Department of Biotechnology, Pondicherry University, Pondicherry, 605 014, India.
Probiotics Antimicrob Proteins. 2022 Aug;14(4):664-674. doi: 10.1007/s12602-022-09908-6. Epub 2022 Mar 14.
A gene encoding lipase enzyme from Bacillus flexus PU2 was cloned and expressed in E. coli BL21 (DE3) pLysS and purified protein having the molecular weight of 34 kDa. This lipase was found to be alkaline (pH 9) and slightly thermophilic. This lipase was observed to retain its activity in the presence of methanol, ethanol, DMSO, and acetone. Ferrous sulfate, copper sulfate, and manganese sulfate highly enhanced the lipase activity. All the surfactants and detergents were found to inhibit the enzyme activity, whereas the bleaching agent hydrogen peroxide was found to increase the activity. This lipase was observed as a metalloenzyme, and its activity was highly inhibited by EDTA. Also, it is moderately halophilic and can retain the activity between 0.2 and 0.8 M NaCl. Biofilm inhibitory potential of purified lipase was tested against pathogenic Vibrio parahaemolyticus, and the minimal inhibitory concentration observed was 350 U. Different concentration of this enzyme significantly changed the morphology and biofilm density of V. parahaemolyticus and was evinced by SEM and CLSM imaging. The transcriptome levels of genes responsible for biofilm formation, motility, and virulence such as, motX, fliG, and trh were significantly downregulated with lipase treatment.
从粘质沙雷氏菌 PU2 中克隆并在 E. coli BL21 (DE3) pLysS 中表达了编码脂肪酶酶的基因,该蛋白的分子量为 34 kDa。该脂肪酶呈碱性(pH9)且略微嗜热。该脂肪酶在甲醇、乙醇、DMSO 和丙酮存在下保持活性。硫酸亚铁、硫酸铜和硫酸锰高度增强了脂肪酶的活性。所有表面活性剂和清洁剂均发现抑制了酶的活性,而过氧化氢漂白剂则发现增加了酶的活性。该脂肪酶被观察为金属酶,其活性被 EDTA 高度抑制。此外,它是中度嗜盐的,可在 0.2 至 0.8 M NaCl 之间保持活性。纯化的脂肪酶对致病性副溶血性弧菌的生物膜抑制潜力进行了测试,观察到的最小抑制浓度为 350 U。不同浓度的该酶显著改变了副溶血性弧菌的形态和生物膜密度,这可以通过 SEM 和 CLSM 成像观察到。用脂肪酶处理后,负责生物膜形成、运动和毒力的基因,如 motX、fliG 和 trh 的转录本水平显著下调。