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Biological control is considered one of the most important methods for preventing and controlling the worldwide fungal disease gray mold, caused by Botrytis cinerea. Among the various agents used in biological control, actinomycetes represent a significant group of microorganisms that offer valuable resources for biocontrol strategies. In this study, a total of 132 actinomycetes, belonging to four genera (Streptomyces, Kitasatospora, Amycolatopsis, and Nocardia), were isolated from soil. Among the five media tested, ISP-2 and GS NO.1 media were found to be highly suitable for isolating actinomycetes. It is worth mentioning that the strain TCS21-117 displayed significant inhibitory effects against Botrytis cinerea and nine other pathogenic fungi. The strain TCS21-117 was identified as Streptomyces roietensis by its morphological characteristics and phylogenetic analysis of the 16S rRNA gene. The optimum culture conditions for the strain TCS21-117 were a potato dextrose broth medium at an initial pH of 8.0, a liquid volume of 125 mL in a 250 mL flask, 180 r·min⁻¹ at 28 °C, and an inoculum size of 1% for 7 days. Under these conditions, the inhibition rate against Botrytis cinerea was 93.31%, a significant increase (31.98%) as compared to the control. Notably, the antifungal compounds produced by the strain TCS21-117 exhibited strong stability across a range of temperatures, pH levels, and durations of storage and UV irradiation. This study showed that the Streptomyces roietensis strain TCS21-117 had strong inhibitory activity against Botrytis cinerea under optimized fermentation conditions, enriching the microbial resources for gray mold control. Full article

The Aedes aegypti mosquito serves as a vector for several diseases, including dengue, Zika, chikungunya, and yellow fever. This species is well adapted to urban environments and poses a significant threat to public health. Some studies suggest that the gut bacteria of insect vectors may play a crucial role in developing resistance to insecticides. This study assessed the resistance of Ae. aegypti from Florencia, Caquetá, to temephos and deltamethrin and analyzed the diversity of gut bacteria in resistant larvae and adult females. Larvae exhibited resistance to temephos at a lethal concentration 50 (LC₅₀) of 0.034 µg/mL, while females showed resistance to deltamethrin at a discriminant concentration of 10 µg/mL. The bacterial load in the guts of deltamethrin-treated females (3.42 × 10⁶ CFU/mL) was significantly higher compared to temephos-treated larvae (9.4 × 10⁵ CFU/mL) and untreated females (8 × 10⁴ CFU/mL). A total of sixty-eight bacterial strains were isolated from the guts of both larval and resistant females Ae. aegypti, with 31 strains identified through 16S rRNA gene analysis and 11 confirmed by gyrB gene sequencing. In untreated females, Bacillus comprised 12.55% of the gut bacteria and was identified as an exclusive genus. In resistant larvae, Serratia was the most abundant and exclusive genus, accounting for 35.29%, while in resistant females, Cedecea was the predominant genus, representing 66.67%. These findings suggest that gut bacteria may influence the resistance of Ae. aegypti to temephos and deltamethrin. Furthermore, this research provides valuable information that can be considered for the design of local vector control strategies. The results highlight new research focused on the study of insecticide tolerance and degradation within the gut microbiota of insect vectors of arboviruses. Full article

Biofilms in aquaculture tanks pose significant challenges, hindering cleaning processes and contributing to antibiotic resistance. This study investigated the effects of four Pseudoalteromonas strains on flat oyster (Ostrea edulis) rearing, with a specific focus on biofilm control and microbial communities. After confirming the safety of these strains for O. edulis, we monitored biofilm development and bacterial communities during a 4-month sexual maturation period. Biofilm biovolume was quantified using confocal laser scanning microscopy (CLSM), and bacterial community composition was analyzed via 16S rRNA gene metabarcoding of both biofilm and seawater samples. Our results revealed differences in bacterial community structure between biofilms and seawater. Furthermore, the presence of specific Pseudoalteromonas strains significantly impacted the composition of bacterial communities within the tanks. β-diversity analyses demonstrated that each strain exerted a unique influence on the bacterial community structure. Some Pseudoalteromonas strains effectively reduced biofilm biovolume without negatively impacting bacterial richness or diversity. These observations suggest that certain Pseudoalteromonas strains can effectively control biofilm formation while maintaining a diverse and potentially beneficial microbial community in O.edulis rearing tanks. The use of these strains as additives in aquaculture systems could offer several advantages, including reduced cleaning time and costs and a potential decrease in biocide usage. Full article

