Hadal trenches extend below 6000 m water depth. The high hydrostatic pressures occurring in the trenches (>60 MPa) create unfriendly for life conditions. Here, we isolated 55 fungal strains from hadal (>6000 m) and non-hadal (∼3500 m and 5500 m) sediments from the Mariana Trench using different pressure incubation experiments. The fungal strains that were successfully isolated, were assigned to Ascomycota (14 genera/25 species) and Basidiomycota taxa (5 genera/5 species). Among them, 41 fungal strains (38 isolates from Ascomycota and 3 isolates from Basidiomycota) were able to grow at hydrostatic pressures of 20 MPa, while 3 of these strains maintained successful growth at 60 MPa, which resembles the hydrostatic pressure at 6000 m water depth. Whole-genome sequencing and physiological activity data from two fungal isolates ( Penicillium bialowiezense A30 and Cladosporium colombiae 601) growing at 20 MPa highlight the metabolic potential of fungal piezotolerants from the Mariana Trench in carbon (e.g., carbohydrate metabolism), nitrogen (e.g., assimilatory nitrate reduction) and sulfur (e.g., assimilatory sulfate reduction) cycling. Overall, our study demonstrates the existence of piezotolerant fungi from the Mariana Trench that can grow successfully under hydrostatic pressures of 20–60 MPa and highlights their potential ecological and metabolic functions in deep sea and hadal trench ecosystems.
Qian Liu,Wanqiu Jing,Wansheng Yang,Min Huang,Ping Lu,Deyu Hu
Microorganisms play important roles in the remediation of contaminated soil. However, the relationship between the soil microbial communities and herbicide degradation remains unclear after applying green manure. The aim of this study was to investigate the effect of green manure on soil physicochemical properties, between acetochlor degradation and microbial communities. Adoption of pot experiments, the effects and mechanism of four fertilization treatments (CK: without green manure; GMV: Vicia villosa Roth; GML: Lolium perenne L.; GMR: Raphanus stativus L.) on the degradation of acetochlor were evaluated. Appling to Raphanus stativus L., acetochlor degraded in 5.82 days, which was 74.81 % higher than that of CK. Community differences in soil microbes were analysed using high-throughput sequencing. The predominant phyla of fungi were Ascomyocta , Mortierellomycota , Basidiomycota , unclassified_k_Fungi, and Chytridiomycota , which accounted for 85.01 %–116.46 % of the fungal OTUs. The green manure treatment showed higher abundance of Mortierella (9.54 %–13.05 %), diversity of saprotrophic fungi and symbiotic fungi and faster rate of degradation of acetochlor as compared to CK. In addition, soil properties such as soil total phosphorus (TP) and pH have significant effects on microorganisms. Fungal functional analysis revealed that the microorganisms associated with acetochlor biodegradation mainly belonged to Ascomycota and Glomeromycota . This study offers new insights into the relationship between soil properties and the environmental risks associated with the presence of pesticides in soil and the related mechanisms.
Shuangshuang Li,Xin Jiang,Chi Zhao,Yuan Ren,Lixin Luo
Biosurfactants combined with bioaugmentation for the remediation of petroleum hydrocarbon-contaminated soils proved to be one of the most effective ways. However, research on lipopeptides combined with bioaugmentation is rare, and the biological mechanisms are undefined. Therefore, the effect of Raoultella planticola and the lipopeptides it produces to restore contaminated soils was investigated using n-hexadecane as a model of petroleum hydrocarbons. After 60 d, n-hexadecane removal rate increased from 31.3% in contaminated soil to 39.9% with R. planticola alone and 59.0% with R. planticola together with 1.0 g intracellular lipopeptide (INLS) and 7.5 g sodium gluconate (SG)/kg dry soil. Meanwhile, the nitrogen and phosphorus components of the soil increased by 13.9% and 8% in the experimental group, respectively. Besides, DHA activity was 6.7 times that of the control group at 28 d, indicating a considerable increase in DHA activity. Microbial community analysis revealed a considerable increase in functional genera of Sphingomonas , Nocardia , Pseudoalteromonas , Povalibacter , Apiotrichum , Pseudallecheria , and Ascodesmis . The amount of fungus in the experimental group was more than 30 times that of the control group after 60 d. Microbial co-occurrence networks showed improved interactions of Firmicutes and Ascomycota, encouraging synergistic cooperation among microbes and thereby accelerating n-hexadecane breakdown. At once, the metabolic pathways ko00071 and ko00980 for n-hexadecane degradation were greatly elevated, indicating that functional genes such as alkane 1-monooxygenase and NADPH-cytochrome P450 reductase were activated. These results implied that combining hydrocarbon-degrading microbial with INLS was a promising bioremediation technique to remove soil petroleum hydrocarbons.
危险品化学品经营许可证（带存储）