Screening and identification of a nitrogen fixing bacteria with 1-aminocyclopropane-1-carboxylate deaminase activity

ACC (1-aminocyclopropane-1-carboxylate) deaminase is a common characteristic enzyme in plant growth promoting bacteria ( PGPB）in rencent years. Many ACC deaminase positive bacteria have the ability to increase plant resistences against envionmental stresses like drought, flood, salinity and high temperature, therefore, screening and investigation on the ACC deaminase positive bacteria are importment for agriculture. In this work, one strain designed as 7037 was screened. The results show that the ACC deaminase activity of the strain is 2.530 mol/(hmg) protein and the nitrogenase activity is C2H4 10.068 nmol /(hmg)protein. The strain 7037 shows a relative extensive utilization for caobon sources and strong environmental adaptability, and is identified as Arthrobacter sp. The pot trial shows that the fresh weight of Chinese cabbage inoculated with the strain 7037 is increased by 139% compared with the no inoculation control. The strain 7037 is possible to be further developed as an excellent strain for microbial fertilizer production.