Trichoderma viride F7 improves peanut performances while remediating cadmium-contaminated soil with microplastics

Microplastics(MPs)and cadmium(Cd)in soil have serious negative impacts on plant growth.As a bioremediator,Trichoderma viride may modulate the impacts of MPs and/or Cd on plant growth and heavy metal uptake.In this study,T.viride F7 was used to treat Cd-contaminated soil with and without the presence of polylactic acid MPs to investigate its effects on peanut growth,Cd uptake efficiency,and soil properties.Results showed that F7 increased soil pH,dissolved organic carbon,cation exchange capacity,microbial biomass nitrogen,and microbial biomass carbon,which resulted in increases of 2.10%-19.83%in peanut biomass and mitigated the negative effects of MPs and Cd on peanut growth.Trichoderma viride F7 reduced the soil bioavailable Cd and plant Cd concentrations by 16.68%-34.20%and 5.37%-25.84%,respectively.Regression path analysis showed that F7 could improve peanut performances by altering soil properties and reducing peanut Cd concentrations in MP-Cd-contaminated soil.Soil fungal community analysis indicated that the microbial community was altered via F7 inoculation,which antagonized Fusarium and promoted peanut growth.This study reveals the mechanisms of F7 in mitigating Cd contamination in the soil with the presence of MPs,which provides new ideas for managing MP-heavy metal-contaminated soil and improving soil health.

Effects of nitrogen and phosphorus concentrations on the bioaccumulation of polybrominated diphenyl ethers by Prorocentrum donghaiense

The growth, cellular total lipids, bioaccumulation amount, and bioaccumulation factors （BAFs） of 2,4,4 ′ -tribromodiphenyl ether （BDE28）, 2,2 ′ ,4,4 ′ -tetrabromodiphenyl ether （BDE47）, and 2,2 ′ ,4,4 ′ ,5-pentabromodiphenyl ether （BDE99） in a semi-continuous culture of Prorocentrum donghaiense were studied in relation to nitrate （0, 128, and 512 μmol/L） and phosphate （0, 8, and 32 μmol/L） concentrations. The BDE28, BDE47, and BDE99 content per cell under 0 μmol N/L were 3.77 × 10 6 , 3.95 × 10 6 , and 4.32 × 10 6 ng/cell, respectively, which were significantly higher than those under 128 and 512 μmol N/L. A nearly 5-fold increase in polybrominated diphenyl ether （PBDE） content per algal cell was found between 0 and 8 μmol P/L and between 8 and 32 μmol P/L. With increasing N and P concentrations, the PBDE content per volume of algal culture and the accumulation percentage of available PBDEs declined slightly. The BAFs for the PBDEs based on lipids showed that the logBAF lip under 0 μmol N/L was higher than those under 128 and 512 μmol N/L. The logBAF lip under 0 μmol P/L was higher than that under 8 μmol P/L but lower than that under 32 μmol P/L. Correlation analysis indicated a significant negative correlation between nutrient concentration and cellular total lipids, as well as the PBDE content per cell. The results indicate that different N and P concentrations change the total lipids content of P. donghaiense, thereby resulting in varying PBDE accumulation.