Background/Objectives: In chronic hepatitis B infection (CHB), the hepatitis B surface antigen (HBsAg) continuously exhausts the hepatitis B surface antibody (HBsAb), which leads to the formation of immune tolerance. Accordingly, the hepatitis B virus (HBV) infection can be blocked by inhibiting the binding of the hepatitis B surface pre-S1/pre-S2 antigen to the hepatocyte receptor NTCP, but the clinical cure rate of pre-S-based vaccines for CHB is limited. Methods: In this study, we designed and prepared multivalent hepatitis B therapeutic mRNA vaccines encoding three hepatitis B surface antigen proteins (L, M, and S) at the cell membrane, verified via in vitro transfection and expression experiments. An in vivo immunization experiment in HBV transgenic (Tg) mice was first completed. Subsequently, an adeno-associated virus plasmid vector carrying the HBV1.2-fold genome (pAAV HBV1.2) model and the adeno-associated virus vector carrying HBV1.3-fold genome (rAAV HBV1.3) model were constructed and immunized with mRNA vaccines. The HBV antigen, antibodies, and HBV DNA in serum were detected. Indirect (enzyme-linked immunosorbent assay) ELISA were made to analyze the activated antigen-specific IgG in HBV Tg mice. Antigen-dependent T-cell activation experiments were carried out, as well as the acute toxicity tests in mice. Results: The L protein/pre-S antigens could be stably presented at the cell membrane with the support of the S protein (and M protein). After vaccinations, the vaccines effectively reactivated the production of high levels of HBsAb, disrupted immune tolerance, and activated the production of high-affinity antibodies against structural pre-S antigen in HBV Tg mice. The HBsAg seroconversion and serum HBV DNA clearance were achieved in two HBV mice models. Furthermore, pre-S antigen-dependent T-cell response against HBV infection was confirmed. The therapeutic vaccine also showed safety in mice. Conclusions: A novel therapeutic mRNA vaccine was developed to break through HBsAg-mediated immune tolerance and treat CHB by stably presenting the pre-S antigen at the membrane, and the vaccine has great potential for the functional cure of CHB. Full article

This study aimed to investigate the effects of early-life supplementation with Lactiplantibacillus plantarum LPJZ-658 on the growth performance and gut microbiota of newborn piglets. Twelve one-day-old suckling piglets were randomly divided into two groups: the control group (C) was orally administered saline and the LPJZ-658 group (LP) was gavaged with 1.0 × 10¹⁰ cfu LPJZ-658. The supplementation was carried out once daily for 28 days. Fresh fecal samples were collected at 7 and 28 days, respectively. The microbiota composition (16S rRNA gene amplicon sequencing) and its predicted functions (PICRUSt2) were analyzed. The body weight and average daily weight gain were significantly increased in the LP group. Statistically significant differences were observed in bacterial diversity and composition of the gut microbial community between the C and LP groups. The predominant bacterial phylum in the piglets changed from Firmicutes, Bacteroidetes, and Proteobacteria at day 7 to Firmicutes, Bacteroidetes, and Spirochaetota at day 28 in both the C group and LP group. We found that LPJZ-658 supplementation suppressed a significant decrease in the relative abundance of Bacteroidota in suckling piglets at 28 days. At the genus level, LPJZ-658 reduced the relative abundance of pathogenic genera such as Clostridium sensu stricto 1, and increased the relative abundance of beneficial genera such as Ruminococcus, Christensenellaceae_R-7_group, Turicibacter, and UCG-002. KEGG metabolic pathway analysis showed that LPJZ-658 may improve amino acid metabolism by regulating the intestinal microbiota of suckling piglets. In summary, the early-life LPJZ-658 interventions significantly improve the growth performance of suckling piglets by the modulation of the gut microbiota. Full article

