The biodegradation of. microcystin by fungus was carried out with white-rot fungus S. commune as degrading bacteria and microcystin-LR (MC-LR) as target microcystin. Effect of pre-incubated method, cultivation pattern, oxygen-infuse method, temperature, initial pH and MC-LR concentration on MC-LR biodegradation was investigated. Results showed that the S. commune,especially those pre-incubated in liquid culture, presented perfect performance for MC-LR biodegradation. The biodegradation ratio could be improved when inflating pure O2 to the biode-grading system (1 min per day) and cultivating the system under stable condition. The optimal initial pH for MC-LR biodegradation by S. commune was 4. 5, and the appropriate temperature was 30-35 ℃. The biodegradation capacity of S. commune to MC-LR was decreased with increasing the initial MC-LR concentration. Under these optimal conditions, when the initial MC-LR was 1 mg/L, MC-LR was completely degraded within 2 days, and when the initial concentration was 15 mg/L, MC-LR would completely degraded within 7 days. Higher MC-LR concentration (more than 30 mg/L) would inhibit the growth of S. commune. The further study was necessary to make clear of the structure of MC-LR intermediate products.%为研究真菌对微囊藻毒素的降解作用,以白腐菌S.commune为降解菌,微囊藻毒素-LR(MC-LR)为降解目标进行生物降解,考察了白腐菌预培养方式及降解过程中的培养方式、充氧方式、温度、初始pH以及MC-LR初始浓度对降解效果的影响.结果表明,白腐菌可有效降解MC-LR,经液体预培养白腐菌对MC-LR的降解效果好于固体预培养,白腐菌静置培养过程中每天充入纯氧1min有助于MC-LR的降解,白腐菌降解MC-LR的最佳初始pH为4.5,适宜温度为30～35℃.白腐菌对MC-LR的降解能力随MC-LR初始浓度的增加而降低.在最佳条件下,当MC-LR初始质量浓度为1 mg/L时,其完全降解需要2d；当MC-LR初始质量浓度为15 mg/L时,其完全降解需要7d.高浓度MC-LR(30 mg/L以上)会对白腐菌生长产生抑制作用.MC-LR降解中间产物的具体结构尚不清楚,有待未来深入分析研究.
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