Whole-genome sequencing of a psychrophilic bacterium, analysis of genes involved in cold adaptation, and exploitation of cold-active enzymes

1.对希瓦氏菌进行了全基因组分析。AC10，一种从南极海洋中分离出来的嗜冷者。基因组大小为4.5Mbp，开放阅读框的数目约为4,800.2个。希瓦氏杆菌属在4℃培养条件下，从大肠杆菌中获得了大量与冷休克蛋白CspA同源的蛋白。希瓦氏菌的一种胶原酶Ac1O产量过高，并被表征。建立了希瓦氏杆菌的转化方法。Ac10，分离出启动子，构建表达载体。一种嗜冷菌，不动杆菌属。菌株6号是从西伯利亚冻土带土壤中分离到的。该菌产生胞外脂解酶，并在低温下降解介质中的各种甘油三酯。该菌有望用于低温下的废水处理。从不动杆菌中克隆了一种对脂肪酸乙烯基酯具有底物选择性的冷活性脂解酶基因。菌株6。该酶可用于以乙烯基酯为酰基供体的酯交换反应合成酯。我们克隆了不动杆菌冷活性酯酶的编码基因。菌株6号，属于酯酶/脂肪酶家族的EST群。我们构建了外源基因导入不动杆菌的载体。6号菌株，筛选出适合外源基因高效表达的高效启动子。

1. We carried out whole-genome analysis of Shewanella sp. Ac10, a psychrophile isolated from the Antarctic Ocean. The genome size was 4.5 Mbp, and the number of ORFs was about 4, 800.2. Shewanella sp. Ac10 grown at 4℃ produced a large quantity of a protein homologous to a cold-shock protein, CspA, from Escherichia coli.3. A collagenase of Shewanella sp. Ac1O was overproduced and characterized.4. We established a transformation method for Shewanella sp. Ac1O, isolated a promoter, and constructed an expression vector.5. A psychrotrophic bacterium, Acinetobacter sp. strain no. 6, was isolated from Siberian tundra soil. The bacterium produced extracellular lipolytic enzymes, and degraded various triglycerides in the medium at low temperatures. The bacterium is expected to be useful for the waste water treatment at low temperatures.6. The gene coding for a cold-active lipolytic enzyme with a substrate preference for fatty acid vinyl esters was cloned from Acinetobacter sp. strain no. 6. The enzyme was shown to be useful for the synthesis of esters by transesterification using vinyl esters as an acyl donor.7. We cloned the gene coding for a cold-active esterase from Acinetobacter sp. strain no. 6 that belongs to the EST group of the esterase/lipase family.8. We constructed a vector to introduce exogenous genes into Acinetobacter sp. strain no. 6 and isolated powerful promoters suitable for overexpression of exogenous genes.