Current Microbiology最新文献

Candida species are components of the normal intestinal microbiota and are under constant exposure to bacterial metabolites, including secondary bile salts. Secondary bile salts are produced by commensal bacteria in the intestine and not only affect lipid absorption through emulsification but also have great effects on other microorganisms. Here, we examined the effect of a secondary bile salt, sodium deoxycholate (NaDCA), on the formation of biofilms by Candida tropicalis. In contrast to C. albicans, C. tropicalis tended to maintain its absolute biofilm biomass and surface hydrophobicity in the presence of NaDCA. Fluorescent 3D microscopic imaging of the biofilm revealed that NaDCA treatment reduced filamentous projection to the top of the biofilm. RNA-seq analysis revealed that some genes, especially those associated with iron metabolism, were differentially expressed in NaDCA-treated C. tropicalis. Although NaDCA altered the appearance of C. tropicalis biofilms, analysis of the expression of key virulence factor genes encoding agglutinin-like sequences and candidalysin revealed that these genes were less affected by NaDCA in C. tropicalis than in C. albicans. High-iron exposure had a negative effect on C. tropicalis biofilm biomass. These results suggest a difference in the intestinal niche occupied by C. albicans and C. tropicalis according to the local availability of secondary bile salts.

In order to understand the influence of different parts of the low-temperature Daqu (LTD) on the fermentation of Jiupei. In this study, Jiupei was prepared separately using the peel and core of Houhuo LTD. The physicochemical properties, sensory characteristics, and microbial community structures of the two groups of Jiupei were subsequently analyzed using conventional physical and chemical assays, electronic tongue sensing, electronic nose sensing, and high-throughput sequencing. In terms of physicochemical indicators, the pH (3.08), protein content (5.97%), and reducing sugar content (3.70%) of peel-fermented Jiupei were significantly higher than those of core-fermented Jiupei (P < 0.05). In terms of taste, peel-fermented Jiupei exhibited significantly higher sourness, astringency, and aftertaste-A, whereas core-fermented Jiupei showed significantly stronger bitterness and umami intensity (P < 0.05). Moreover, core-fermented Jiupei was richer in aromatic compounds, whereas peel-fermented Jiupei contained higher levels of organic sulfides (P < 0.05). Finally, microbial analysis revealed that core-fermented Jiupei had significantly higher bacterial richness, bacterial diversity, and fungal diversity than peel-fermented Jiupei (P < 0.05). Notably, peel-fermented Jiupei was enriched with Lactobacillus (86.38%) and Saccharomycopsis (70.94%), while Bacillus (6.04%), Saccharomyces (29.32%), and Pichia (2.35%) showed dominance in core-fermented Jiupei (P < 0.05). Correlation analysis revealed that Lactobacillus, Bacillus, Lentilactobacillus, Saccharomycopsis, and Saccharomyces were the key genera influencing the physicochemical and sensory qualities of Jiupei. These findings demonstrate that core-fermented Jiupei exhibits richer microbial diversity, stronger umami taste, and higher aromatic compound levels. From this, it can be seen that Jiupei was prepared using the core of Houhuo LTD is beneficial for the growth of microorganisms and the formation of flavor quality in the Jiupei.

Passiflora edulis (P. edulis Sims) is prevalent in tropical regions, and its distinctive taste and aroma are highly appreciated due to its unique nutritional profile. With the increasing recognition of the added value of P. edulis Sims wine, an expanding number of researchers have begun to focus on the related studies concerning the brewing process of this wine. Isolating high-quality yeast strains from the natural fermentation broth of P. edulis Sims is crucial for this purpose. In this study, 38 yeast strains were isolated and purified from the fermentation broth of P. edulis Sims. Nine yeast strains were selected using WL medium for further analysis. The fermentation characteristics of these strains were evaluated based on their production of esters, ethanol, and hydrogen sulfide (H₂S), as well as through tolerance tests. The results indicated that the nine yeast strains exhibited favorable fermentation performance characterized by low H₂S production while demonstrating high levels of ester and ethanol production, along with certain antimicrobial activity. Among these strains, GZH-20 displayed a notably low capacity for H₂S production coupled with exceptional abilities in both ester and ethanol generation. Furthermore, this strain demonstrated good tolerance under various conditions, including pH levels ranging from 2.8 to 3.8, a glucose concentration of 200 g/L, and varying sulfur dioxide (SO₂) concentrations between 60 g/L and 360 g/L; it showed superior capacities for producing esters and ethanol under these conditions. Molecular identification confirmed that this strain is classified as Wickerhamomyces anomalus. These findings hold significant implications for advancing our understanding of specialized yeasts involved in P. edulis Sims wine production.

