Keratinase Production by Endophytic Bacteria Aneurinibacillus aneurinilyticus VRCS-4 Isolated from Xerophytic Plant Opuntia ficus - indica (Prickly pear)

Bacterial endophytes colonize an ecological niche which is unexplored site makes them suitable to produce pharmacologically active substances with vast biotechnological potential therefore, xerophytes were chosen to isolate the endophytes. In the present study forty endophytic bacterial isolates were isolated from xerophytic plants grown near poultry farms and feather dumping sites. Of them eight isolates showed zone of hydrolysis and the maximum zone of hydrolyisis of 36mm was with VRCS-4 on skimmed milk agar. This isolate exhibited efficient feather degradation and was identified as Aneurinibacillus aneurinilyticus based on its morphological, biochemical test and molecular sequencing method. The isolate was deposited in NCBI with an accession number MW227423.The isolate showed maximum en-zyme activity of 140.24U/ml at 72h, pH 7.5 and 40º C at 140 rpm. Chicken feather 1% (w/v) used as a sole source of carbon and nitrogen. Feather deg-radation by A.aneurinilyticus VRCS-4 showed 90% degradation in feather meal broth. Ours appears to be the first report on keratinase production by endophytic bacteria from xerophytic plant (Opuntia ficus -indica).

Characterization, screening, and application of bacteria with probiotic properties isolated from the gut of Labeo calbasu (Hamilton)

Labeo calbasu is not reared in aquaculture because of the unavailability of proper feed and the risk of infection. The ability of probiotics to promote growth and immunological defense barriers in the gut has led to the use of autochthonous probiotic bacteria. Hence, the present study was conducted to screen potential probiotic bacteria from the gut of L. calbasu and to supplement the same to study the effect on growth and immunity. Strains with probiotic properties were assayed for exogenous enzyme production and identified based on phylogenetic analysis and nucleotide homology. Four of nine isolates showed promising antibacterial activity against Aeromonas hydrophila. The strains survived in relatively low pH and high bile concentrations and were investigated for hydrophobicity, autoaggregation, and coaggregation. Based on the positive results of this study, the LC1 and LC4 strains (analysed with 16S rRNA gene sequencing and showing similarity with Aneurinibacillus aneurinilyticus and Stenotrophomonas sp.) were further incorporated into diets to explore their probiotic effects on the growth performance and immunity of the fish. Administering the probiotics elevated growth parameters and benefitted the immune system by increasing the phagocytic index and decreasing the mortality rate with exposure to A. hydrophila.

Aneurinibacillus soli sp. nov., isolated from mountain soil

A novel bacterial strain designated CB4T was isolated from soil from the Hallasan, Jeju, Korea. Strain CB4T was found to be strictly aerobic, Gram-stain-positive, rod-shaped, motile and formed creamy greyish colonies on nutrient agar. The major fatty acids were identified as iso-C15 : 0 and iso-C16 : 0, and the predominant isoprenoid quinone as MK-7. The cell-wall peptidoglycan contained glycine and alanine as the diagnostic amino acids and phosphatidyl-N-methylethanolamine, phosphatidylethanolamine, diphosphatidylglycerol and an unidentified aminophospholipid as the polar lipids. The genomic DNA G+C content of strain CB4T was 46.5 mol%. Phylogenetic analysis, based on 16S rRNA gene sequence similarities, showed that strain CB4T forms a deep branch within the genus Aneurinibacillus , sharing the highest level of sequence homology with Aneurinibacillus aneurinilyticus DSM 5562T (96.5 %). On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain CB4T is considered to represent a novel species within the genus Aneurinibacillus , for which the name Aneurinibacillus soli sp. nov. is proposed. The type strain is CB4T ( = KCTC 33505T = CECT 8566T). An emended description of the genus Aneurinibacillus is also proposed.