• 研究报告 •

### 水分含量对紫色土自养微生物丰度与活性的影响

1. （西南大学资源环境学院， 重庆 400715）
• 出版日期:2020-02-10 发布日期:2020-02-10

### Effects of water content on the abundance and activity of autotrophic microbes in purple soil.

WEI Wan-ling, CHENG Yong-yi, ZHOU Zhi-feng, WANG Ming-xia*

1. (College of Resources and Environment, Southwest University, Chongqing 400715, China).
• Online:2020-02-10 Published:2020-02-10

Abstract: With cbbL (ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large-subunit gene) and RubisCO (1,5-bisphosphate ribulose carboxylase) enzyme as markers, we investigated the effects of soil water content on the abundance and activity of soil autotrophic microbes in an indoor incubation experiment for 28 days. There were four treatments with different soil water contents (mass percentage of water to dry soil), including 10% (W10), 15% (W15), 25% (W25), and waterlogging (WL). Soil samples were harvested after 3, 7, 14, and 28 days of incubation, with soil organic carbon content, cbbL abundance, and RubisCO enzyme activity being measured. The results showed that soil cbbL abundance increased with increasing soil water content during the first 14 days. WL treatment had the highest cbbL abundance during the whole period of incubation. At the initial stage of incubation (day 3), there was no significant difference of soil RubisCO enzyme activity among these treatments (P<0.05). At the end of incubation (day 28), however, RubisCO enzyme activity in the treatments with lower water content (W10 and W15) was significantly lower than that in the treatments with higher water content (W25 and WL; P<0.05). Soil organic carbon content (F=11.91,P=0.03), cbbL abundance (F=42.33,P<0.01), and RubisCO enzyme activity (F=51.55,P<0.01) significantly varied among different treatments. Soil cbbL abundance and RubisCO enzyme activity were positively correlated (R2=0.23,P<0.01), and both of them were negatively correlated with soil organic carbon content. Our results indicated that soil water content played an important role in controlling the abundance and activity of soil autotrophic microbes, which should be valuable for further mechanistic understanding of responses of soil carbon transformation to soil moisture variation.