Search

Twenty-three Saccharomyces cerevisiae strains isolated from different fermented foods of Western Himalayas have been studied for strain level and functional diversity in our department. Among these 23 strains, 10 S. cerevisiae strains on the basis of variation in their brewing traits were selected to study their organoleptic effect at gene level by targeting ATF1 gene, which is responsible for ester synthesis during fermentation. Significant variation was observed in ATF1 gene sequences, suggesting differences in aroma and flavor of their brewing products. Apple is a predominant fruit in Himachal Pradesh and apple cider is one of the most popular drinks all around the world hence, it was chosen for sensory evaluation of six selected yeast strains. Organoleptic studies and sensory analysis suggested Sc21 and Sc01 as best indigenous strains for soft and hard cider, respectively, indicating their potential in enriching the local products with enhanced quality. [ABSTRACT FROM AUTHOR]

This study reports characterization of fibrolytic enzymes from rumen bacteria of migratory Gaddi sheep in North- West Himalayan Region (NWHR). A total of 70 cellulolytic bacteria were isolated. Two isolates viz., CDB1 and CDB5 due to higher secretion of fibrolytic enzymes, namely endoglucanase and β-glucosidase were studied. The endoglucanase and βglucosidase activities in isolate CDB1 and isolate CDB5 were found to be 0.720 and 0.696 U/mL and 0.820 and 0.758 U/mL, respectively. The isolate CDB1showed optimal enzyme production using yeast extract, while isolate CDB5 used peptone as nitrogen source for production of the enzyme. The endoglucanase (0.720 and 0.750 U/mL) and βglucosidase (0.710 and 0.722 U/mL) activities in CDB1 and CDB5 were optimal at 40°C and 50°C, respectively. Highest level of endoglucanase (0.742 and 0.850 U/mL) and βglucosidase activities (0.724 and 0.810 U/mL) produced by CDB1 and CDB5 were detected at pH 6.0 to 7.0, and 6.0 to 8.0, respectively. In view of ability of the isolates to inhibit some undesirable microorganisms, and activity of enzymes produced at 40°C and 50°C, it is envisaged that these isolates may have applications as probiotics and additives in silage making. [ABSTRACT FROM AUTHOR]

In the present study, different transcripts of Trichoderma harzianum ThHP-3 were evaluated for their response against four fungal pathogens Fusarium oxysporum, Colletotrichum capsici, Colletotrichum truncatum and Gloesercospora sorghi using RT-qPCR. The time course study of T. harzianum transcripts related to signal transduction, lytic enzymes, secondary metabolites and various transporters revealed variation in expression against four fungal pathogens. In a broader term, the transcripts were upregulated at various time intervals but the optimum expression of cyp3, abc, nrp, tga1, pmk, ech42 and glh20 varied with respect to host fungi. Additionally, the expression of transcripts related to transporters/cytochromes was also observed against Fusarium oxysporum after 96h whereas transcripts related to secondary metabolites and lytic enzymes showed significant difference in expression against Colletotrichum spp. from 72 to 96h. This is first study on transcriptomic response of T. harzianum against pathogenic fungi which shows their host specific response., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In the present study, endochitinase of T. harzianum isolate-ThHP3 induced against mycelium of F. oxysporum was cloned, sequenced and characterized. The complete nucleotide sequence contained an ORF of 1293bp corresponding to 430 amino acids with 46kDa molecular weight and theoretical pI 5.59. The precursor protein contained 22 amino acids long signal peptide at N terminus. The domain architecture of endochitinase showed low complexity regions, presence of 1W9P domain specific to cyclopentapeptide and lack of carbohydrate binding modules. The ligand binding site of ech46 endochitinase was constituted by 10 amino acids. The cDNA encoding ech46 endochitinase was ligated into pET28a vector and transformed to E. coli BL21. The predicted molecular weight of recombinant endochitinase without signal peptide was 49.4kDa with a theoretical pI 6.67. SDS-PAGE analysis of purified 6xHis tagged protein showed a single band of 49kDa. The refolded enzyme was active under acidic conditions with a temperature and pH optima of 50°C and 4. Km and V max for recombinant endochitinase using 4-pNP-(GlcNAc) 3 were 315.2±0.36μM and 0.140±0.08μMmin -1 , respectively and the calculated k cat was 6.44min -1 . The RT-qPCR revealed induction of ech46 by phytopathogenic fungi., (Copyright © 2016 Elsevier B.V. All rights reserved.)