Significant hemolytic activity of a Bacillus strain isolated from aquaculture water of shrimps farm

Abstract

Background and Aim: Hemolysin as a pore forming toxin is an important virulence factor in many bacteria especially Bacillus species.<br><br>This toxin causes lysis of erythrocytes by destroying cell membrane. According to its concentration, hemolysin can induce apoptosis or<br><br>necrosis in host cells. The aim of this study was to evaluate the hemolytic activity and hemolysin characteristics of a naturally occurring<br><br>bacterium isolated from shrimp’s farm for further anticancer studies.<br><br>Methods: shrimp farm samples had been collected in previous studies and kept in laboratory stock cultures. After recultivation of samples,<br><br>hemolysin screening was performed on blood agar medium and bacteria with highest alpha zone were selected, purified and designated as<br><br>HGM96. Bacterium (HGM96) was molecularly identified by 16S ribosomal RNA gene sequencing. Then HGM96 hemolysin was<br><br>extracted by ammonium sulphate precipitation. Bradford assay was performed for measuring the protein concentration and Zymogram and<br><br>SDS-PAGE methods were respectively used to purify and measure the molecular weight of hemolysin.<br><br>Results: molecular identification showed up to %99 homology of HGM96 strain with Bacillus zhangzhouensis. The hemolysin was<br><br>successfully extracted and its lysis properties were confirmed. SDS-PAGE method showed that HGM96 is able to produce two hemolysins<br><br>with molecular weights of 54 and 18 kDa.<br><br>Conclusion: isolated bacillus strain from aquaculture water of shrimp presented a strong hemolytic activity and the ability of this toxin in<br><br>pore formation and apoptosis induction can be a valuable tool in cancer studies.