Search Results (41)

Monascus spp. are renowned for producing valuable Monascus azaphilone pigments (MonAzPs), yet their biosynthesis is intrinsically linked to the co-production of the mycotoxin citrinin, posing a significant safety challenge and limiting industrial application. Conventional approaches to disrupt citrinin synthesis often inadvertently reduce MonAzPs yield. To circumvent this limitation, we employed a dual-targeting strategy in Monascus ruber. In this study, we selected the mresa1-overexpressed strain—which can produce more MonAzPs and citrinin—as wild strain to construct a pksCT-deleted strain and explore whether pksCT deletion can affect the enhancement of MonAzPs caused by MrEsa1 overexpression. The results showed that the growth, development, and production of MonAzPs in △pksCT-M7::PtrpC-mresa1 were comparable to those in M7::PtrpC-mresa1, showing accelerated growth and higher MonAzPs yields than in M7. In addition, the relative expression levels of genes involved in MonAzPs synthesis in △pksCT-M7::PtrpC-mresa1 and M7::PtrpC-mresa1 showed the same trend compared with M7, indicating that MrEsa1 overexpression can resist the reduction in MonAzPs caused by pksCT deletion. This study establishes a novel and effective paradigm for decoupling desirable metabolite production from toxin synthesis in fungi, providing a strategic framework for the safe and enhanced production of MonAzPs. Full article

Recently, co-fermentation of functional medicinal plants with fungi has emerged as a promising strategy to enhance the overall quality of fermented foods. Monascus fermentation products have long been confronted with bottlenecks in both functionality and palatability, such as low monacolin K (MK) yield and poor flavor. Therefore, this study investigated the effects of co-fermenting Monascus purpureus with honeysuckle (Lonicera japonica Thunb.) on the bioactive metabolites and volatile flavor compounds of the fermented product. Through single-factor optimization, the addition of 0.8 g/L honeysuckle powder was identified as optimal, resulting in a 1.54-fold increase in MK yield compared to the control. Additionally, nine key genes were upregulated in the MK biosynthetic cluster (mokA–mokI). Co-fermentation also significantly increased the total flavonoid and polyphenol contents by 3.93-and 2.01-fold, respectively, and enhanced in vitro antioxidant activity. Gas chromatography-mass spectrometry analysis revealed that ketones, esters, and alcohols were the dominant volatile compounds. Orthogonal partial least squares-discriminant analysis identified 11 differential volatile compounds (variable importance in projection > 1), indicating a substantial shift in the flavor profile toward more desirable notes, with a reduction in undesirable aldehydes. These findings demonstrate that honeysuckle co-fermentation enhances the biofunctional properties of M. purpureus fermentation products and improves their sensory appeal, providing a viable bioprocessing strategy for developing high-value Monascus-based functional foods or ingredients. Full article

Fermenting seaweed with koji fungi transforms its chemical composition, generating bioactive compounds absent in the raw material. We previously reported that the fungal fermentation of the edible red alga Pyropia yezoensis (Nori) produces betaine structural analogs (such as betaine, stachydrine, and carnitine), which are of particular interest because of their physiological roles and potential health benefits. Using metabolomic profiling, we compared non-fermented Nori with powders fermented by three industrially important fungi: Aspergillus luchuensis mut. kawachii (white koji fungus), Aspergillus oryzae (yellow koji fungus), and Monascus purpureus (red koji fungus). All fermentations enhanced the levels of betaine and carnitine, but stachydrine production was unique to the yellow koji fungus. Precursor patterns revealed distinct metabolic strategies: the yellow koji fungus exhibited an intermediate detectable choline oxidation route and strong proline methylation, the white koji fungus rapidly converted choline without intermediate accumulation, and the red koji fungus favored carnitine and proline but produced little stachydrine. Fermentation also shifted the methylation balance toward a state that supports methyl-dependent pathways. These findings reveal clear species-specific strategies for the production of betaine structural analogs, providing a mechanistic basis for understanding the metabolic divergence among koji fungi and guiding the targeted design of functional seaweed products. Full article

The increasing global prevalence of hyperuricemia (HUA), particularly among younger populations, underscores the urgent need for safe and effective dietary interventions. Monascus fungi, long utilized in East Asian food culture, ferment rice to produce red yeast rice (RYR), a functional food rich in monacolin K and Monascus pigments. Among these, Monascus yellow pigments (MYPs)—natural azaphilone compounds used as food additives and colorants—have shown antioxidant, anti-inflammatory, and metabolic regulatory activities. However, their potential to alleviate hyperuricemia remains unexplored. This study investigates the urate-lowering and organ-protective effects of MYPs through a combination of in vitro, in vivo, and gut microbiota analyses. MYPs exhibited significant xanthine oxidase (XOD) inhibitory activity, and molecular docking confirmed that monascin (MS) and ankaflavin (AK) competitively bind to the XOD active site. In a murine HUA model, MYPs significantly reduced serum uric acid (SUA) levels without causing hepatic or renal toxicity. Mechanistically, MYPs downregulated renal UA reabsorption transporters (URAT1, GLUT9) and upregulated the excretory transporter ABCG2, enhancing uric acid (UA) excretion. These findings highlight MYPs as promising food-derived bioactives with dual XOD inhibition and uricosuric effects, offering a novel nutraceutical strategy for hyperuricemia prevention and management. Full article

