Project description:The spread of antibiotic resistance genes (ARG) into agricultural soils, products, and foods severely limits the use of organic fertilizers in agriculture. In this study, experimental land plots were fertilized, sown, and harvested for two consecutive agricultural cycles using either mineral or three types of organic fertilizers: sewage sludge, pig slurry, or composted organic fraction of municipal solid waste. The analysis of the relative abundances of more than 200,000 ASV (Amplicon Sequence Variants) allowed the identification of a small, but significant (<10%) overlap between soil and fertilizer microbiomes, particularly in soils sampled the same day of the harvest (post-harvest soils). Loads of clinically relevant ARG were significantly higher (up to 100 fold) in fertilized soils relative to the initial soil. The highest increases corresponded to post-harvest soils treated with organic fertilizers, and they correlated with the extend of the contribution of fertilizers to the soil microbiome. Edible products (lettuce and radish) showed low, but measurable loads of ARG (sul1 for lettuces and radish, tetM for lettuces). These loads were minimal in mineral fertilized soils, and strongly dependent on the type of fertilizer. We concluded that at least part of the observed increase on ARG loads in soils and foodstuffs were actual contributions from the fertilizer microbiomes. Thus, we propose that adequate waste management and good pharmacological and veterinarian practices may significantly reduce the potential health risk posed by the presence of ARG in agricultural soils and plant products.
Project description:Land cover change has long been recognized that marked effect the amount of soil organic carbon. However, little is known about microbial-mediated effect processes and mechanism on soil organic carbon. In this study, the soil samples in a degenerated succession from alpine meadow to alpine steppe meadow in Qinghai-Tibetan Plateau degenerated, were analyzed by using GeoChip functional gene arrays.
Project description:Fungal necromass in soil represents the stable carbon pools. While fungi are known to decompose fungal necromass, how fungi decomopose melanin, remains poorly understood. Recently, Trichoderma species was found to be one of the most commonly associated fungi in soil, we have used a relevant fungal species, Trichoderma reesei, to characterized Genes involved in the decomposition of melanized and non-melanized necromass from Hyaloscypha bicolor.
Project description:In order to get insights into the ability of ectomycorrhizal fungi to perceive their biotic environment as well as into the mechanisms of the interactions between ectomycorrhizal fungi and soil bacteria, we analysed the transcriptomic response of the ectomycorrhizal fungus L. bicolor and of two beneficial, and neutral soil bacteria during their interactions in vitro.
