凝结芽孢杆菌XZQ-16抗菌脂肽分离鉴定及抗菌特性

对凝结芽孢杆菌（Bacillus coagulans） XZQ-16脂肽分离鉴定并探讨其抗腐败菌特性。通过酸沉、硅胶柱层析和Sephadex LH-20层析对脂肽分离纯化，利用傅里叶红外光谱（FT-IR）和反相高效液相色谱（RP-HPLC）对脂肽分析鉴定。结果表明，硅胶柱层析得到三个流分具有明显抗菌活性；Sephadex LH-20层析分离出四个洗脱峰，洗脱峰Ⅲ抑菌活性明显；FT-IR确定纯化的抗菌物质中含有脂肽类化合物；RP-HPLC分析并与标准样对照确定分离的抗菌物质为伊枯菌素（iturin）和表面活性素（surfactin）同系物。脂肽宽泛的pH范围（4.0~12.0）酸碱耐受性好，在120℃以下保温30 min抗菌活性在80%以上。脂肽能抑制多种常见的食源性致病菌，包括革兰氏阳性菌如蜡样芽孢杆菌、金黄色葡萄球菌、单核增生李斯特菌、藤黄微球菌等以及革兰氏阴性菌如大肠杆菌、铜绿假单胞菌、沙门氏菌、痢疾志贺氏菌等。同商业化应用的乳酸链球菌素（nisin）和多粘菌素相比，菌株XZQ-16脂肽除了对细菌具有明显抑制作用，还对真菌如白色念珠菌、毕赤酵母和黑曲霉也有抑制作用。B.coagulans XZQ-16脂肽表现出极高的稳定性和广谱抗菌活性，为在食品、畜牧、医药、化妆品及植物保护等领域的应用奠定理论基础。

Isolation,Identification and Antibacterial Properties of Antimicrobial Lipopeptide from Bacillus coagulans XZQ-16

The aim of the study was to purify and identify antibacterial lipopeptide produced by Bacillus coagulans XZQ-16 and to explore the functional characteristics in anti-spoilage bacteria.The antibacterial lipopeptide was isolated and purified by acid precipitation,column chromatography on silica gel and Sephadex LH-20.Lipopeptide compounds were identified by using Fourier infrared spectroscopy(FT-IR)and reversed phase high performance liquid chromatography(RP-HPLC)techniques.The results showed that three flow fractions obtained by silica gel column chromatography had significant antibacterial activity.Four elution peaks were isolated by Sephadex LH-20 chromatography,among which,elution peak III had significant antibacterial activity.FT-IR analysis confirmed that the purified antibacterial substance contained lipopeptide compounds.RP-HPLC further identified the presence of three components in the isolated antimicrobial substances,and identified the two groups as homologues of iturin and surfactin compared with the standard sample.The purified antimicrobial lipopeptide was stable over a broad pH range(4.0~12.0)and at temperatures up to 120℃for 30 min.Antibacterial lipopeptide could inhibit the growth of a broad range of foodborne Gram-positive bacteria,including Bacillus cereus,Staphylococcus aureus,Listeria monocytogenes,Micrococcus luteus and Gram-negative bacteria such as E.Coli,Salmonella,Shigella and Pseudomonas aeruginosa.Moreover,unlike commercially available nisin and polymyxin B,which only worked on bacteria,the lipopeptide produced by strain XZQ-16 also inhibited fungi such as Candida albicans,Pichia pastoris and Aspergillus niger.Lipopeptide produced by Bacillus pumilus XZQ-16 showed high stability and broad antibacterial activity.This paper lays a theoretical foundation for its application in the fields of food,animal husbandry,medicine,cosmetics and plant protection.