ISOLATION AND SCREENING OF ANTIBIOTIC PRODUCING ACTINOMYCETES FROM GARDEN SOIL OF SATHYABAMA UNIVERSITY, CHENNAI

Objectives: To isolate and screen Actinomycetes with anti bacterial and antifungal activity from garden soil samples of Sathyabama University, Chennai.Methods: Six soil samples were collected, serially diluted and plated on starch casein agar supplemented with nalidixic acid and cyclohexamide for inhibition of bacteria and fungi, respectively. Primary screening of actinomycetes isolates was done by following cross streak method against test organisms. Submerged fermentation was followed for the production of crude antibiotics. Agar well diffusion method was done to determine the antimicrobial activity of the crude extract. The MIC also quantified for the crude extract by microtiter plate assay. The promising isolate was characterized by conventional methods.Results: On primary screening 13 out of 22 actinomycete isolates (59%) showed potential antimicrobial activity against one or more test bacteria and/or fungus.  The isolate BN8 shows antagonistic activity against all the tested bacteria and fungi, isolates BN5 and BN16 were active against only bacteria not fungi, and Isolate BN2 was active against all tested fungi. The zone of inhibition was measured by using the crude extracts of all the four isolates. The crude extract produced by isolate BN8 showed zone on inhibition against all the tested bacterium in 100 µg/ml against Pseudomonas aeroginosa (22mm), Klebsiella pneumonia (25mm), Bacillus cereus (20mm), Staphylococcus aureus (22mm),  Escherichia coli (15mm),  Aspergillus flavus (14mm),  Aspergillus niger (20mm),   Aspergillus fumicatus (10mm) respectively. The crude extracts of isolates BN2, BN5, BN16 were not exhibited any zone of inhibition against the test microbes on agar well diffusion assay. The MIC of crude extract against Pseudomonas aeroginosa (50 μg/ml), Staphylococcus aureus(25 μg/ml), Klebsiella pneumonia (25 μg/ml) and Bacillus cereus(25 μg/ml) . The MIC value of the crude extract against the bacterium Escherichia coli was 12.5 μg/ml. The MIC of 12.5 μg/ml was observed in the crude extract against Aspergillus flavus, 25 μg/ml against Aspergillus niger, and 50 μg/ml against Aspergillus fumicatus respectively.Conclusion: This groundwork concluded that the soil samples of Sathyabama University have actinomycetes with metabolites inhibits bacterial and fungal pathogens. One of the promising isolate was identified which active against the test bacteria and fungi. The crude metabolite exhibits very large zone of inhibition when compared to the control antibiotic. The type of antimicrobial agents produced by the isolate and the phylogenic relationship of the isolate has to be investigated as well

ANALYSIS OF BIOACTIVE CONSTITUENTS FROM A NEW STREPTOMYCES VARIABILIS STRAIN SU5 BY GAS CHROMATOGRAPHY - MASS SPECTROMETRY

Objectives: To analyze the bioactive constituents found in the crude extract of a new Streptomyces variabilis strain SU5 by gas chromatography - mass spectrometry. Methods: A total of fifty two actinomycetes were isolated from sediment samples of South east coast of Tamil Nadu by the serial dilution method. A new strain was identified based on cultural and molecular analysis as Streptomyces variabilis strain SU 5 and submitted in GENBANK with the accession number KF551876. The ethyl acetate extract of the new strain was produced by submerged fermentation and has been subjected to GC-MS analysis. Results: The major chemical constituents are Diisobutyl phthalate (31.84), Monoethylhexyl phthalate (20.33), tributylamine (13.24), Dibutyl phthalate (5.51), 2-Bromotetradecane (3.79) with the retention time 15.635, 21.606, 7.164, 16.608, 12.657 respectively. Conclusion: The presence of some of these constituents in the actinomycetes extract provides the scientific evidences for eliminating tumor cells in bone marrow, purging agent in autologous bone marrow transplantation, cytotoxic activity, stimulates adipogenesis and glyceroneogenesis, affects the differentiation of Human Liposarcoma

CHROMATOGRAPHY-BASED PARTIAL PURIFICATION AND CHARACTERIZATION OF ANTIMICROBIAL COMPOUND ISOLATED FROM A TERRESTRIAL STREPTOMYCES

Objectives: A potent Streptomyces strain isolated from garden soil samples of Sathyabama University, Chennai, and the characterization and its antimicrobial activity was reported previously. This report deals with partial purification and characterization of the partially purified antimicrobial compound by liquid chromatography-mass spectrum (LC-MS) method.Method: The crude extract was characterized by ultra violet-visible spectrum (UV) and Fourier transform infrared spectroscopy (FTIR) subsequently partial purification was done by thin-layer chromatography, and the bands were used for LC-MS analysis. The obtained mass spectrum was searched in NIST for species data by molecular weight. The compound was identified by comparing the mass spectrum with the known compounds mass spectrum having 98-100% identical. The biological activity of the identified compound was searched in PubChem.Results: The UV and FTIR spectrum indicate the presence of hydroxyl group, aliphatic chain, aromatic, aliphatic amines, and ethers in the crude extract. The LC-MS spectrum revealed the presence of 12 compounds in high intensity resembling antimicrobial compounds such as imidazole, N-trifluoroacetyl, cyclohexane, 2-nitro, and stigmasterol.Conclusion: The instrumental analysis shows the presence of 14 different compounds, and PubChem compound search shows these compounds having various biological activities including antibacterial, antifungal, anticancer, antitumor, and antidepressant. This report insists us further to evaluate the anticancer, antitumor, and antitrypanosomal activities of the partially purified compound

CHROMATOGRAPHY-BASED PARTIAL PURIFICATION AND CHARACTERIZATION OF ANTIMICROBIAL COMPOUND ISOLATED FROM A TERRESTRIAL STREPTOMYCES

Objectives: A potent Streptomyces strain isolated from garden soil samples of Sathyabama University, Chennai, and the characterization and its antimicrobial activity was reported previously. This report deals with partial purification and characterization of the partially purified antimicrobial compound by liquid chromatography-mass spectrum (LC-MS) method.Method: The crude extract was characterized by ultra violet-visible spectrum (UV) and Fourier transform infrared spectroscopy (FTIR) subsequently partial purification was done by thin-layer chromatography, and the bands were used for LC-MS analysis. The obtained mass spectrum was searched in NIST for species data by molecular weight. The compound was identified by comparing the mass spectrum with the known compounds mass spectrum having 98-100% identical. The biological activity of the identified compound was searched in PubChem.Results: The UV and FTIR spectrum indicate the presence of hydroxyl group, aliphatic chain, aromatic, aliphatic amines, and ethers in the crude extract. The LC-MS spectrum revealed the presence of 12 compounds in high intensity resembling antimicrobial compounds such as imidazole, N-trifluoroacetyl, cyclohexane, 2-nitro, and stigmasterol.Conclusion: The instrumental analysis shows the presence of 14 different compounds, and PubChem compound search shows these compounds having various biological activities including antibacterial, antifungal, anticancer, antitumor, and antidepressant. This report insists us further to evaluate the anticancer, antitumor, and antitrypanosomal activities of the partially purified compound