Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, Ceredigion, UK.
PLoS One. 2013 Aug 12;8(8):e69076. doi: 10.1371/journal.pone.0069076. eCollection 2013.
Following the isolation, cultivation and characterization of the rumen bacterium Anaerovibrio lipolyticus in the 1960s, it has been recognized as one of the major species involved in lipid hydrolysis in ruminant animals. However, there has been limited characterization of the lipases from the bacterium, despite the importance of understanding lipolysis and its impact on subsequent biohydrogenation of polyunsaturated fatty acids by rumen microbes. This study describes the draft genome of Anaerovibrio lipolytica 5ST, and the characterization of three lipolytic genes and their translated protein. The uncompleted draft genome was 2.83 Mbp and comprised of 2,673 coding sequences with a G+C content of 43.3%. Three putative lipase genes, alipA, alipB and alipC, encoding 492-, 438- and 248- amino acid peptides respectively, were identified using RAST. Phylogenetic analysis indicated that alipA and alipB clustered with the GDSL/SGNH family II, and alipC clustered with lipolytic enzymes from family V. Subsequent expression and purification of the enzymes showed that they were thermally unstable and had higher activities at neutral to alkaline pH. Substrate specificity assays indicated that the enzymes had higher hydrolytic activity against caprylate (C8), laurate (C12) and myristate (C14).
20 世纪 60 年代，在对反刍动物瘤胃细菌 Anaerovibrio lipolyticus 进行分离、培养和特性描述后，人们认识到它是参与反刍动物脂类水解的主要细菌之一。然而，尽管了解脂解作用及其对瘤胃微生物随后对多不饱和脂肪酸的生物氢化的影响非常重要，但对该细菌的脂酶的特性描述却非常有限。本研究描述了 Anaerovibrio lipolytica 5ST 的草图基因组，以及对三种脂解基因及其翻译蛋白的特性描述。未完成的草图基因组为 2.83 Mbp，包含 2673 个编码序列，GC 含量为 43.3%。使用 RAST 鉴定到三个推定的脂肪酶基因，alipA、alipB 和 alipC，分别编码 492、438 和 248 个氨基酸的肽。系统发育分析表明 alipA 和 alipB 与 GDSL/SGNH 家族 II 聚类，而 alipC 与家族 V 的脂肪酶聚类。随后对酶的表达和纯化表明，它们的热稳定性差，在中性到碱性 pH 值下具有更高的活性。底物特异性测定表明，这些酶对辛酸盐 (C8)、月桂酸盐 (C12) 和肉豆蔻酸盐 (C14) 具有更高的水解活性。