Urogenital infections impact millions of individuals globally each year, with vulvovaginal candidiasis (VVC) being one of the most prevalent conditions affecting women. Candida albicans is the primary pathogen responsible for VVC. The utilization of probiotics as an alternative therapeutic approach to antibiotics in managing such infections has gained increasing attention. This study aimed to evaluate the potential of THY-F51, a lactic acid bacterium isolated from kiwi, as a probiotic to support vaginal health through its antifungal, anti-biofilm, and anti-inflammatory properties against C. albicans. The identification of THY-F51 was confirmed through 16S rRNA gene sequencing. A series of evaluations were performed to determine its antifungal efficacy against C. albicans, biofilm-inhibitory activity, antioxidant properties, and effects on inflammatory cytokines. Cytotoxicity assays and assessments of bacterial survival under vaginal pH conditions (pH 3.8–4.5) were also conducted. The results demonstrated that THY-F51, identified as Leuconostoc citreum, exhibited potent antifungal activity against C. albicans, with an MIC of 1.25 mg/mL and an MFC of 2.5 mg/mL. Furthermore, THY-F51 displayed a strong inhibition of C. albicans biofilm formation, as well as notable antioxidant activity in the supernatant. Additionally, THY-F51 demonstrated high survival rates under vaginal pH conditions, an absence of cytotoxic effects, and a significant reduction in C. albicans adhesion to HeLa cells. Moreover, THY-F51 effectively suppressed C. albicans-induced inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-8. These findings suggest that THY-F51, isolated from kiwi, holds substantial promise as a safe and effective probiotic for reducing vaginal inflammation and promoting vaginal health. Full article

The relationship between microbial communities and mineralogical/mechanical changes was studied regarding the biodeterioration of Portland cement (PC) and calcium sulfoaluminate cement (CSAC) in a wastewater treatment plant. An in situ experiment was conducted by submerging 12 independent PC and CSAC specimens in a sand-trap structure for 10, 30, 75, 150, and 240 days. The microbiological analyses of the 16S rRNA genes of bacteria and Archaea from the biofilms and the geochemical analysis were performed on the studied specimens. The results showed that while there were characteristic changes in PC specimens over time, CSAC specimens showed few biodeterioration effects. The dominant bacteria identified from the biofilms of specimens belonged to the classes of Gammaproteobacteria (8.4–32.4%), Bacilli (1.6–21.6%), Clostridia (4–15.4%), Bacteroidia (2–18.8%), Desulfovibronia (0.5–19%), Campylobacteria (0.4–26.8%), and Actinobacteria (1.8–12.8%). The overall relative abundance of the bacteria linked to biodeterioration processes increased to more than 50% of the total bacterial communities after 75 days of sewage exposure and was found to be strongly correlated with several PC deterioration parameters (e.g., mass loss, calcite and ettringite minerals), whereas no significant correlation was revealed between these genera and CSAC characteristics. Full article

The family Rhinonyssidae includes endoparasitic, blood-feeding mites that are parasitic on birds and that remain largely unstudied despite their potential role as vectors or reservoirs for various pathogens, like other Dermanyssoidea. Traditionally, the taxonomy of the group has been based on morphometric characteristics, which makes identification very difficult in many groups of closely related species. On the other hand, studies on the phylogenetic relationships within this group of mites have been neglected until the early years of the present century. In this study, twelve species belonging to five different species complexes were identified, and domains D1–D3 28S rRNA of each one were sequenced, for the first time, to investigate the sequence variation and its taxonomic implications for phylogenetic inference. Our data indicate that this molecular marker can effectively differentiate between species within the “motacillae”, “sairae”, “pari”, and “hirsti” complexes of the genus Ptilonyssus and the “melloi” and “columbae” complexes of the genus Tinaminyssus. Furthermore, the phylogenetic tree that can be derived from the domain D1–D3 28S rRNA sequences presented in this study is congruent with the current taxonomy of the Rhinonyssidae. This research calls for a reassessment of the taxonomic status of some group of species. Full article

The Taklamakan Desert is an extreme environment supporting a unique and diverse microbial community with significant potential for exploration. Strain TRM70308^T, isolated from desert soil, shares 98.43% 16S rRNA gene sequence similarity with Streptomyces alkaliterrae OF1^T. Polyphasic taxonomy confirmed TRM70308^T as a novel species, named Streptomyces xanthus. Genomic analysis revealed that only one of the strain’s 25 biosynthetic gene clusters (BGCs) formed a cluster of gene families (CGFs) within the MIBiG database, emphasizing its genomics uniqueness. LC-MS/MS and Feature-Based Molecular Networking (FBMN) identified 33 metabolites across various categories, including alkaloids, saponins, benzoic acids, and benzofurans, most of which remain uncharacterized. Further chemical investigation led to the isolation of one novel compound, aconicarpyrazine C, and four known compounds: thiolutin, dibutyl phthalate, bis(2-ethylhexyl) phthalate, and N-acetyltryptamine. Thiolutin exhibited strong activity against five local fungal pathogens that cause plant diseases, with a production yield of 270 mg/L. These results establish a foundation for pilot-scale thiolutin production and its potential development as an antifungal agent for agricultural applications. Our findings highlight deserts as a valuable source of novel actinomycetes and bioactive natural products with immense potential for future research and development. Full article

