中文摘要：

以我国6个省的水稻土为供试样品,采用厌氧恒温培养方法,研究了分别以葡萄糖、丙酮酸盐、乳酸盐和乙酸盐为惟一碳源时不同淹水时间土壤微生物群落对Fe（Ⅲ）的还原能力.结果表明：不同淹水时间对Fe（Ⅲ）还原特征值Vmax的影响显著,表现为淹水20d〉30d〉12d〉1d〉5d,不同淹水时间下水稻土微生物群落结构不同是导致Fe（Ⅲ）还原能力不同的主要原因.不同碳源对微生物铁还原过程有显著影响,葡萄糖和丙酮酸盐在不同淹水时间中始终为优势碳源,其Fe（Ⅲ）还原率分别为88.1%～99.9%和58.0%～97.9%;不同土壤铁还原微生物群落对乳酸盐的利用差距较大,湖南和浙江水稻土在整个淹水周期中Fe（Ⅲ）还原率达到87.1%～100%,而其他土壤则表现为淹水前5d为5.0%～49.4%,12d后增加到52.2%～99.9%;乙酸盐处理在不同淹水时间中都表现为随时间推移Fe（Ⅲ）还原率逐渐增大的趋势,其中浙江水稻土的变化最大,在5.3%～75.8%.

英文摘要：

Paddy soil samples were collected from six provinces of China,and an anaerobic incubation test was conducted to examine the microbial Fe（ Ⅲ） reduction potential under the conditions of different flooding time and with glucose,pyruvate,lactate,or acetate as the sole carbon source. The results showed that flooding time had significant effects on the eigenvalue of Fe（ Ⅲ） reduction, Vmax,with the order of 20 d 30 d 12 d 1 d 5 d,which suggested that the difference in the microbial community structure in different flooding periods was the main reason inducing the different potential of Fe（ Ⅲ） reduction. In all test flooding periods,glucose and pyruvate were the su- perior carbon sources,with the Fe （ Ⅲ） reduction rate being 88. 1% - 99. 9% and 58. 0% - 97. 9% ,respectively. When lactate was amended,the Fe（ Ⅲ） reduction rate varied greatly among different paddy soils. For the paddy soils from Hunan and Zhejiang,the Fe（ Ⅲ） reduction rate during flooding period could reach 87. 1% - 100% ; while for other soils,it was 5. 0% - 49. 4% in the first 5 days of flooding and 52. 2% - 99. 9% in 12 days after flooding. When acetate was used as a carbon source,the Fe（ Ⅲ） reduction rate increased with flooding time. Especially in the paddy soil from Zhejiang,the Fe（ Ⅲ） reduction rate changed greatly from 5. 3% to 75. 8% .