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Environmental Science & Technology May 2024Biological pretreatment is a viable method for enhancing biogas production from straw crops, with the improvement in lignocellulose degradation efficiency being a...
Biological pretreatment is a viable method for enhancing biogas production from straw crops, with the improvement in lignocellulose degradation efficiency being a crucial factor in this process. Herein, a metagenomic approach was used to screen core microorganisms (, , , and ) possessing lignocellulose-degrading abilities among samples from three environments: pile retting wheat straw (WS), WS returned to soil, and forest soil. Subsequently, synthetic microbial communities were constructed for fermentation-enzyme production. The crude enzyme solution obtained was used to pretreat WS and was compared with two commercial enzymes. The synthetic microbial community enzyme-producing pretreatment (SMCEP) yielded the highest enzymatic digestion efficacy for WS, yielding cellulose, hemicellulose, and lignin degradation rates of 39.85, 36.99, and 19.21%, respectively. Furthermore, pretreatment of WS with an enzyme solution, followed by anaerobic digestion achieved satisfactory results. SMCEP displayed the highest cumulative biogas production at 801.16 mL/g TS, which was 38.79% higher than that observed for WS, 22.15% higher than that of solid-state commercial enzyme pretreatment and 25.41% higher than that of liquid commercial enzyme pretreatment. These results indicate that enzyme-pretreated WS can significantly enhance biogas production. This study represents a solution to the environmental burden and energy use of crop residues.
Topics: Triticum; Biofuels; Anaerobiosis; Fermentation; Lignin
PubMed: 38748977
DOI: 10.1021/acs.est.4c02789 -
Journal of Global Antimicrobial... Mar 2024
Topics: Humans; Acinetobacter; Plasmids; DNA, Bacterial; Hospitals
PubMed: 38122984
DOI: 10.1016/j.jgar.2023.12.011 -
Journal of Applied Microbiology Jan 2024Despite metatranscriptomics becoming an emerging tool for pathogen surveillance, very little is known about the feasibility of this approach for understanding the fate...
AIMS
Despite metatranscriptomics becoming an emerging tool for pathogen surveillance, very little is known about the feasibility of this approach for understanding the fate of human-derived pathogens in drinking water sources.
METHODS AND RESULTS
We conducted multiplexed microfluidic cards and metatranscriptomic sequencing of the drinking water source in a border city of North Korea in four seasons. Microfluidic card detected norovirus, hepatitis B virus (HBV), enterovirus, and Vibrio cholerae in the water. Phylogenetic analyses showed that environmental-derived sequences from norovirus GII.17, genotype C of HBV, and coxsackievirus A6 (CA6) were genetically related to the local clinical isolates. Meanwhile, metatranscriptomic assembly suggested that several bacterial pathogens, including Acinetobacter johnsonii and V. cholerae might be prevalent in the studied region. Metatranscriptomic analysis recovered 349 species-level groups with substantial viral diversity without detection of norovirus, HBV, and CA6. Seasonally distinct virus communities were also found. Specifically, 126, 73, 126, and 457 types of viruses were identified in spring, summer, autumn, and winter, respectively. The viromes were dominated by the Pisuviricota phylum, including members from Marnaviridae, Dicistroviridae, Luteoviridae, Potyviridae, Picornaviridae, Astroviridae, and Picobirnaviridae families. Further phylogenetic analyses of RNA (Ribonucleic Acid)-dependent RNA polymerase (RdRp) sequences showed a diverse set of picorna-like viruses associated with shellfish, of which several novel picorna-like viruses were also identified. Additionally, potential animal pathogens, including infectious bronchitis virus, Bat dicibavirus, Bat nodavirus, Bat picornavirus 2, infectious bursal disease virus, and Macrobrachium rosenbergii nodavirus were also identified.
CONCLUSIONS
Our data illustrate the divergence between microfluidic cards and metatranscriptomics, highlighting that the combination of both methods facilitates the source tracking of human viruses in challenging settings without sufficient clinical surveillance.
