Chen Chuntan, Wang Yu, Dai Qunwei, Du Weiqi, Zhao Yulian, Song Qianxi
School of Environment and Resource, Southwest University of Science and Technology, Mianyang 621002, China.
Key Laboratory of Low-Cost Rural Environmental Treatment Technology at Sichuan University of Arts and Science, Education Department of Sichuan Province, Sichuan University of Arts and Science, Dazhou 635000, China.
Biology (Basel). 2025 Feb 3;14(2):157. doi: 10.3390/biology14020157.
The cooperation between microalgae and bacteria can enhance the carbon fixation efficiency of microalgae. In this study, a microalgae-bacteria coexistence system under high-concentration CO stress was constructed, and the bacterial community structure of the entire system was analyzed using the 16S rDNA technique. sp., sp., and sp. were screened and demonstrated to promote carbon fixation in HL 01 ( HL 01). Among them, the sp. + HL 01 experimental group exhibited the most significant effect, with an increase of about 24% in the final biomass yield and a daily carbon fixation efficiency increase of about 245% (day 7) compared to the control group. Continuous cultivation of microalgae and bacterial symbiosis showed that bacteria could utilize the compounds secreted by microalgae for growth and could produce nutrients to maintain the vitality of microalgae. Detection of extracellular organic compounds of microorganisms in the culture broth by excitation-emission matrix spectral analysis revealed that bacteria utilized the aromatic proteinaceous compounds and others secreted by HL 01 and produced new extracellular organic compounds required by HL 01. The metabolic organic substances in the liquids of the experimental groups and the control group were analyzed by liquid chromatography-mass spectrometry, and it was found that 31 unique organic substances of HL 01 were utilized by bacteria, and 136 new organic substances were produced. These differential compounds were mainly organic acids and their derivatives, benzene compounds, and organic heterocyclic compounds, etc. These results fully demonstrate that the carbon fixation ability and persistence of HL 01 are improved through material exchange between microalgae and bacteria. This study establishes a method to screen carbon-fixing symbiotic bacteria and verifies that microalgae and bacteria can significantly improve the carbon fixation efficiency of microalgae for high-concentration CO through material exchange, providing a foundation for further research of microalgae-bacterial carbon fixation.
微藻与细菌之间的合作可以提高微藻的碳固定效率。在本研究中，构建了高浓度CO胁迫下的微藻-细菌共存系统，并采用16S rDNA技术分析了整个系统的细菌群落结构。筛选出了sp.、sp.和sp.，并证明它们能促进HL 01（HL 01）中的碳固定。其中，sp. + HL 01实验组效果最为显著，与对照组相比，最终生物量产量增加了约24%，第7天的每日碳固定效率提高了约245%。微藻与细菌共生的连续培养表明，细菌可以利用微藻分泌的化合物进行生长，并能产生营养物质来维持微藻的活力。通过激发-发射矩阵光谱分析检测培养液中微生物的细胞外有机化合物，结果表明细菌利用了HL 01分泌的芳香蛋白质类化合物等，并产生了HL 01所需的新的细胞外有机化合物。通过液相色谱-质谱联用分析实验组和对照组液体中的代谢有机物质，发现细菌利用了HL 01的31种独特有机物质，并产生了136种新的有机物质。这些差异化合物主要是有机酸及其衍生物、苯化合物和有机杂环化合物等。这些结果充分表明，通过微藻与细菌之间的物质交换，HL 01的碳固定能力和持久性得到了提高。本研究建立了一种筛选碳固定共生细菌的方法，并验证了微藻与细菌可以通过物质交换显著提高微藻对高浓度CO的碳固定效率，为进一步研究微藻-细菌碳固定提供了基础。
