Bioscience, Biotechnology, and Biochemistry最新文献

Lactic acid bacteria (LAB) shape diverse communities in fermented foods. Developing comprehensive quantification methods for community structure will revolutionize our understanding of food LAB microbiome. For this purpose, 16S rRNA gene amplicon-based quantification, using spiked exogenous bacterial cells as an internal standard, shows potential for comprehensiveness and accuracy. We validated cell spike-in amplicon sequencing for quantifying LAB communities in food. Low efficiency of LAB DNA extraction underscores the importance of compensating for DNA loss by spiking internal standard cells. Quantitative equations generated using 15 selected LAB mock species showed positive relationships between the ratio of MiSeq read counts and the expected 16S rRNA gene copy numbers, with coefficients of determination (R2) ≥ 0.6823. The fold differences between observed and expected 16S copy numbers were within the range of 1/3 to 3-fold. Our validation highlights that accurate preparation of the LAB mock community is crucial for cell spike-in amplicon sequencing accuracy.

Burkholderia sp. HME13 utilizes ergothioneine, a strong antioxidant, as the nitrogen source. We have previously shown that ergothionase, thiourocanate hydratase, 3-(5-oxo-2-thioxoimidazolidin-4-yl) propionic acid desulfhydrase, and hydantoin-5-propionic acid amidohydrolase may be involved in ergothioneine utilization in this strain. In this study, we identified the ertE gene in Burkholderia sp. HME13, which encodes a bivalent metal-dependent N-carbamyl-l-glutamic acid amidohydrolase (ErtE). ErtE showed maximum activity at 60 °C and pH 7.0 and was stable at temperatures up to 55 °C and pH 6.5-8.0. The Km and Vmax values of ErtE for N-carbamyl-l-glutamic acid were 0.74 m m and 140 U/mg, respectively. Ethylenediaminetetraacetic acid-treated ErtE showed no enzymatic activity, which was restored upon the addition of Co2+, Mn2+, Ni2+, and Fe2+. Expression analyses and enzymatic assays suggested that ErtE is involved in ergothioneine utilization in this strain. Finally, we propose a mechanism for ergothioneine utilization in Burkholderia sp. HME13.

Functional food science in Japan actively began approximately 40 years ago in the form of specific research projects funded by Grants-in-Aids for Scientific Research from the Ministry of Education, Science and Culture. Then, a new category of healthy food, that is "Food for Specified Health Use" (FOSHU), was established. Toshihiko Osawa organized and held the First International Conference on Food Factors in Hamamatsu, Japan, in 1995. As examples of key achievements in basic science, the chemical identification of numerous active principles in foods, elucidation of their metabolism pathways, and mechanistic findings using "omics" technologies and the discovery of target molecules are remarkable. However, whether FOSHU truly contributes to public health is still unknown. In this minireview, the author looks back on functional food science in Japan to date and, at the same time, describes the prospects to share a vision of the future in the next 10 years.

Keratinocytes are the primary component of the epidermis, so maintaining the precise balance between proliferation and differentiation is essential for conserving epidermal structure and function. Rosae multiflorae fructus extract (RMFE) has wide application in the cosmetic industry, but the molecular mechanisms underlying beneficial effects on keratinocytes are still not fully understood. In this study, we found that RMFE promoted epidermal differentiation and enhanced the barrier function of normal human epidermal keratinocytes (NHEKs) and three-dimensional epidermis model in culture. In addition, RMFE promoted human umbilical vein endothelial cell (HUVEC) proliferation and angiogenesis, whereas the conditioned medium from RMFE-treated HUVECs further promoted NHEK proliferation and increased wound healing ability. Analysis of constituent bioactivities identified a quercetin derivative as a potential mediator of NHEK and HUVEC responses to RMFE. Taken together, these results suggest that RMFE enhances epidermal functions through both direct effects on keratinocytes and indirect effects mediated by endothelial cells.