Monascus is a fungus widely used in food fermentation. This study employed microbial technology, combined with microscopic morphological observations and ITS sequence analysis, to isolate, purify, and identify 10 strains of red yeast mold from various Monascus products. After the HPLC detection of metabolic products, the M8 strain containing the toxic substance citrinin was excluded. Using the EWM-TOPSIS model, the remaining nine safe Monascus strains were evaluated for their inhibitory activities against pancreatic lipase, α-glucosidase, α-amylase, and the angiotensin-converting enzyme. The M2 strain with the highest comprehensive scores for lowering blood sugar, blood lipids, and blood pressure was selected. Its fermentation product at a concentration of 3 mg/mL had inhibition rates of 96.938%, 81.903%, and 72.215%, respectively. The contents of the blood lipid-lowering active substance Monacolin K and the blood sugar and blood pressure-lowering active substance GABA were 18.078 mg/g and 5.137 mg/g, respectively. This strain can be utilized for the biosynthesis of important active substances such as Monacolin K and GABA, as well as for the fermentation production of safe and effective functional foods to address health issues like high blood lipids, high blood sugar, and high blood pressure in people. This study also provides insights into the use of natural fungi to produce healthy foods for combating chronic diseases in humans. Full article

Citrinin (CIT), a mycotoxin commonly found in cereals, is produced by fungi from the Aspergillus, Penicillium, and Monascus genera. While its nephrotoxic effects are well studied, its impact on neurons is less understood. This study investigates CIT-induced toxicity in human neuroblastoma cells (SH-SY5Y). The IC₅₀ values for cells treated with CIT were 77.1 μM at 24 h and 74.7 μM at 48 h using MTT assay, and 101.0 μM at 24 h and 54.7 μM at 48 h using neutral red assay. CIT exposure caused G2/M phase arrest, with cells in this phase increasing from 11.83% (control) to 33.10% at 50 μM CIT. At 50 μM, the percentage of cells in the S phase also increased, which may suggest that cellular stress pathways were activated. Moreover, an increase in late apoptosis process was noted in cells exposed to CIT for 24 h, particularly at the highest concentrations (38.75 and 50 µM). Western blot analysis confirmed a rapid change in the anti-apoptotic protein Bcl-2, but no significant changes in Bax. In conclusion, CIT induces apoptosis and cell cycle arrest in SH-SY5Y cells. However, further transcriptomic studies in specific proteins involved in different pathways described in this work are needed to gain a comprehensive understanding of the specific mechanisms underlying CIT’s toxicity in SH-SY5Y cells. Full article

The histone acetylation modification is a conservative post-translational epigenetic regulation in fungi. It includes acetylation and deacetylation at the lysine residues of histone, which are catalyzed by histone acetyltransferase (HAT) and deacetylase (HDAC), respectively. The histone acetylation modification plays crucial roles in fungal growth and development, environmental stress response, secondary metabolite (SM) biosynthesis, and pathogenicity. One of the most important roles is to regulate the gene expression that is responsible for SM biosynthesis in fungi. This mini-review summarized the regulation of histone acetylation modification by HATs and HDACs on the biosynthesis of SMs in fungi. In most cases, histone acetylation by HATs positively regulated the biosynthesis of fungal SMs, while HDACs had their negative regulations. Some HATs and HDACs were revealed to regulate fungal SM biosynthesis. Hda1 was found to be the most efficient regulator to affect the biosynthesis of SMs in fungi. The regulated fungal species were mainly from the genera of Aspergillus, Calcarisporium, Cladosporium, Fusarium, Monascus, Penicillium, and Pestalotiopsis. With the strategy of histone acetylation modification, the biosynthesis of some harmful SMs will be inhibited, while the production of useful bioactive SMs will be promoted in fungi. The subsequent research should focus on the study of regulatory mechanisms. Full article

