Microorganisms on the human skin and host form a close and complex community. Abnormal proliferation of certain commensal microorganisms can disrupt this balanced interaction, resulting in the development of skin diseases. Cosmetics is a significant factor affecting the balance of the skin microbiome. We focused a major commensal coagulase-negative Staphylococcus and evaluated the growth effect by five cosmetic ingredients including polyamines. Two polyamines showed notable effects, although others showed no impact effects. They significantly reduced the turbidity during the active growth phase and recovered in the stationary phase. During the death phase, they prolonged the stationary phase turbidity in a concentration-dependent manner, continued by the end of experiments. Our findings could be a previously uncharacterized effect under these experimental conditions.

Band-pass filters, which selectively transmit signals within a defined range of input magnitudes, are fundamental components of signal-processing systems. In cellular gene circuits, band-pass behavior has likewise been pursued as a mean to implement complex signal-processing functions. However, previously reported genetic band-pass circuits have typically relied not only on a large number of regulatory components but also on transcriptional cascades involving multiple transcription factors, resulting in long DNA sequences and increased circuit complexity. Here, we first propose a band-pass gene circuit that operates without transcriptional cascades. By co-expressing two variants of the transcription factor BetI that exhibit opposite input-response behaviors-one acting as an inducer-dependent activator and the other as an inducer-dependent repressor-band-pass filtering is achieved solely through differential tuning of their inducer sensitivities. This minimal architecture enables gene expression only within a specific range of intracellular choline concentrations. Furthermore, we demonstrate that this cascade-free band-pass circuit can be exploited to generate spatial expression patterns in Escherichia coli populations in response to a choline diffusion gradient, illustrating its utility for pattern formation in multicellular contexts.

Plastics are indispensable in modern society, but their increasing production and disposal pose serious environmental challenges, including pollution and the depletion of non-renewable resources. Poly(ethylene furanoate) (PEF), a bio-based polyester composed of ethylene glycol and 2,5-furandicarboxylic acid (FDCA), is attracting attention as a sustainable alternative to poly(ethylene terephthalate) (PET). In this study, we developed a fully biotechnological upcycling system for PEF. Our approach involved enzymatic depolymerization of PEF to release FDCA, followed by microbial conversion of FDCA into polyhydroxyalkanoate (PHA), a biodegradable polyester. From soil samples enriched with FDCA as the sole carbon source, we isolated two bacterial strains: Pseudomonas sp. S8-1 and Caballeronia sp. S8-5. These strains produced medium-chain-length and short-chain-length PHAs, respectively, in defined medium containing FDCA. For enzymatic depolymerization, we employed the thermostable ICCG variant (F243I/D238C/S283C/Y127G) of leaf-branch compost cutinase, known for its high PET-degrading activity. The depolymerization of PET by this enzyme was enhanced by the addition of calcium carbonate (CaCO3) powder to suppress acidification. Furthermore, the enzyme retained high activity even after partial purification by heat treatment at 60°C and efficiently depolymerized PEF as well. Finally, the PEF degradation solution was successfully utilized as a carbon source for PHA production by strain S8-5. These results demonstrate a proof-of-concept biorecycling system for PEF and represent a first step toward sustainable plastic management.

An efficient bacterial consortium (designated BPA-1), comprising Bacillus subtilis SX-6, Pseudomonas sp. SX-10, and Georgenia sp. SY-1, was successfully constructed for the decolorization of the azo dye Congo Red (CR). BPA-1 exhibited significant thermotolerance and heavy metal resistance, achieving over 90% CR decolorization within 60 h at 47°C under co-stress conditions with Zn²⁺, Mn²⁺, and Pb²⁺ (50 mg/L each). The consortium demonstrated broad substrate specificity, effectively decolorizing 12 structurally diverse azo dyes. Enzymatic assays revealed the involvement of laccase, manganese peroxidase, lignin peroxidase, and azoreductase in CR biodegradation. Metabolic pathway analysis indicated a three-stage degradation mechanism: (1) Asymmetric cleavage of azo bonds (-N=N-) generated 4,4'-diazaldenylbiphenyl and 4-amino-1-naphthalenesulfonic acid (Intermediate II); (2) Deamination converted Intermediate II to 3,4-dihydroxy-1-naphthalenesulfonic acid, followed by desulfurization to form naphthalene-1,2,3,4-tetraol; (3) Complete mineralization of intermediates occurred through subsequent oxidative steps. Notably, 4,4'-diazaldenylbiphenyl was further transformed into 4,4'-diaminobiphenyl, confirming the consortium's capacity for multi-step detoxification.

