-
Current Microbiology May 2024The fungus Monascus is a well-known source of secondary metabolites with interesting pharmaceutical and nutraceutical applications. In particular, Monascus pigments...
The fungus Monascus is a well-known source of secondary metabolites with interesting pharmaceutical and nutraceutical applications. In particular, Monascus pigments possess a wide range of biological activities (e.g. antimicrobial, antioxidant, anti-inflammatory or antitumoral). To broaden the scope of their possible application, this study focused on testing Monascus pigment extracts as potential photosensitizing agents efficient in antimicrobial photodynamic therapy (aPDT) against bacteria. For this purpose, eight different extracts of secondary metabolites from the liquid- and solid-state fermentation of Monascus purpureus DBM 4360 and Monascus sp. DBM 4361 were tested against Gram-positive and Gram-negative model bacteria, Bacillus subtilis and Escherichia coli and further screened for ESKAPE pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. To the bacterial culture, increasing concentration of extracts was added and it was found that all extracts showed varying antimicrobial activity against Gram-positive bacteria in dark, which was further increased after irradiation. Gram-negative bacteria were tolerant to the extracts' exposure in the dark but sensitivity to almost all extracts that occurred after irradiation. The Monascus sp. DBM 4361 extracts seemed to be the best potential candidate for aPDT against Gram-positive bacteria, being efficient at low doses, i.e. the lowest total concentration of Monascus pigments exhibiting aPDT effect was 3.92 ± 1.36 mg/L for E. coli. Our results indicate that Monascus spp., forming monascuspiloin as the major yellow pigment and not-forming mycotoxin citrinin, is a promising source of antimicrobials and photoantimicrobials.
Topics: Monascus; Anti-Bacterial Agents; Mycelium; Microbial Sensitivity Tests; Photosensitizing Agents; Biological Products; Gram-Positive Bacteria; Complex Mixtures; Pigments, Biological; Photochemotherapy
PubMed: 38771359
DOI: 10.1007/s00284-024-03725-6 -
Scientific Reports May 2024Intercropping with Pleurotus ostreatus has been demonstrated to increase the tea yield and alleviate soil acidification in tea gardens. However, the underlying...
Intercropping with Pleurotus ostreatus has been demonstrated to increase the tea yield and alleviate soil acidification in tea gardens. However, the underlying mechanisms remain elusive. Here, high-throughput sequencing and Biolog Eco analysis were performed to identify changes in the community structure and abundance of soil microorganisms in the P. ostreatus intercropped tea garden at different seasons (April and September). The results showed that the soil microbial diversity of rhizosphere decreased in April, while rhizosphere and non-rhizosphere soil microbial diversity increased in September in the P. ostreatus intercropped tea garden. The diversity of tea tree root microorganisms increased in both periods. In addition, the number of fungi associated with organic matter decomposition and nutrient cycling, such as Penicillium, Trichoderma, and Trechispora, was significantly higher in the intercropped group than in the control group. Intercropping with P. ostreatus increased the levels of total nitrogen (TN), total phosphorus (TP), and available phosphorus (AP) in the soil. It also improved the content of secondary metabolites, such as tea catechins, and polysaccharides in tea buds. Microbial network analysis showed that Unclassified_o__Helotiales, and Devosia were positively correlated with soil TN and pH, while Lactobacillus, Acidothermus, and Monascus were positively correlated with flavone, AE, and catechins in tea trees. In conclusion, intercropping with P. ostreatus can improve the physical and chemical properties of soil and the composition and structure of microbial communities in tea gardens, which has significant potential for application in monoculture tea gardens with acidic soils.
Topics: Soil Microbiology; Pleurotus; Plant Roots; Tea; Microbiota; Soil; Rhizosphere; Camellia sinensis; Nitrogen; Phosphorus; Fungi; Bacteria; Hydrogen-Ion Concentration
PubMed: 38760401
DOI: 10.1038/s41598-024-61883-w -
Biotechnology For Biofuels and... May 2024Taurine, a semi-essential micronutrient, could be utilized as a sulfur source for some bacteria; however, little is known about its effect on the accumulation of...
Taurine-mediated gene transcription and cell membrane permeability reinforced co-production of bioethanol and Monascus azaphilone pigments for a newly isolated Monascus purpureus.
