouses of a diverse array of metabolites viz., antibiotics, antitumor agents, pharmacological agents, enzymes, immunosuppressant's, etc. [3][4][5].…”

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confidence: 99%

Characterization and Antimicrobial Spectrum of a Potent Streptomyces Sp. Gos2 Isolated From Western Ghats of Karnataka, India

Gautham

Mesta²,

2016

Int J Pharm Pharm Sci

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Objective: Western Ghats of Karnataka, India-a biodiversity hotspot is a rich source of microorganisms with undiscovered metabolic capabilities. The upsurge of antibiotic-resistant pathogens has created a greater demand for novel antibiotics. In context to the above a potent soil Streptomyces sp. GOS2 isolated from Agumbe regions of Western Ghats, and its metabolite was assessed and characterized for its antimicrobial spectrum. Methods:The isolation was carried out by soil serial dilution plating on Starch Casein Nitrate agar media (SCN). The obtained isolate was characterized by morphological and biochemical tests. The antimicrobial activity was assessed by well in agar methods against 28 test organisms. The partial characterization of the bioactive metabolite was carried out by thin layer chromatography (TLC) and UV-Visible spectroscopy studies. Results:The isolated GOS2 was observed as a raised powdery colony with grey colored aerial mycelium and media impregnated substrate mycelium. The spore chain was rectus with smooth spore surface. The isolate was gram positive, non-acid fast, positive for catalase, hydrogen sulphide production and starch hydrolysis, negative for casein and gelatin hydrolysis. The carbohydrate fermentation studies showed acid production in dextrose and alkali production in sucrose, lactose, maltose and starch. A prominent antibacterial activity was observed with a zone of inhibition measuring 21-27 mm. The TLC showed a purple spot and UV spectroscopy revealed λ max at 233.2 and 235 nm indicating macrolide group of antibiotics. Conclusion:Western Ghats actinomycetes are a potent source of novel antibiotic molecules.

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“…No longer were microbial sources looked upon solely as potential solutions for infectious diseases, but for other applications, such as cholesterol-lowering, immunosuppresion, enzyme inhibition, and so on. The change in screening philosophy was accompanied by ingenious applications of molecular biology to detect receptor antagonists and agonists, and other agents inhibiting or enhancing cellular activities on a molecular level (175).…”

Section: Closing Remarksmentioning

confidence: 99%

Natural Products and Drug Discovery

Demain

Zhang

Natural Products

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SummaryFor more than 50 yr, natural products have served us well in combating infectious bacteria and fungi. During the 20th century, microbial and plant secondary metabolites helped to double our life span, reduced pain and suffering, and revolutionized medicine. The increased development of resistance to older antibacterial, antifungal, and antitumor drugs has been challenged by (1) newly discovered antibiotics (e.g., candins, epothilones); (2) new semisynthetic versions of old antibiotics (e.g., ketolides, glycylcyclines); (3) older underutilized antibiotics (e.g., teicoplainin); and (4) new derivatives of previously undeveloped narrow-spectrum antibiotics (e.g., streptogramins). In addition, many antibiotics are used commercially, or are potentially useful in medicine for purposes other than their antimicrobial action. They are used as antitumor agents, enzyme inhibitors including powerful hypocholesterolemic agents, immunosuppressive agents, antimigraine agents, and so on. A number of these products were first discovered as antibiotics that failed in their development as such, or as mycotoxins.It is unfortunate that the pharmaceutical industry has downgraded natural products just at the time that new assays are available and major improvements have been made in detection, characterization, and purification of small molecules. With the advent of combinatorial biosynthesis, thousands of new des4oeatives can now be made by a biological technique complementary to combinatorial chemistry. Furthermore, only a minor proportion of bacteria and fungi, i.e., 0.1-5%, have thus far been examined for secondary metabolite production. New methods are being developed to cultivate the so-called unculturable microbes from the soil and the sea. High-throughput screening (HTS) of combinatorial chemicals has not provided the numbers of high-quality leads that were anticipated. It has virtually eliminated the most unique source of chemical diversity, i.e., natural products, from the playing field, in favor of combinatorial chemistry. Combinatorial chemistry mainly yields minor modifications of present-day drugs and absolutely requires new scaffolds on which to build. Although comparative genomics is capable of disclosing new targets for drugs, the number of targets is so large that it requires tremendous investments of time and money to set up all the screens necessary to exploit this resource. This can be handled only by HTS methodology, which demands libraries of millions of chemical entities. Although such targets would be excellent for screening natural products, the industry has failed to exploit this unique opportunity and has opted to save funds by eliminating natural-product departments or decreasing their relevance in the hunt for new drugs. It is clear that the future success of the pharmaceutical industry depends on the combining of complementary technologies such as natural product discovery, HTS, integrative and systems biology, combinatorial biosynthesis, and combinatorial chemistry.

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Screening of Novel Receptor‐Active Compounds of Microbial Origin

Cited by 3 publications

References 84 publications

Screening Of Antibiotic Producing Actinomycetes From The Sediments Of Undisturbed Forest Areas And Its Hyper Activity After Mutation

Screening Of Antibiotic Producing Actinomycetes From The Sediments Of Undisturbed Forest Areas And Its Hyper Activity After Mutation

Characterization and Antimicrobial Spectrum of a Potent Streptomyces Sp. Gos2 Isolated From Western Ghats of Karnataka, India

Natural Products and Drug Discovery

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