Screening and purification of dominant spoilage bacteria from fresh-cut green pepper

Objective:To select dominant spoilage bacteria of fresh- cut green pepper, and to reveals its corruption ability.Method:Four pepper varieties, Jingtian 3, Zhongjiao 7, Guanjunjiaowang and Qiangzhou in Beijing area were chosen as experimental materials. The samples were stored until being corrupted after fresh cut processing. The dilution separation process and streak plate method were applied for the following research. Dominant bacterial strains were selected from the decayed organization.Then, inversed grafting was used to determine their corruption ability.Furthermore, morphology of dominant bacterial was observed by the microscope, and physiological and biochemical characteristics were carried out by API20E system and API50CH system.Results:The strains A and B were screened in four green pepper varieties.The strain B had the ability of corruption on fresh cut green pepper, while the stain A did not exhibit this ability.Based on microscopic examination, the strain B was bacillus of gram negative bacteria which was preliminary identified as Erwinia app by API20E system and API50CH system. Conclusion:the stain B was Erwinia spp., which was dominant spoilage bacterial of fresh cut green pepper.