Plasmid borne BAC-IB 17: localization of a potential antibacterial positive marker [Bac[+]] encoded broad inhibitory spectrum bacteriocin

Production of antimicrobial compounds is considered as ubiquitous anti-competitor strategy in bacterial ecosystem. Bacteriocins are heterogeneous; highly specific and efficient anti-competitor agents and the gene responsible for the production of bacteriocins mostly exist in an autosomal state and associated with plasmids. BAC-IB17 is a broad spectrum bacteriocin and its production was observed at different stages of the growth cycle from Bacillus subtilis KIBGE-IB17. Growth kinetics of B. subtilis KIBGE-IB17 along with the production of BAC-IB17 showed that it exhibited secondary metabolite kinetics. Plasmid curing technique revealed that the gene responsible for the bacteriocinogenecity in B. subtilis KIBGE-IB17 was located on the plasmid of the bacterium. Overlay method also demonstrated the plasmid-mediated bacteriocinogenesis of the isolated colonies. With the advancement in genomics and proteomics, the plasmid borne BAG-IB 17 can play a significant role in the transfer of bacteriocinogenic factor to other incompetent cells and also in the maintenance of plasmid in bacterial population

Isolation and characterization of different strains of bacillus licheniformis for the production of commercially significant enzymes

Utilization of highly specific enzymes for various industrial processes and applications has gained huge momentum in the field of white biotechnology. Selection of a strain by efficient plate-screening method for a specific purpose has also favored and boosted the isolation of several industrially feasible microorganisms and screening of a large number of microorganisms is an important step in selecting a potent culture for multipurpose usage. Five new bacterial isolates of Bacillus licheniformis were discovered from indigenous sources and characterized on the basis of phylogeny using 16S rDNA gene analysis. Studies on morphological and physiological characteristics showed that these isolates can easily be cultivated at different temperatures ranging from 30°C to 55°C with a wide pH values from 3.0 to 11.0 All these 05 isolates are salt tolerant and can grow even in the presences of high salt concentration ranging from 7.0 to 12.0%. All these predominant isolates of B. licheniformis strains showed significant capability of producing some of the major industrially important extracellular hydrolytic enzymes including alpha-amylase, glucoamylase, protease, pectinase and cellulase in varying titers. All these isolates hold great potential as commercial strains when provided with optimum fermentation conditions

Bacteriocin [BAC-IB17]: screening, isolation and production from Bacillus subtilis KIBGE IB-17

Bacteriocins are peptides produced by a variety of different microbes and have antimicrobial activity against closely related species. These antimicrobial agents are gaining more and more attention as an alternative therapeutics not only in pharmaceutical but also as a preservative in food industries. In this study several bacterial strains were isolated from soil and screened for bacteriocin production. Among them, one strain identified as Bacillus subtilis KIBGE IB-17 on the basis of taxonomic studies and confirmed by 16S rDNA analysis. This newly isolated strain showed antibacterial activity against several Gram positive and Gram negative bacteria. Different concentrations of tryptone, yeast extract and NaCl and physiochemical factors such as temperature, pH and incubation period were selected as variables for maximum production of bacteriocin by using agar well diffusion method and significant effects of variables were observed on the production of Bac-IB17. A newly designed modified TY medium showed maximum bacteriocin production containing 1.0% tryptone, 0.5% yeast extract and 0.5% NaCl. Maximum Bac-IB17 production was observed at 37°C after 24 hours with initial medium pH 7.0. Bacillus subtilis KIBGE IB-17 is capable of producing a bacteriocin at a wide range of pH and temperature that makes it an ideal strain that can be used for the production of bacteriocin on industrial scale level. The identification and production of such bacteriocin like compound against a wide spectrum of microbial species is very important for food and pharmaceutical industry