Screening for Enzyme Inhibitors in Marine Bacteria (original) (raw)

Isolation of marine Streptomyces, characterization and metabolites' screening for antibacterial activity

To combat drug resistant, searching of new broad-spectrum antibiotics is urgent and Marine Streptomyces can be potential new sources of antibacterial agents. With this aim, present study was carried out to search new, safe and effective antibacterial compounds. Twenty nine strains were isolated from marine sediments and soil samples of mangrove forest, Sundarban, Bangladesh using spread plate technique. Among them AIAH-5 and AIAH-10 were finally selected for further study owing to their promising activity against a series of pathogenic strains (done by streak plate method). The organisms were identified on the basis of cultural, morphological and biochemical properties. At least four compounds were isolated by chromatographic means, from the crude extracts of both organisms. But pure compounds, AI-5 and AI-10 were finally selected for their highest antibacterial efficacy. Antimicrobial activities of both AI-5 and AI-10 were performed against a series of pathogenic microorganisms. The minimum inhibitory concentrations (MIC) of the compound AI-5 and AI-10 varied between 8- 32 and 1- 4 μg/ml, respectively against a wide range test bacteria. The minimum bactericidal concentration (MBC) of the compound AI-5 and AI-10 were ranges from 16- 128 and 2- 16 μg/ml, respectively. The compound AI-5 and AI-10 also exhibited satisfactory activity against azithromycin and ciprofloxacin induced resistant Escherichia coli strain. This study demonstrates the diversity of the mangrove forest, Sundarbans, Bangladesh as a rich and interesting source of antibiotic molecules producing new and potential marine bacterial species.

A Perspective on Enzyme Inhibitors from Marine Organisms

Marine Drugs, 2020

Marine habitats are promising sources for the identification of novel organisms as well as natural products. Still, we lack detailed knowledge on most of the marine biosphere. In the last decade, a number of reports described the potential of identifying novel bioactive compounds or secondary metabolites from marine environments. This is, and will be, a promising source for candidate compounds in pharma research and chemical biology. In recent years, a number of novel techniques were introduced into the field, and it has become easier to actually prospect for natural products, such as enzyme inhibitors. These novel compounds then need to be characterized and evaluated in comparison to well-known representatives. A number of current research projects target the exploitation of marine organisms and thus the corresponding diversity of metabolites. These are often encountered as potential drugs or biological active compounds. Among these, the class of enzyme inhibitors is an important g...

Characterization and optimization of a bioactive Streptomyces sp. F-7 isolated from marine carangid fish Alepes melanoptera in the offshore waters of Puducherry coast

Actinomycetes isolated from marine environment are found to be important sources of a bioactive compounds with antibiotic, anti-inflammatory, antiviral and antitumour properties. Cultural characteristics of the active Actinomycetes isolate F-7 associated with carangid fish Alepes melanoptera caught from Puducherry, South East coast of India was investigated under this study. Morphological, physiological and biochemical characteristics of the actinomycetes isolate F-7 was studied in different ph, temperatures, NaCl concentrations and growth media. Distinct aerial and substrate mycelia colouration and diffusible pigmentation was formed by the actinomycetes isolate F-7. Antimicrobial activity of the isolate F-7 grown in Zobell marine agar, PDA and ISP-6 were tested against Escherichia coli, Pseudomonas fluorescens, Shewanella putrefaciens, Vibrio parahaemolyticus, Alteromonas sp., Staphylococcus aureus and Candida sp. The degree of inhibition of the isolate against selected fish spoilage and pathogen organisms were recorded and found to differ in different media. The present investigation concludes the potentiality of actinomycetes associated with marine fishes as a promising source of antibacterial bioactive substances which needs to be explored further. Introduction Micro organisms have time and again proved as potential source of bioactive compounds used for the treatment of a number of diseases. Actinobacteria is one of the largest group of bacteria that has contributed widely in drug discovery. Streptomycetes alone has been found to be a large source of a wide variety of antibiotics [1] with far reaching implications in the Public health sector. Increase in the incidence of new diseases in human beings and economically important animals have led to the search of new actinomycetes from previously unexplored sources. Recent problems of drug resistant pathogen strains have further strengthened the search for new strains of actinomycetes. Microbes of the same phylogenetic family when isolated from different habitat exhibit different bioactive properties. A large number of bioactive actinomycetes have already been isolated from the terrestrial environment redirecting the scientist to explore the marine environment in search of novel bioactive compound producing actinomycetes. Many studies are available on the regulated antibiotic production by actinomycetes [2, 3]. A number of factors from the environment to the availability of nutrients influence the growth and bioactivity of the microorganism. Optimal conditions in form of medium, pH, temperature, sources of carbon, nitrogen, phosphorus etc., influence the production of secondary metabolites by the organism [4]. The present study deals with the identification, characterization and optimization of the conditions for the growth and bioactivity of an actinomycete isolated from a marine carangid fish Alepes melanoptera collected from the coast of Puducherry, India.

Exploration of Culturable Marine Streptomyces from Southern Coastal Region of India with Antibacterial Properties

The Southern coastal region is a geographically positioned area with rich source of microbial diversity, of which producing broad spectrum of bioactive compounds. The marine sediments are collected from the various sites of south east coastal region of Tamil nadu and are processed. Out of 78 isolates, the 4 strains of actinomycetes are showing broad spectrum activity against Klebsiella pneumoniae (MTCC 1687), Proteus vulgaris (MTCC 3160), Salmonella typhi (MTCC 3231), Shigella dysenteriae (MTCC 3642) and Vibrio cholerae (MTCC 3906). The bioactive isolates are proceeded for further morphological features like growth pattern and mycelial coloration, biochemical and polyphasic taxonomical characterisation were documented. Isolates are investigated for abiotic stress condition to study the growth rate of isolates. Finally, the 16S rRNA molecular identification and phylogenetic analysis of the isolates were explored. Further, bioactive isolates may be potential source for discovery of molecules with industrial applications.