Investigation of halophilic microorganisms in salt lakes and development of novel halogenating and dehalogenating enzymes

为了获得参与卤素代谢、催化卤化和脱卤的新型酶，我们从含不同种类不同浓度盐的盐湖中采集了嗜盐微生物。在澳大利亚墨尔本大学Mike Dyall-Smith教授的建议下，我们从西澳大利亚罗特内斯特岛的几个盐湖中采集了水样，从中分离出各种嗜盐微生物。我们还从美国加利福尼亚州的莫诺湖等盐湖中分离到了嗜盐菌。我们使用含有以下卤化化合物中的一种的培养基进行筛选：4,6 -二氯oreorcinol， 1,2 -二氯乙烷，氟乙酸酯，4-氯oreorcinol， 2-氯丙酸酯，2-氯丙酰胺，甘油-α-一氯丙烷和氯乙酸酯。我们观察到，微生物在含有4,6 -二氯氨基甲酸酯、1,2 -二氯乙烷或氟乙酸酯的培养基中生长。在用4,6 -二氯氨基甲酸二醇获得的培养物中发现了球菌，这表明这种微生物产生了一种降解4,6 -二氯氨基甲酸二醇的酶，或者有另一种机制使细胞对这种化合物产生抗性。我们还与中国云南大学微生物研究所蒋教授合作，分离了吸收3-氯-1-丙醇的微生物（1株细菌、2株放线菌和3株真菌）。还获得了能吸收氯丙酸和甘油-α-一氯丙烷的菌株。

We collected halophilic microorganisms from salt lakes containing various kinds of salts of various concentrations in order to obtain novel enzymes involved in halogen metabolism, catalyzing halogenation and dehalogenation. Taking advice from Professor Mike Dyall-Smith at University of Melbourne in Australia, we collected water samples from several salt lakes in Rottnest Island in West Australia, from which various halophilic microorganisms were isolated. We also isolated halophiles from salt lakes, such as Mono Lake, in California, USA. We carried out screening using media containing on of the following halogenated compounds : 4, 6-dichlororesorcinol, 1, 2-dichloroethane, fluoroacetate, 4-chlororesorcinol, 2-chloropropionate, 2-chloropropionamide, glycerol-α-monochlorohydrin, and chloroacetate. We observed that microorganisms grew in the media containing 4, 6-dichlororesorcinol, 1, 2-dichloroethane, or fluoroacetate. Cocci were found in the culture obtained with 4, 6-dichlororesorcinol, suggesting that this microorganism produces an enzyme degrading 4, 6-dichlororesorcinol or has another mechanism that makes the cell resistant to this compound. We also collaborated with Professor Jiang at Institute of Microbiology, Yunnan University, China, and isolated microorganisms assimilating 3-chloro-1-propanol (one bacterial strain, two actinomycetous strains, and three fungous strains). Bacterial strains that can assimilate chloropropionate and glycerol-α-monochlorohydrin were also obtained.