Microbial survival strategies in biological soil crusts of polymetallic tailing wetlands
Zekai Feng,
Guobao Wang,
Yuanyuan Jiang,
Chiyu Chen,
Daijie Chen,
Mengyao Li,
Jean Louis Morel,
Hang Yu,
Yuanqing Chao,
Yetao Tang,
Rongliang Qiu,
Shizhong Wang
Affiliations
Zekai Feng
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Guobao Wang
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Corresponding authors at: Sun Yat-Sen University, No. 132 Outer Ring East Road, Panyu District, Guangzhou 510006, China.
Yuanyuan Jiang
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Chiyu Chen
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Daijie Chen
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Mengyao Li
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Jean Louis Morel
Laboratoire Sols et Environnement, UMR 1120, Université de Lorraine, INRAE, Vandoeuvre-lès-Nancy 54518, France
Hang Yu
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China
Yuanqing Chao
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
Yetao Tang
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China
Rongliang Qiu
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Agricultural & Rural Pollution Abatement and Environmental Safety, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, China
Shizhong Wang
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510006, China; Guangdong Provincial Key Laboratory for Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou 510006, China; Corresponding authors at: Sun Yat-Sen University, No. 132 Outer Ring East Road, Panyu District, Guangzhou 510006, China.
The role of biological soil crusts (biocrusts) in ecological restoration is dominated by microbiota. This has been extensively studied in arid ecosystems characterized by nutrient deficiencies and poor soil substrates, including metal(loid)-rich mining regions. However, in the prior study areas, water constraints obscured the toxicity and restriction of succession by heavy metals, which were essential for soil remediation in mining regions using biocrusts. Accordingly, in the current study, we characterized biocrusts from a typical polymetallic tailing wetland and performed pot incubation to evaluate microbial community succession and microbial co-occurrence patterns. Results showed that adequate water and heavy-metal stress produced thicker and more hydrophobic biocrusts than did arid conditions, promoting stronger microbial activity in tailing wetlands. Moreover, the bioinformatic analyses during pot incubation suggest three potential survival strategies. (1) Cyanobacteria variation improved the succession level of cyanobacterial crusts. Even under heavy-metal stress, succession from light to dark cyanobacterial crusts still occurred, with Coleofasciculaceae decreasing 63% and Scytonema increasing 59% compared with the control groups. (2) Keystone taxa variation maintained high inorganic nitrogen turnover. Organisms potentially capable of inorganic nitrogen turnover, including Chloroflexi A4b and SBR1031, maintained a high relative abundance accounting for 42% (15/36) of the keystone taxa. (3) Variations in the interactions among microbiota created closer-knit microbial networks. Compared with the control groups, fewer nodes (15.2%) maintained higher average clustering coefficient values (1.8%) through 14% more positive interactions in the groups exposed to heavy-metal stress at the end of the incubation experiment. This study provides insights into the distinctive survival strategies of biocrusts in metal-rich extreme environments, offering theoretical support for biocrust-mediated ecological restoration in humid metal-contaminated regions.
