Project description:The functional diversity of soil microbial communities was explored for a poplar plantation, which was treated solely with biogas slurry, or combined with biochar at different fertilization intensities over several years.
Project description:The use of biofertilizers is becoming an economical and environmentally friendly alternative to promote sustainable agriculture. Biochar from microalgae can be applied to enhance the productivity of food crops through soil improvement, slow nutrient absorption and release, increased water uptake, and long-term mitigation of greenhouse gas sequestration. Therefore, the aim of this study was to evaluate the stimulatory effects of biochar produced from Spirulina platensis biomass on the development and seed production of rice plants. Biochar was produced by slow pyrolysis at 300°C, and characterization was performed through microscopy, chemical, and structural composition analyses. Molecular and physiological analyses were performed in rice plants submitted to different biochar concentrations (0.02, 0.1, and 0.5 mg mL-1) to assess growth and productivity parameters. Morphological and physicochemical characterization revealed a heterogeneous morphology and the presence of K and Mg minerals in the biochar composition. Chemical modification of compounds post-pyrolysis and a highly porous structure with micropores were observed. Rice plants submitted to 0.5 mg mL-1 of biochar presented a decrease in root length, followed by an increase in root dry weight. The same concentration influenced seed production, with an increase of 44% in the number of seeds per plant, 17% in the percentage of full seeds per plant, 12% in the weight of 1,000 full seeds, 53% in the seed weight per plant, and 12% in grain area. Differential proteomic analyses in shoots and roots of rice plants submitted to 0.5 mg mL-1 of biochar for 20 days revealed a fine-tuning of resource allocation towards seed production. These results suggest that biochar derived from Spirulina platensis biomass can stimulate rice seed production.
Project description:Bacteriophage – host dynamics and interactions are important for microbial community composition and ecosystem function. Nonetheless, empirical evidence in engineered environment is scarce. Here, we examined phage and prokaryotic community composition of four anaerobic digestors in full-scale wastewater treatment plants (WWTPs) across China. Despite relatively stable process performance in biogas production, both phage and prokaryotic groups fluctuated monthly over a year of study period. Nonetheless, there were significant correlations in their α- and β-diversities between phage and prokaryotes. Phages explained 40.6% of total prokaryotic community composition, much higher than the explainable power by abiotic factors (14.5%). Consequently, phages were significantly (P<0.010) linked to parameters related to process performance including biogas production and volatile solid concentrations. Association network analyses showed that phage-prokaryote pairs were deeply rooted, and two network modules were exclusively comprised of phages, suggesting a possibility of co-infection. Those results collectively demonstrate phages as a major biotic factor in controlling bacterial composition. Therefore, phages may play a larger role in shaping prokaryotic dynamics and process performance of WWTPs than currently appreciated, enabling reliable prediction of microbial communities across time and space.
Project description:Two-stage two-phase biogas reactor systems consisting each of one batch downflow hydrolysis reactor (HR, vol. 10 L), one process fluid storage tank (vol. 10 L), and one downstream upflow anaerobic filter reactor (AF, vol. 10 L), were operated at mesophilic (M, 37 °C) and thermophilic (T, 55 °C) temperatures and over a period of > 750 d (Figure 1, Additional file 1). For each reactor system and for each process temperature, two replicates were conducted in parallel, denominated further as biological replicates. Further process details were as previously published. Start-up of all fermenters were performed using liquid fermenter material from a biogas plant converting cattle manure in co-digestion with grass and maize silage and other biomass at varying concentrations and at mesophilic temperatures. Silage of perennial ryegrass (Lolium perenne L.) was digested as sole substrate in batches of varying amounts with retention times of 28 d (storage of bale silage at -20 °C, cutting length 3 cm, volatile substances (VS) 32 % of fresh mass (FM), total Kjeldahl nitrogen 7.6 g kgFM-1, NH4+-N 0.7 g kgFM-1, acetic acid 2.6 g kgFM-1, propionic acid < 0.04 g kgFM-1, lactic acid 2.6 g kgFM-1, ethanol 2.2 g kgFM-1, C/N ratio 19.3, chemical oxygen demand (COD) 357.7 g kgFM-1, analysis of chemical properties according to [6]. No spoilage was observed in the silage. Biogas yields were calculated as liters normalized to 0 °C and 1013 hPa (LN) per kilogram volatile substances (kgVS). For chemical analysis, samples were taken from the effluents of HR and AF. For sequencing of 16S rRNA gene amplicon libraries, microbial metagenomes, and microbial metatranscriptomes, samples were taken from the silage digestate in the HR digested for 2 d. At this time point, high AD rates were detected as indicated by the fast increase of volatile fatty acids (VFA), e.g., acetic acid. Sampling was performed at two different organic loading rates (OLR), i.e., batch-fermentation of 500 g (denominated as “low OLR”, samples MOLR500 and TOLR500) and 1,500 g silage (denominated as “increased OLR”, samples MOLR1500 and TOLR1500).
Project description:Volatilization of lower-chlorinated polychlorinated biphenyls (LC-PCBs) from sediment poses health threats to nearby communities and ecosystems. Biodegradation combined with black carbon (BC) materials is an emerging approach to remove PCBs from sediment, but development of aerobic biofilms on BC for long-term, sustained LC-PCBs remediation is poorly understood. This work aimed to characterize cell enrichment and activity of biphenyl- and benzoate-grown Paraburkholderia xenovorans strain LB400 on various BCs. Biphenyl dioxygenase gene (bphA) abundance on four BC types demonstrated corn kernel biochar hosted at least four orders of magnitude more attached cells per gram than other feedstocks, and microscopic imaging revealed the attached live cell fraction was >1.5X more on corn kernel biochar than GAC. BC characteristics (i.e., sorption potential, surface area, pH) drove cell attachment differences. Reverse transcription qPCR indicated BC feedstocks significantly influenced bphA expression in attached cells. The bphA transcript-per-gene ratio of attached cells was >10-fold more than suspended cells, confirmed by transcriptomics. RNA-seq also demonstrated significant upregulation of biphenyl and benzoate degradation pathways on attached cells, revealing biofilm formation potential and cell-cell communication pathway connections. These novel findings demonstrate aerobic PCB-degrading cell abundance and activity could be tuned by adjusting BC feedstocks/ attributes to improve LC-PCBs biodegradation.
2023-11-03 | GSE246487 | GEO
Project description:Biochar and modified biochar amended soils
Project description:Meta-proteomics analysis approach in the application of biogas production from anaerobic digestion has many advantages that has not been fully uncovered yet. This study aims to investigate biogas production from a stable 2-stage chicken manure fermentation system in chemical and biological perspective. The diversity and functional protein changes from the 1st stage to 2nd stage is a good indication to expose the differential metabolic processes in anaerobic digestion. The highlight of identified functional proteins explain the causation of accumulated ammonia and carbon sources for methane production. Due to the ammonia stress and nutrient limitation, the hydrogenotrophic methanogenic pathway is adopted as indicative of meta-proteomics data involving the key methanogenic substrates (formate and acetate). Unlike traditional meta-genomic analysis, this study could provide both species names of microorganism and enzymes to directly point the generation pathway of methane and carbon dioxide in investigating biogas production of chicken manure.