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Abstract

Microbes present in soil exist in close association to other microbial species and formulate the shape of microbial communities in soil. This interaction can be in the form of positive or negative towards each other. Present study deals with analysis of interaction and motility behavior and biofilm formation during monoculture and two-specie culture (on the basis of salt tolerance) among previously isolated strains HFF (Bacillus cereus KY435717), HFP (Bacillus subtilis) and AQ-1 (Alkali gene faecalis KR052007) from plant or soil. The results showed that strain AQ-1 showed highest cell densities at 0.5 M NaCl stress while HFF and HFP showed best growth at 1.5 M NaCl stress. Biofilm formation pattern in single specie culture was relatively high in all three strains when compared to two-specie culture of A.faecalis with B.cereus or A.faecalis with B.subtilis experiment showing antagonistic effects species towards each other in co-culture. Despite lower cell densities recorded AQ-1, individual cell densities and biofilm formation was highest at 1.5 M NaCl stress in co culture showing the benefit of co culturing. Bacterial motility patterns were also determined on the basis of twitching, swimming and swarming assay. Interdependence of motility behavior of bacterial strains was recorded. Moreover, twitching motility was correlated to swimming and swarming. Neither was motility behavior was associated with biofilm formation. Results of current study showed that A.faecalis improve its survival in two specie biofilms with B.cereus and B.subtilis at 1.5 M NaCl stress and facilitates the improvement in plant growth. Future implication of this study dealing with microbial interaction will pave the way for further understanding of the interactions of microbes associated with plants.
Keywords: Alkali gene faecalis; Bacillus cereus; Bacillus subtilis; Biofilm; Motility
http://dx.doi.org/10.19045/bspab.2018.70033