title: Assessment of hemolytic activity, enzyme production and bacteriocin characterization of Bacillus subtilis LR1 isolated from the gastrointestinal tract of fish.
abstract: In the present investigation, probiotic potential (antagonistic activity, enzyme production, hemolytic activity, biosafety, antibiotic sensitivity and bile tolerance level) of Bacillus subtilis LR1 was evaluated. Bacteriocin produced by the bacterial strain B. subtilis LR1 isolated from the gastrointestinal tract of Labeo rohita was purified and characterized. The molecular weight of the purified bacteriocin was ~50 kDa in 12 % Native PAGE and showed inhibitory activity against four fish pathogens such as Bacillus mycoides, Aeromonas salmonicida, Pseudomonas fluorescens and Aeromonas hydrophila. The purified bacteriocin was maximally active at temperature 40 °C and pH 7.0, while none of the tested surfactants affect the bacteriocin activity. Extracellular enzyme activity of the selected bacterial strain was also evaluated. Amylase activity was estimated to be highest (38.23 ± 1.15 µg of maltose liberated mg-1protein ml-1of culture filtrate) followed by cellulase and protease activity. The selected bacterium was sensitive to most of the antibiotics used in this experiment, can tolerate 0.25 % bile salt and non-hemolytic in nature. Finally, the efficiency of the proposed probiotic candidate was evaluated in in vivo condition. It was detected that the bacterial strain can effectively reduce bacterial pathogenicity in Indian major carps.
authors: Department of Zoology, Visva-Bharati University, Santiniketan, 7131235, India. banerjee.goutam2@gmail.com.
authors: Goutam
authors: G
authors: Banerjee
authors: Department of Zoology, Visva-Bharati University, Santiniketan, 7131235, India.
authors: Ankita
authors: A
authors: Nandi
authors: Department of Zoology, Visva-Bharati University, Santiniketan, 7131235, India.
authors: Arun Kumar
authors: AK
authors: Ray
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001412:Bacillus subtilis / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001430:Bacteriocins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D003530:Cyprinidae / Q000382:microbiology*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D008970:Molecular Weight; D019936:Probiotics / Q000737:chemistry / Q000494:pharmacology; D012336:RNA, Ribosomal, 16S / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001430:Bacteriocins; D012336:RNA, Ribosomal, 16S
keywords: Bacillus subtilis; Bacteriocin characterization; Enzyme activity; Fish pathogens; Hemolytic activity