（毕业设计论文）《大豆根际固氮菌筛选与鉴定》.docVIP

精品 PAGE 精品 齐 齐 哈 尔 大 学 毕业设计（论文） 题 目 大豆根际固氮菌筛选与鉴定 学 院 生命科学与农林学院 专业班级 生物技术 学生姓名 指导教师 成 绩 年 6 月 17 日 摘 要 自生固氮菌是指在土壤中能够独立进行固氮的细菌。由于培养等处理容易，在实验室里可固定大量氮素，所以对固氮菌的研究多使用此种生物。固氮菌对人类来说有着重要的用途，它可以提高大豆的产量，改善土壤的质量，可以用作环境改良剂，也可以作为一种生物产品。所以越来越多的科学家开始对它进行了研究。 自生固氮菌是植物根际促生细菌(PGPR)的重要组成成分，并且可以将大气中的N2通过生物固氮作用供给植物生长，提高植物对氮素的利用。本试验从固氮菌的分离、筛选入手，Ashby无氮培养基上共生长了六种菌，从这六种菌中提取分离得到固氮菌。然后进行革兰氏染色，选取其中长势良好的三种菌进行生理生化鉴定，根据其反应鉴定出细菌的种类，所选择的三种菌是LLN1、LLN2、LLN9，最终的鉴定结果是LLN1为未知， LLN 2为真细菌目，固氮菌属，敏捷固氮菌；LLN 9：为真细菌目，固氮菌属，褐色固氮菌。 关键词：固氮菌；根际促生细菌；固氮酶 Abstract Since the birth of adopting refers to the soil on nitrogen-fixing bacteria can be independent. Due to the training and easy, can be fixed in the laboratory of nitrogen, so for the use of such research colony. Adopting for humans have important purpose, it can improve the soybean yield and improve the quality of the soil and can be used for environmental improver, also can be used as a biological products. So more scientists began to it are studied. The colonys plant rhizosphere grows bacteria (the) is an important component of PGPR atmosphere, and can be supplied by biological nitrogen fixation of N2 function of plant growth and improve the utilization of nitrogen plants. This test from the separation of colony, screening, medium total nitrogen Ashby without the growth of bacteria, six from six different extraction and separation of bacteria get colony. Then select one gram stain, decent of three kinds of bacteria on physiological and biochemical reactions, according to the types of bacteria, identified by choice of three kinds of bacteria is LLN1, LLN2, LLN9, final appraisal result is unknown, LLN1 for LLN 2 for bacteria, adopting agile colony, LLN 9: for bacteria, brown, adopting colony. Keywords: Nitrogen-fixing bacteria; PGPR;