Monascus, a genus of fungi known for its fermentation capability and production of bioactive compounds, such as Monascus azaphilone pigments and Monacolin K, have received considerable attention because of their potential in biotechnological applications. Understanding the genetic basis of these metabolic pathways is crucial for optimizing the fermentation and enhancing the yield and quality of these products. However, Monascus spp. are not model fungi, and knowledge of their genetics is limited, which is a great challenge in understanding physiological and biochemical phenomena at the genetic level. Since the first application of particle bombardment to explore gene function, it has become feasible to link the phenotypic variation and genomic information on Monascus strains. In recent decades, accurate gene editing assisted by genomic information has provided a solution to analyze the functions of genes involved in the metabolism and development of Monascus spp. at the molecular level. This review summarizes most of the genetic manipulation tools used in Monascus spp. and emphasizes Agrobacterium tumefaciens-mediated transformation and nuclease-guided gene editing, providing comprehensive references for scholars to select suitable genetic manipulation tools to investigate the functions of genes of interest in Monascus spp. Full article

Monascus species are known to produce various secondary metabolites with polyketide structures, including Monacolins, pigments, and citrinin. This study investigates the effects of 5-azacytidine on Monascus M1 and RP2. The dry weight, red, yellow, and orange pigment values, and Monacolin K yield of both Monascus strains were measured, and their hyphae observed through electron microscopy. The experimental group showed higher dry weights and pigment values than the control group for both strains. However, Monacolin K production increased substantially only for Monascus M1. Electron micrographs revealed surface wrinkles and large protrusions in both strains after 5-azacytidine treatment. As a potent DNA methylation-promoting agent, 5-azacytidine is very useful for epigenetic and cancer biology studies and for studying secondary metabolism in fungi. Full article

Finding new molecules to prevent the growth of antimicrobial resistance is a hot topic for scientists worldwide. It has been reported that some raw bioproducts containing Monascus polyketides have antimicrobial activities, but extensive studies on this effect have not been conducted. In this context, our studies aimed to evaluate the antimicrobial properties of six raw bioproducts containing three classes of microbial polyketides biosynthesized by three Monascus strains through solid-state biosynthesis. As a methodology, we performed in silico predictions using programs such as PyMOL v3.0.4 and employed ESI-MS techniques to provide evidence of the presence of the six studied compounds in our bioproducts. The results obtained in silico were validated through in vitro studies using the Kirby-Bauer diffusion method on bacteria and fungi. The test performed in silico showed that Monascorubramine has the highest affinity for both Gram-positive and Gram-negative bacteria, followed by yellow polyketides such as Ankaflavin and Monascin. The estimated pharmacokinetic parameters indicated high gastrointestinal absorption and the potential to cross the blood-brain barrier for all studied compounds. However, the compounds also inhibit most enzymes involved in drug metabolism, presenting some level of toxicity. The best in vitro results were obtained for S. aureus, with an extract containing yellow Monascus polyketides. Predictions made for E. coli were validated in vitro for P. aeruginosa, S. enterica, and S. marcescens, as well as for fungi. Significant antibacterial properties were observed during this study for C. albicans, S. aureus, and fungal dermatophytes for crude bioproducts containing Monascus polyketides. In conclusion, the antimicrobial properties of Monascus polyketides were validated both in silico and in vitro. However, due to their potential toxicity, these bioproducts would be safer to use as topical formulations. Full article

Beta-glucan (β-glucan), a naturally occurring complex polysaccharide, has drawn attention for its diverse health benefits, including immune system modulation. β-glucan was extracted from two fungi, Monascus purpureus (Mp) and Monascus kaoliang (Mk), cultured in Saccharina japonica via submerged fermentation. The yield, solubility, total sugar, reducing sugar, protein content, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), in vitro free radical scavenging activity, and cytotoxicity were analyzed. A significant yield of β-glucans, with the contents of 51.30 ± 1.54% in Mp and 44.24 ± 1.18% in Mk was observed on a dry weight basis. Water solubility slightly varied, measuring 36.25 ± 1.14% in Mp and 31.25 ± 0.94% in Mk. Total sugar and reducing sugar content in Mp and Mk derived β-glucans were 114.75 ± 2.54 mg/g and 100.25 ± 1.86 mg/g, 7.38 ± 0.78 mg/g, and 8.39 ± 0.46 mg/g, respectively. FTIR spectra resembled the standard, and TGA confirmed heat stability. XRD patterns indicated that the extracted β-glucans, including the standard one, showed the most prominent diffraction peaks in the lower 2θ range, suggesting similar crystalline phases; however, they differed in crystallinity and degree of amorphous content. SEM images displayed characteristic rough and fibrous shapes and surfaces for extracted β-glucans but it was uniform and of a regular shape in the standard sample. The isolated β-glucans exhibited in vitro free radical scavenging and no cytotoxicity was observed in the MTS assay. Therefore, utilizing S. japonica as a substrate in the fermentation process by Monascus spp. presents a unique opportunity in the production and utilization of β-glucans. Full article

Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an S-adenosylmethionine binding site and displays methyltransferase activity. The members of velvet proteins include VeA, VelB, VelC, VelD and VosA for each member with a velvet domain. LaeA and velvet proteins can form multimeric complexes such as VosA-VelB and VelB-VeA-LaeA. They belong to global regulators and are mainly impacted by light. One of their most important functions is to regulate gene expressions that are responsible for secondary metabolite biosynthesis. The aim of this mini-review is to represent the newest cognition of the biosynthetic regulation of mycotoxins and other fungal secondary metabolites by LaeA and velvet proteins. In most cases, LaeA and velvet proteins positively regulate production of fungal secondary metabolites. The regulated fungal species mainly belong to the toxigenic fungi from the genera of Alternaria, Aspergillus, Botrytis, Fusarium, Magnaporthe, Monascus, and Penicillium for the production of mycotoxins. We can control secondary metabolite production to inhibit the production of harmful mycotoxins while promoting the production of useful metabolites by global regulation of LaeA and velvet proteins in fungi. Furthermore, the regulation by LaeA and velvet proteins should be a practical strategy in activating silent biosynthetic gene clusters (BGCs) in fungi to obtain previously undiscovered metabolites. Full article

Selenium-enriched Lentinus edodes (SL) is a kind of edible fungi rich in organic selenium and nutrients. Monascus purpureus with high monacolin K (MK) production and Saccharomyces cerevisiae were selected as the fermentation strains. A single-factor experiment and response surface methodology were conducted to optimize the production conditions for MK with higher contents from selenium-enriched Lentinus edodes fermentation (SLF). Furthermore, we investigated the nutritional components, antioxidant capacities, and volatile organic compounds (VOCs) of SLF. The MK content in the fermentation was 2.42 mg/g under optimal fermentation conditions. The organic selenium content of SLF was 7.22 mg/kg, accounting for 98% of the total selenium content. Moreover, the contents of total sugars, proteins, amino acids, reducing sugars, crude fiber, fat, and ash in SLF were increased by 9%, 23%, 23%, 94%, 38%, 44%, and 25%, respectively. The antioxidant test results demonstrated that 1.0 mg/mL of SLF exhibited scavenging capacities of 40%, 70%, and 79% for DPPH, ABTS, and hydroxyl radicals, respectively. Using gas chromatography–ion mobility spectrometry technology, 34 unique VOCs were identified in SLF, with esters, alcohols, and ketones being the main components of its aroma. This study showed that fungal fermentation provides a theoretical reference for enhancing the nutritional value of SL. Full article

China has a 9000-year-long history of cereal-based alcohol production, with the use of molds (filamentous fungi) likely being one of the earliest fermentation techniques. This method later developed into the uniquely East Asian qu (koji) starter compound, containing grains, molds, yeasts, and bacteria. Recent studies have revealed that this method was already widely applied during the Neolithic period. However, much less is known about its development during the early dynastic times, and our knowledge of this innovation has mainly relied on textual materials. Here, we present direct evidence, based on microbotanical, microbial, and chemical analyses, for the fermentation method of a 2300-year-old liquid preserved in a sealed bronze bottle unearthed in a Qin tomb at Yancun, Shaanxi. The results of this research suggest that this liquid is likely a fermented beverage made from wheat/barley, rice, Job’s tears, broomcorn millet, and pulses. The fermentation starter may have been a cereal-based qu, consisting of a wide range of microorganisms, including molds (Aspergillus and Monascus), yeasts, and bacteria. Our findings suggest that the tradition of selecting suitable grains and microbial communities for brewing alcohol, possibly with a maiqu starter (primarily wheat/barley-based qu), may have been well established more than two thousand years ago. Full article

Enhancing the aerobic stability of whole-plant corn silage is essential for producing high-quality silage. Our research assessed the effect of inoculation with Lactobacillus buchneri or Bacillus licheniformis and its modulation of the bacterial and fungal microbial community structure in an aerobic stage of whole-plant corn silage. Following treatment with a distilled sterile water control, Lactobacillus buchneri, and Bacillus licheniformis (2 × 10⁵ cfu/g), whole-plant corn was ensiled for 60 days. Samples were taken on days 0, 3, and 7 of aerobic exposure, and the results showed that inoculation with Lactobacillus buchneri or Bacillus licheniformis improved the aerobic stability of silage when compared to the effect of the control (p < 0.05). Inoculation with Bacillus licheniformis attenuated the increase in pH value and the decrease in lactic acid in the aerobic stage (p < 0.05), reducing the filamentous fungal counts. On the other hand, inoculation with Lactobacillus buchneri or Bacillus licheniformis increased the diversity of the fungal communities (p < 0.05), complicating the correlation between bacteria or fungi, reducing the relative abundance of Acetobacter and Paenibacillus in bacterial communities, and inhibiting the tendency of Monascus to replace Issatchenkia in fungal communities, thus delaying the aerobic spoilage process. Due to the prevention of the development of aerobic spoilage microorganisms, the silage injected with Lactobacillus buchneri or Bacillus licheniformis exhibited improved aerobic stability. Full article