抗生素溶杆菌13-1对魔芋土壤微生物群落的影响*

 采用传统培养分离法和Biolog方法研究了施用抗生素溶杆菌13-1对魔芋土壤微生物数量和群落代谢功能多样性的影响。分离法试验结果表明：生防细菌的施入对土壤中可培养细菌、真菌的种群数量有短期影响，随着施入时间及魔芋生育期的延长，土壤中的细菌、真菌数量逐渐恢复到对照水平；生防细菌对土壤中放线菌的种群数量影响较小。Biolog试验结果表明，生防细菌使土壤细菌群落对底物碳源利用的丰富度提高；平均颜色变化率AWCD值受魔芋生长周期的影响，具体表现为魔芋换头期生防细菌处理能提高土壤微生物群落代谢活性，而在魔芋膨大期施用生防细菌处理能降低土壤微生物群落代谢活性；主成分分析显示，在魔芋换头期和膨大期施用生防菌处理的魔芋土壤微生物群落代谢功能与对照组相比差异性达到了显著水平（P<0.05）。

Effects of Lysobacter antibioticus Strain 13-1 on Soil Microbial Communities of Konjac

The effects of applying biocontrol agents Lysobacter antibioticus strain 13 1 on the konjac soil microbial communities and the metabolic functional diversity was evaluated by using dilution plating and Biolog ECO microplate. The dilution plating results showed that biocontrol bacterial treatment revealed short term effects on total soil population of culturable bacteria and fungi, however, total bacterial and fungal population gradually declined to the similar levels as those of control with time and the konjak growth; biocontrol bacterial treatment had less effect on actinomycetes populations in different soils samples. The profiles derived from Biolog Eco plates indicated higher substrate richness; average well color development (AWCD, microbial activity) were influenced by plant growth phase, specifically, applying biocontrol bacterial 13 1 significantly enhanced the community diversity of soil microorganisms during the seed new tuber conversion phase and inhibited them during the new tuber expansion phase. Principal components analysis (PCA) revealed that biocontrol bacterial 13 1 treatment achieved an obvious difference of the metabolic functional diversity between the seed new tuber conversion phase and the new tuber expansion phase (P<0.05).