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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 Biological... Feb 2024The impact of the cell wall structure of Monascus purpureus M9 on the secretion of extracellular monascus pigments (exMPs) was investigated. To modify the cell wall...
Disruption of UDP-galactopyranose mutase expression: A novel strategy for regulation of galactomannan biosynthesis and monascus pigments secretion in Monascus purpureus M9.
The impact of the cell wall structure of Monascus purpureus M9 on the secretion of extracellular monascus pigments (exMPs) was investigated. To modify the cell wall structure, UDP-galactopyranose mutase (GlfA) was knocked out using Agrobacterium-mediated transformation method, leading to a significant reduction in the Galf-based polysaccharide within the cell wall. Changes in mycelium morphology, sporogenesis, and the expression of relevant genes in M9 were also observed following the mutation. Regarding MPs secretion, a notable increase was observed in six types of exMPs (R1, R2, Y1, Y2, O1 and O2). Specifically, these exMPs exhibited enhancement of 1.33, 1.59, 0.8, 2.45, 2.89 and 4.03 times, respectively, compared to the wild-type strain. These findings suggest that the alteration of the cell wall structure could selectively influence the secretion of MPs in M9. The underlying mechanisms were also discussed. This research contributes new insights into the regulation of the synthesis and secretion of MPs in Monascus spp..
Topics: Monascus; Pigments, Biological; Carbohydrate Metabolism; Fermentation; Galactose; Mannans; Intramolecular Transferases
PubMed: 38218271
DOI: 10.1016/j.ijbiomac.2024.129369 -
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 -
Food Chemistry May 2024The present study aimed to explore the key volatile compounds (VCs) that lead to the formation of characteristic flavors in ripe Pu-erh tea (RIPT) fermented by Monascus...
The present study aimed to explore the key volatile compounds (VCs) that lead to the formation of characteristic flavors in ripe Pu-erh tea (RIPT) fermented by Monascus purpureus (M. purpureus). Headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC-MS), orthogonal partial least square-discriminant analysis (OPLS-DA) were employed for a comprehensive analysis of the VCs present in RIPT fermented via different methods and were further identified by odor activity value (OAV). The VCs 1,2-dimethoxybenzene, 1,2,3-trimethoxybenzene, (E)-linalool oxide (pyranoid), methyl salicylate, linalool, β-ionone, β-damascenone were the key characteristic VCs of RIPT fermented by M. purpureus. OAV and Gas chromatography-olfactometry (GC-O) further indicated that β-damascenone was the highest contribution VCs to the characteristic flavor of RIPT fermented by M. purpureus. This study reveals the specificities and contributions of VCs present in RIPT under different fermentation methods, thus providing new insights into the influence of microorganisms on RIPT flavor.
Topics: Tea; Monascus; Fermentation; Gas Chromatography-Mass Spectrometry; Odorants; Volatile Organic Compounds; Norisoprenoids
PubMed: 38183708
DOI: 10.1016/j.foodchem.2023.138249 -
Journal of Agricultural and Food... Jan 2024Natural products are a rich resource for the discovery of innovative drugs. Microbial cocultivation enables discovery of novel natural products through tandem enzymatic...
Natural products are a rich resource for the discovery of innovative drugs. Microbial cocultivation enables discovery of novel natural products through tandem enzymatic catalysis between different fungi. In this study, , as a food fermentation strain capable of producing abundant natural products, was chosen as an example of a cocultivation pair strain. Cocultivation screening revealed that and led to the production of two novel cyclohexyl-furans, Monaspins A and B. Optimization of the cocultivation mode and media enhanced the production of Monaspins A and B to 1.2 and 0.8 mg/L, respectively. Monaspins A and B were structurally elucidated by HR-ESI-MS and NMR. Furthermore, Monaspin B displayed potent antiproliferative activity against the leukemic HL-60 cell line by inducing apoptosis, with a half-maximal inhibitory concentration (IC) of 160 nM. Moreover, in a mouse leukemia model, Monaspin B exhibited a promising in vivo antileukemic effect by reducing white blood cell, lymphocyte, and neutrophil counts. Collectively, these results indicate that Monaspin B is a promising candidate agent for leukemia therapy.
Topics: Animals; Mice; Monascus; Aspergillus oryzae; Coculture Techniques; Fermentation; Furans; Biological Products; Leukemia; Pigments, Biological
PubMed: 38166364
DOI: 10.1021/acs.jafc.3c08187 -
Frontiers in Microbiology 2023To reduce the production cost of pigments (MPs), the utilization of rice bran (RB), an agricultural waste product, as a substrate in submerged fermentation was...