BACKGROUND
Taurine, a semi-essential micronutrient, could be utilized as a sulfur source for some bacteria; however, little is known about its effect on the accumulation of fermentation products. Here, it investigated the effect of taurine on co-production of bioethanol and Monascus azaphilone pigments (MonAzPs) for a fungus.
RESULTS
A newly isolated fungus of 98.92% identity with Monascus purpureus co-produced 23.43 g/L bioethanol and 66.12, 78.01 and 62.37 U/mL red, yellow and orange MonAzPs for 3 d in synthetic medium (SM). Taurine enhanced bioethanol titer, ethanol productivity and ethanol yield at the maximum by 1.56, 1.58 and 1.60 times than those of the control in corn stover hydrolysates (CSH), and red, yellow and orange MonAzPs were raised by 1.24, 1.26 and 1.29 times, respectively. Taurine was consumed extremely small quantities for M. purpureus and its promotional effect was not universal for the other two biorefinery fermenting strains. Taurine intensified the gene transcription of glycolysis (glucokinase, phosphoglycerate mutase, enolase and alcohol dehydrogenase) and MonAzPs biosynthesis (serine hydrolases, C-11-ketoreductase, FAD-dependent monooxygenase, 4-O-acyltransferase, deacetylase, NAD(P)H-dependent oxidoredutase, FAD-dependent oxidoredutase, enoyl reductase and fatty acid synthase) through de novo RNA-Seq assays. Furthermore, taurine improved cell membrane permeability through changing cell membrane structure by microscopic imaging assays.
CONCLUSIONS
Taurine reinforced co-production of bioethanol and MonAzPs by increasing gene transcription level and cell membrane permeability for M. purpureus. This work would offer an innovative, efficient and taurine-based co-production system for mass accumulation of the value-added biofuels and biochemicals from lignocellulosic biomass.
PubMed: 38702823
DOI: 10.1186/s13068-024-02511-7 -
Foods (Basel, Switzerland) Apr 2024Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further...
Grape pomace seeds contain abundant phenolic compounds, which are also present in both soluble and insoluble forms, similar to many other plant matrices. To further increase the extractable soluble phenolics and their antioxidant activities, grape pomace seeds were fermented with different fungi. Results showed that solid-state fermentation (SSF) with , , and at 28 °C and 65% humidity had a significantly positive impact on the release of soluble phenolics in grape pomace seeds. Specifically, SSF with increased the soluble phenolic contents by 6.42 times (calculated as total phenolic content) and 6.68 times (calculated as total flavonoid content), leading to an overall improvement of antioxidant activities, including DPPH (increased by 2.14 times) and ABTS (increased by 3.64 times) radical scavenging activity. Furthermore, substantial changes were observed in the composition and content of individual phenolic compounds in the soluble fraction, with significantly heightened levels of specific phenolics such as chlorogenic acid, syringic acid, ferulic acid, epicatechin gallate, and resveratrol. Notably, during SSF, positive correlations were identified between the soluble phenolic content and hydrolase activities. In particular, there is a strong positive correlation between glycosidase and soluble phenols (r = 0.900). The findings present an effective strategy for improving the soluble phenolic profiles and bioactivities of grape pomace seeds through fungal SSF, thereby facilitating the valorization of winemaking by-products.
PubMed: 38672831
DOI: 10.3390/foods13081158 -
Applied Microbiology and Biotechnology Mar 2024Monascus spp. are commercially important fungi due to their ability to produce beneficial secondary metabolites such as the cholesterol-lowering agent lovastatin and...
