单播草地匍茎翦股颖根际联合固氮菌筛选及部分特性初探

Preliminary study on isolation and characteristics of associative nitrogen fixation bacteria from rhizosphere of single-sowing Agrostis stolonifera turf

从西安地区单播草坪匍茎翦股颖的根际分离到固氮菌株188株,通过气相色谱仪,利用乙炔还原法最终筛选出4株固氮酶活性较高的菌株进行固氮菌部分特性测定及初步对菌株进行鉴定.结果表明:4株菌株中,X4菌株固氮酶活性最高,C2H4达180.20 nmol.mL-1.h-1,与其他菌株相比差异极显著(P<0.01),X2菌株固氮酶活性最低,C2H4为39.32 nmol.mL-1.h-1;筛选出的4株菌株除X4菌株生长较慢外,其余菌株都生长迅速;X2、X3和X4菌株为革兰氏阳性菌株,X1为革兰氏阴性菌株;除X4为中性兼性厌氧性菌株外,其余均为碱性好氧性菌株.经生理生化实验初步鉴定,X1和X4分别属于Enterobacters和Staphylococcu属,X2和X3菌株属于Bacillus属.

Total 188 associative nitrogen fixation bacteria strains were isolated from the rhizosphere of single-sowing Agrostis stolonifera turf in Xi＇an. In which, 4 strains （coded with X1, X2, X3 and X4） with higher nitrogenase activity were finally identified and studied by using acetylene reduction assay with gas chromatogrphy. The results showed that Nitrogenase activity of X4 was the highest,C2 H4 of X4 reached to 180. 20 nmol·mL^-1·h^-1,which was significantly higher than other strains. Nitrogenase activity of X2 was the lowest,C2H4 of which was 39.32 nmol·mL^-1·h^-1. All strains grew fast except X4,Xz,X3 and X4 were gram positive bacteria while X1 was gram negative bacteria. X4 was neutral and semi-anaerobe while the other 3 strains were alkaline and aerobic. The identification results through physiological and physiochemical reactions showed that X1 and X4 belonged to Enterobacter and Staphylococcus respectively,X2 and X3 belonged to Bacillus.