Bioscience, Biotechnology, and Biochemistry最新文献

A simple one-pot and biomimetic synthetic method for producing pimeforazine A and B, fluorescent benzoxazines with neuroprotective activity isolated from the olive weevil Pimelocerus perforatus, was developed. This synthesis uses the oxidation of commercially available 4-(2-hydroxyethyl)phenol (tyrosol) with 2-iodoxybenzoic acid (IBX), followed by the addition of concentrated aqueous ammonia. The reaction produced pimeforazines A and B in a ratio of 3.4:1, which is consistent with the natural product ratio. This method provides a practical and efficient alternative to extracting these compounds from the olive weevil.

Rising global demand for food has led to excessive use of chemical fertilizers and pesticides, increasing yields but damaging soils, biodiversity, and microbial communities. Alternatives such as the application of beneficial bacteria could restore diminished soil health and maintain productivity without these long-term costs. Bacillus species and related genera, such as Paenibacillus and Priestia, combine several useful traits, including phosphorus solubilization, nitrogen fixation, production of growth hormones, enzyme release, and generation of antimicrobial compounds. These abilities improve nutrient use, protect plants from pathogens, and increase stress tolerance. Applied as single strains or in microbial consortia, they have consistently increased yields, improved soil health, and reduced reliance on synthetic agrochemicals. Continued work on strain optimization, consortia design and modeling, and adaptation to specific environments will further unlock their potential for sustainable agriculture.

In skeletal muscle cells, the resting membrane potential is primarily determined by Cl-, necessitating precise regulation of intracellular and extracellular Cl- balance. Potassium chloride cotransporters (KCCs), members of the cation-chloride cotransporter superfamily, facilitate the efflux of K+ and Cl- at a 1:1 ratio. However, the specific roles of KCCs in skeletal muscle remain poorly understood. In this study, we investigated the function of KCCs in skeletal muscle cells using [(dihydroindenyl)oxy]acetic acid (DIOA), a KCCs inhibitor. DIOA treatment of cultured C2C12 myotubes impaired contractility in response to electrical pulse stimulation. Additionally, DIOA-treated myotubes exhibited muscle atrophy, accompanied by increased expression of atrogenes such as Atrogin-1 and MuRF1. These findings reveal a novel role for KCCs in skeletal muscle and provide insights that may contribute to the development of preventive or therapeutic strategies for muscle disorders and atrophy.

Ferritin, a protein ubiquitously found in living organisms, is well known for its major role in iron homeostasis. However, recent studies in invertebrates have revealed that it possesses diverse physiological functions beyond iron homeostasis. Especially in mollusks, ferritin has been suggested to be involved in functions such as restricting iron availability to pathogens during immune responses, mediating iron transport to specific tissues via hemolymph, and contributing to the formation of mineralized tissues, such as shells and radulae. Furthermore, it has been demonstrated that mollusks possess not only the cytoplasmic ferritin found in vertebrates, but also a secretory ferritin, which contains a signal peptide. This review provides a comprehensive overview of molluscan ferritin, summarizing the broad aspects of its molecular structure and physiological functions.

Carbonic anhydrase accelerates the hydration of carbon dioxide (CO₂) and is an attractive biocatalyst for carbon capture and utilization. Acinetobacter sp. Tol 5 shows high adhesiveness via its cell-surface protein AtaA. We previously demonstrated its application to bacterial immobilization and gas-phase bioproduction. Here, we developed Tol 5 cells expressing carbonic anhydrase and evaluated CO₂ conversion ability as whole-cell biocatalysts. A codon-optimized carbonic anhydrase from Sulfurihydrogenibium yellowstonense (SyCA) was produced in the cytoplasm, but the cells showed little activity as a whole-cell biocatalyst. To enhance activity, we fused six signal peptides (SPs) to SyCA for periplasmic expression. The Omp38-SP fusion of SyCA was properly processed to the mature size, yielding higher whole-cell activity. By contrast, the other constructs were either undetectable or remained unprocessed, resulting in lower activities. These results show that periplasmic expression of SyCA is important for efficient CO₂ hydration in Tol 5 cells as whole-cell biocatalysts.

