Changes in meat quality, metabolites and microorganisms of mutton during cold chain storage.

During the cold chain storage process, changes in metabolites and microorganisms are highly likely to lead to changes in meat quality. To elucidate the changes in the composition of metabolites and microbiota during cold chain storage of mutton, this study utilized untargeted metabolome and 5R 16S rRNA sequencing analyses to investigate the changes in the longissimus dorsi under different cold chain temperatures (4 °C and -20 °C). With the extension of cold chain storage time, the meat color darkened and the content of C18:2n-6, C20:3n-6, and C23:0 were significantly increased in mutton. In this study, nine metabolites, including 1,2-Dioleoyl-sn-glycero-3-phosphoethanolamine, alanylphenylala-nine, indole-3-acrylic acid and the others, were significantly altered during cold chain storage. The abundance of the dominant microorganisms, including Brachymonas, Aeromonas, Corynebacterium and Steroidobacter, was significantly altered. Furthermore, a high correlation was observed between the different metabolites and microorganisms. These findings provide an in-depth understanding of the effects of different cold chain storage temperatures and times on the quality of mutton.

Impacts of mixed ferrous sulfate-biochar additives on humification and bacterial community during electric field-assisted aerobic composting.

This study assessed the impact of nine mixed ferrous sulfates and biochars on electric field-assisted aerobic composting (EAC), focusing on the spectroscopy of dissolved organic matter (DOM) and microbial communities. Adding 1.05% ferrous sulfate and 5.25% biochar to EAC increased the specific ultraviolet absorbances at 254 and 280 nm by 142.3% and 133.9% on day 35, respectively. This ratio accelerated the early response of carboxyl groups (-COOH) and lignin (CꘌC), enhancing the relative abundance of Thermobifida (4.0%) and Thermopolyspora (4.3%). The condition contributed to humus precursor formation on day 5, increasing the maximum fluorescence intensity of the humus-like component by 74.2% compared to the control on day 35. This study is the first to develop a combined and efficient organic and inorganic additive by multiple-variable experimentation for DOM humification. Consequently, it optimizes EAC for solid waste recycling.

Prebiotics Inulin Metabolism by Lactic Acid Bacteria From Young Rabbits.

Inulin as a commercial prebiotic could selectively promote the growth of beneficial gut microbes such as lactic acid bacteria (LAB). Whether LAB in rabbit gut possesses the capability to metabolize and utilize inulin is little known. Therefore, this study recovered 94 LAB strains from neonate rabbits and found that only 29% (28/94) could metabolize inulin with both species- and strain-specificity. The most vigorous inulin-degrading strain, Lacticaseibacillus paracasei YT170, could efficiently utilize both short-chain and long-chain components through thin-layer chromatography analysis. From genomic analysis, a predicted fosRABCDXE operon encoding putative cell wall-anchored fructan ß-fructosidase, five fructose-transporting proteins and a pts1BCA operon encoding putative ß-fructofuranosidase and sucrose-specific IIBCA components were linked to long-chain and short-chain inulin utilization respectively. This study provides a mechanistic rationale for effect of inulin administration on rabbits and lays a foundation for synbiotic applications aimed at modulating the intestinal microbiota of young rabbits.

Tryptophan supplements promote pregnancy success in mice challenged with pseudorabies virus (PRV) by regulating the expression of systemic cytokines, immunoglobulins, PRV-specific protein profiles, and toll-like receptors.

Tryptophan (Trp) plays an important role in regulating the maternal immune response, a key determinant of the success or failure of pregnancy, but whether Trp supplements can prevent a pseudorabies virus (PRV)-induced failure of pregnancy remains unknown. This study examined the effect of three dietary Trp levels (0.25%, 0.35%, and 0.5%) on the immunity and reproduction of PRV-challenged pregnant mice. PRV challenge resulted in decreased live embryo numbers, live litter sizes, and serum progesterone and interleukin (IL)-10 concentrations, but increased the levels of serum immunoglobulins (Igs) (PRV-specific antibody [IgG, IgA, and IgM]) and IL-1ß. Live embryo numbers, live litter sizes, serum progesterone concentration, and IgG and PRV-specific antibody levels on day 9 of pregnancy were all increased dose-dependently by Trp inclusion in the diet of PRV-challenged mice. Increased Trp levels in PRV-challenged mice promoted the up-regulation of uterine and embryonic indoleamine 2,3-dioxygenase expression, but attenuated the up-regulation of uterine and embryonic Toll-like receptor (TLR) 3 and TLR9 expression and increased serum interferon-γ concentration. Collectively, Trp supplements might improve reproductive performance of PRV-challenged pregnant mice by down-regulating TLR expression and pro-inflammatory cytokine synthesis, by up-regulating PRV-specific antibody and immunoglobulin synthesis, and by elevating the concentrations of anti-inflammatory cytokines and progesterone.