Selective isolation of rare Actinomycetes producing novel antimicrobial compounds (original) (raw)
Related papers
2020
Actinomycetes are Gram-positive, aerobic and thread like bacteria with high DNA G+C contents. They are free-living, saprophytic, and abundant in soil, water, and colonizing nodulating plants. Actinomycetes assume a significant job in reusing squanders in the earth and they are additionally the makers of thousands of metabolic items, which display organic action. Due to the outstanding history of actinomycetes in the production of bioactive molecules for human interest, a large number of efforts have been made on the isolation, characterization and identification from terrestrial sources in the past half-decade. Secondary metabolites obtained from various potential strains of actinomycetes are very effective against Gram-positive and Gram-negative bacteria. Many researchers both nationally and internationally isolated this potential group of microorganisms from soil, water, sediment etc. and checked their potential antimicrobial activity. In the present review, antibiotic potential o...
Metabolic Profiling of Actinomycetes Having Antimicrobial Properties
Chemical screening is a simple and an efficient approach for identifying the possible chemical class of compounds present in culture extracts. It includes separation of fractions from crude extract of a microbe by thin layer chromatography (TLC) and subsequent staining with range of chemical reagents. In the present study, eight actinomycetes isolated from diverse ecological habitats including sanitary landfill soil, pesticide contaminated soil, agricultural soil, radiation exposed soil, industrial soil and possessing antimicrobial activity against pathogenic strains, were subjected to chemical screening. Bioactive compounds were extracted either from culture broth or culture plates of the isolates using organic solvents like ethyl acetate and methanol with different polarities. Metabolic pattern/profiling of extracts was observed with help of TLC followed by visualization under UV as well as staining with chemical reagents including anisaldehyde/H 2 SO 4 , vanillin/H 2 SO 4 and met...
Actinomycetes are a diverse group of medically, industrially and ecologically important bacteria, studied as much for the diseases they cause as for the cures they hold. Along with also as a source of industrial important product which are helpful for mankind. However, many of the rare genera of actinomycetes have been neither explored nor manipulated for their biotechnological and industrial potential. With the help of molecular approaches and recent advances in genomics and sequencing technologies, microbial community analyses using culture-independent molecular techniques have initiated a new era of actinomycetes ecology. This review summarizes recent progress in the area of molecular microbial ecology with an emphasis on novel techniques and approaches that offer new insights into the phylogenetic and functional diversity of actinomycetes assemblages for better production of qualitative and quantitative industrial and pharmaceutical products .
Reappraisal of actinomycetes for novel bioactive metabolites
Annals of Phytomedicine: An International Journal, 2017
The appearance of new deadly diseases like cancer and the burgeoning problem of drug resistance among common bacteria l pathogens are a serious threat to a vailable trea tments. Since the channels of compounds under development are limited, this necessitates the discovery of new drugs. It is where actinomycetes can complement in the accomplishment of development of thera peu tically new bioactive compounds, predomina ntly u sed in antibiotic production. Actinomycetes are diverse in their location and have proven ability to produce new bioactive compounds. By employing modern microbiological and molecular technologies, the target-directed search for detection and isolation of bioactive actinomycetes is gaining more strength. Therefore, the innova tive isolation of actinomycetes from extreme ecosystems, their identification and cultivation using novel techniques are imperative to pursue for drug discovery.
2011
Actinomycetes are group of bacteria, which are present widely in ecological diversity. Actinomycetes are the major microbial population in soil which can produce active secondary metabolites. Aim of this study is to isolate varieties of Actinomycetes from different locations to evaluate its antimicrobial activity. Soil samples were collected from different niche habitats of Gwalior (Dry soil from Hostel zone of Madhav Institute of Technology and Science (MITS), Cancer hospital territory, IIITM ground, forest areas of Sanjeevani nursery) and used for actinomycetes isolation. The seven actinomycetes isolates were isolated from different soil samples based on their colony morphology, mycelium colouration and diffusion of pigmentation. The isolates were analysed for their biochemical activity and found that all the isolates were positively active for catalase, starch and casein utilization. The isolates were screened for their secondary metabolites activity on three human pathogenic bacteria are Escherichia coli, Staphylococcus epidermis and Vencomycin resistant Enterococci (vre). The isolate 5 was found to be more active against the test bacteria. The isolate 5 was further tested for its zone of inhibition and found maximum activity (14 mm) against the test bacteria. It was concluded that actinomycetes isolate 5 had potentials as sources of new antibacterial compounds against pathogenic microorganisms (unicellular Gram positive and Gram negative bacteria and drug resistance microorganism) to humans.
