Shifts of the nirS and nirK denitrifiers in different land use types and seasons in the Sanjiang Plain, China

Abstract

Denitrification is a key nitrogen removal process that involves many denitrifying bacteria. In this study, the denitrification performance was estimated for soil samples from different land use types including farmland soil, restored wetland soil, and wetland soil. The quantitative real-time polymerase chain reaction results showed that the average abundance of nirS and nirK genes was notably affected by seasonal changes, increasing from 2.34 × 10 6 and 2.81 × 10 6 to 1.97 × 10 6 and 4.55 × 10 6 gene copies/g of dry soil, respectively, from autumn to spring. This suggests that the abundance of nirS and nirK denitrifiers in spring is higher than those in autumn. Furthermore, the abundance of nirS and nirK genes was higher in the farmland soil than in restored wetland soil and wetland soil in both seasons. According to the analyses of MiSeq sequencing of nirS and nirK genes, Halobacteriaceae could be used as a special strain to distinguish wetland soil from farmland soil and restored wetland soil. Furthermore, redundancy analysis indicated that the soil environmental variables of total carbon, total nitrogen, moisture content, and organic matter were the main factors affecting the community structures of nirS and nirK denitrifiers existing in wetland soil. These findings could contribute to understanding the differences in nirS and nirK denitrifiers between different land use types during seasonal changes. K E Y W O R D Sdenitrification, denitrifying bacteria, nirK, nirS, wetland

Driving Factors of Microbial Community Abundance and Structure in Typical Forest Soils of Sanjiang Plain, Northeast China

“…DNA was extracted by the OMEGA-soil DNA kit [24]. DNA concentration was measured by a NanoDrop 2000 UV-vis spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA).…”

“…DNA concentration was measured by a NanoDrop 2000 UV-vis spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA). The extracted DNA was purified with a DNeasy Tissue kit (Qiagen, Valencia, CA, USA) and then checked for qPCR and Illumina high-throughput sequencing [24].…”

“…[19,21]. Previous studies mainly concentrated on the discussion of microorganisms in the wetland soil and cultivated soil of Sanjiang Plain [22][23][24][25][26]. However, the key factors driving the community abundance and structure in the typical forest soils in Sanjiang Plain have not yet been well documented.…”

Soil physicochemical properties drive the variation in soil microbial communities along a forest successional series in a degraded wetland in northeastern China

“…Wetlands, accounting for 5%–8% of the Earth's surface, play a key role in regulating global greenhouse gases and act as carbon sinks (Liu, Zheng, et al., 2014; Taufik et al., 2015; Zheng et al., 2013; Wang et al, 2019). The Sanjiang Plain in northeastern China covers a region with 10.89 million hectares and features the biggest freshwater wetland with in China.…”

“…Soil microorganisms are important constituents of ecosystems and are essential for plant material decomposition (Gryta et al., 2014; Xiong et al., 2016; Wang et al, 2019) and help maintain stability of the ecosystem (Mania et al., 2014; Yin et al., 2014; Liu et al, 2019). Hence, the examination of soil microbes is critical for understanding local biogeochemical processes, emissions of greenhouse gases from soils, and degradation of pollutants (Dan et al., 2014; Song et al., 2013).…”