Monascus spp. are commercially important fungi due to their ability to produce beneficial secondary metabolites such as the cholesterol-lowering agent lovastatin and natural food colorants azaphilone pigments. Although hyphal branching intensively influenced the production of these secondary metabolites, the pivotal regulators of hyphal development in Monascus spp. remain unclear. To identify these important regulators, we developed an artificial intelligence (AI)-assisted image analysis tool for quantification of hyphae-branching and constructed a random T-DNA insertion library. High-throughput screening revealed that a STE kinase, MpSTE1, was considered as a key regulator of hyphal branching based on the hyphal phenotype. To further validate the role of MpSTE1, we generated an mpSTE1 gene knockout mutant, a complemented mutant, and an overexpression mutant (OE::mpSTE1). Microscopic observations revealed that overexpression of mpSTE1 led to a 63% increase in branch number while deletion of mpSTE1 reduced the hyphal branching by 68% compared to the wild-type strain. In flask cultures, the strain OE::mpSTE1 showed accelerated growth and glucose consumption. More importantly, the strain OE::mpSTE1 produced 9.2 mg/L lovastatin and 17.0 mg/L azaphilone pigments, respectively, 47.0% and 30.1% higher than those of the wild-type strain. Phosphoproteomic analysis revealed that MpSTE1 directly phosphorylated 7 downstream signal proteins involved in cell division, cytoskeletal organization, and signal transduction. To our best knowledge, MpSTE1 is reported as the first characterized regulator for tightly regulating the hyphal branching in Monascus spp. These findings significantly expanded current understanding of the signaling pathway governing the hyphal branching and development in Monascus spp. Furthermore, MpSTE1 and its analogs were demonstrated as promising targets for improving production of valuable secondary metabolites. KEY POINTS: • MpSTE1 is the first characterized regulator for tightly regulating hyphal branching • Overexpression of mpSTE1 significantly improves secondary metabolite production • A high-throughput image analysis tool was developed for counting hyphal branching.
Topics: Hyphae; Monascus; Artificial Intelligence; Protein Serine-Threonine Kinases; Lovastatin; Threonine; Serine
PubMed: 38446219
DOI: 10.1007/s00253-024-13093-7 -
PeerJ 2024Fungi can have important beneficial and detrimental effects on animals, yet our understanding of the diversity and function of most bee-associated fungi is poor. Over 2...
Fungi can have important beneficial and detrimental effects on animals, yet our understanding of the diversity and function of most bee-associated fungi is poor. Over 2 million bumblebee colonies are traded globally every year, but the presence and transport of viable fungi within them is unknown. Here, we explored whether any culturable fungi could be isolated from commercial bumblebee nests. We collected samples of various substrates from within 14 bumblebee colonies, including the honey, honey cup wall, egg cup wall, and frass then placed them on agar and recorded any growth. Fungal morphotypes were then subcultured and their ITS region sequenced for identification. Overall, we cultured 11 fungal species from the various nest substrates. These included both pathogenic and non-pathogenic fungi, such as sp., sp., and sp. Our results provide the first insights into the diversity of viable fungal communities in commercial bumblebee nests. Further research is needed to determine if these fungi are unique to commercial colonies or prevalent in wild bumblebee nests, and crucially to determine the ecological and evolutionary implications of these fungi in host colonies.
Topics: Bees; Animals; Aspergillus; Penicillium; Agar
PubMed: 38313023
DOI: 10.7717/peerj.16713 -
Food Chemistry: X Mar 2024The Xiecun Huangjiu (XCHJ), an exemplary representation of North Huangjiu, exhibits a distinct and invigorating aroma predominantly formed during its aging period. In...
The Xiecun Huangjiu (XCHJ), an exemplary representation of North Huangjiu, exhibits a distinct and invigorating aroma predominantly formed during its aging period. In this study, we observed dynamic changes in 16 key aroma compounds by gas chromatography-mass spectrometry (GC-MS) during the aging of XCHJ, with compounds such as phenethylalcohol, isoamylalcohol, benzaldehyde, and ethylbenzoate initially increasing and then decreasing. Ultra-Performance Liquid Chromatography (UPLC) detected nineteen amino acids, with total content ranging from 1901.45 to 3764.45 mg/L. High-throughput sequencing indicated that and et al. were abundant in aged XCHJ. Totally, 4 bacteria and 8 fungi exhibited strong associations with aroma compounds production. Physicochemical properties were primarily interacted with , , , , and . Furthermore, co-occurrence network analysis highlighted significant interactions between , , , and amino acids. These findings provide valuable insights for the regulation of aroma in aged XCHJ.
PubMed: 38292673
DOI: 10.1016/j.fochx.2024.101132 -
Foods (Basel, Switzerland) Jan 2024The microbial composition and volatile components of fermented grains (FG) and pit mud (PM) are crucial for the quality and flavor of compound-flavor baijiu (CFB). The...