Background/Objectives: Diabetes mellitus is often accompanied by mental health complications, including anxiety, depression, and cognitive decline. Recent research suggested that capsaicin, the active component of chili peppers, may influence mental health. This study aimed to determine the effect of dietary capsaicin on mental disorders in a type 1 diabetes (T1D) mouse model, while also exploring the potential involvement of the microbiota-gut-brain axis. Methods: We induced T1D in mice using streptozotocin (STZ) and administered a diet supplemented with 0.005% capsaicin for five weeks. Behavioral assessments, including the open field test (OFT), tail suspension test (TST), forced swimming test (FST), elevated plus maze (EPM) test, and Morris water maze (MWM) test, were conducted to evaluate depressive and anxiety-like behaviors as well as cognitive function. Targeted and untargeted metabolomics analyses were performed to assess neurotransmitter levels in the hippocampus and serum metabolites, while 16S rRNA sequencing was utilized to analyze gut microbiota composition. Intestinal barriers were determined using western blot detection of the tight junction proteins ZO-1 and occludin. Results: Dietary capsaicin exacerbated anxiety and depressive-like behaviors along with cognitive declines in T1D mice. Capsaicin reduced gut microbiota diversity and levels of beneficial bacteria, while broad-spectrum antibiotic treatment further intensified anxiety and depression behaviors. Metabolomic analysis indicated that capsaicin disrupted metabolic pathways related to tryptophan and phenylalanine, leading to decreased neuroprotective metabolites, such as kynurenic acid, hippurate, and butyric acid. Additionally, capsaicin diminished the expression of ZO-1 and occludin, indicating increased intestinal permeability. Conclusions: Dietary capsaicin aggravates gut microbiota and metabolic disturbances in diabetic mice, thereby worsening anxiety, depression, and cognitive decline. Full article

Dry-aged beef has gained interest worldwide in recent years due to its improved sensory attributes. This enhancement is thought to be partially driven by microbial activities, particularly lipolysis and proteolysis. In this study, dry-aged beef manufactured by seven commercial producers in China was analyzed. The pH value and total volatile base nitrogen value of dry-aged beef were determined. High-throughput amplicon sequencing of full-length 16S rRNA genes and internal transcribed spacer (ITS) regions was used to analyze the microbial community. A total of 207 proteolytic and lipolytic isolates were identified by sequencing 16S rRNA genes for bacteria and sequencing the D1/D2 region of 28S rRNA genes and the ITS region for fungi. The results revealed that the crust harbored greater numbers of bacteria and fungi than the interior. The bacterial community was dominated by Pseudomonas species, which were core members in both the crust and interior, while Brochothrix thermosphacta was identified as a core bacterium exclusively in the crust. The fungal community primarily constituted Candida sake, Kurtzmaniella species, and members of the phylum Chytridiomycota. Proteolytic and lipolytic isolates were mainly identified as Pseudomonas sp., B. thermosphacta, Carnobacterium maltaromaticum, Candida zeylanoides (teleomorph: Kurtzmaniella zeylanoides), C. sake, and Debaryomyces hansenii. Two strains of C. zeylanoides and C. sake exhibiting high proteolytic and lipolytic activities effectively hydrolyzed beef fat, myofibrillar protein, and sarcoplasmic protein. This study characterized the main microorganisms and their enzymatic functions associated with dry-aged beef, highlighting the need to explore their contributions to the sensory attributes of dry-aged beef. Full article

Crab roe sauce (CRS) is prone to spoilage due to microbial contamination. Therefore, this study aimed to investigate the inhibitory effects and mechanisms of a mixed bio-preservative (0.025% ε-polylysine hydrochloride (ε-PL) + 0.01% nisin (NS) + 0.01% tea polyphenols (TPs)) on the specific spoilage bacteria (SSB) in CRS. First, the SSB in CRS were isolated and identified by 16S rRNA sequencing. Two isolates were selected as representative strains based on their enzymatic spoilage potential and spoilage capability in CRS. By comparing the inhibition zones, ε-PL, NS, and TPs were selected from five conventional bio-preservatives (ε-PL, NS, TPs, grape seed extract (GSE), and rosemary extract (RE)) to prepare the mixed bio-preservative. The results showed that the minimum inhibitory concentration (MIC) of the mixed bio-preservative against Bacillus pumilus and Bacillus subtilis was 56.3 µg/mL. The growth curves and cell viability tests revealed that the mixed bio-preservative reduced the viability of both strains. The conductivity, alkaline phosphatase activity, and nucleic acid and soluble protein leakage indicated that the mixed bio-preservative disrupted the integrity of the cell walls and membranes of the two isolates in a concentration-dependent manner. Scanning electron microscopy further confirmed the damage to the cell membranes of the two isolates by the mixed bio-preservative. Overall, the mixed bio-preservative exhibited excellently inhibitory effects on the SSB and could be a promising method for the preservation of CRS. Full article