This study systematically elucidated the microbial community succession and functional gene dynamics during the postharvest spoilage process of Stropharia rugosoannulata by integrating physiological and biochemical indicators with metagenomic analysis. The experimental results demonstrated that as storage time extended, the activities of antioxidant enzymes (superoxide dismutase, peroxidase) in S. rugosoannulata significantly declined, while the content of membrane lipid peroxidation product malondialdehyde increased, leading to compromised cell membrane integrity and creating favorable conditions for microbial colonization. Metagenomic analysis revealed that during the spoilage phase (post-harvest day 14), the relative abundance of Pseudomonadota increased to 85.7%, with Pseudomonas replacing Ewingella as the absolutely dominant microbial population. Further functional gene analysis showed that the post-harvest day 14 exhibited significant enrichment of glycosyltransferases (GT0, GT1, GT2, GT4) and carbohydrate-binding modules (CBM10, CBM16, CBM50), along with pectinase (GH78), chitinase (GH19), and polysaccharide-modifying enzymes (CE4, CE11). This indicated a metabolic shift towards cell wall synthesis and substrate recognition. In contrast, the post-harvest day 7, prior to fruiting body softening, demonstrated high expression of glycoside hydrolases (GH1, GH2, GH4, GH94) and carbohydrate esterase CE8, focusing on the degradation of cellulose and starch. These findings, for the first time from a molecular ecology perspective, clarify that the essence of postharvest spoilage in S. rugosoannulata is a quality deterioration process driven by a Pseudomonas-dominated microbial community. The study provided a basis for the development of targeted antibacterial preservation strategies.

Sanghuangporus baumii polysaccharides (SBP) are recognized for their valuable pharmacological activities, driving increasing interest in their medicinal potential. However, the biosynthetic pathway of SBP remains incompletely characterized. Phosphoglucose isomerase (PGI), a key enzyme in carbohydrate metabolism, catalyzes the reversible isomerization between glucose-6-phosphate (G-6-P) and fructose-6-phosphate (F-6-P) and is hypothesized to regulate polysaccharide biosynthesis in this fungus. In this study, the pgi gene from S. baumii (sbpgi) was cloned and created sbpgi-silenced mutants using RNA interference (RNAi) to investigate its function. Silencing sbpgi resulted in an approximately 20% reduction in mycelial biomass but concurrently enhanced the production of exopolysaccharide (EPS) and intracellular polysaccharide (IPS) by approximately 2.0-fold and 1.9-fold after 9 days, respectively. Furthermore, suppression of sbpgi expression markedly decreased the content of cell wall β-1,3-glucan (by ~23%) while increasing chitin deposition by about 1.7-fold, leading to alterations in cell wall architecture, including thickness, and changes in stress tolerance. Transcriptional analysis revealed that sbpgi silencing significantly upregulated the expression of key genes in the polysaccharide biosynthetic pathway, including ugpg and pmm, highlighting the critical regulatory role of sbpgi in polysaccharide production. Our findings provide a foundation for metabolic engineering strategies to develop high-yielding strains for the industrial production of SBP.

