Departamento de Ingeniería Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Carpio y Plan de Ayala, Col Santo Tomás, CP 11340, Mexico, D.F., Mexico.
J Ind Microbiol Biotechnol. 2012 Aug;39(8):1169-77. doi: 10.1007/s10295-012-1123-z. Epub 2012 Apr 11.
By decolorization of azo dyes, caused by reductive cleavage of the azo linkage, toxic or recalcitrant amines are generated. The present study deals with the effect of the inflowing medium composition (C:N ratio) on the kinetic behavior of a bacterial biofilm-forming consortium, able to use as carbon, nitrogen and sulfur source, the molecule of 4-aminonaphthalene-1-sulfonic acid (4ANS), which is one of the most recalcitrant byproducts generated by decolorization of azo dyes. All the experiments were carried out at room temperature in a lab-scale packed-bed biofilm reactor. Because environmental conditions affect the bioreactor performance, two mineral salts media containing 4ANS, with distinct C:N ratios; 0.68 (carbon as the limiting nutrient) and 8.57 (nitrogen as the limiting nutrient) were used to evaluate their effect on 4ANS biodegradation. By HPLC and COD measurements, the 4ANS removal rates and removal efficiencies were determined. The cultivable bacterial strains that compose the consortium were identified by their 16S rDNA gene sequence. With the enrichment technique used, a microbial consortium able to use efficiently 4ANS as the sole carbon source and energy, nitrogen and sulfur, was selected. The bacterial strains that constitute the consortium were isolated and identified. They belong to the following genera: Bacillus, Arthrobacter, Microbacterium, Nocardioides, and Oleomonas. The results obtained with this consortium showed, under nitrogen limitation, a remarkable increase in the 4ANS removal efficiency η(ANS), and in the 4ANS volumetric removal rates R (V,4ANS), as compared to those obtained under carbon limitation. Differences observed in bioreactor performance after changing the nutrient limitation could be caused by changes in biofilm properties and structure.
通过偶氮染料的还原裂解，生成有毒或难降解的胺。本研究探讨了流入介质组成（C:N 比）对能够利用 4-氨基萘-1-磺酸（4ANS）作为碳、氮和硫源的细菌生物膜形成共生物种的动力学行为的影响，4ANS 是偶氮染料脱色产生的最顽固的副产物之一。所有实验均在实验室规模的填充床生物膜反应器中于室温下进行。由于环境条件会影响生物反应器的性能，因此使用两种含有 4ANS 的无机盐培养基，具有不同的 C:N 比；0.68（碳为限制营养物）和 8.57（氮为限制营养物），以评估它们对 4ANS 生物降解的影响。通过 HPLC 和 COD 测量，确定了 4ANS 的去除率和去除效率。通过其 16S rDNA 基因序列鉴定组成共生物种的可培养细菌菌株。使用富集技术，选择了一种能够有效利用 4ANS 作为唯一碳源和能源、氮和硫的微生物共生物种。分离并鉴定了构成共生物种的细菌菌株。它们属于以下属：芽孢杆菌、节杆菌、微杆菌、诺卡氏菌和食油菌。与碳限制相比，该共生物种在氮限制下，4ANS 的去除效率 η(ANS) 和 4ANS 容积去除率 R(V,4ANS) 显著提高。改变营养限制后生物反应器性能的差异可能是由生物膜性质和结构的变化引起的。
