活性碳纤维耦合白腐菌强化控制蓝藻生长代谢机理及生物毒性研究

Cyanobacteria bloom poses a serious threat to water and ecological security, and it has become one of the difficult problems to be solved in the global water pollution control. Under the circumstance that conventional methods have had little effect, microbial control of algae has become a research hotspot. At present, bacteria are used to control algae, but a new method that combines bio-carbon fiber and white-rot fungi to effectively eliminate algae and reduce secondary pollution is still needed. In this study, a bio-carbon fiber coupled white rot fungi enhanced algae control system is constructed by biofilm method.The typical cyanobacteria- microcystis aeruginosa is used as the research object to investigate the effects of environmental factors and biological factors on the growth of algae cells and the activity of antioxidant enzymes,and to elucidate control effect of algae and mechanism of growth damage on algal cells. Based on the levels of endogenous metabolites of white-rot fungi and the molecular level of algal cells, this method is used to analyze the pattern of algal cell components and expression of genes associated with the growth of algal cells, thereby revealing the mechanism of algae control.In order to qualitatively and quantitatively evaluate the impact on aquatic environment,toxicological and molecular genetic techniques are used to comprehensively analyze the physiological toxicity of white rot fungi and the biogenetic toxicity of water samples after algae dissolution, respectively. This study will provide a new idea for controlling cyanobacteria blooms, and laying a theoretical foundation for deepening control water eutrophication.

蓝藻水华对水体和生态安全构成严重威胁，已成为全球水污染治理中亟待解决的难题之一。在常规方法治理收效甚微的情况下，微生物控藻成为研究的热点。目前大多采用细菌控藻，而将活性碳纤维与白腐菌耦合研发一种既能有效溶藻，又能显著降低二次污染的白腐菌生物碳纤维控藻新方法，还需进一步的深入研究。本课题通过生物膜法构建白腐菌生物碳纤维耦合强化控藻系统，以典型蓝藻-铜绿微囊藻为研究对象，考察环境因子和生物因子对藻细胞生长胁迫效应及抗氧化物酶活特性的影响，明确控藻效果，阐明其对藻细胞生长损伤机理。基于白腐菌内源代谢物水平及藻细胞分子水平，探析该方法对藻细胞组分结构及藻细胞生长相关基因的响应表达，从而揭示控藻机制。采用毒理学和分子遗传学技术综合分析白腐菌的生理毒性及溶藻后水样的生物遗传毒性，定性定量评价其对水生态环境的影响。本研究成果可为控制蓝藻水华提供新的思路，对于推动该方法深化治理水体富营养化奠定理论基础。

蓝藻水华对水体和生态安全构成严重威胁，已成为全球水污染治理中亟待解决的难题之一。在常规方法治理蓝藻水华收效甚微的情况下，微生物控藻成为目前的研究热点。本课题以典型水华蓝藻-铜绿微囊藻为研究对象，基于单因素优化实验确定了该控藻系统最优工况为：白腐菌投加量250mg/L，进水pH值7.0，温度25℃，DO 7mg/L，HRT 48h。在该最优工况下，DHA和可溶性蛋白质均发生了明显的降低，而MDA出现了上升。综合处理前后藻细胞生理生化指标、傅里叶红外光谱图、扫描电镜和流式细胞仪实验结果发现正常的铜绿微囊藻和经过该系统处理后的藻细胞红外光谱主要吸收峰位置及波形形状仍大致一致，但诸峰的相对强度有较为明显的差异，经该系统处理后的铜绿微囊藻藻细胞的吸收峰强度明显要弱于铜绿微囊藻胞原样，铜绿微囊藻藻细胞的空间结构遭到了明显的破坏，藻细胞内的营养物质几乎被消耗殆尽，出现了藻细胞大量死亡的现象。基于白腐真菌内源代谢物水平及藻细胞基因水平研究发现，该系统处理铜绿微囊藻后能显著的改变铜绿微囊藻细胞内的基因表达，与对照组相比，实验组中藻细胞的抗氧化蛋白酶合成基因prx、生物大分子损伤及修复基因rec A, grp E，fab Z均有所上升，而和光合作用系统相关基因psa B , psb D1和rbc L转录表达量均有明显的降低，表明白腐菌能够有效的控制铜绿微囊藻藻细胞的生长，结合代谢组学实验结果可以看出，白腐真菌能够影响铜绿微囊藻光合作用途径和氧化磷酸化途径中的一些关键代谢物的含量，进而对铜绿微囊藻的光合作用、白腐真菌三羧酸循环等一些重要的能量代谢通路也会受到影响，进而达到抑藻作用。采用毒理学和遗传学技术综合分析了该系统的生理毒性及溶藻后水样的生物遗传毒性，研究结果发现该系统溶藻的过程中能有效的降解部分毒素，不易对水环境产生二次污染。本研究成果可为控制蓝藻水华提供新的思路，对于推动该方法深化治理水体富营养化奠定理论基础。