Study On The Genome Of Pseudomonas Stutzeri A1501

Pseudomonas stutzeri A1501 was first isolated from rice paddies in China in 1980. The bacteria has a good capacity of nitrogen fixation in natural environment and microaerophilic condition, and the production can be directly absorbed by rice. The scientists in China have deeply studied the bacteria and developed it as crop growth-promoting bacteria.In order to exploit this bacteria deeply, we performed the research of the genome of A1501.By shotgun strategy, two random gene libraries were constructed with different insert fragments of 2-4 kb (S library) and 4-6 kb (L library). The L library clones were sequenced two terminals in order to construct the frame, and the S library were sequenced only one terminal to enrich the content of the frame. By cosmically sequence technique, we got 50408 available reads with an average length of 609bp. The total length is 30.7M, 7 folds coverage of the genome. After computer splice and low quantity zone verification, we got the accurate genome map.At 4567418 bp, the A1501genome is markedly smaller than the other three Pseudomonas with finished genome P. aeruginosa PA01, P. putida KT2440 and P. syringae pv. tomato DC3000.The genome encodes 4145 ORFs, only 73% of that of P. aeruginosa PA01. The comparative analysis of the protein of A1501 with three Pseudomonas shows that, 2734 ORFs can be found the high identity orthologous genes in Pseudomonas putida KT2440, 2560 ORFs in Pseudomonas syringae pv. tomato DC3000 and 2954 ORFs in Pseudomonas aeruginosa PA01. 2085 ORFs were shared in all these four Pseudomonas. The predicted genes can be devided into 3 types by the comparative identity with the known function gene: first, homologues of reported genes with demonstrated function from other organisms; the second, homologues of reported genes with unknown function; and the thud, no homology to any reported sequence. The number of the ORFs is 3366, 473 and 316 individually.The ORFs also can be divided into 23 functional group and one function predicted group and function unknown group by COGs. Analysis of these genes shows that, A1501 have formed a very suitable system with the living conditions. For example, in absolutely anaerobic condition, this bacteria can digest lactic acid as carbon source, ammonium as nitrogen source and nitrate as terminal electron acceptor to carry out denitrification. The bacteria has flagellum, with which it can move freely and arrive the root to gain the carbon source. The bacteria also has IV type fimbrail, which can help to attach the root and establish a stable long-term living conditions.The genome can help us to recognize the genetic background, the metabolize pathway and the nitrogen fixation mechanism in a system view. This is the most general and important date for the study of this bacteria.