褐球固氮菌的培养

The Culture of Azotobacter Chroococcum

生物固氮是自然系统中氮的重要来源,可以作为生物肥料,在生产实际中发挥着重要作用。而褐球固氮菌作为自生固氮微生物,广泛存在于土壤中,可以固定空气中的氮气。本文通过用阿须贝(Ashby)无氮培养基培养褐球固氮菌,观察其形态学,发现呈革兰氏阴性,形状呈球杆状或杆状,大小为2.4μm,常成对或八叠状排列,有荚膜,周生鞭毛,能运动。并通过比浊法测定褐球固氮菌的生长曲线,分别在0~6 h为迟缓期,6~16 h为对数生长期,16~20 h为稳定期,20 h后进入衰亡期。

Biological nitrogen fixation is an important source of nitrogen in the natural system, and can be used as a biological fertilizer, which plays an important role in the production practice. Azotobacter chroococcum, which is a kind of nitrogen fixing bacteria, exists widely in the soil. This paper through the use of a Ashby nitrogen free medium A. chroococcum, observe its morphology, found a gram negative, rod-shaped or rod shape of a ball, the size is 2.4 lain, usually paired or eight stacked arrangement, a capsule, week flagella, motile. The growth curve ofA. chroococcum was determined by turbidimetric method, and the growth period was 0 to 6 h, and the logarithmic growth period was from 6 to 16 h, and the stable period was from 16 to 20 h, and then entered the decline stage after 20 h.