Department of Food Engineering, Faculty of Engineering, Hitit University, Çorum, Turkey.
Department of Food Engineering, Faculty of Engineering, Süleyman Demirel University, Isparta, Turkey.
Arch Microbiol. 2022 May 19;204(6):337. doi: 10.1007/s00203-022-02940-8.
Yeasts can produce toxins in protein or glycoprotein structures that can act as an inhibitor on some bacteria and yeast species. The effects of those toxins on the growth of pathogenic and food spoilage microorganisms are subject to various studies. Metschnikowia pulcherrima was determined to be a killer toxin-producing yeast that was tested against three selected microorganisms, namely Escherichia coli Type-I, Micrococcus luteus and Candida albicans. The killer toxin only showed inhibitory activity against M. luteus. Different pH (5-6-7-8), temperature (20-25-30-35 °C) and carbon source (glucose-glycerol-ethanol-acetate) combinations were applied to stimulate the growth and toxin production of the killer yeast. The greatest increase among the different combinations was obtained at 20 °C and pH 7 when glycerol was used as the main carbon source. It was then also tested against other pathogen indicators or pathogens under these conditions. The killer toxin was partially purified by ethanol precipitation and showed inhibitory activity against M. luteus (36 mm). According to the protein profile obtained by SDS-PAGE, the molecular weight of the inhibitor toxin was measured about 7.4 kDa. The molecular weight with amino acid sequence of the killer toxin was 10.3 kDa and determined by MALDI-TOF mass spectrometry.
酵母可以在蛋白质或糖蛋白结构中产生毒素，这些毒素可以作为某些细菌和酵母的抑制剂。这些毒素对致病性和食品腐败微生物生长的影响受到各种研究的关注。秀丽隐杆酵母被确定为一种产杀伤毒素的酵母，该酵母已针对三种选定的微生物（即大肠杆菌 I 型、藤黄微球菌和白色念珠菌）进行了测试。杀伤毒素仅对藤黄微球菌显示出抑制活性。不同的 pH 值（5-6-7-8）、温度（20-25-30-35°C）和碳源（葡萄糖-甘油-乙醇-醋酸盐）组合被应用于刺激杀伤酵母的生长和毒素产生。在使用甘油作为主要碳源时，在 20°C 和 pH 7 下，不同组合中的生长和毒素产量得到了最大的提高。然后在这些条件下，还针对其他病原体指标或病原体进行了测试。杀伤毒素通过乙醇沉淀进行部分纯化，并对藤黄微球菌（36mm）显示出抑制活性。根据 SDS-PAGE 获得的蛋白质图谱，抑制剂毒素的分子量约为 7.4kDa。通过 MALDI-TOF 质谱法确定杀伤毒素的分子量为 10.3kDa 和氨基酸序列。
