Effect of the cellulose as the electron donor on the Fe (III) reduction.

【Objective】 In order to ascertain the utilization character of cellulose by the iron-reducing microbial from different sources,the experiment was done to find out the difference of cellulose usage by microbial communities from different paddy soils and the relationship between the concentration of electron donor and iron reduction.【Method】 The paddy soils were used as test materials from Jilin,Tianjin and Sichuan.The effect of the cellulose as an electronic donor on the iron oxides reduction process was studied with the methods of slurries incubation,paddy soil microbial community anaerobic culture and pure culture.【Result】 The results show that,compared to control,the biggest Fe(Ⅲ) reduction potential in paddy soil from Sichuan,Jilin and Tianjin was enhanced separately by 10.5%-16.0%,-1.9%-0.6% and 5.3%-14.4% when 5-40 g/L cellulose was added;The rate constant respectively increased by 19%-89%,53%-96% and 75%-164% and the biggest rate increased by 37%-109%,41%-79% and 74%-148% respectively.pH was significantly different in different cellulose treatments.In the experiment of inoculating microbial community from Jilin,Tianjin,Sichuan and Hunan paddy soils,Fe(Ⅱ) of accumulated changes were separately 341.62-493.87,90.75-246.78,164.02-540.16 and 235.47-488.75 mg/L when the concentration of cellulose added was 2-10 g/L.With the increasing concentration of cellulose added,Vmax increased.In pure culture of 12 bacteria of iron reduction,four Fe(Ⅲ) reduction rate was 20.9%-23.6%,six the 16.17%-19.94%,two only 9.64% and 9.66%.【Conclusion】 The max-rate of Fe(Ⅲ) reduction increased with the added cellulose,so did the rate constant.The extent increased with the concentration of the added cellulose.There was significant difference between the iron-reduction ability of the microbial communities using cellulose.Compared with the process of iron-reduction of inoculating different paddy soil microbial communities,Fe(Ⅱ) cumulant was significantly low in pure culture experiment.The ability of the 12 iron-reduction microbial using cellulose was limited.