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Sci Total Environ ; 792: 148363, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34465051


The alpine meadow in the Qinghai-Tibet Plateau has been seriously degraded due to human activities and climate change in recent decades. Understanding the changes of the soil microbial community in response to the degradation process helps reveal the mechanism underlying the degradation process of alpine meadows. We surveyed and analyzed changes of the vegetation, soil physicochemical properties, and soil microbial community in three degradation levels, namely, non-degradation (ND), moderate degradation (MD), and severe degradation (SD), of the alpine meadows in the northeastern Qinghai-Tibet Plateau. We found that as the level of degradation increased, plant cover, plant density (PD), above-ground biomass (AGB), plant Shannon-Wiener index (PS), soil water content (SWC), soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) decreased significantly, while the soil pH increased from 7.20 to 8.57. Alpine meadow degradation significantly changed the composition of soil bacterial and fungal communities but had no significant impact on the diversity of the microbial communities. Functional predictions indicated that meadow degradation increased the relative abundances of aerobic_chemoheterotrophy, undefined_saprotroph, and plant_pathogen, likely increasing the risk of plant diseases. Redundancy analysis revealed that in ND, the soil microbial community was mainly regulated by PS, PH, PD, SWC, and soil pH. In MD, the soil microbial community was regulated by the soil's available nutrients and SOC. In SD, the soil microbial community was not only regulated by the soil's available nutrients but also influenced by plant characteristics. These results indicate that during alpine meadow degradation, while the changes in the plants and soil environmental factors both affect the composition of the soil microbial community, the influence of soil factors is greater. The soil's available nutrients are the main driving factors regulating the change in the soil microbial community's composition alongside degradation levels.

Microbiota , Solo , Carbono/análise , Pradaria , Humanos , Nutrientes , Microbiologia do Solo , Tibet
J Hazard Mater ; 389: 121834, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-31843407


Environmental problems caused by the large-scale use of chemical pesticides are becoming more and more serious, and the removal of chemical pesticides from the ecological environment by microbial degradation has attracted wide attention. In this study, using enrichment screening with seven chemical pesticides as the sole carbon source, a mixed microbial culture (PCS-1) was obtained from the continuous cropping of strawberry fields. The microbial community composition, degradation ability, and detoxification effect of PCS-1 was determined for the seven pesticides. Inoculation with PCS-1 showed significant degradation of and tolerance to the seven pesticides. Microbial community composition analysis indicated that Pseudomonas, Enterobacter, Aspergillus, and Rhodotorula were the dominant genera for the degradation of the seven pesticides by PCS-1. The concentration of the seven pesticides was 10 mg L-1 in hydroponic and soil culture experiments. The fresh weight, plant height, and root length of PCS-1-inoculated alfalfa (Medicago sativa) significantly increased compared with those of non-PCS-1-inoculated M. sativa. PCS-1 not only effectively degraded the residual content of the seven pesticides in water and soil but also reduced the pesticide residues in the roots, stems, and leaves of M. sativa. This study shows that PCS-1 may be important in environmental remediation involving the seven pesticides.

Poluentes Ambientais/análise , Medicago sativa/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Praguicidas/análise , Microbiologia do Solo , Poluentes do Solo/análise , Aspergillus/efeitos dos fármacos , Aspergillus/crescimento & desenvolvimento , Biodegradação Ambiental , Enterobacter/efeitos dos fármacos , Enterobacter/crescimento & desenvolvimento , Poluentes Ambientais/toxicidade , Medicago sativa/crescimento & desenvolvimento , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/toxicidade , Praguicidas/toxicidade , Pseudomonas/efeitos dos fármacos , Pseudomonas/crescimento & desenvolvimento , Rhodotorula/efeitos dos fármacos , Rhodotorula/crescimento & desenvolvimento , Poluentes do Solo/toxicidade