Bioscience, Biotechnology, and Biochemistry最新文献

The cholesterol balance and bile acid metabolism in a mouse model of hepatic lipid accumulation induced by a diet supplemented with cholesterol and cholic acid (CA) were quantitatively evaluated. The mice were fed diets supplemented with different levels of cholesterol (0, 3, or 6 g/kg diet) and CA (0.5 g/kg diet) for six weeks. Cholesterol supplementation doubled the hepatic triglyceride concentration, regardless of the supplementation level, without inflammation or gallstone formation. Both cholesterol supplementations enhanced fecal excretion of muricholic acid. Additionally, the higher cholesterol supplementation led to an increase in fecal cholesterol excretion, accompanied by elevated expression of hepatic cholesterol exporters and a reduction in fecal bile acid excretion. In this mouse study, supplementation with 3 g cholesterol/kg diet and 0.5 g CA/kg diet was sufficient to induce hepatic lipid accumulation.

We successfully constructed a heterologous expression system for L-glutamate oxidase from the marine actinomycete Streptomyces lydicamycinicus NBRC 110027 (Sl-LGOX) in Escherichia coli BL21(DE3) as a host. This is the first example of L-glutamate oxidase from a marine microorganism. A chemically synthesized gene optimized for codon usage in E. coli was used as the inserted fragment, which was effective for enzyme expression. We expressed Sl-LGOX in the soluble fraction of E. coli BL21(DE3)/pET21b-Sl-lgox. We also succeeded in purifying recombinant Sl-LGOX (rSl-LGOX) to homogeneity from the cell-free extract of this clone via an Ni-NTA column. rSl-LGOX showed high specificity for L-Glu and was active and stable over a wide range of temperatures and pH values. In particular, it showed high specific activity and stability at an acidic pH. A variety of applications can take advantage of the unique enzymatic properties of rSl-LGOX.

Manipulation and analysis methods for large DNAs are critical for epidemiological, clinical, diagnostic, and fundamental research on bacteria, membrane vesicles, plants, yeast, and human cells. However, the physical properties of large DNAs often challenge their manipulation and analysis with high accuracy and speed using the conventional methods such as gel electrophoresis and column-based methods. This review presents the approaches that leverage micrometer- and nanometer-sized gaps within microchannels to control the dynamics and conformations of large DNAs, thereby overcoming these challenges. By designing gap structures and migration conditions based on the relationship between gap parameters and the physical characteristics of large DNAs-such as diameter and persistence length-these methods enable swifter and more precise manipulation and analysis of large DNAs, including size separation, concentration, purification, and single-molecule analysis.

Caenorhabditis elegans is a type of nematode that has significantly contributed to aging research as a multicellular animal model because of its high reproductive rate, ease of cultivation, low cost, short generation cycle, body transparency, and eukaryotic nature. Since the discovery of long-lived mutant strains of C. elegans, signaling pathways involved in lifespan have been elucidated. Some of these pathways are shared with mammals, indicating that aging research in C. elegans may be applied to other animals, including humans. Studies on the mechanisms of aging have advanced with the availability of mutants for these pathways. In recent years, C. elegans has also contributed to the discovery of antioxidants and the elucidation of the molecular mechanisms responsible for the anti-aging effects of foods and traditional medicines with lifespan as an indicator. This review summarizes the characteristics of C. elegans for life span analysis associated with functional foods.

Vitamin B12 (B12) is a water-soluble substance that is a member of the B-vitamin family. Its recommended daily dose in adult men and women is 2.4 µg, which is the lowest among the 13 vitamins. B12 deficiency causes megaloblastic anemia and neurological disorders. It is also associated with cognitive decline, growth retardation, infertility, and other symptoms. Nevertheless, the detailed mechanisms of which remain unclear. Caenorhabditis elegans is a small organism, with a length of approximately 1 mm and a lifespan of approximately 3 weeks. It has similar fundamental biological structures, such as the muscles, nervous system, and digestive tract, with mammals. Previous studies have shown that B12 is required for the normal development of C. elegans, similar to that of mammals. The current study aimed to perform a detailed investigation of the mechanisms underlying the development of B12 deficiency using a dietary B12-deficient C. elegans model.

