MICROBIOLOGYExploitation of India’s rich microbial diversity (NWP006)In studies on diversity analysis of pea root-nodulating bacteria based on 16S rRNA, sequencing ofnodC and nifH genes revealed a distinct pattern of Rhizobium leguminosarum bv. viciae distributionin Lahaul and Spiti valleys, H.P. The Lahaul and Spiti strains showed maximum similarity withthe western and Chinese strains, respectively. Phylogenetic analysis of concatenated sequencesof atpD and recA genes revealed a common Rlv sublineage in Spiti and three sequence types inLahaul strains. Carbon-source utilization pattern (BIOLOG) and whole-cell fatty acid profilingelucidated intraspecies polymorphism. Adaptation to specific ecological niches demonstratedby the principal component analysis of whole-cell fatty acids distinguished the genetically andphenotypically similar Spiti valley strains into two clusters.In a separate study on developing microbial consortium for plant growth promotion, formulationsbased on Pseudomonas sp. BIHB 756, P. putida NBRI 03 and inorganic fertilizers on cauliflowerwere demonstrated in farmers’ fields. Significant increase in yield with reduced application ofinorganic fertilizers was observed.In yet another study on discovery of new antimicrobial metabolites, a total of 503 culture extractsof 469 bacteria, 20 actinomycetes and 14 fungal cultures were tested for antimicrobial activity.Nineteen bacteria, 2 actinomycetes and 4 fungal cultures showed broad-spectrum activity againstBacillus subtilis, Candida albicans, Escherichia coli, Klebsiella planticola, Micrococcus luteus, P. aeruginosa,Staphylococcus aureus MLS16 and S. aureus. A total of fresh 256 cultures of bacteria, actinomycetesand fungi were isolated from the cold deserts and preserved.Among 14 active cultures, 13, 11, 7 and 3 cultures showed antimicrobial activity against MethicillinresistantS. aureus (MRSA), Vancomycin-resistant Entrerococcus (VRE), C. albicans (FCZr) andAspergillus fumigatus at Indian Institute of Integrative Medicine, Jammu. The cultures showingbroad-spectrum activity against drug resistant strains were identified as Aspergillus flavipes, Bacillusamyloliquefaciens, B. thuringiensis, Brevibacillus laterosporus, Burkholderia stabilis, Janthinobacteriumlividum, Lentinula edodes, Penicillium rolfsii, Streptomyces aureus, S. blastmyceticus, S. netropsis, S. sioyaensis,S. spiroverticillatus, S. subrutilis, S. xcanthophaeus and Ulocladium tuberculatum.In studies on screening of microbial cultures for other biological activities, 1400 culture extractswere prepared. Of these, 24, 19 and 12 extracts showed inhibition of β-lactamase (NIIST), AChEand α-glucosidase (CFTRI), respectively. Sixty eight and four extracts showed cytotoxicity againstHuT-78 cells and anti-NIK1 activity (IMTECH), respectively.61
CSIR-<strong>IHBT</strong> <strong>Annual</strong> <strong>Report</strong> 2010-11Enzymes from microbes of low temperature environments (psychrotrophs and psychrophiles)have potential industrial applications. Among 340 isolated bacteria, those positive for protease(91), CMCase (62), amylase (49), lipase (216) and cyclodextrin glucanotransferase (3) activitiesat 28°C were selected. Thirty six fungal isolates among 41 were also found positive for cellulaseproduction.An extracellular protease of 35 kDa was partially purified (9.8-fold) from Acinetobacter sp. MN12.The enzyme showed optimum activity at pH 9.0 and 40°C. It was stable at pH 7.0-11.0 andretained >75% activity. The activity was inhibited in presence of Hg +2 and Cu +2 and was enhancedby Ca +2 , Na + , Mn +2 and Zn +2 . The enzyme removed dried blood stains from cotton fabrics at lowtemperature and was compatible with commercial detergents. The Michaelis-Menten constant(Km) for casein and gelatin was 0.35 and 2.03 mg/ml, respectively.In another study, a partially purified CMCase from a promising Paenibacillus IHB B 3084isolate was found to be stable at 5-50ºC and pH 5-9. The activity was enhanced by Na + , Ca +2 ,Zn +2 , Mg +2 and EDTA. Sixteen bacterial isolates showing either protease or CMCase wereidentified as Acinetobacter sp., Bacillus sp., B. cereus, B. pumilus, Enterobacter sp., Exiguobacteriumundae, Mycoplana bullata, Paenibacillus sp., Serratia marcescens by 16S rRNA sequencing.62
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