土壤微生物燃料电池电极微生物分析及其运行对水稻生长活性的影响

Analysis of electrode bacteria of soil microbial fuel cell(MFC)and the effects of its operation on rice growth activities

采用盆栽水稻试验,研究微生物燃料电池电极富集微生物种类及其运行对水稻生长活性的影响。用双层琼脂平板法对阳、阴极碳毡微生物进行培养,通过平板计数法计算碳毡富集微生物数量。通过细菌个体形态、生理生化试验及16Sr DNA分析确定其分类地位;用称重、α-萘胺氧化法研究微生物燃料电池运行(闭路组)对水稻生长活性的影响。成功构建微生物燃料电池。闭路组阳极细菌B1、B2和B3总量是3.4×10^(8)CFU·g^(-1),其中优势微生物B1为2.9×10^(8)CFU·g^(-1)。开路组(组装有微生物燃料电池,但处于断路状态)阳极细菌B1、B3和B4总量是1.5×10^(8)CFU·g^(-1),其中优势微生物B3为1.1×10^(8)CFU·g^(-1),闭路组与开路组阴极都只培养出B3和B4,闭路组阴极B4数量是开路组的7倍;闭路组与空白组(未组装有微生物燃料电池)、开路组相比,在水稻须根数方面无显著差异,但在植株鲜重、干重及根系活力方面存在明显差异。在所有分析指标中,空白组和开路组间无明显差异。微生物燃料电池(MFC)运行能促进水稻的生长和产电微生物B1(Bacillus subtilis)和B2(Bacillus sp.)在阳极碳毡的富集。

The enriched bacterial genus on the electrodes of MFC and the effects of MFC operation on rice growth activities were investigated in the present study with pot experiments.The bacteria of the carbon felt on the cathodes and anodes were cultured with a two-layer agar plate and counted according to the number of viable colonies on plates.The bacteria were identified based on the characteristics of cell morphology,the results of physiological and biochemical tests and the analysis of 16 S rDNA sequence.The effects of MFC(closed circuit group)operation on the growth activities of rice were investigated with weighting andα-naphthylamine oxidation methods.MFC was successfully constructed in this experiment.The results showed that the total quantity of B1,B2 and B3 existing in the carbon felts of the anode in closed circuit group was 3.4×10^(8)CFU·g^(-1),especially the dominant strain B1 was 2.9×10^(8)CFU·g^(-1).While the whole quantity of B1,B3 and B4 living in the carbon felts of the anode in open circuit group was 1.5×10^(8)CFU·g^(-1),and the dominant strain B3 was 1.1×10^(8)CFU·g^(-1).Only culturable B3 and B4 appeared in the cathodes of the closed and open circuit group,and the quantity of B4 in the closed circuit group was seven times as that in open circuit group.Compared with open circuit and blank groups,no significant differences existed on the number of fibrous roots for closed circuit group,but the striking differences in fresh and dry weight and root activities.There were no obvious differences among all the items assayed in this experiment for open circuit and blank groups.MFC operation could promote the growth of rice and the enrichment of electrogenic microorganisms B1(Bacillus subtilis)and B2(Bacillus sp.)on carbon felts of the anode in the closed circuit group.