To reveal the differences in the properties of visceral adipose tissue in healthy unstimulated mice, we performed transcriptome analysis using RNA sequencing. Among visceral adipose tissues, perinephric adipose tissue was found to exclusively express beige adipocyte markers while expressing white adipocyte markers. These results imply potential specific roles of perinephric adipose tissue in both physiological and pathological conditions.

Epidermal keratinocytes undergo morphological and functional changes during differentiation, eventually being enucleated to become corneocytes. Calcium has been shown to be involved in various cellular functions of epidermal cells, including proliferation, differentiation, and apoptosis. Cerium is a lanthanide-series element and rare earth metal. For skin, cerium oxide has been investigated for use in absorbing UV and promoting wound healing. However, the functions and physiological effects of inorganic cerium on the skin have rarely been investigated. Here, we focused on cerium's function in epidermal keratinocytes and its interaction with calcium by investigating their effects on cell differentiation and intracellular calcium concentration. This study showed that applying cerium chloride to epidermal keratinocytes altered calcium signaling. It also suggested that cerium and calcium induced an increase in intracellular calcium concentration and promoted keratinocyte differentiation.

Helicases are involved in almost every nucleic acid metabolism process. Within this family, RecQ helicase proteins protect genome integrity across all organisms through DNA recombination, repair, and replication. This study focused on five Arabidopsis thaliana RecQ-like (AtRecQl) genes with diverse functionalities. Analysis of ProAtRecQl: GUS expression during vegetative and reproductive development stages revealed organ- and tissue-specific patterns. Changes in AtRecQls transcript levels in response to abiotic stressors suggest their involvement in diverse stimuli responses. Notably, germination and growth rates were lower in atrecql2 and atrecql3 mutants under various salt concentrations and cold conditions. These findings indicate that AtRecQl2 and AtRecQl3 act as positive regulators of abiotic stress tolerance during the germinative and postgerminative phases.

The culture filtrate extract of golden bootleg (Phaeolepiota aurea) exhibited strong antifungal activity in a bioassay for volatile compounds. Purification of active compounds through silica gel column chromatography and high performance liquid chromatography isolated two compounds, 1 and 2, with molecular weights of 234 and 259, respectively, as confirmed by mass spectrometry. Nuclear magnetic resonance analysis identified these compounds as new sesquiterpenoids with the α-bourbonene skeleton. Both compounds had an aldehyde group, while 2 possessed a cyanohydrin group. These compounds were named phaeolep aldehydes A (1) and B (2). Phaeolep aldehyde A inhibited hyphae elongation of Penicillium citrinum, Aspergillus niger, Cladosporium sphaerospermum, and Alternaria brassicicola at 10 ppm, but did not exhibit any antibacterial activity. In contrast, phaeolep aldehyde B exhibited potent inhibitory effects on the spore germination of Pe. citrinum, achieving 58.2% inhibition at 0.25 ppm, outperforming phaeolep aldehyde A, which exhibited 25.7% inhibition at 10 ppm.

Brown algae are one of the most abundant biomasses on Earth. To recycle them as blue carbon sources, an effective decomposition system is necessary. This study focused on microorganisms present in seawater that decompose brown algae which contain laminarin and alginate. Where Undaria and Sargassum spp. were present, genera Psychromonas, Psychrobacter, and Pseudoalteromonas were predominant in seawater, while genera Arcobacter and Fusobacterium increased in abundance during the process of decomposition. The inoculation of Undaria samples into laminarin-minimal media led to a predominance of Pseudoalteromonas species. A Pseudoalteromonas isolate, identified as Pseudoalteromonas distincta, possesses genes encoding a putative laminarinase, polysaccharide lyase family 6 (PL6) alginate lyases, and a PL7 alginate lyase. The culture media of P. distincta contained no monosaccharides, suggesting the rapid conversion of polysaccharides to metabolites. These findings indicated that Pseudoalteromonas species play a major role in the decomposition of brown algae and affect the microbiota associated with them.