雷竹林土壤染料降解真菌筛选与脱色效果初步研究

Decolorizing synthetic dyes with fungi screened from a Phyllostachys violascens stand

应用平板分离培养和内转录间隔区(internal transcribed spacers,ITS)序列分析的方法,筛选鉴定集约栽培雷竹Phyllostachys violascens林土壤中染料降解真菌菌株,并通过摇瓶发酵研究其染料脱色效果。结果表明:土壤样品中分离频次最高的真菌种类为木霉菌属Trichoderma,对5株接种到苯胺蓝平板上能形成明显水解圈的真菌分离物,测试它们对偶氮和三苯甲烷类染料的降解能力。综合脱色效果较好的菌株为P7-2-3和P12-2-4,ITS序列比对和形态学观察表明菌株分别是卷枝毛霉Mucor circinelloides和木霉菌Trichoderma sp.,接种不超过500.0 mg·L^(-1)质量浓度结晶紫染料液体发酵脱色均可获得较高的脱色率;但染料质量浓度为300.0 mg·L^(-1)和400.0 mg·L^(-1)时分别对2菌株的脱色能力产生明显抑制,降解染料质量与菌丝生物量之间存在显著的正相关性。

This study aimed to screen high efficiency decolorizing fungi for degradation of structurally different synthetic dyes. Fungal strains were isolated and screened from soil of bamboo plantation （Phyllostachys violascens） using conventional separation, cultivation methods, and sequence alignment analysis of nuclear ribosomal internal transcribed spacers （ITS）. The bamboo plantation for isolating soil fungi consisted of bamboo forests aged 1, 7, 12, and 15 years, which applied no heavy fertilization and organic mulch until year 5. Result showed that Trichoderma sp. had the highest isolation frequency in the cultured fungi from topsoil based on morphological identification and phylogenetic analysis. Decolorization capacity of the five isolated fungi （（P7-2-1, P7-2-2, P1-2-2, P7-2-3, P12-2-4） to the five different synthetic dyes （Congo red, orange G, crystal violet, fuchsin acid, and methyl orange） showed that P7-2-3 （identified as Mucor circinelloides） and P12-2-4 （identified as Tri- choderrna spp.） had the strongest capacity to decolorize the five kinds of dyes. The decolorization efficiency of P7-2-3 and P12-2-4 to crystal violet was similar at different crystal violet concentrations below 500.0 mg＇L-i; however, crystal violet inhibited the decolonization reaction at concentrations of 300.0 mg.L-1 for strain P7-2-3 and 400.0 mg.L-1 for strain P12-2-4. The fungal biomass and dye decolorization had a positive relationship for different concentrations of crystal violet, and strains of P7-2-3 and P12-2-4 have potential value for application in decolorization and degradation of dyes wastewater. [ Ch, 4 fig. 2 tab. 31 ref.]