The aromatic aldehyde synthase (AAS), PonAAS2, from the gall-inducing sawfly has been identified as a biosynthetic enzyme for indole-3-acetic acid (IAA), a key molecule of the plant hormone auxin, which is thought to play a role in gall induction. Unlike other insect AASs that convert Dopa, PonAAS2 uniquely converts L-tryptophan (Trp) into indole-3-acetaldehyde, a precursor of IAA. In this study, an examination of AAS enzymes from various insect species revealed that the ability to convert Trp has been acquired in only a very limited taxonomic group. Comparative analysis between PonAAS2 and DjAAS2 from a gall wasp showed that, despite having conserved substrate-recognition amino acids, they exhibit different substrate specificities. This difference likely arises from variations in how these enzymes' monomers interact during dimer formation, as demonstrated by amino acid substitution experiments and structural predictions.

This study developed water-dispersible γ-oryzanol (WD-OZ) using microemulsion system and assessed their absorption in rats. While γ-oryzanol itself is hardly soluble in water, WD-OZ exhibited high water dispersibility, and γ-oryzanol, along with its metabolites, was detected in rat plasma. These findings provide a solid basis for future application of the microemulsion-based approach to enhance the bioavailability of γ-oryzanol in food.

FMRFamide-like peptides (FLPs) and their receptors FMRFamide-related peptide receptors (FRPRs) are widely conserved in free-living and parasitic nematodes. Herein, we identified FRPR-1 as a of FLP-1 receptor candidate involved in larval development and diapause in the model nematode Caenorhabditis elegans. Our molecular genetic study, supported by in silico research, revealed the following: 1) frpr-1 loss-of-function completely suppresses the promotion of larval diapause caused by flp-1 overexpression; 2) AlphaFold2 analysis revealed the binding of FLP-1 to FRPR-1; 3) FRPR-1 as well as FLP-1modulates the production and secretion of the predominant insulin-like peptide DAF-28, which is produced in ASI neurons; and 4) the suppression of larval diapause by frpr-1 loss-of-function is completely suppressed by a daf-28 defect. Thus, FRPR-1 regulates larval development and diapause by modulating DAF-28 production and secretion. This study may provide new insights into the development of novel nematicides targeting parasitic nematodes using FRPR-1 inhibitors.

Food-derived polyphenols and some alkaloids have reported bioactivities related the prevention of systemic metabolic disorders such as obesity, glucose intolerance, and dyslipidemia. For food-derived components to exert their functions in vivo, it is essential the interaction with biological factors such as proteins, lipids, and nucleic acids. However, it is still unclear whether bioactive components in foods express functions related to their target factors. In this review, I introduce the target proteins in which food-derived components express functions in cells.

Obesity, often driven by high-fat diets (HFD), is a major global health issue, necessitating effective preventive measures. Tetragonia tetragonoides, a plant with known medicinal properties, has not been extensively studied for its effects on HFD-induced obesity and related genetic changes in mice. This study explores the impact of Tetragonia tetragonoides extract (TTE; 300 mg/kg) on obesity-related traits in C57BL/6J male mice, with a focus on transcriptomic changes in the liver and white adipose tissue (WAT). Over eight weeks, TTE supplementation led to significant reductions in obesity-related phenotypes and modulated gene expression altered by HFD. Key genes like Cd180 and MUPs, linked to immune responses and lipid metabolism, were notably influenced by TTE. The study highlighted TTE's effects on lipid metabolism pathways in the liver and immune processes in WAT, underscoring its potential as an anti-obesity agent, while advocating for further research into its bioactive components.

Plasmodium falciparum is a major cause of severe malaria. This protozoan infects human red blood cells and secretes large quantities of histidine-rich protein 2 (PfHRP2) into the bloodstream, making it a well-known diagnostic marker. Here, however, we identified PfHRP2 as a pathogenic factor produced by P. falciparum. PfHRP2 showed cell penetration and cytotoxicity against various human cells. PfHRP2 also exhibited significant cytotoxicity at concentrations found in P. falciparum-infected patients' blood (90-100 nM). We also showed that PfHRP2 binds to Ca2+ ions, localizes to intracellular lysosomes, increases lysosomal Ca2+ levels, and inhibits the basal level of autophagy by preventing autolysosome formation. Furthermore, the Ca2+-dependent cytotoxicity of PfHRP2 was suppressed by the metal ion chelator ethylenediaminetetraacetic acid. In summary, our findings suggest PfHRP2 as a crucial pathogenic factor produced by P. falciparum and its mode of action. Overall, this study provides preliminary insights into P. falciparum malaria pathogenesis.