Bifidobacteria are Gram-positive, anaerobic bacteria known for their health-promoting effects. However, a comprehensive analysis of middle- and long-chain fatty acids in bifidobacteria remains elusive. This study aimed to evaluate fatty acid accumulation among 43 strains covering 40 species/subspecies, and to elucidate interspecies and interstrain variations. Analysis of their cell-associated fatty acids revealed significant differences in total fatty acid levels. Bifidobacterium thermacidophilum and related species exhibited notably high accumulation of multiple fatty acids (eg decanoic acid, cis-7-C16:1). Among Bifidobacterium breve strains, M-16V produced significantly more cis-7-C16:1 than the others. Additionally, a homology analysis targeting cyclopropane fatty acid synthase was performed to determine the genetic basis of cis-9,10-methyleneoctadecanoic acid (cyclo-C19:0) production. Only strains possessing the homolog produced cyclo-C19:0. These results highlight substantial variation in fatty acid accumulation among bifidobacteria, which could influence their probiotic functionalities. This study provides a foundation for future research on the health benefits of bifidobacterial fatty acid profiles.

Inulin, a soluble dietary fiber, is widely recognized for its gut health benefits; however, its role in the progression of ulcerative colitis remains unclear. In this study, we investigated the effects of inulin supplementation on colitis induced by administering dextran sodium sulfate (DSS) to BALB/c mice. Mice were fed diets containing 10% inulin or cellulose, followed by administration of 2% DSS in drinking water. Inulin-supplemented mice exhibited a higher disease activity index and more severe epithelial damage compared to cellulose-fed controls. Similar pathological features were observed in mice administered polyethylene glycol to induce osmotic diarrhea, suggesting that increased luminal osmotic pressure may exacerbate colitis. Notably, co-administration of polycarbophil calcium with inulin ameliorated clinical symptoms and attenuated tissue damage. These findings suggest that inulin may aggravate colitis, potentially through increased luminal osmotic pressure. Therefore, managing osmotic diarrhea may represent a therapeutic strategy to mitigate colitis symptoms associated with certain dietary fibers.

Amniotic fluid (AF) constitutes a dynamic environment containing diverse bioactive molecules derived from both maternal and fetal sources that support fetal development. As the fetus develops in continuous contact with AF, it is plausible that AF influences the formation of the skin epidermis. However, the mechanisms through which AF promotes keratinocyte differentiation remain largely unclear. Here, we showed that goat AF enhanced the expression of key functional proteins involved in epidermal barrier formation, including small proline-rich proteins, loricrin, and transglutaminase. We further obtained the bioactive fractions that promote the expression of these differentiation-related proteins through multistep protein fractionation via column chromatography. Proteomic analysis subsequently revealed 291 candidate proteins, including 85 distinct extracellular proteins, primarily grouped into calcium-binding proteins, proteases and their regulators, extracellular matrix components, and signaling molecules. Collectively, these results suggest that proteins secreted or released into AF contribute to establishing a microenvironment conducive to epidermal differentiation.

This study aimed to elucidate the functions of saline-alkaline inducible genes encoding OsCHX11 and OsCHX16, members of the cation/H+ exchanger (CHX) family, under different component of saline-alkaline conditions. Rice biomass under carbonate-based (50 mm Na+ with carbonates) and high-pH (50 mm Na+ without carbonates) conditions was similar, whereas higher Na+/K+ ratio was observed under carbonate-based conditions. Under carbonate-based conditions, only OsCHX16 was significantly expressed, whereas both OsCHX11 and OsCHX16 were highly expressed under high pH conditions. The yeast complementation assay showed that OsCHX11 and OsCHX16 improved the yeast growth under saline, carbonate-based, and high-pH conditions by increasing K+ concentration. Taken together, these results suggest that OsCHX11 and OsCHX16 may contribute to the K+ uptake system under saline-alkaline conditions with or without carbonates at cell level.

Co-administration of histidine and soy isoflavones induced beige adipogenesis in male rats, as demonstrated by the formation of multilocular lipid droplets and increased uncoupling protein 1 gene expression in white adipose tissue. This response was accompanied by fat depot-specific enhancement of mitochondrial activity and suppression of lipogenesis, suggesting the potential for dietary strategies to combat obesity via beige adipocytes activation.