Project description:Inhibition of the anaerobic digestion process through accumulation of volatile fatty acids (VFA) is a recurring problem which is the result of unbalanced growth between acidogenic bacteria and methanogens. A speedy recovery is essential for an establishment of a feasible economical biogas productions. Yet, little is known regarding the organisms participating in the recovery. In this study the organisms involved in the recovery were studied using protein-stable isotope probing (Protein-SIP) and mapping this data onto a binned metagenome. Under acetate-accumulated simulating conditions a formation of 13C-labeled CO2 and CH4 was detected immediately after the addition of [U-13C]acetate, indicative of a high turnover rate of acetate. Several labeled peptides were detected in protein-SIP analysis. These 13C-labeled peptides were mapped onto a binned metagenome for improved taxanomical classification of the organisms involved. The results revealed that Methanosarcina and Methanoculleus were actively involved in acetate turnover, as were five subspecies of Clostridia and one Bacteroidetes. The organisms affiliating with Clostridia and Bacteroidetes all contained the FTFHS gene for formyltetrahydrofolate synthetase, a key enzyme for reductive acetogenesis; indicating that these organisms are possible syntrophic acetate-oxidizing bacteria (SAOB) that can facilitate acetate consumption via syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis (SAO-HM). This study represents the first study applying protein-SIP for analysis of complex biogas samples, a promising method for identifying key microorganisms involved in specific pathways.
Project description:Hepatopancreas transcriptome analyses provides new insights into the molecular regulatory mechanism of ovary maturation of Macrobrachium nipponense
| PRJNA830321 | ENA
Project description:Proteotranscriptomic Integration Analyses Reveals New Insights mechanism into the Bombyx mori fluorosis
Project description:Biogas plants (BGPs) produce methane and carbon dioxide through the anaerobic digestion of agricultural waste. Identification of strategies for more stable biogas plant operation and increased biogas yields require better knowledge about the individual degradation steps and the interactions within the microbial communities. The metaprotein profiles of ten agricultural BGPs and one laboratory reactor were investigated using a metaproteomics pipeline. Fractionation of samples using SDS-PAGE was combined with a high resolution Orbitrap mass spectrometer, metagenome sequences specific for BGPs, and the MetaProteomeAnalyzer software. This enabled us to achieve a high coverage of the metaproteome of the BGP microbial communities. The investigation revealed approx. 17,000 protein groups (metaproteins), covering the majority of the expected metabolic networks of the biogas process such as hydrolysis, transport, fermentation processes, amino acid metabolism, methanogenesis and bacterial C1-metabolism. Biological functions could be linked with the taxonomic composition. Two different types of BGPs were classified by the abundance of the acetoclastic methanogenesis and by abundance of enzymes implicating syntrophic acetate oxidation. Linking of the identified metaproteins with the process steps of the Anaerobic Digestion Model 1 proved the main model assumptions but indicated also some improvements such as considering syntrophic acetate oxidation. Beside the syntrophic interactions, the microbial communities in BGPs are also shaped by competition for substrates and host-phage interactions causing cell lysis. In particular, larger amounts of Bacteriophages for the bacterial families Bacillaceae, Enterobacteriaceae and Clostridiaceae, exceeding the cell number of the Bacteria by approximately four-fold. In contrast, less Bacteriophages were found for Archaea, but more CRISPR proteins were detected. On the one hand, the virus induced turnover of biomass might cause slow degradation of complex biomass in BGP. On the other hand, the lysis of bacterial cells allows cycling of essential nutrients.