耐氨固氮型催娩克氏菌的某些生理特性

SOME PHYSIOLOGICAL PROPERTlES OF AMMONI A-RESISTANT STRAIN OF NITROGEN-FIXING KIEBSIEIIA OXYTOCA

耐氨固氮型催娩克氏菌（KlebsiellaoxytocaNG13／pMC73A）的生长特性与其野生型亲本菌株相似。在好气和微好气环境中均能生长，对生长所需的碳源、氮源和无机盐类要求不严格。最适pH值为6—9，其生长温度范围较宽，10℃开始生长，最适生长温度30－35℃，45℃才受到抑制。具有比野生型菌株强的固氮能力，在含有10mM硫酸铵的培养基中能正常固氮，乙炔还原活性可达636．5nmolC2H4／ml·h，而野生型菌株在相同培养基中无固氮能力。

The physiological properties of ammonia-resistant strain of nitrogen fixing bacterium, Klebsiella oxytoca NG13/pMC73A was similar to that of wild strain. It could grow in aerobic and microaerobic culture. The growing requirement on carbon source,nitrogen source and inorganic salts were not strict. The optimum pH was from 6 to 9. The growth tem-perature range was wide. It began growing in 10℃. The optimum growth temperature was from 30℃ to 35℃. The growth-inhibiting temperature was 45℃. It had higher nitrogen fixing activity than the wild strain, when 10mM (NH4)2SO4 existed in medium, ammonia-resistant strain would also keep normal nitrogen fixing activity. Acetylene reduction activity reached 636.5 nmol C2H4/ml·h. But its wild strain had no nitrogen fixing activity in the same medium.