红树林混合菌群协同降解偶氮染料活性黑5脱色性能研究

Synergistic decolorization of azo dye reactive black 5 by mangrove mixed microbial community

通过对福建省龙海市海门岛红树林保护区的近海沉积物样品进行富集驯化,得到了能够协同降解偶氮染料活性黑5的混合菌群HMD9-Q7。经过生化试验和16SrDNA序列分析,鉴定该混合菌群主要由越南蔷薇菌(Rossellomorea vietnamensis)、转化异源物食烷菌(Alcanivorax xenomutans)和近海生微泡菌(Microbulbifer maritimus)组成。与单一菌株相比较,混合菌群具有显著的脱色效果,可能因其菌株之间存在着相互协同促进作用。该混合菌群对含20~100 mg/L浓度的活性黑5均产生脱色作用。混合菌群HMD9-Q7可以广泛利用外加碳源和氮源,如葡萄糖、硝酸铵、牛肉膏等;NaCl浓度在5~30 g/L范围内都可对活性黑5进行脱色;在pH 7和温度30℃条件下脱色率最高。在最优条件下,该混合菌群在60 h内对活性黑5的脱色率可达到85%~90%。该新型混合菌群主要通过生物降解途径来实现对活性黑5的脱色。随着降解反应的发生,活性黑5的最大吸收峰逐渐变小直至完全消失,降解产物吸收峰位于近紫外光区。

Through the enrichment and separation of mangrove sediment samples from Haimen Island Mangrove Reserve in Longhai City,Fujian Province,a mixed microbial community HMD9-Q7 was obtained and could synergistically degrade azo dye reactive black 5(RB5).Based on biochemical assays and 16S rDNA sequence analysis,the community was identified as mainly composed of Rossellomorea vietnamensis,Alcanivorar senomutans,and Microbulbifer maritimus.Compared with single strains,the community had a significant decolorization effect,which may be due to the synergistic promotion between various strains of the community.The community had decolorization effect on RB5 at concentrations of 20-100 mg/L.The community HMD9-Q7 could widely utilize external carbon and nitrogen sources,such as glucose,ammonium nitrate,beef extract paste;in the range of NaCl concentrations of 5-30 g/L,the RB5 could be decolored;the decolorization rate was highest under the conditions of pH 7 and temperature of 30℃.Under the optimal conditions,the decolorization rate of the community on RB5 within 60 hours could reach 85%-90%.The new community mainly achieves decolorization of RB5 through biodegradation pathways,and with the occurrence of degradation reaction,the maximum absorption peak of RB5 gradually becomes smaller until it disappears completely,and the absorption peak of degradation products is located in the near ultraviolet region.