Vidhyasagar Venkatasubramanian, Jeevaratnam Kadirvelu
Department of Biochemistry and Molecular Biology, Pondicherry University, R.V. Nagar, Kalapet, Puducherry, 605014, India.
Biomed Chromatogr. 2013 Nov;27(11):1497-502. doi: 10.1002/bmc.2948. Epub 2013 Jun 11.
Bacteriocins, an antimicrobial peptide, is known to have wide spectrum antimicrobial activity against various pathogens. Because they are easily digested in the intestine, they are considered as safe and are widely used as food preservatives. Hence their purification and characterization have attracted considerable attraction, especially for those having activity against human pathogens. In this study, the bacteriocin produced by Pediococcus pentosaceus VJ13 was precipitated with cold acetone and purified by gel permeation chromatography and hydrophobic interaction chromatography. The bacteriocin exhibited antimicrobial activity against various pathogens, like Mycobacterium smegmatis, Klebsiella pneumonia, Clostridium perfringens and Staphylococcus epidermidis. The activity of bacteriocin was lost completely after treatment with protease, which revealed its proteinaceous nature. The bacteriocin was stable up to 100°C and exhibited antilisterial property which is a characteristic feature of class IIa bacteriocins. It was active within the pH range of 2-8 and stable against various chemicals and denaturants. Tricine SDS-PAGE revealed its molecular weight to be 4.0 kDa, where the corresponding activity against Listeria monocytogenes was also noted. Treatment of L. monocytogenes with bacteriocin decreased the viable cell count, and scanning electron microscope analysis revealed membrane pore formation that resulted in the release of intracellular content, suggesting its bactericidal effect.
细菌素是一种抗菌肽，已知对多种病原体具有广谱抗菌活性。由于它们在肠道中易于消化，因此被认为是安全的，并被广泛用作食品防腐剂。因此，它们的纯化和表征引起了相当大的关注，特别是对于那些对人类病原体具有活性的细菌素。在本研究中，戊糖片球菌VJ13产生的细菌素用冷丙酮沉淀，并用凝胶渗透色谱和疏水相互作用色谱进行纯化。该细菌素对多种病原体具有抗菌活性，如耻垢分枝杆菌、肺炎克雷伯菌、产气荚膜梭菌和表皮葡萄球菌。用蛋白酶处理后，细菌素的活性完全丧失，这揭示了其蛋白质性质。该细菌素在高达100°C时稳定，并表现出抗李斯特菌特性，这是IIa类细菌素的一个特征。它在pH 2-8范围内具有活性，并且对各种化学物质和变性剂稳定。Tricine SDS-PAGE显示其分子量为4.0 kDa，同时也观察到了对单核细胞增生李斯特菌的相应活性。用细菌素处理单核细胞增生李斯特菌可降低活菌数，扫描电子显微镜分析显示形成了膜孔，导致细胞内物质释放，表明其具有杀菌作用。