Frontiers in Microbiology, 2016
The search for novel bioactive compounds from the natural environment has rapidly been gaining momentum with the increase in multi-drug resistant (MDR) pathogens. In the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. Primary and secondary screening was performed against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans, Candida tropicalis, Trichophyton rubrum, and other MDR bacterial and fungal test strains, thirteen active isolates were selected for further study. Microbial strains were identified on the basis of growth conditions and other biochemical characters. Five most active microbial strains were identified using 16S rRNA sequence homology and designated as Streptomyces xanthophaeus MTCC 11938, Streptomyces variabilis MTCC 12266, Streptomyces xanthochromogenes MTCC 11937, Streptomyces levis EU 124569, and Streptomyces sp. NCIM 5500. Four antibacterial and three antifungal compounds isolated from the above five isolates were purified and partially characterized using UV absorption and IR spectra. Two antibacterial metabolites, belong to chromone and peptide antibiotic, respectively. The antifungal compounds were found to be of non-polyene nature. In conclusion, we study the isolation of novel bacterial strains of actinomycetes for producing novel compounds having antibacterial and antifungal activities from the unexplored agro-ecological niches of India. Also, this study paves the way for further characterization of these isolates of Streptomyces sp. for their optimum utilization for antimicrobial purposes.
Present work includes isolation of actinomycetes from marine, mangrove, and terrestrial environments followed by their screening for bioactivity. Study led to the isolation of 109 actinomycete isolates. Broth supernatants and ethyl acetate crude extracts were analyzed for bioactivity of which, 19 isolates showed a potent inhibition against E. coli, 17 isolates showed activity against S. aureus, 10 isolates exhibited activity against K. pneumoniae and B. subtilis each, and 9 isolates showed zone of inhibition against C. albicans. Potential actinomycetes were and identified by 16S rRNA gene analysis and their sequences were deposited in GenBank. Two isolates belonging to non-Streptomyces genera viz., Micromonospora and Nocardiopsis were obtained. The broad-spectrum antimicrobial activity against all the test organisms at very low concentration was shown by soil isolates D, D2, F30 (brown pigment), TS13 (Orange red), TS14 (green), TS4 (cherry red), and marine isolate M11 (yellow).
Uttarakhand region is less explored, but possess a great biodiversity. This diversity can be explored for isolation and characterization of new actinomycetes strains for seeking antimicrobial molecules. It can therefore be predicted that novel bioactive metabolite producing actinomycetes can be discovered to combat multidrug resistant bacterial pathogens. Materials and Methods: Variations in the viable count of actinomycetes were accessed in different altitudes. Actinomycetes were isolated, indentified and screened for their antibacterial activity. Results: The highest viable counts of actinomycetes were recorded in valleys followed by mid hills and high hills. A total of 512 actinomycetes were isolated which were found to belong the 14 different genera of actinomycetes. Mainly the genus Streptomyces was dominant in all the soil samples. Out of 512 isolates recovered, 23.44% exhibited antibacterial activity against one or more tested bacterial pathogens. Of these 56.67% showed activity against Gram-positive bacteria, 26.67% against Gram-negative bacteria while 16.67% showed broad spectrum activity. Isolate DV1S and GR9a-5 showed highest antibacterial properties against several multi-drug resistant bacterial pathogens and were identified using polyphasic approach. DV1S and GR9a-5 were found to be most closely related with S. massasporeus NBRC 12796 T and Nocardia nova JCM 6044 T respectively.