4株海洋红球菌产类胡萝卜素分析及其全基因组测序

以源于东太平洋海水的4株红球菌分离菌Rhodococcussp. EPR-134、Rhodococcus sp. EPR-147、Rhodococcus sp. EPR-157和Rhodococcus sp. EPR-279为研究对象,开展了菌株的色素提取和色素全波长扫描,并基于全基因组测序分析了4株细菌类胡萝卜素代谢通路中的相关基因。色素全波长扫描结果显示,菌株EPR-134不具备类胡萝卜素产生能力,而其它3株红球菌能够产生类胡萝卜素,且所产类胡萝卜素组分不同。基因组分析表明,4个细菌基因组中存在较为完整的促使类胡萝卜素形成的基因簇。对菌株参与番茄红素形成的3个关键基因crt E、crt B和crt I的氨基酸序列同源性两两比对分析表明,菌株EPR-134 3个基因氨基酸序列与其它3个菌株相应基因氨基酸序列同源性最低,这可能是导致该菌株不产类胡萝卜素的关键原因。该研究结果为产类胡萝卜素红球菌的遗传改造,以及为产类胡萝卜素工程菌的构建奠定了前期基础。

Analysis on caroteniod producing of four marine Rhodococcus and its genome sequence determining

Rhodococcus sp. EPR-134, Rhodococcus sp. EPR-147, Rhodococcus sp. EPR-157 and Rhodococcus sp. EPR-279 were isolated from water samples of East Pacific Ocean, extraction of pigment and pigment full wavelength scan were carried out in this study. Based on the whole genome sequencing, the related genes in carotenoid metabolic pathways were analyzed. Pigment full wavelength scan results show that strain EPR-134 does not have a kind of caroteniod production ability, while other 3 strains of Rhodococcus can produce carotenoids, and the carotenoid composition was different. Genome analysis show that there are more complete gene clusters in the 4 bacterial genomes. crt E gene、crt B gene and crt I gene are very important in the metabolic pathway of caroteniod producing, and by analyzing amino acid sequence homology of these genes in different strains, it is find that amino acid sequences of these genes in the strain EPR-134 share the lowest sequence homology compared with other 3 strains. This may be the key reason why strain EPR-134 can't produce carotenoid. The results of this study may lay a preliminary foundation for genetic modification of the carotenoid producing Rhodococcus and construction of carotenoids producing engineering bacteria.