Wang Ya-nan, Wang Lei, Shan Yi-na, Hu Jiajun, Tsang Yiufai, Hu Yu, Fu Xiaohua, Le Yiquan
a State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering , Tongji University , Shanghai 200092 , People's Republic of China.
Environ Technol. 2015 May-Jun;36(9-12):1246-55. doi: 10.1080/09593330.2014.983991. Epub 2014 Dec 1.
As the non-photosynthetic microbial community (NPMC) isolated from seawaters utilized inorganic carbon sources for carbon fixation, the concentrations and ratios of Na2CO3, NaHCO3, and CO2 were optimized by response surface methodology design. With H2 as the electron donor, the optimal carbon sources were 270 mg/L Na2CO3, 580 mg/L NaHCO3, and 120 mg/L CO2. The carbon fixation efficiency in response to total organic carbon (TOC) was up to 30.59 mg/L with optimal carbon sources, which was about 50% higher than that obtained with CO2 as the sole carbon source. The mixture of inorganic carbon sources developed a buffer system to prevent acidification or alkalization of the medium caused by CO2 or Na2CO3, respectively. Furthermore, CO2 and HCO3(-), the starting points of carbon fixation in the pathways of Calvin-Benson-Bassham and 3-hydroxypropionate cycles, were provided by the carbon source structure to facilitate carbon fixation by NPMC. However, in the presence of mixed electron donors composed of 1.25% Na2S, 0.50% Na2S2O3, and 0.457% NaNO2, the carbon source structure did not exhibit significant improvement in the carbon fixation efficiency, when compared with that achieved with CO2 as the sole carbon source. The positive effect of mixed electron donors on inorganic carbon fixation was much higher than that of the carbon source structure. Nevertheless, the carbon source structure could be used as an alternative to CO2 when using NPMC to fix carbon in industrial processes.
由于从海水中分离出的非光合微生物群落（NPMC）利用无机碳源进行碳固定，因此通过响应面法设计优化了Na2CO3、NaHCO3和CO2的浓度及比例。以H2作为电子供体时，最佳碳源为270mg/L Na2CO3、580mg/L NaHCO3和120mg/L CO2。在最佳碳源条件下，响应总有机碳（TOC）的碳固定效率高达30.59mg/L，比以CO2作为唯一碳源时提高了约50%。无机碳源混合物形成了一个缓冲系统，以防止分别由CO2或Na2CO3引起的培养基酸化或碱化。此外，卡尔文-本森-巴斯姆循环和3-羟基丙酸循环途径中碳固定的起始点CO2和HCO3(-)由碳源结构提供，以促进NPMC的碳固定。然而，在存在由1.25% Na2S、0.50% Na2S2O3和0.457% NaNO2组成的混合电子供体时，与以CO2作为唯一碳源相比，碳源结构在碳固定效率方面未表现出显著改善。混合电子供体对无机碳固定的积极作用远高于碳源结构。尽管如此，在工业过程中使用NPMC固定碳时，碳源结构可作为CO2的替代品。