Bacteriophytochrome-derived near-infrared fluorescent proteins (NIR FPs) provide deep tissue penetration, low autofluorescence, and endogenous biliverdin compatibility, enabling non-invasive visualization of viral processes in living systems. Engineering advances (iRFPs, monomeric miRFPs, photoactivatable PAiRFPs) have improved brightness, stability, and genetic encodability for robust use in mammalian models. These reporters support real-time tracking of infection dynamics and host-virus interactions and power diagnostic platforms including reporter viruses, CRISPR-based assays, and nanotechnology-enhanced biosensors. Multimodal integration with photoacoustic tomography and PET further extends their translational utility. Remaining challenges include brightness/photostability limits and the need for broader translational validation, yet progress in structure-guided mutagenesis, computational/AI-assisted protein design, and hybrid imaging strategies promises to close these gaps. This mini-review synthesizes the design principles, viral imaging/detection use cases, and translational prospects of bacteriophytochrome-derived NIR FPs, highlighting their potential to advance viral surveillance, therapeutic evaluation, and precision diagnostics.

The virus communities of inland aquatic ecosystems have typically received less attention from the research perspective than those of marine ecosystems. In this study, we compared the viromes of an estuarine creek (Santana Creek) belonging to the khazan ecosystem and an agriculturally relevant freshwater lake (Verna Lake), both located in Goa, India. Taxonomically, the viral realm Duplodnaviria predominated in both the lake and creek communities, Varidnaviria had a minor presence in both, and Monodnaviria was exclusively present in the lake community. Sequences identified in the creek virome bore a greater resemblance to those of marine ecosystems than those in the lake virome. Functional annotation confirmed the taxonomic findings, indicating most proteins were involved in the infective and replicative functions of bacteriophages. Predicted complete viral genomes included those of Synechococcus and Proteus phages in the creek dataset, and of Gokushovirinae phages in the lake dataset. Viral communities of the khazan ecosystem and similar ecosystems worldwide are understudied, and hence the present virome analysis offers a valuable reference for further studies on these ecosystems.

Widespread chemical pesticide use in agriculture threatens environmental and human health, creating urgent demand for sustainable alternatives like entomopathogenic fungi. However, effective entomopathogenic fungi for Protaetia brevitarsis remain scarce. This study first isolated and identified the Aspergillus aculeatus strain JBQM-1 from naturally infected P. brevitarsis larvae. Its identity was confirmed via morphological analysis, ITS rDNA sequencing, and calmodulin gene phylogeny. The calmodulin gene was used to address the limitation of ITS alone in distinguishing closely related Aspergillus species, ensuring accurate identification. JBQM-1 spores showed time-dependent germination in potato dextrose broth(PDB)medium, reaching 96.75% by 8 h. This rapid germination is key to timely host infection, supporting its biocontrol potential. Pathogenicity assays revealed JBQM-1's dose- and time-dependent virulence: 71% larval mortality at 1.0 × 10⁹ conidia per milliliter by day 7, with no mortality in the first 48 h. A heat-inactivated control assay was conducted to rule out non-infectious factors. The heat-inactivated group had 6.67 ± 3.34% mortality, which was not statistically different from the control group's 4.44 ± 1.92% mortality. No hyphal outgrowth was observed on dead larvae from the heat-inactivated group after 72 h incubation in moist chambers. This confirms JBQM-1's high virulence, expands A. aculeatus' host range, and highlights its potential as a biocontrol agent, providing new microbial resources for sustainable pest control.