两株海洋放线菌的产色素特性

【背景】生物产生的天然色素在工业、农业和纺织工业上有潜在应用价值。【目的】通过对产色素海洋放线菌的分离与筛选，为开发细菌所产生的天然色素在纺织与食品工业中的应用奠定基础。【方法】筛选胞外产可溶性色素的放线菌，并通过16S rRNA基因序列测定和分析构建其系统发育树，并对影响色素产量的因素和色素稳定性进行实验。【结果】获得了一株产蓝色色素的放线菌Q2N-42和一株产黄绿色色素的放线菌X4C-5，16S rRNA基因序列分析表明它们分别与天蓝色链霉菌(Streptomyces coelicolor)或紫红链霉菌(Streptomyces violaceoruber)和普拉滕斯链霉菌(Streptomyces pratensis)的16S rRNA基因序列存在较高的相似性。通过研究不同碳源和氮源对放线菌Q2N-42和X4C-5产色素的影响，发现甘油和硝酸钠能明显地增加天蓝色链霉菌(S. coelicolor) Q2N-42的色素产量，而淀粉和硝酸钠能明显地增加普拉滕斯链霉菌(S. pratensis) X4C-5的色素产量。这两种色素对不同浓度的氧化剂、还原剂、盐和pH都表现出良好的稳定性；色素的红外光谱测定表明，其结构分别包含了?OH、?CH3和C=C基团。通过色素和不同媒染剂对棉线染色，发现硫酸铜是蓝色色素良好的媒染剂，毛线着色较深，洗涤不易脱色；而硫酸亚铁是绿色色素良好的媒染剂，毛线着色较深、有光泽，洗涤不易脱色。【结论】放线菌株Q2N-42和X4C-5所产生的色素为其工业应用提供了潜在的天然色素资源。

Pigments production by two marine actinobacteria

Background] Biogenic natural pigments have potential applications in industry, agriculture, and textile industries. Objective] The isolation and screening of marine pigment-producing actinobacteria is aimed to lay a foundation for the applications of bacterial pigments in the textile and food industry. Methods] Actinobacteria, producing extracellular soluble pigment, were screened, and 16S rRNA gene phylogenetic tree was constructed based on their 16S rRNA gene sequences. Subsequently, factors affecting pigment yield and stability were investigated. Results] A blue pigment-producing actinobacterium Q2N-42 and a yellow-green pigment-producing actinobacterium X4C-5 were obtained. Phylogenetic analyses of the 16S rRNA gene sequences of Q2N-42 and X4C-5 showed that they have high similarity with Streptomyces coelicolor or Streptomyces violaceoruber and Streptomyces pratensis, respectively. Comparative analyses of the effects of carbon and nitrogen sources on pigment yields showed that glycerol and sodium nitrate can significantly increase the blue pigment yield of S. coelicolor Q2N-42, whereas, starch and sodium nitrate can significantly increase the yellow-green pigment yield of S. pratensis X4C-5. Both the blue and yellow-green bacterial pigments displayed fine stability when they were treated with different concentrations of the oxidant, reductant, salinity, and pH. FTIR spectral analyses of the pigments showed that the pigment molecules contain the functional groups of ?OH, ?CH3, and C=C. Different mordants coupled with the bacterial pigments were used to check the dyeing propriety on the cotton threads. The results demonstrated that copper sulfate combined with the bacterial blue pigment presented a excellent performance when the cotton threads were dyed with it, the cotton threads were stained in darker blue, and enough to withstand the water wash treatment. Whereas, ferrous sulfate combined with the bacterial yellow-green pigment gave a good performance for the cotton thread staining. Conclusion] Those data indicate that both the blue pigment produced by Q2N-42 and the yellow-green pigment produced by X4C-5 are potential resources towards their industrial applications.