味之素

Antibiotic growth promoters (AGPs) are widely used in animal feed; however, owing to the risk of antimicrobial resistance, regulations on AGPs are being tightened, making it crucial to research and develop safe and effective alternatives. Probiotics are promising alternatives to AGPs, and studies have indicated their potential to enhance poultry growth performance. However, they are not cost-effective because of their inability to adequately resist acid and colonize the gut, resulting in the loss of viable cells. We examined the impact of Lactiplantibacillus plantarum TUA2424L on acid resistance, transepithelial electrical resistance (TEER) in Caco-2 cells, and genetic factors involved in colonization of the intestinal tract. L. plantarum TUA2424L exhibited robust resistance to acidic conditions at pH 2 for 1 h, and the culture supernatant of the strain enhanced TEER in Caco-2 cells (p < 0.01), similar to that of AGPs. Additionally, the results of the Basic Local Alignment Search Tool analysis indicated the presence of the glutamate decarboxylase gene and the elongation factor Tu gene in TUA2424L, which are associated with acid resistance and intestinal colonization, respectively. Furthermore, the use of protectants during the freeze-drying process, including skim milk (5.0), MSG (1.5), Arg HCl (1.5), Gln (1.0), and SiO₂ (0.35) (g/g_dry cell weight), maintained survivors at 108 CFUg− 1 in simulated gastric juice for 4 h (p < 0.05 compared with other conditions). These findings suggest that freeze-dried TUA2424L can be considered a potential candidate alternative to AGPs without the risk of superbug infection.

Background: L-tyrosine, classified as a dispensable amino acid, is widely consumed as a component of commonly consumed foods and as a dietary supplement. However, 4-week safety data on supplementation with this amino acid remain limited. Methods: The aim of this study was to evaluate the safety and tolerability of L-tyrosine supplementation over a 4-week period and to estimate the no-observed-adverse-effect level (NOAEL). In a randomized, double-blind, placebo-controlled crossover trial, 30 healthy adult men received L-tyrosine at graded daily doses (0, 1, 2, 3, or 4 g/day). Each participant received four of the five doses in a randomized sequence, with each intervention period separated by a 2-week washout period. The primary endpoints were clinical laboratory parameters, and the secondary endpoint was the incidence of adverse events. Anthropometric and dietary parameters were also assessed. In addition, plasma amino acid concentrations following L-tyrosine supplementation were evaluated as exploratory outcomes. Results: No clinically meaningful or statistically significant dose-related abnormalities were observed in hematological, biochemical, or electrolyte parameters at any dose. Anthropometric and dietary parameters remained unchanged. No serious adverse events occurred, and the incidence of mild-to-moderate adverse events was comparable to that observed with placebo. At the end of each supplementation period and under fasting conditions, plasma L-tyrosine concentrations modestly increased at the highest dose (4 g/day), whereas concentrations of other amino acids remained unchanged. Conclusions: Four-week supplementation with L-tyrosine at doses up to 4 g/day was well tolerated in healthy adult men and was not associated with biochemical and clinically relevant adverse effects under the conditions of this study. These findings suggest that 4 g/day represents the highest tested intake level without observable adverse effects and may serve as the NOAEL under the present 4-week study conditions.

Enzymatic deamidation of proteins, catalyzed by protein glutaminase (PG) for Gln or by protein asparaginase (PA) for Asn residues, is a key strategy for improving functional properties such as solubility and foaming. However, the only known PA, from Luteimicrobium album (LalPA), is a large, thermally unstable multidomain protein (1355 aa) that has proven challenging to express heterologously. To overcome these limitations, we identified a novel, compact PA from Amycolatopsis deserti (AdePA) using a comprehensive database search. We then solved the first experimental structure of any PA, which revealed a catalytic mechanism utilizing a Ser-His-Asp catalytic triad indicative of a serine protease-like function, which is distinct from that of L-asparaginase. AdePA offers significant advantages over LalPA; it is a smaller (785 aa) single-domain enzyme with superior thermal stability (retaining 50% activity at 40°C, where LalPA is inactivated) and is readily produced through heterologous expression. Furthermore, AdePA shows inverted substrate specificity, preferring sterically small N-terminal groups, making it highly effective for modifying unstructured proteins like gelatin. These findings demonstrate that AdePA is a robust candidate for industrial applications in protein modification.

ABSTRACT Intensive efforts have been made to capture structural features of the gut microbiome for assessing microbiota status in relation to host health. However, gut microbiome function emerges not only from individual microbial taxa but also from their organization into ecological guilds, complicating microbiome structure-function relationships. To address this challenge, we applied a co-abundance-based analytical framework to identify gut microbiome types (GMTs) across a discovery cohort (D-cohort) and an independent validation cohort (V-cohort) of Japanese adults. Using paired fecal samples collected one month apart from 116 participants in the D-cohort, we identified 27 co-abundance groups (CAGs) based on 16S rRNA amplicon sequence variants. These CAGs defined seven GMTs (MT-1 to MT-7) with characteristic short-chain fatty acid and bile acid profiles. The GMTs showed temporal stability, with more than 70% of participants remaining in the same GMT across sampling points. The 27-CAG framework classified 404 participants in the independent V-cohort into the seven GMTs, which represented reproducible microbial ecological states across cohorts. MT-4 exhibited dysbiosis-like features, including reduced microbial diversity, depletion of Faecalibacterium and butyrate, and enrichment of inflammation-associated taxa, and was associated with higher alcohol consumption and elevated γ-glutamyl transferase levels. In contrast, Bifidobacterium -enriched MT-5 was associated with favorable renal function profiles. Collectively, co-abundance-defined microbial guilds capture coherent ecological and functional states of the gut microbiota, providing a transferable framework for linking gut microbiome organization to host physiology beyond conventional taxonomy-based classification.

Automotive radar and other sensing applications are driving interconnect operation into the sub-terahertz frequency regime, particularly across the G-band (100–300 GHz) and beyond, where dielectric materials experience increased frequency-dependent attenuation and temperature-induced electrical variation. This work presents the first temperature-dependent electrical characterization of Ajinomoto Build-up Film® (ABF) Type-A dielectric material from 10 to 220 GHz. Dielectric properties at elevated temperatures (80°C and 115°C) are extracted using the microstrip ring resonator (MRR) method. In addition, microstrip transmission lines fabricated on 30 µm-thick ABF Type-A using a semi-additive patterning (SAP) process were used to evaluate insertion loss behavior. Results show that the dielectric constant (Dk) increases with both frequency and temperature. At 80°C, the extracted dielectric constant (Dk) increases from 3.412 at 16.5 GHz to 3.491 at 216 GHz, while at 115°C it varies from 3.419 to 3.532 over the same frequency range. The loss tangent (Df) reaches 0.0091 at 80 °C and 0.0101 at 115 °C at 216 GHz. Consistent with these material trends, microstrip lines exhibit maximum average insertion loss of 0.519 dB/mm at 80°C and 0.596 dB/mm at 115°C at 200 GHz. These results demonstrate stable dielectric performance under elevated temperature conditions and confirm the suitability of ABF Type-A for high-frequency, multi-layer chip embedding and glass-based antenna-in-package architectures intended for next-generation sensing and communication platforms.