Beneficial effects of bio-controlling agent Bacillus cereus IB311 on the agricultural crop production and its biomass optimization through response surface methodology.

Disease in agricultural field is a big problem that causes a massive loss in production. In this present investigation, we have reported a soil-borne bacterium Bacillus cereus IB311 which is antagonistic to plant pathogens (Pseudomonas syringae and Agrobacterium tumefaciens), and could make a substantial contribution to the prevention of plant diseases. To prove the practical application, the strain was directly applied in agricultural field. The results demonstrated that B. cereus IB311 has increased the production (20% and 26% in term of average pod number per plant, average seed number per pod, and seed yield per experimental plot) in ground nut (Arachis hypogaea var. Koushal, G201) and sesame (Sesamum indicum var. Kanak), respectively. To reduce the production cost, the biomass production was optimized through response surface methodology (RSM). Interactions of three variables (glucose, beef extract and inoculum) were studied using Central Composite Design. According to our analysis, optimum production of Bacillus cereus IB311 (5.383 µg/ mL) may be obtained at glucose 1.985%, beef extract 1.615% and inoculums size 0.757%. Therefore, we strongly believe that the application of this strain in agricultural field as bio-controlling agent will definitely enhance the production yield and will reduce the disease risk.

Bacterial Diversity in the Digestive Tracts of Four Indian Air-Breathing Fish Species Investigated by PCR Based Denaturing Gradient Gel Electrophoresis

ABSTRACT An investigation was conducted to identify the allochthonous microbiota (entire intestine) and the autochthonous microbiota in proximal intestine (PI) and distal intestine (DI) of four species of Indian air-breathing fish (climbing perch; Anabas testudineus, murrel; Channa punctatus, walking catfish; Clarias batrachus and stinging catfish; Heteropneustes fossilis) by PCR based denaturing gradient gel electrophoresis (DGGE). High similarities of the allochthonous microbiota were observed between climbing perch and murrel, walking catfish and stinging catfish, indicating similar food behavior. The autochthonous microbiota of PI and DI from climbing perch and murrel revealed more similarity, than the result obtained from walking catfish and stinging catfish. The autochthonous microbiota of climbing perch and murrel were similar with regard to the allochthonous microbiota, but no such similarity was observed in case of walking catfish and stinging catfish. The fish genotype and intestinal bacteria are well matched and show co-evolutionary relationship. Three fish species has its unique bacteria; autochthonous Enterobacter cloacae, Edwardsiella tarda and Sphingobium sp. in DI of climbing perch, Pseudomonas sp.; allochthonous and autochthonous in PI of walking catfish and uncultured bacterium (EU697160.1), uncultured bacterium (JF018065.1) and uncultured bacterium (EU697160.1) for stinging catfish. In murrel, no unique bacteria were detected.