光照、氧气、pH和盐度对沼泽红假单胞菌2-8菌株生长和亚硝酸盐消除的影响

以1株具有亚硝酸盐消除能力的沼泽红假单胞菌（Rhodopseudomonas palustris）2-8菌株（简称2-8菌株）为材料,研究了不同光照和氧组合、pH、盐度对菌株生长和亚硝酸盐消除能力的影响。结果发现,光照厌氧条件最利于2-8菌株的生长,该条件下菌株亚硝酸盐消除能力最强,25h消除率达（91.33±1.27）%;菌株在pH7.0时生长和亚硝酸盐消除能力最强,25h亚硝酸盐消除率达到（95.58±4.34）%,在pH9.0以上和5.0以下时基本不生长;菌株在w（NaCl）为0和0.4%的培养基中生长和亚硝酸盐消除能力最强,在w（NaCl）为0.8%～2.0%的培养基中,生长和亚硝酸盐消除能力随w（NaCl）增高而减弱。测定的4个环境因子主要通过影响菌株的生长来影响其对亚硝酸盐的消除能力。

Influence of illumination, oxygen, pH and salinity on growth and nitrite removal effect of Rhodopseudomonas palustris strain 2-8

We used Rhodopseudomonas palustris strain 2-8,a denitrifying non-sulfur photosynthetic bacterium,to study its growth and nitrite removal effect with different illumination-oxygen combinations,pH level and NaCl concentrations.The results show that illumination without oxygen is best for the strain′s growth and nitrite removal,with a nitrite removal efficiency of （91.33±1.27）% after 25 h inoculation;pH 7.0 is best for its growth and nitrite removal,and the nitrite removal efficiency reaches （95.58±4.34）% after 25 h inoculation,however,it does not grow at pH below 5.0 or above 9.0.Moreover,the strain grows best and removes nitrite most quickly with NaCl culture medium of 0.0% or 0.4%,but with a 0.8%～2.0% NaCl concentration,its growth and nitrite removal effect weaken with the increasing concentration.These four environmental factors influence the nitrite removal effect of stain 2-8 by influencing its growth.