厌氧发酵产氢细菌的筛选及其产氢优化

Anaerobic Biohydrogen Production Bacteria Selection and Its Optimization of Biohydrogen Fermentation Process

摘要:

本研究以河底泥为来源, 使用产氢培养基进行初筛, 再利用小管产氢试验进行复筛, 得到5株产氢能力较好的菌株。对产氢量最高的菌株FML-C1进行16S rDNA序列分析, 鉴定为阴沟肠杆菌, 确定了其分类地位。培养基优化采用Plackett-Burman试验设计筛选出影响产氢的3个主要因素: 葡萄糖、缓冲液和还原剂。利用最陡爬坡路径逼近最大响应区, 采用中心复合试验设计(CCD)及响应面分析法(RSM)进行回归分析, 建立产氢培养基优化的二次模型。模型求解产氢最佳培养基为葡萄糖21.5 g/L、缓冲液 13.6 mL/L 和还原剂10.0 mL/L, 最大理论产氢量2367.83 mL/L。5批验证试验结果平均值与预测值接近, 表明该模型与实际情况拟合良好, 实际最大产氢量2347.40 mL/L, 较优化前产氢量提高127.42%。

Abstract:

This research adopted silt as the sample, and the five highest hydrogen production performing strains contained in the sample were isolated. The strain whose hydrogen production was the highest was identified as Enterobacter cloacae by the analysis of 16S rDNA sequencing and comparison. It is showed by Plackett-Burman Experimental Design that only glucose, citric buffer and reducing agent had significant effects on hydrogen production by Enterobacter cloacae FML-C1. The path of steepest ascent was undertaken to approach the optimal response region of those three factors. Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed to investigate the interaction of the variables and to ascertain the optimal values of the factors, which finally led to the maximum hydrogen production (VH2). The theoretical optimal medium conditions were: glucose 21.5 g/L, citric buffer 13.6 mL/L, reducing agent 10.0 mL/L. The five tentative tests matched this model well. The final VH2 was up to 2347.4 mL/L, which was 127.42% enhanced in comparison to the original. The result shows that PB experiment design and RSM analytical method work well in selecting factors which have significant influences on the hydrogen production and, moreover, achieve the ideal optimal result.