To reduce the production cost of pigments (MPs), the utilization of rice bran (RB), an agricultural waste product, as a substrate in submerged fermentation was conducted in this study. To improve MP production, different nutritional ingredients including mannitol (Man), NHNO (AN), ZnSO (Zn), and optimization (Opti), which was a synthesis of the three above ones, were added in rice bran (RB) medium. The yields of MPs, pigment constituents, and growth and development of M9 were investigated in this study. Man had the maximum color value of 3,532 U/g, which was 18.69 times more than that of RB and reached up to 76.65% of the value of rice (Rice) fermentation. Man significantly increased the production of two orange pigments, monascorubrin and rubropunctatin, of which the yields were 69.49 and 95.36% of the counterpart of Rice. The biomass and colony diameter of Opti presented the maximum value among different groups. AN and RB induced more asexual spore formation, whereas Opti and Man promoted sexual spore production. Comparative transcriptomic analysis showed that different nutritional ingredients led to changes in pigment production, promoting the growth and development of M9 through the regulation of related gene expression. Man and Opti improved MP production by regulating the primary metabolism, including the Embden-Meyerhof pathway (EMP), the pentose phosphate (PP) pathway, the tricarboxylic (TCA) cycle, fatty acid degradation (FAD), fatty acid biosynthesis (FAB), amino acid metabolism (AAM), and fructose and mannose metabolism (FMM), to provide the precursors (acetyl-CoA and malonyl-CoA) for MP biosynthesis. This study presents a low-cost method for increasing MP production and explains the molecular mechanisms of different nutritional ingredients for enhancing MP biosynthesis.
PubMed: 38156009
DOI: 10.3389/fmicb.2023.1300461 -
Food Chemistry: X Dec 2023Red pigments (MPs) are a large group of polyketides from the fungus which have been widely used as food colorants. In this study, a variety of red MPs congeners were...
Red pigments (MPs) are a large group of polyketides from the fungus which have been widely used as food colorants. In this study, a variety of red MPs congeners were prepared to explore promising water-soluble candidates for application in liquid food formulations. The results showed that by combining the two-stage, low-pH fermentation strategy with a downstream purification step of fractional crystallization, precursors of red MPs, namely monascorubrin and rubropunctatin, were obtained with a purity of 91.9%. Then, via the azaphilic addition reaction, 18 types of red MPs congeners carrying different amino acid moieties (MPs-aa) were semi-synthesized. Compared to rubropunctamine and monascorubramine, the water solubility, pH and thermal stability of MPs-aa were improved greatly. MPs-His, MPs-Phe, MPs-Tyr and MPs-Trp were identified to be the most resistant to pasteurization. These findings provide water-soluble red MPs candidates with high thermal stability and an attractive approach for their large scale production.
PubMed: 38144809
DOI: 10.1016/j.fochx.2023.100940 -
Journal of Fungi (Basel, Switzerland) Dec 2023Citrinin (CIT), a secondary metabolite produced by the filamentous fungi species, exhibits nephrotoxic, hepatotoxic, and carcinogenic effects in mammals, remarkably...
Citrinin (CIT), a secondary metabolite produced by the filamentous fungi species, exhibits nephrotoxic, hepatotoxic, and carcinogenic effects in mammals, remarkably restricting the utilization of -derived products. CIT synthesis is mediated through the gene and modified by multiple genetic factors. Here, the regulatory effects of two transcripts, α, and β, generated via pre-mRNA alternative splicing (AS), were investigated using hairpin RNA (ihpRNA) interference, and their impact on CIT biosynthesis and the underlying mechanisms were assessed through chemical biology and transcriptome analyses. The CIT yield in ihpRNA-pksCTα and ihpRNA-pksCT (α + β) transformants decreased from 7.2 μg/mL in the wild-type strain to 3.8 μg/mL and 0.08 μg/mL, respectively. Notably, several genes in the CIT biosynthetic gene cluster, specifically , , and in the ihpRNA-pksCT (α + β) transformant, were downregulated. Transcriptome results revealed that silencing has a great impact on carbohydrate metabolism, amino acid metabolism, lipid metabolism, and AS events. The key enzymes in the citrate cycle (TCA cycle) and glycolysis were significantly inhibited in the transformants, leading to a decrease in the production of biosynthetic precursors, such as acetyl-coenzyme-A (acetyl-coA) and malonyl-coenzyme-A (malonyl-coA). Furthermore, the reduction of CIT has a regulatory effect on lipid metabolism via redirecting acetyl-coA from CIT biosynthesis towards lipid biosynthesis. These findings offer insights into the mechanisms underlying CIT biosynthesis and AS in , thus providing a foundation for future research.
PubMed: 38132775
DOI: 10.3390/jof9121174 -
Microbiology Resource Announcements Jan 2024In China, certain strains are traditionally used as edible fungi. We sequenced the genome of FM39-7 strain, an isolate from fermented rice. The genome is 25.89 Mb with...
In China, certain strains are traditionally used as edible fungi. We sequenced the genome of FM39-7 strain, an isolate from fermented rice. The genome is 25.89 Mb with a G + C content of 48.86%, containing 8485 annotated genes.
PubMed: 38099680
DOI: 10.1128/mra.00805-23