Welz Pamela, Swanepoel Gustav, Weels Shandré, Le Roes-Hill Marilize
Applied Microbial and Health Biotechnology Institute, Cape Peninsula University of Technology, P.O. Box 1906, Bellville 7535, South Africa.
Microorganisms. 2021 Sep 18;9(9):1987. doi: 10.3390/microorganisms9091987.
Wastewaters generated from various stages of edible oil production in a canola processing facility were collected with the aim of determining the presence of lipase-producing actinobacteria of potential industrial significance. The high chemical oxygen demand (COD) readings (up to 86,700 mg L in some samples) indicated that the wastewater exhibited the nutritional potential to support bacterial growth. A novel approach was developed for the isolation of metagenomic DNA from the oil-rich wastewater samples. Microbiota analysis of the buffer tank and refinery condensate tank wastewater samples showed a dominance of subsp. , followed by a limited number of other actinobacterial genera, indicating the presence of a highly specialized actinobacterial population. Cultured isolates with typical actinobacterial morphology were analyzed for their ability to produce lipases and biosurfactants. Two strains, designated as BT3 and BT4, exhibited the highest lipase production levels when grown in the presence of tributyrin and olive oil (1.39 U mg crude protein and 0.8 U mg crude protein, respectively) and were subsequently definitively identified by genome sequencing to be related to . Cultivation of the strains in media containing different types of oils did not markedly increase the level of enzyme production, with the exception of strain BT4 (1.0 U mg crude protein in the presence of peanut oil). Genome sequencing of the two strains, BT3 and BT4, revealed the presence of a range of lipase and esterase genes that may be involved in the production of the enzymes detected in this study. The presence of gene clusters involved in the production of biosurfactants were also detected, notably moreso in strain BT3 than BT4.
收集了油菜籽加工设施中食用油生产各个阶段产生的废水，目的是确定具有潜在工业意义的产脂肪酶放线菌的存在。高化学需氧量（COD）读数（某些样品中高达86,700 mg/L）表明，该废水具有支持细菌生长的营养潜力。开发了一种从富含油脂的废水样品中分离宏基因组DNA的新方法。对缓冲罐和炼油厂冷凝罐废水样品的微生物群分析表明，亚种占主导地位，其次是数量有限的其他放线菌属，这表明存在高度专业化的放线菌种群。对具有典型放线菌形态的培养分离株进行了产脂肪酶和生物表面活性剂能力的分析。两株分别命名为BT3和BT4的菌株，在三丁酸甘油酯和橄榄油存在下生长时，产脂肪酶水平最高（分别为1.39 U/mg粗蛋白和0.8 U/mg粗蛋白），随后通过基因组测序最终确定与……相关。除BT4菌株（在花生油存在下为1.0 U/mg粗蛋白）外，在含有不同类型油的培养基中培养这些菌株并没有显著提高酶的产量。对BT3和BT4这两株菌株的基因组测序揭示了一系列可能参与本研究中检测到的酶产生的脂肪酶和酯酶基因的存在。还检测到了参与生物表面活性剂产生的基因簇的存在，尤其是在BT3菌株中比在BT4菌株中更明显。
