关键词: 旱地, 地膜覆盖, 作物产量, N效率

Abstract: In this study,a bacterial strain named as Jp-A was isolated from the activated sludge of a steel factory.Through morphological observation,physiological and biochemical test,and 16srRNA sequence analysis,the strain was identified as Bacillus cereus.Under laboratory condition,the phenol at its initial concentration of 5,10 and 15 mmol·L-1 could be completely degraded by the strain within 16,24 and 32 h,respectively,but the growth of the strain was inhibited when the phenol concentration was 30 mmol·L^-1.The strain could also utilize and degrade other aromatic hydrocarbons, e.g., benzene, toluene, chlorophenol and nitrophenol,as its sole source of carbon and energy. Dioxygenase test indicated that the strain degraded phenol via metapathways.The key enzyme catechol 2,3-dioxygenase was an induced enzyme,which was mainly located on the cell membrane,and adding glucose could inhibit its generation.

Key words: Dryland, Plastic film mulching, Crop yield, Nitrogen efficiency