从植物根际定向批量筛选广谱有机溶剂耐受性脂肪酶产生菌

A Rapid and Efficient Method for Directed Screening of Lipase-producing Burkholderia cepacia Complex with Organic Solvent Tolerance from Plant Rhizosphere

洋葱伯克霍尔德菌脂肪酶是一类具有重要工业应用价值的优良脂肪酶之一。根据已公布的洋葱伯克霍尔德菌基因组信息,在传统的洋葱伯克霍尔德菌选择性培养基中添加适量的氨苄青霉素和卡那霉素,从植物根际的土壤中筛选洋葱伯克霍尔德菌。对获得的单菌落再用含罗丹明B指示剂的产脂肪酶定性检测平板检测,从4个根际土壤中筛选到35株产脂肪酶的洋葱伯克霍尔德菌,阳性率达到65%。其中15株对体积浓度为10%的苯、己烷和正庚烷同时具有耐受性。用recA基因分子鉴定上述15株菌种,全部属于洋葱伯克霍尔德菌菌群。

Lipase from Burkholderia cepacia complex is one of the most versatile biocatalyst and is used widely in many biotechnological application fields including detergent additives, the resolution of racemic compounds, etc. Based on the known whole genomic information of B. cepacia, both ampicillin and kanamycin were added to the TB-T media, the traditional selective media, to screen B. cepacia complex strains from rhizosphere soil samples. The single colonies on the plates with the modified TB-T media were then qualitatively determined the ability to produced the extracellular lipase in the rhodamine B-olive oil agar plates. Thirty-five strains of lipolytic pseudo-B. cepacia complex were isolated and the positive rate of lipolytic bacteria was 65%. Among them, 15 pseudo-B. cepacia complex strains with the tolerance to benzene, n-hexane and n-heptane at the concentration of 10% （V/V） were selected and identified by the recA gene sequence. All of the 15 lipolytic bacteria belonged to the B. cepacia complex.