Zhang Ying, Deng Chun-Ping, Shen Bin, Yang Jin-Shui, Wang En-Tao, Yuan Hong-Li
State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, 100193, China.
School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
Microb Ecol. 2016 Oct;72(3):538-48. doi: 10.1007/s00248-016-0799-4. Epub 2016 Jun 20.
Butane oxidation by the hydrocarbon degradation bacteria has long been described, but little is known about the microbial interaction in this process. To investigate this interaction, the efficiency of butane oxidation was estimated in monocultures and co-cultures of six strains of butane-oxidizing bacteria (BOB) and a butanol-oxidizing strain. Results showed that the butane degradation velocity was at least 26 times higher in the co-culture of the seven strains (228.50 nmol h(-1)) than in the six individual monocultures (8.71 nmol h(-1)). Gas chromatographic analysis of metabolites in the cultures revealed the accumulation of butanol in the monocultures of BOB strains but not in the co-culture with the butanol-oxidizing strain. These results evidenced a novel syntrophic association between BOB and butanol-oxidizing bacteria in the butane oxidation. The BOB strains oxidized butane into butanol, but this activity was inhibited by the accumulated butanol in monocultures, whereas the removal of butanol by the butanol-oxidizing strain in co-culture could eliminate the suppression and improve the butane degradation efficiency. In the co-culture, both BOB and butanol-oxidizing bacteria could grow and the time needed for butane complete removal was shortened from more than 192 h to less than 4 h. The unsuppressed effect of the co-culture was also consistent with the results of reverse transcription quantitative real-time PCR (RT-qPCR) of bmoX gene because increased expression of this gene was detected during the syntrophic growth compared with that in monoculture, pointing to the upregulation of bmoX in the syntrophic interaction.
长期以来，人们一直描述烃降解细菌对丁烷的氧化作用，但对该过程中的微生物相互作用却知之甚少。为了研究这种相互作用，在六种丁烷氧化细菌（BOB）菌株和一种丁醇氧化菌株的单培养物和共培养物中评估了丁烷氧化效率。结果表明，七种菌株的共培养物（228.50 nmol h(-1)）中丁烷降解速度比六种单独的单培养物（8.71 nmol h(-1)）中至少高26倍。对培养物中代谢物的气相色谱分析表明，丁醇在BOB菌株的单培养物中积累，而在与丁醇氧化菌株的共培养物中则没有积累。这些结果证明了BOB和丁醇氧化细菌在丁烷氧化过程中存在一种新的互营共生关系。BOB菌株将丁烷氧化为丁醇，但这种活性在单培养物中受到积累的丁醇的抑制，而在共培养物中丁醇氧化菌株去除丁醇可以消除这种抑制并提高丁烷降解效率。在共培养物中，BOB和丁醇氧化细菌都可以生长，丁烷完全去除所需的时间从超过192小时缩短到不到4小时。共培养物的无抑制作用也与bmoX基因的逆转录定量实时PCR（RT-qPCR）结果一致，因为与单培养相比，在互营共生生长过程中检测到该基因的表达增加，表明在互营共生相互作用中bmoX上调。
