Abstract: Periphytic biofilms are important primary producers and decomposers and play an important role in the ecosystem. This study investigated the effect of indole-3-acetic acid (IAA) on the metabolic characteristics of the periphyton microbial community from the perspective of carbon source utilization. After periphytons were cultured in greenhouse for 20 d, different concentrations of IAA  were applied. Biology ecoplates were used for the quantitative analysis of microbial carbon source utilization characteristics at the community level, the average well color development (AWCD) and multifunctional indexes were determined. The results showed that, with the increase of incubation time, AWCD of the treatments with 25, 50, 100 mg·L^-1 IAA were significantly increased, the utilization abilities to specific carbon source (e.g., carbohydrate) were changed and microbial functional diversity indexes (Shannon index, McIntosh index) were significantly increased. These results suggested that high concentration of IAA could promote the carbon metabolism activity of periphyton, and provide a foundation for intermediate culture of periphyic biofilms.

Key words: periphytic biofilms, indole-3-acetic acid (IAA), microbial carbon metabolism, average well color development (AWCD)

摘要： 周丛生物是重要的初级生产者和分解者，在生态系统中扮演着重要角色。从碳源利用角度探讨了吲哚乙酸（indole-3-acetic acid，IAA）对周丛生物微生物群落代谢特性的影响。以人工培育的周丛生物为材料，在温室培育20 d后施加不同浓度的吲哚乙酸，使用Biology生态测试板在群落水平上对微生物碳源利用特性进行定量分析，测定平均每孔颜色变化率和多功能指数。结果表明:随着培养时间的增加，25、50、100 mg·L^-1高浓度IAA处理后，平均每孔颜色变化率显著增加，特定的碳源（如碳水化合物）利用能力发生变化，微生物功能多样性指数（Shannon指数、McIntosh指数）显著升高，说明高浓度IAA可以促进周丛生物的碳代谢活性，为探讨周丛生物的扩大培养与富集方法奠定了基础。

关键词: 周丛生物, 吲哚乙酸, 微生物碳代谢, 平均颜色变化率