The microbial composition and volatile components of fermented grains (FG) and pit mud (PM) are crucial for the quality and flavor of compound-flavor baijiu (CFB). The physicochemical indices, culturable microorganisms, microbial communities, and volatile components of FG and PM were analyzed and correlated in our research. Considering FG and PM, amplicon sequencing was used to analyze the microbial community and the volatile components were detected by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME). For FG, redundancy analysis and correlation perfume Circos were used to clarify the correlations between the dominant microbial community and volatile components. The results showed that , and were the main fungal microflora in FG and PM, whereas and were the dominant bacteria in FG, and and were the dominant bacteria in the PM. The microbial community and volatile compounds in the CB sampled from the bottom layers of the FG were greatly affected by those in the PM. There were 32 common volatile components in CB and PM. For FG, most of the volatile components were highly correlated with , , , and , which includes alcohols, acids and esters. This study reveals correlations between microbial composition, volatile components, and the interplay of FG and PM, which are conducive to optimizing the fermentation process and improving the quality of CFB base.
PubMed: 38254504
DOI: 10.3390/foods13020203 -
CRISPR/Cas9 system is a suitable gene targeting editing tool to filamentous fungus Monascus pilosus.Applied Microbiology and Biotechnology Jan 2024Monascus pilosus has been used to produce lipid-lowering drugs rich in monacolin K (MK) for a long period. Genome mining reveals there are still many potential genes...
Monascus pilosus has been used to produce lipid-lowering drugs rich in monacolin K (MK) for a long period. Genome mining reveals there are still many potential genes worth to be explored in this fungus. Thereby, efficient genetic manipulation tools will greatly accelerate this progress. In this study, we firstly developed the protocol to prepare protoplasts for recipient of CRISPR/Cas9 system. Subsequently, the vector and donor DNA were co-transformed into recipients (10 protoplasts/mL) to produce 60-80 transformants for one test. Three genes (mpclr4, mpdot1, and mplig4) related to DNA damage response (DDR) were selected to compare the gene replacement frequencies (GRFs) of Agrobacterium tumefaciens-mediated transformation (ATMT) and CRISPR/Cas9 gene editing system (CGES) in M. pilosus MS-1. The results revealed that GRF of CGES was approximately five times greater than that of ATMT, suggesting that CGES was superior to ATMT as a targeting gene editing tool in M. pilosus MS-1. The inactivation of mpclr4 promoted DDR via the non-homologous end-joining (NHEJ) and increased the tolerances to DNA damaging agents. The inactivation of mpdot1 blocked DDR and led to the reduced tolerances to DNA damaging agents. The inactivation of mplig4 mainly blocked the NHEJ pathway and led to obviously reduced tolerances to DNA damaging agents. The submerged fermentation showed that the ability to produce MK in strain Δmpclr4 was improved by 52.6% compared to the wild type. This study provides an idea for more effective exploration of gene functions in Monascus strains. KEY POINTS: • A protocol of high-quality protoplasts for CGES has been developed in M. pilosus. • The GRF of CGES was about five times that of ATMT in M. pilosus. • The yield of MK for Δmpclr4 was enhanced by 52.6% compared with the wild type.
Topics: Gene Editing; Monascus; CRISPR-Cas Systems; Gene Targeting; Lovastatin; Agrobacterium tumefaciens; DNA
PubMed: 38240803
DOI: 10.1007/s00253-023-12865-x -
International Journal of Molecular... Dec 2023Statins have been used in the treatment of hyperlipidemia, both as monotherapy and in combination therapy. Natural fermentation processes of fungi such as spp., spp.,... (Review)
Review
Statins have been used in the treatment of hyperlipidemia, both as monotherapy and in combination therapy. Natural fermentation processes of fungi such as spp., spp., , and have given rise to natural statins. Compactin (mevastatin), the original naturally occurring statin, is the primary biotransformation substrate in the manufacturing process of marketed drugs. Statins are classified into natural, semi-synthetic derivatives of natural statins, and synthetic ones. Synthetic statins differ from natural statins in their structural composition, with the only common feature being the HMG-CoA-like moiety responsible for suppressing HMG-CoA reductase. Statins do not differ significantly regarding their pleiotropic and adverse effects, but their characteristics depend on their pharmacokinetic parameters and chemical properties. This paper focuses on describing the processes of obtaining natural statins, detailing the pharmacokinetics of available statins, divided into natural and synthetic, and indicating their pleiotropic effects.
Topics: Hydroxymethylglutaryl-CoA Reductase Inhibitors; Pharmacy; Fungi; Lovastatin
PubMed: 38203637
DOI: 10.3390/ijms25010466