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This study explored the complete replacement of sodium nitrite with a combination of Monascus pigments (MPs)-calcium carbonate colorant lake (MPs-CaCO3 lake) and nisin in smoked sausage production. The effects of the replacement on color stability, total aerobic mesophilic bacteria count (TAMB), and physicochemical properties of sausages were assessed. The results indicated that combining 0.26 g/kg of lake and 0.4 g/kg of nisin effectively replaced the coloring and preservative functions of nitrite. Physicochemical analyses revealed that the addition of pigment lake significantly increased the pH and calcium content and reduced juice loss rates (at low lake concentrations) of sausage in the lake group compared to the blank and pigment groups. Gas chromatography–mass spectrometry (GC-MS) based flavor compounds analysis demonstrated notable changes in the profile of volatile flavor compounds with the addition of MPs, marked by the appearance of paraldehyde and the disappearance of butanediol in the pigment and lake groups. Electronic nose analysis confirmed that sausages with MPs and lake had similar odors, distinctly different from the blank group. However, electronic tongue analysis showed no significant flavor differences among the three groups. Overall, the combination of MPs-CaCO3 lake and nisin effectively replaced nitrite, enhanced pigment stability, and did not adversely affect the flavor quality of smoked sausage. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Monascus species are capable of producing various active metabolites, including monacolin K (MK) and pigments. Studies have shown that the overexpression of the mok I gene from the MK synthesis gene cluster in Monascus species can significantly increase MK production; however, the molecular mechanism has not yet been fully elucidated. Therefore, this study focused on the mok I gene of Monascus pilosus to construct overexpression strains of the mok I gene, resulting in high-yield MK production. Sixteen positive transformants were obtained, seven of which produced 9.63% to 41.39% more MK than the original strain, with no citrinin detected in any of the transformants. The qRT-PCR results revealed that the expression levels of mok I in the transformed strains TI-13, TI-24, and TI-25 increased by more than 50% compared to the original strain at various fermentation times, with the highest increase being 10.9-fold. Furthermore, multi-omics techniques were used to analyze the molecular mechanisms underlying enhanced MK production in transformed strains. The results indicated that mok I overexpression may enhance MK synthesis in M. pilosus by regulating the expression of key genes (such as MAO, HPD, ACX, and PLC) and the synthesis levels of key metabolites (such as delta-tocopherol and alpha-linolenic acid) in pathways linked to the biosynthesis of cofactors, the biosynthesis of unsaturated fatty acids, tyrosine metabolism, ubiquinone and other terpenoid-quinone biosynthesis, alpha-linolenic acid metabolism, and glycerophospholipid metabolism. These findings provide a theoretical basis for further study of the metabolic regulation of MK in Monascus species and for effectively enhancing their MK production. [ABSTRACT FROM AUTHOR]

Monascus is a filamentous fungus with a long history of application in China, which can produce a variety of secondary metabolites, including Monascus red pigments, Monascus orange pigments, Monascus yellow pigments, and citrinin. There is widespread attention being paid to natural pigments because of their safety. Among the many natural pigments, orange pigment has a wide range of applications because of its unique color, but current production levels in the orange pigment industry are limited to a certain extent due to the insufficiently wide range of sources and low production. In this study, the ARTP mutation was used to obtain a strain with high-yield orange pigment and low citrinin. The strain RS7 was obtained through two-step mutagenesis, and all three pigments were improved to different degrees. The color value of orange pigment was elevated from the original 108 U/mL to 180 U/mL, an increase of 66.7% compared to the original strain, and the citrinin content was reduced by 69%. The result of microscopic morphology showed that RS7 has more wrinkles and is more convex than the R1 strain, but there was little change between the two strains. Therefore, the ARTP mutation influenced the growth and the biosynthesis of pigments in Monascus. In addition, the conditions of ultrasonic extraction of Monascus pigments were optimized using the response surface, and the separation of pigments was achieved with the method of thin-layer chromatography. Pigment stability results showed that the temperature had no significant effect on orange pigment, while tea polyphenol could improve its stability. This study generated a strain with high-yielding orange pigment and could lay a foundation for the future application of Monascus orange pigment in the food industry. [ABSTRACT FROM AUTHOR]