Microbial diversity plays a crucial role in litter decomposition. However, the relationships between microbial diversity and substrate successional stage are the drivers of this decomposition. In this study, we experimentally manipulated microbial diversity and succession in post-mining soil. We used leaf litter samples from two forests of a post-mining site near Sokolov, Czech Republic: one alder plantation and one mixed forest with birch aspen and willow. Litter from each site was decomposed in the field for 3 and 12 months. The litter was X-ray sterilized and part of the litter was kept unsterilized to produce inoculum. Leaf litter samples of two different ages (3 and 12 months) from each site were each inoculated with litter of two different ages (3 and 12 months), using less and more diluted inoculum, producing two levels of microbial diversity. In each of these eight treatments, the bacterial community was then characterized by amplicon sequencing of the 16S rRNA gene and microbial respiration was used to assess the rate of decomposition. A significantly higher respiration (p < 0.05) was found for the litter inoculated with the higher level of microbial diversity. Higher respiration was also found for the younger litter compared to the older litter and both litter origins. This shows a reduction in microbial respiration with substrate age and inoculation diversity, suggesting that microbial diversity supports the decomposition of soil organic matter. Full article

The screening of cellulose-degrading microorganisms from herbivores and the optimization of fermentation conditions are of great significance for the utilization of cellulose resources. In this study, we initially employed a metagenomic analysis to investigate the fecal microbiota of both captive and semi-free-ranging Père David’s deer (Elaphurus davidianus) under varying environmental conditions. Subsequently, we isolated and cultured cellulase-degrading microorganisms from the fecal samples using Congo red medium. There was consistency in the dominant phyla and genera of gut microorganisms between the two groups, with only differences in abundance. Then, a cellulose-degrading strain identified as Bacillus pumilus XM was isolated after a morphological analysis and molecular identification by 16S rRNA amplicon. In addition, a series of single factor experiments and response surface analysis were conducted to determine the optimal conditions for best cellulase activity. The optimum temperature, culture time, and shaking speed for the reaction of cellulase produced by the strain Bacillus pumilus XM were 34 °C, 28 h, and 154 r/min, respectively. Under these conditions, the cellulase activity reached a maximum of 10.96 U/mL, which was relatively close to the predicted value of 10.975 U/mL. The results have enriched the existing bacterial resources and laid a foundation for the development of new enzymes, providing a theoretical basis for the rational utilization of cellulase from wild animal resources. Full article

A new species of Asian horned toad, Boulenophrys, is described from Yongzhou City, Hunan Province, China. The species is a phylogenetically sister to B. yunkaiensis, based on 16S rRNA and COI genes. The new species differs from its congeners, possessing the following combination of characters: (1) moderate body size: SVL 37.6–40.2 mm (38.9 ± 1.3, n = 7) in adult males and SVL 41.8–45.9 mm (43.6 ± 2.1, n = 3) in adult females; (2) tympanum boundary clear: TD/ED 0.48–0.57 in males and 0.47–0.57 in females; (3) the presence of a small horn-like tubercle at the edge of the upper eyelid; (4) vomerine ridge present and vomerine teeth absent; (5) margin of tongue rounded, not notched posteriorly; (6) rough dorsal skin: a discontinuous “V”-shaped ridge with two discontinuous dorsolateral ridges on two sides on the back, dense tubercles on the skin of the ventral surface of the dorsal shank and thigh, and spiny tubercles surrounding the cloaca; (7) slender hindlimbs with heels overlapping when the flexed hindlimbs are held at right angles to the body axis; tibio-tarsal articulation reaching forward between anterior margin of tympanum and posterior corner of eye when leg stretched forward; (8) relative finger length IV < II < I < III, with a subarticular tubercle present at the base of each finger; (9) distinct supernumerary tubercles below the base of I and II toes; (10) toes without lateral fringes and with rudimentary webbing (webbing formula: I1 − 1-II1 − 2-III2 − 3IV3- − 2V). Full article