Ansari Asma, Aman Afsheen, Siddiqui Nadir Naveed, Iqbal Samina, Ali ul Qader Shah
The Karachi Institute of Biotechnology & Genetic Engineering, University of Karachi, Karachi, Pakistan.
Pak J Pharm Sci. 2012 Jan;25(1):195-201.
Bacteriocins are peptides produced by a variety of different microbes and have antimicrobial activity against closely related species. These antimicrobial agents are gaining more and more attention as an alternative therapeutics not only in pharmaceutical but also as a preservative in food industries. In this study several bacterial strains were isolated from soil and screened for bacteriocin production. Among them, one strain identified as Bacillus subtilis KIBGE IB-17 on the basis of taxonomic studies and confirmed by 16S rDNA analysis. This newly isolated strain showed antibacterial activity against several Gram positive and Gram negative bacteria. Different concentrations of tryptone, yeast extract and NaCl and physiochemical factors such as temperature, pH and incubation period were selected as variables for maximum production of bacteriocin by using agar well diffusion method and significant effects of variables were observed on the production of Bac-IB17. A newly designed modified TY medium showed maximum bacteriocin production containing 1.0% tryptone, 0.5% yeast extract and 0.5% NaCl. Maximum Bac-IB17 production was observed at 37° after 24 hours with initial medium pH 7.0. Bacillus subtilis KIBGE IB-17 is capable of producing a bacteriocin at a wide range of pH and temperature that makes it an ideal strain that can be used for the production of bacteriocin on industrial scale level. The identification and production of such bacteriocin like compound against a wide spectrum of microbial species is very important for food and pharmaceutical industry.
细菌素是由多种不同微生物产生的肽，对密切相关的物种具有抗菌活性。这些抗菌剂作为一种替代疗法越来越受到关注，不仅在制药领域，而且在食品工业中作为防腐剂。在本研究中，从土壤中分离出几种细菌菌株，并筛选其细菌素产生情况。其中，一株根据分类学研究鉴定为枯草芽孢杆菌KIBGE IB-17，并通过16S rDNA分析得到证实。这种新分离的菌株对几种革兰氏阳性和革兰氏阴性细菌表现出抗菌活性。通过琼脂孔扩散法选择不同浓度的胰蛋白胨、酵母提取物和氯化钠以及温度、pH值和培养时间等理化因素作为变量，以实现细菌素的最大产量，并观察到这些变量对Bac-IB17产量有显著影响。一种新设计的改良TY培养基在含有1.0%胰蛋白胨、0.5%酵母提取物和0.5%氯化钠时显示出最大细菌素产量。在初始培养基pH值为7.0的情况下，24小时后在37°观察到Bac-IB17的最大产量。枯草芽孢杆菌KIBGE IB-17能够在广泛的pH值和温度范围内产生细菌素，这使其成为一种理想的菌株，可用于工业规模水平的细菌素生产。鉴定和生产针对广泛微生物物种的此类细菌素样化合物对食品和制药行业非常重要。
