Anaerobic digestion (AD) offers great potential for pollutant removal and bioenergy recovery. However, it faces challenges when using livestock manure…

The turnover of dissolved organic matter (DOM) in soil regulated by biodegradable microplastics (MPs) has garnered much attention due to its profound impact on the storage and stability of soil organic matter. However, the transformation and reactivity of plant-derived and microbially derived DOM by microorganisms adapted to biodegradable MPs, and the involved microbial physiological processes, remain nearly unknown. Here, we added virgin and aged polylactic acid (PLA) and polyhydroxyalkanoate (PHA) to agricultural soils and incubated for 56 days. Using stable isotope techniques, reactomics, and metagenomics, we found that the addition of both virgin and aged PLA induced hydroxylation, demethylation, and dehydrogenation of lignin-derived DOM, resulting in a 3-fold increase in their oxidation degree. PLA activated the enzymatic pathway for lignin-derived DOM decomposition and downregulated genes involved in bacterial anabolism, such as those related to protein, amino sugar, and peptidoglycan biosynthesis. In contrast, PHA increased the content of microbially derived DOM compounds such as proteins and amino sugars by 2.1-fold relative to the control with peptide chain elongation. PHA resulted in the degradation of lignin-derived DOM into pyruvate and acetyl-CoA, accelerated bacterial ATP synthesis, the de novo biosynthesis of proteins and peptidoglycan, and cell renewal and death, thereby increasing PHA- and soil organic matter-derived microbial necromass carbon. Our study provides new insights into the impact of biodegradable MPs on soil DOM transformation and underscores the importance of the microbial physiological processes involved.

The biological age of individual cell types can be evaluated using plasma proteomics, revealing diverse aging profiles across more than 40 cell types and links between the accelerated aging of specifi...

This study investigated molecular humification mechanisms of dissolved organic matter during maize straw composting enhanced by humus soil biomaterial using paired-molecule mass difference reactomics analysis and high-throughput sequencing. Results indicated that the composting process predominantly involved three molecular humification pathways, namely, the phenol–protein reaction, polyphenol self-condensation, and Maillard reaction, with N-containing molecules showing the highest reactivity. Proteins were hydrolyzed into N-containing intermediates in the initial composting stage, which rapidly polymerized with phenol from humus soil biomaterial to form humic acids, improving organic nitrogen retention. Lignin was decomposed and oxidized into phenolics and quinones mainly during the middle and later composting stages, which either self-condensed or polymerized with protein derivatives to assemble humic acids. Concurrently, some amino acids and monosaccharides underwent the Maillard reaction to produce humic acids. Furthermore, humus soil biomaterial introduced the genus Alicyclobacillus into the composting system, contributing to microbial community stability. This work provides valuable molecular insights into the maize straw composting humification process and promotes the sustainable utilization of agricultural waste in soil.

Paired mass distance (PMD) analysis proposed in Yu, Olkowicz and Pawliszyn (2018) &lt;<a href="https://doi.org/10.1016%2Fj.aca.2018.10.062" target="_top">doi:10.1016/j.aca.2018.10.062</a>&gt; and PMD based reactomics analysis proposed in Yu and Petrick (2020) &lt;<a href="https://doi.org/10.1038%2Fs42004-020-00403-z" target="_top">doi:10.1038/s42004-020-00403-z</a>&gt; for gas/liquid chromatography–mass spectrometry (GC/LC-MS) based non-targeted analysis. PMD analysis including GlobalStd algorithm and structure/reaction directed analysis. GlobalStd algorithm could found independent peaks in m/z-retention time profiles based on retention time hierarchical cluster analysis and frequency analysis of paired mass distances within retention time groups. Structure directed analysis could be used to find potential relationship among those independent peaks in different retention time groups based on frequency of paired mass distances. Reactomics analysis could also be performed to build PMD network, assign sources and make biomarker reaction discovery. GUIs for PMD analysis is also included as 'shiny' applications.