Monascus ruber is an important fungus that causes spoilage in table olives, resulting in the darkening of the brine, the softening of the fruit, increased pH, and apparent mycelial growth. This study aimed to evaluate this resistance, providing a model to determine the optimal processing conditions for mitigating fungal contamination and prolonging shelf life without antifungal agents while optimizing pasteurization to reduce energy consumption. The resistance in brine (3.5% NaCl; pH 3.5) from Arauco cultivar green olives imported from Argentina was assessed. Four predictive models (log linear, log linear + shoulder, log linear + tail, log linear + shoulder + tail) estimated kinetic parameters for each survival curve. Log linear + shoulder + tail provided the best fit for 70 °C and 75 °C, with low RMSE (0.171 and 0.112) and high R2 values (0.98 and 0.99), respectively, while the log linear model was used for 80 °C. Decimal reduction times at 70, 75, and 80 °C were 24.8, 5.4, and 1.6 min, respectively, with a z-value of 8.2 °C. The current regulatory processes are insufficient to eliminate M. ruber at requisite levels, considering reduced antifungal agents. [ABSTRACT FROM AUTHOR]

Monascus pigments (MPs), a class of secondary metabolites produced by Monascus spp., can be classified into yellow, orange, and red MPs according to their differences in the wavelength of the maximum absorption. However, the biosynthetic sequence and cellular biosynthesis mechanism of different MPs components are still not yet completely clear in Monascus spp. In this study, the subcellular localization of five MPs synthases was investigated using fluorescent protein fusion expression. The results revealed that the proteins encoded by the MPs biosynthetic gene cluster were compartmentalized in various subcellular locations, including the mitochondrial polyketide synthase MrPigA, cytosolic enzymes consisting of the ketoreductase MrPigC, the oxidoreductase MrPigE, and the monooxygenase MrPigN, and the cell-wall-bound oxidoreductase MrPigF. Moreover, the correct localization of MrPigF to the cell wall was crucial for the synthesis of orange MPs. Lastly, we discussed the compartmentalized biosynthetic pathway of MPs. This study will not only be helpful in clarifying the biosynthetic sequence and biosynthesis mechanism of different MPs but also provides new insights into the cellular biosynthesis of secondary metabolites in filamentous fungi. [ABSTRACT FROM AUTHOR]

wetA, one of the conidiation center regulatory genes in many filamentous fungi, plays an important role in promoting asexual spores (conidia) maturation. Our recent research has found that knocking out or overexpressing MrwetA (a homolog of wetA) in Monascus ruber M7 does not affect the development of its asexual spores like other fungi, but both repress the development of its sexual spores (ascospores). However, the mechanism remains unclear. In this study, the function of MrwetA on sexual reproduction and secondary metabolism in M. ruber M7 was confirmed by a complementary experiment. Moreover, the regulatory roles of MrwetA in modulating the expression of genes involved in sexual reproduction, meiosis, and biosynthesis of Monascus pigment and citrinin were analyzed based on the transcriptional data. These results not only contribute to clarifying the regulation of the reproduction and secondary metabolism of Monascus spp., but also to enriching the regulation molecular mechanism of reproduction in filamentous fungi. [ABSTRACT FROM AUTHOR]

Trichosanthis Fructus (TrF) is an edible medicinal fruit with a sweet taste and pleasant flavor. In this study, different concentrations of TrF were added into the media to brew Monascus rice wine using a pure culture method, and the physicochemical properties, volatile compounds, antioxidant activity, and sensory quality of the brewed samples were characterized. In addition, the effect of TrF on the growth and metabolism of Monascus purpureus and Saccharomyces cerevisiae was investigated. The results show that addition of TrF reduces the growth and metabolism of M. purpureus and S. cerevisiae in a dose-dependent manner, but also enriches the flavor components, in addition to increasing the total phenolic and flavonoid contents, and antioxidant activity of rice wine. Combined with the results of sensory evaluation, we find that 15% TrF is optimal for improving the flavor of Monascus rice wine. The results from this study can serve as a basis for improving the quality and flavor of rice wine brewed using pure strain culture. [ABSTRACT FROM AUTHOR]