Topics: Animals; Humans; Drinking Water; Seasons; Chiroptera; Phylogeny; Microfluidics; RNA Viruses; Viruses; Picornaviridae; Norovirus; RNA; RNA, Viral
PubMed: 38130237
DOI: 10.1093/jambio/lxad310 -
The Science of the Total Environment Apr 2024Straw is a typical biomass resource which can be converted into high nutritional value feed via microbial fermentation. The degradation and conversion of straw using a...
Straw is a typical biomass resource which can be converted into high nutritional value feed via microbial fermentation. The degradation and conversion of straw using a synthetic microbial community (SMC-8) was functionally investigated to characterise its nitrogen conversion and carbon metabolism. Four species of bacteria were found to utilise >20 % of the inorganic nitrogen within 15 h, and the ratio of the diameter of fungal transparent circles (D) to the diameter of the colony (d) of the four fungal species was >1. Solid-state fermentation of corn straw increased the total amino acid (AA) content by 41.69 %. The absolute digestibility of fermented corn straw dry weight (DW) and true protein was 34.34 % and 45.29 %, respectively. Comprehensive analysis of functional proteins revealed that Aspergillus niger, Trichoderma viride, Cladosporium cladosporioides, Bacillus subtilis and Acinetobacter johnsonii produce a complex enzyme system during corn straw fermentation, which plays a key role in the degradation of lignocellulose. This study provided a new insight in utilizing corn straw.
Topics: Fermentation; Zea mays; Bacillus subtilis; Nitrogen; Animal Feed
PubMed: 38369147
DOI: 10.1016/j.scitotenv.2024.171034 -
Plant Physiology and Biochemistry : PPB May 2024In the face of the formidable environmental challenges precipitated by the ongoing climate change, Plant Growth-Promoting Bacteria (PGPB) are gaining widespread...
Unveiling stress-adapted endophytic bacteria: Characterizing plant growth-promoting traits and assessing cross-inoculation effects on Populus deltoides under abiotic stress.
In the face of the formidable environmental challenges precipitated by the ongoing climate change, Plant Growth-Promoting Bacteria (PGPB) are gaining widespread acknowledgement for their potential as biofertilizers, biocontrol agents, and microbial inoculants. However, a knowledge gap pertains to the ability of PGPB to improve stress tolerance in forestry species via cross-inoculation. To address this gap, the current investigation centres on PGPBs, namely, Acinetobacter johnsonii, Cronobacter muytjensii, and Priestia endophytica, selected from the phyllosphere of robust and healthy plants thriving in the face of stress-inducing conditions. These strains were selected based on their demonstrated adaptability to saline, arid, and nitrogen-deficient environments. The utilization of PGPB treatment resulted in an improvement of stomatal conductance (gs) and transpiration rate (E) in poplar plants exposed to both salt and drought stress. It also induced an increase in essential biochemical components such as proline (PRO), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD). These reactions were accompanied by a decrease in leaf malonaldehyde (MDA) content and electrolyte leakage (EL). Furthermore, the PGPB treatment demonstrated a notable enhancement in nutrient absorption, particularly nitrogen and carbon, achieved through the solubilization of nutrients. The estimation of canopy temperature via thermal imaging proved to be an efficient method for distinguishing stress reactions in poplar than conventional temperature recording techniques. In summation, the utilization of PGPB especially Cronobacter muytjensii in this study, yielded profound improvements in the stress tolerance of poplar plants, manifesting in reduced membrane lipid peroxidation, enhanced photosynthesis, and bolstered antioxidant capacity within the leaves.
Topics: Populus; Stress, Physiological; Endophytes; Plant Leaves; Droughts; Proline; Adaptation, Physiological; Acinetobacter
PubMed: 38615447
DOI: 10.1016/j.plaphy.2024.108610