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

1. 我们对分离自南冰洋的嗜冷菌希瓦氏菌sp. Ac10进行了全基因组分析。基因组大小为4.5 Mbp， orf数约为48002个。在4℃条件下培养的希瓦氏菌Ac10产生大量与大肠杆菌冷休克蛋白（CspA）同源的蛋白。希瓦氏菌ac10胶原酶的过量产生和表征。我们建立了希瓦氏菌ac10的转化方法，分离了一个启动子，构建了表达载体。一种嗜冷性细菌，不动杆菌属。从西伯利亚冻土带土壤中分离出来。该细菌产生胞外脂解酶，并在低温培养基中降解各种甘油三酯。该细菌有望用于废水的低温处理。从不动杆菌（Acinetobacter sp.） no.株中克隆了一种以脂肪酸乙烯酯为底物的冷活性脂解酶的编码基因。6. 该酶可用于乙烯基酯作为酰基供体的酯交换反应合成酯。从不动杆菌中克隆了一株冷活性酯酶基因。6 .属于酯酶/脂肪酶家族的EST组。构建了外源基因导入no.不动杆菌的载体。6、分离出适合外源基因过表达的强力启动子。

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.