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 Aspergillus, Pichia, and Rhizopus were the main fungal microflora in FG and PM, whereas Lactobacillus and Bacillus were the dominant bacteria in FG, and Methanosarcina and Clostridium sensu stricto 12 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 Lactobacillus, Bacillus, Aspergillus, Pichia, and Monascus, 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. [ABSTRACT FROM AUTHOR]

Citrinin (CIT), a secondary metabolite produced by the filamentous fungi Monascus species, exhibits nephrotoxic, hepatotoxic, and carcinogenic effects in mammals, remarkably restricting the utilization of Monascus-derived products. CIT synthesis is mediated through the pksCT gene and modified by multiple genetic factors. Here, the regulatory effects of two pksCT transcripts, pksCTα, and pksCTβ, 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 mrl3, mrl5, mrr1, and mrr5 in the ihpRNA-pksCT (α + β) transformant, were downregulated. Transcriptome results revealed that silencing pksCT 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 Monascus, thus providing a foundation for future research. [ABSTRACT FROM AUTHOR]

The tea plant is a vital strategic forest resource in China. Dark tea produced from its leaves is an indispensable health-promoting product in western China due to its unique lipid-lowering function. Eurotium cristatum is the dominant strain in Fuzhuan brick tea (a variety of Anhua dark tea) and could produce many functional components, including lovastatin, a lipid-lowering compound. In this study, the lovastatin yield of dark tea was improved by breeding Eurotium cristatum using the protoplast fusion method. The experiments were carried out by inducing a fusion between inactivated Eurotium cristatum JH1205 and Monascus CICC5031. Among the 92 fusants screened the HPLC method, four strains (A4, A36, A54, and A76) with higher lovastatin production (more than three times as high) were obtained. The A76 strain had the highest lovastatin yield, which was 23.93 μg/mL. The location of the tea forest strongly influenced the lovastatin yield of loose dark tea. The strain bred in this study improved the lovastatin yield of loose dark tea by more than three times when compared to wild Eurotium cristatum. These results are promising for the development of tea forest resources. [ABSTRACT FROM AUTHOR]

Filamentous fungi are well-known for their ability to form mycelial pellets during submerged cultures, a characteristic that has been extensively studied and applied. However, Monascus, a filamentous saprophytic fungus with a rich history of medicinal and culinary applications, has not been widely documented for pellet formation. This study aimed to investigate the factors influencing pellet formation in Monascus and their impact on citrinin production, a key secondary metabolite. Through systematic exploration, we identified pH and inoculum size as critical factors governing pellet formation. Monascus exhibited optimal pellet growth within the acidic pH range from 5 to 6, resulting in smaller, more homogeneous pellets with lower citrinin content. Additionally, we found that inoculum size played a vital role, with lower spore concentrations favoring the formation of small, uniformly distributed pellets. The choice of carbon and nitrogen sources also influenced pellet stability, with glucose, peptone, and fishmeal supporting stable pellet formation. Notably, citrinin content was closely linked to pellet diameter, with larger pellets exhibiting higher citrinin levels. Our findings shed light on optimizing Monascus pellet formation for enhanced citrinin production and provide valuable insights into the cultivation of this fungus for various industrial applications. Further research is warranted to elucidate the molecular mechanisms underlying these observations. [ABSTRACT FROM AUTHOR]

