RESUMO
Long-chain fatty acids (LCFAs) are recognized as a significant inhibitory factor in anaerobic digestion of food waste (FW), yet they are inevitably present in FW due to lipid hydrolysis. Given their distinct synthesis mechanism from traditional anaerobic digestion, little is known about the effect of LCFAs on FW acidogenic fermentation. This study reveals that total volatile fatty acids (VFAs) production increased by 9.98 % and 4.03 % under stearic acid and oleic acid loading, respectively. Acetic acid production increased by 20.66 % under stearic acid loading compared to the control group (CK). However, the LCFA stress restricted the degradation of solid organic matter, particularly under oleic acid stress. Analysis of microbial community structure and quorum sensing (QS) indicates that LCFA stress enhanced the relative abundance of Lactobacillus and Klebsiella. In QS system, the relative abundance of luxS declined from 0.157 % to 0.116 % and 0.125 % under oleic acid and stearic acid stress, respectively. LCFA stress limited the Autoinducer-2 (AI-2) biosynthesis, suggesting that microorganisms cannot use QS to resist the LCFA stress. Metagenomic sequencing showed that LCFA stress promoted acetic acid production via the conversion of pyruvate and acetyl-CoA to acetate. Direct conversion of pyruvate to acetic acid increased by 47.23 % compared to the CK group, accounting for the enhanced acetic acid production under stearic acid loading. The abundance of ß-oxidation pathway under stearic acid loading was lower than under oleic acid loading. Overall, the stimulating direct conversion of pyruvate plays a pivotal role in enhancing acetic acid biosynthesis under stearic acid loading, providing insights into the effect of LCFA on mechanism of FW acidogenic fermentation.
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Phosphorus recycling from organic wastes to prepare a fertilizer by composting is promising. The aim of this study was to compare the effect of diverse carbon-containing additives (T1, glucose; T2, biochar; T3, woody peat) on phosphorus (P) fractions transformations, humus formation and bacterial community succession in chicken manure composting. Results showed that orthophosphate monoester was significantly related to the humification process, and glucose or woody peat addition increased the P in humus. Lentibacillus was a key carbon cycle bacteria related to organics stabilization affected by carbon-containing additives. Redundancy analysis and variation partitioning indicated that phosphatase enzyme activity driven by bacterial community and humic substance had 59.7% contribution to P fractions dynamics. The findings highlight an efficient humus-regulation P stabilization way, notably in composting adding glucose to form humus with a better binding ability to labile P forms and phosphatase.
Assuntos
Compostagem , Fósforo , Carbono/metabolismo , Solo , Bactérias/metabolismo , Esterco , Monoéster Fosfórico HidrolasesRESUMO
This study aimed to explore the effect of phosphate-solubilizing bacteria (PSB) Bacillus inoculation in the cooling stage on hydroxyapatite dissolution, phosphorus (P) forms transformation, and bacterial P cycling genes in food waste composting with hydroxyapatite. Results indicated that PSB inoculation promoted the dissolution of hydroxyapatite, increased P availability of compost by 8.1% and decreased the ratio of organic P to inorganic P by 10.2% based on sequential fractionation and 31P nuclear magnetic resonance spectroscopy. Illumina sequencing indicated Bacillus relative abundance after inoculation increased up to one time higher than control after the cooling stage. Network analysis and metabolic function of bacterial community analysis suggested inorganic P solubilizing genes of Bacillus and organic P mineralization genes of other genera were improved after inoculation in the core module. Therefore, bioaugmentation of PSB in the cooling stage may be a potential way to improve P bioavailability of bone and food waste in composting.
Assuntos
Bacillus , Compostagem , Eliminação de Resíduos , Fósforo/metabolismo , Fosfatos/química , Durapatita , Alimentos , Solo/química , Bactérias/genética , Bactérias/metabolismo , Bacillus/genética , Bacillus/metabolismoRESUMO
This study focused on the application value of the newly prepared 129Xe nanoprobe-based functional magnetic resonance imaging (fMRI) in exploring the mechanism of the acupuncture treatment for intractable facial paralysis, expected to provide a theoretical reference for the mechanism of acupuncture for the treatment of facial paralysis. In this study, 30 patients with intractable peripheral facial paralysis (experimental group) and 30 healthy volunteers (control group) were selected. All patients were scanned by the newly prepared 129Xe nanoprobe-based fMRI technology, and then brain functional status data and rating data were collected. fMRI scanning results showed that multiple brain regions were activated in the experimental group before treatment, among which the central posterior brain, insula, and thalamus were positively activated, while the precuneus, superior frontal gyrus, and other parts showed signal reduction. After treatment, several brain regions also showed signal enhancement. Comparisons within the healthy control group also showed activation in multiple brain regions, including the lenticular nucleus, inferior frontal gyrus, and superior temporal gyrus, while in the experimental group, no signal changes were detected in these brain regions. At the same time, comparison of fMRI images of patients with intractable peripheral facial paralysis before and after treatment showed that the cerebellar amygdala, superior frontal gyrus, cerebellar mountaintop, and other brain areas were activated, and all showed positive activation. After treatment, the average House-Brackmann (H-B) and Sunnybrook scores of the experimental group were 3.82 and 51, respectively, and the change was significant compared with that before treatment (P < 0.05). In conclusion, the newly prepared 129Xe nanoprobe-based fMRI scan can reflect the functional changes of cerebral cortex after acupuncture. The acupuncture treatment may achieve its therapeutic effect by promoting the functional reorganization of the cerebral cortex in the treatment of intractable facial paralysis.
Assuntos
Terapia por Acupuntura , Paralisia Facial , Encéfalo/diagnóstico por imagem , Paralisia Facial/diagnóstico por imagem , Paralisia Facial/terapia , Humanos , Imageamento por Ressonância Magnética , Isótopos de XenônioRESUMO
Parkinson's disease (PD) is a most common progressive neurodegenerative disease mainly occurring in the elderly. Plenty of miRNAs are reported to involve in the progression of PD. However, the role of miR-9-5p in the regulation of PD pathogenesis remains unclear. The expressions of miR-9-5p and Sirtuin 1 (SIRT1) at mRNA and protein levels were determined by qRT-PCR and western blotting (WB) analyses. Cell viability and apoptosis were evaluated by MTT and flow cytometry. The levels of apoptosis-related proteins Bcl-2, Bax, Caspase-3 were detected by WB analysis. The releases of inflammatory cytokines IL-1ß and TNF-α were examined by ELISA assay. ROS generation, LDH and SOD activity were evaluated using commercially available kits. Bioinformatics analysis, luciferase reporter, and qRT-PCR assays were performed to demonstrate the true interaction between miR-9-5p and SIRT1. Results showed miR-9-5p was upregulated and SIRT1 was downregulated in MPP+-treated SH-SY5Y cells in dose- and time- dependent manners. miR-9-5p knockdown attenuated MPP+-induced neurotoxicity in SH-SY5Y cells, as evidenced by the enhancement in cell viability, and the suppression in cell apoptosis, inflammation, and oxidative stress. SIRT1 was identified to be a target of miR-9-5p. Restoration of miR-9-5p aggravated SIRT1-attenuated neurotoxicity in MPP+-treated SH-SY5Y cells. Our data suggested these data indicated that miR-9-5p exerted a neurotoxic role in MPP+-derived PD by directly targeting STAT1, providing a potential therapeutic strategy for patients troubled by PD.