Yu Lei, Cao Ming-Yue, Wang Peng-Tao, Wang Shi, Yue Ying-Rong, Yuan Wen-Duo, Qiao Wei-Chuan, Wang Fei, Song Xin
Department of Environmental Engineering, Nanjing Forestry University, Nanjing, China
Jiangsu Key Laboratory of Biomass Energy and Materials, Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry, Nanjing, China.
Appl Environ Microbiol. 2017 May 1;83(10). doi: 10.1128/AEM.00508-17. Print 2017 May 15.
Biohydrogen production from the pulp and paper effluent containing rich lignocellulosic material could be achieved by the fermentation process. Xylose, an important hemicellulose hydrolysis product, is used less efficiently as a substrate for biohydrogen production. Moreover, azo dyes are usually added to fabricate anticounterfeiting paper, which further increases the complexity of wastewater. This study reports that xylose could serve as the sole carbon source for a pure culture of GS-4-08 to achieve simultaneous decolorization and biohydrogen production. With 2 g liter of xylose as the substrate, a maximum xylose utilization rate (UR) and a hydrogen molar yield (HMY) of 93.99% and 0.259 mol of H mol of xylose, respectively, were obtained. Biohydrogen kinetics and electron equivalent ( equiv) balance calculations indicated that methyl red (MR) penetrates and intracellularly inhibits both the pentose phosphate pathway and pyruvate fermentation pathway, while methyl orange (MO) acted independently of the glycolysis and biohydrogen pathway. The data demonstrate that biohydrogen pathways in the presence of azo dyes with sulfonate and carboxyl groups were different, but the azo dyes could be completely reduced during the biohydrogen production period in the presence of MO or MR. The feasibility of hydrogen production from industrial pulp and paper effluent by the strain if the xylose is sufficient was also proved and was not affected by toxic substances which usually exist in such wastewater, except for chlorophenol. This study offers a promising energy-recycling strategy for treating pulp and paper wastewaters, especially for those containing azo dyes. The pulp and paper industry is a major industry in many developing countries, and the global market of pulp and paper wastewater treatment is expected to increase by 60% between 2012 and 2020. Such wastewater contains large amounts of refractory contaminants, such as lignin, whose reclamation is considered economically crucial and environmentally friendly. Furthermore, azo dyes are usually added in order to fabricate anticounterfeiting paper, which further increases the complexity of the pulp and paper wastewater. This work may offer a better understanding of biohydrogen production from xylose in the presence of azo dyes and provide a promising energy-recycling method for treating pulp and paper wastewater, especially for those containing azo dyes.
利用富含木质纤维素材料的制浆造纸废水通过发酵过程来生产生物氢是可行的。木糖是一种重要的半纤维素水解产物，作为生物氢生产的底物时利用效率较低。此外，偶氮染料通常被添加用于制造防伪纸张，这进一步增加了废水的复杂性。本研究报道木糖可以作为GS - 4 - 08纯培养物的唯一碳源，以实现同步脱色和生物氢生产。以2 g/L的木糖作为底物时，木糖最大利用率（UR）和氢气摩尔产率（HMY）分别达到93.99%和0.259 mol H/mol木糖。生物氢动力学和电子当量（equiv）平衡计算表明，甲基红（MR）渗透并在细胞内抑制磷酸戊糖途径和丙酮酸发酵途径，而甲基橙（MO）独立于糖酵解和生物氢途径起作用。数据表明，含有磺酸基和羧基的偶氮染料存在时生物氢途径不同，但在MO或MR存在下生物氢生产期间偶氮染料可被完全还原。如果木糖充足，该菌株从工业制浆造纸废水生产氢气的可行性也得到了证明，并且不受此类废水中通常存在的有毒物质（除氯酚外）的影响。本研究为处理制浆造纸废水，特别是含偶氮染料的废水提供了一种有前景的能量回收策略。制浆造纸工业是许多发展中国家的主要产业，预计2012年至2020年间全球制浆造纸废水处理市场将增长60%。此类废水含有大量难降解污染物，如木质素，其回收在经济上至关重要且环境友好。此外，通常添加偶氮染料以制造防伪纸张，这进一步增加了制浆造纸废水的复杂性。这项工作可能有助于更好地理解在偶氮染料存在下木糖生产生物氢的过程，并为处理制浆造纸废水，特别是含偶氮染料的废水提供一种有前景的能量回收方法。
