一株氢氧化细菌的生长条件及其对不同氮源利用的研究

Growth Conditions of a Hydrogen-Oxidizing Bacterium and Its Utilization of Different Nitrogen Sources

从污水处理厂活性污泥中成功地筛选出一株自养型氢氧化细菌(Hydrogen-oxidizing Bacterium,HOB),命名为Rhodoblastus sp.TH20。以模拟氨氮(NH_(4)^(+)-N)废水作为培养基,该菌株能够以H_(2)为能源,CO_(2)为碳源,其最适宜的生长条件为25℃、160 rpm和pH=7.0。当初始NH_(4)^(+)-N浓度为100 mg/L时,菌株在72小时内能有效地去除NH_(4)^(+)-N(>99%)。其中,77.8%的NH_(4)^(+)-N被同化为有机氮,储存在细胞体内,剩余的转化为气态氮。结果表明:Rhodoblastus sp.TH20具有高效的氨同化能力,可实现NH_(4)^(+)-N向微生物蛋白的资源转化,为含NH_(4)^(+)-N污水的资源化处理提供一条新途径。

An autotrophic hydrogen-oxidizing bacterium,named Rhodoblastus sp.TH20,was successfully enriched and isolated from municipal activated sludge in a domestic wastewater treatment plant.With simulated ammonium-containing wastewater as culture medium,the strain could utilize H_(2)and CO_(2)as energy and carbon sources respectively and the growth conditions were optimized at 25℃,160 rpm and pH=7.0.At initial concentration of 100 mg/L,efficient ammonium removal(>99%)was achieved within 72 hours.Up to 77.8%of ammonium was assimilated to organic nitrogen and stored intracellularly,while the rest ammonium was transformed to gaseous N_(2).These results indicated that Rhodoblastus sp.TH20 was able to efficiently convert ammonium into microbial protein,thereby providing a sustainable pathway of wastewater treatment.