Assessment of hemolytic activity, enzyme production and bacteriocin characterization of Bacillus subtilis LR1 isolated from the gastrointestinal tract of fish

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• 作者：Goutam Banerjee ; Ankita Nandi ; Arun Kumar Ray
• 关键词：Bacillus subtilis ; Bacteriocin characterization ; Enzyme activity ; Hemolytic activity ; Fish pathogens
• 刊名：Archives of Microbiology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：199
• 期：1
• 页码：115-124
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Microbiology; Microbial Ecology; Biochemistry, general; Cell Biology; Biotechnology; Ecology;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-072X
• 卷排序：199

文摘

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−1 protein ml−1 of 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.