Bacillus thuringiensis (Bt) has broad spectrum multipotent functionalities for pest and disease suppression, and growth promotion (PGP) of plants. Therefore, potency of 27 rice rhizospheric and 2 commercial Bt isolates was assessed for biocidal and PGP traits. Functionally rhizospheric Bts were broadly superior than commercial Bts. Virulence of the Bts varied against rice leaf folder (LF, Cnaphalocrocis medinalis) and stripe stem borer (SSB, Chilo suppresalis) larvae in laboratory, net house and field tests. Drosophila diet (DD) incorporation, cut leaf and field assays proved virulence of 5-9 Bt isolates against LF larvae with LC50s 1.99 - 6.31 x 108, 2.18 x 106 - 2.25 x 109 and 3.16 x 106 - 1.25 x 109 bacteria-spore-crystal (BSC)/ml, respectively, and TB261 was most (LC50s 2.18 x 106 - 3.98 x 108 BSC/ml) infective. DD and cut stem assays for SSB proved virulence of 5 and 6 Bts with LC50s 9.20 x 106 - 3.62 x 108 and 9.21 x 106- 3.24 x 108 BSC/ml, respectively, and maximum (LC50s 9.20 - 9.21 x 108 BSC/ml) infectivity of TB263. Eight Bts inhibited 1-4 out of 7 rice pathogens and 16 Bts antagonized 1-4 out of 9 entomopathogenic fungi. Biocidal principles of the Bts were cell wall/membrane hydrolyzing exoenzymes, toxin/inhibitors and crystal toxins. Furthermore, the Bts were also inhibited by 3 insecticides and 2 fungicides. The Bts possessed 1-4 PGP and phytostimulation traits also. The potent rhizospheric Bt can be prospected for overall improvement/sustenance of rice.

Superoxide dismutases (SODs) play crucial roles in cellular oxidative stress defense. In Aspergillus nidulans, SodB is a mitochondria-localized SOD whose physiological function remains poorly understood. Here, we show that a ΔsodB mutant displays impaired growth on non-fermentable carbon sources including acetate, ethanol, threonine, and Tween 20/80, suggesting compromised mitochondrial function. Oxygen consumption assays using an extracellular oxygen consumption reagent revealed a ~50% reduction in respiratory activity in the ΔsodB strain compared to the wild type. When mitochondrial respiration was inhibited by Antimycin A or salicylhydroxamic acid, giant colony growth was equally suppressed across wild-type, ΔsodA, ΔsodB, and complemented strains. However, conidial production was significantly reduced in ΔsodB under Antimycin A treatment, and morphological abnormalities in conidiophore heads were observed under this condition. These results indicate that SodB is not only involved in mitochondrial respiration but also required for maintaining normal sporulation under mitochondrial stress conditions. This study provides new insights into the role of mitochondrial ROS defense systems in filamentous fungal development.

At the 2025 Osaka/Kansai Expo, a bacterial-bioluminescence-based lighting system, called BIOLIGHT, was exhibited. It consists of 80 liters of liquid culture medium and produces enough brightness to illuminate a room. In this study, to make clear the relationship between the liquid culture thickness and the brightness using BIOLIGHT, the world's largest liquid culture aquarium of bioluminescent bacteria, we investigated the brightness of the bacterial liquid culture in relation to optical density (OD). The theoretical brightness of BIOLIGHT was calculated using the transmittance of the liquid culture at 475 nm (the peak luminescence wavelength) derived from the measured OD and was then compared with the brightness actually measured. The calculated (theoretical) brightness was lower than the measured one, suggesting that the light output of BIOLIGHT is influenced not only by cell-induced light shielding but also by another factor, presumably forward scattering. Additionally, depth-dependent brightness measurements showed that brightness became saturated at a liquid culture thickness greater than 7 cm. These findings will contribute to the design of future lighting solutions using bacterial bioluminescence.

Methionine gamma-lyase enzyme was isolated and purified from Mucor irregularis PQ344458 fungal isolates, that obtained from plant root, the isolates were identified through observation of their colony morphological features, implementation of PCR and DNA sequencing via sanger-chain termination approach, then data of DNA sequence alignment, phylogenetic tree, percent identity was generated. Through implementation of several stages that involved using of ion-exchange chromatography, gel-filtration chromatography, ammonium sulphate, enzyme isolation and purification stages were accomplished. The enzyme extract then, was analyzed for its protein content, specific activity and Impact of pH, temperature, inhibitors and activators on its kinetics. Additionally, MTT and DPPH radical scavenging assays were carried-out to reveal information about anti-cancer and anti-oxidant activities of methionine gamma-lyase enzyme. MTT assay results of %viable cells were 15% for HeLa cells and 6.6% for U937 cells at maximum concentration of the enzyme extract. Moreover, DPPH scavenging activity results were 82% at maximum concentration.