Jia Tong, Liang Xiaoxia, Guo Tingyan, Chai Baofeng
Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China.
Microorganisms. 2021 Oct 28;9(11):2250. doi: 10.3390/microorganisms9112250.
In nature, protists directly participate in litter decomposition and indirectly affect litter decomposition processes by means of their influence on litter microbial communities. To date, relevant studies on litter microbial communities have primarily focused on bacteria and fungi, while relatively little attention has been paid to the characteristics of protozoan communities within damaged ecosystems. Two dominant grass species ( and ) were selected from China's "Eighteenth" River tailings dam to explore protozoan community composition and diversity in a degraded mining area and to clarify the influence among key ecological factors and protozoan community characteristics in litter. High-throughput sequencing was used to analyze protozoan community composition and diversity, while correlation analysis was used to explore the relationships between protozoan communities and litter nutrient characteristics, including associative enzyme degradation. Although protozoan communities in litter shared a dominant group at an order level (Colpodida), they differed at a genus level (i.e., and ). Moreover, although the order Cryomonadida positively correlated to total nitrogen (TN) and sucrose, it exhibited an extreme negative correlation to total carbon (TC) and cellulase. Colpodida and Oomycota_X significantly and negatively correlated to litter urease activity. Nutrient characteristics of grass litter in copper tailing dams are important ecological factors that affect protozoan community characteristics. Notable differences were observed among protozoan communities of these two grass species, while litter enzyme activities were closely correlated to protozoan community diversity. The results suggested that Colpodida may play important roles in litter decomposition and nutrient cycling in mining areas.
在自然界中，原生生物直接参与凋落物分解，并通过影响凋落物微生物群落间接影响凋落物分解过程。迄今为止，关于凋落物微生物群落的相关研究主要集中在细菌和真菌上，而受损生态系统中原生动物群落的特征相对较少受到关注。从中国“十八河”尾矿库中选取两种优势草种（ 和 ），以探究退化矿区原生动物群落组成和多样性，并阐明凋落物中关键生态因子与原生动物群落特征之间的影响。采用高通量测序分析原生动物群落组成和多样性，同时采用相关性分析探究原生动物群落与凋落物养分特征（包括相关酶降解）之间的关系。虽然凋落物中的原生动物群落在目水平上有一个优势类群（肾形目），但在属水平上存在差异（即 和 ）。此外，虽然隐滴虫目与总氮（TN）和蔗糖呈正相关，但与总碳（TC）和纤维素酶呈极显著负相关。肾形目和卵菌纲_X与凋落物脲酶活性呈显著负相关。铜尾矿库中草本凋落物的养分特征是影响原生动物群落特征的重要生态因子。这两种草种的原生动物群落之间存在显著差异，而凋落物酶活性与原生动物群落多样性密切相关。结果表明，肾形目可能在矿区凋落物分解和养分循环中发挥重要作用。