Monascus, a key player in fermented food production, is known for generating Monascus pigments (MPs) and monacolin K (MK), possessing bioactive properties. However, the limited stability of MPs and mycotoxin citrinin (CTN) constrain the Monascus industry. Extremolytes like ectoine, derived from bacteria, exhibit cytoprotective potential. Here, we investigated the impact of ectoine on Monascus purpureus ATCC 16365, emphasizing development and secondary metabolism. Exogenous 5 mM ectoine supplementation substantially increased the yields of MPs and MK (105%–150%) and reduced CTN production. Ectoine influenced mycelial growth, spore development, and gene expression in Monascus. Remarkably, ectoine biosynthesis was achieved in Monascus, showing comparable effects to exogenous addition. Notably, endogenous ectoine effectively enhanced the stability of MPs under diverse stress conditions. Our findings propose an innovative strategy for augmenting the production and stability of bioactive compounds while reducing CTN levels, advancing the Monascus industry. [ABSTRACT FROM AUTHOR]

Hong Qu (HQ), obtained through fermentation of various grains using Monascus spp., has been widely utilized as the main and characteristic initial saccharification and traditional fermentation starter in the food brewing industry. The quality, color, and flavor of HQ and HQ wine are closely related to the saccharifying power (SP) and Monascus pigments (MPs) of Monascus spp. In this study, to optimize the culture medium in submerged fermentation by M. purpureus G11 for improving SP and MPs, the effects of carbon source, nitrogen source, inorganic salts, and vitamins on SP activity and biosynthesis of MPs were explored through single-factor analysis and response surface Box–Behnken experiments. The results showed that the optimal medium composition was 6.008% rice powder, 1.021% peptone, 0.0049% CuSO4, and 0.052% vitamin B1. Validation experiments performed under the optimized fermentation conditions showed a significant increase in MPs and SP by 14.91% and 36.24%, with maximum MPs and SP reaching 112.61 and 365.12 u/mL, respectively. This study provides a theoretical basis for enhancing MPs and SP in M. purpureus for HQ production, to improve the production efficiency and shorten the production cycle of HQ-related fermentation products. [ABSTRACT FROM AUTHOR]

This study is focused on the preparation, characterization, and multifunctional properties of intelligent hybrid nanopigments. The hybrid nanopigments with excellent environmental stability and antibacterial and antioxidant properties were fabricated based on natural Monascus red, surfactant, and sepiolite via a facile one-step grinding process. The density functional theory calculations demonstrated that the surfactants loaded on sepiolite were in favor of enhancing the electrostatic, coordination, and hydrogen bonding interactions between Monascus red and sepiolite. Thus, the obtained hybrid nanopigments exhibited excellent antibacterial and antioxidant properties, with an inhibition effect on Gram-positive bacteria that was superior to that of Gram-negative bacteria. In addition, the scavenging activity on DPPH and hydroxyl free radicals as well as the reducing power of hybrid nanopigments were higher than those of hybrid nanopigments prepared without the addition of the surfactant. Inspired by nature, gas-sensitive reversible alochroic superamphiphobic coatings with excellent thermal and chemical stability were successfully designed by combining hybrid nanopigments and fluorinated polysiloxane. Therefore, intelligent multifunctional hybrid nanopigments have great application foreground in related fields. [ABSTRACT FROM AUTHOR]

Histone acetyltransferase (HAT) has been reported to be pivotal for various physiological processes in many fungi. However, the functions that HAT Rtt109 perform in edible fungi Monascus and the underlying mechanism remains unclear. Here, we identified the rtt109 gene in Monascus, constructed the rtt109 knockout strain (Δrtt109) and its complementary strain (Δrtt109:com) by CRISPR/Cas9 methods, and functionally characterized the roles that Rtt109 play in Monascus. Deletion of rtt109 significantly reduced conidia formation and colony growth, whereas, it increased the yield of Monascus pigments (MPs) and citrinin (CTN). Further real-time quantitative PCR (RT-qPCR) analysis indicated that Rtt109 remarkably affected the transcriptional expression of key genes related to development, morphogenesis, and secondary metabolism of Monascus. Together, our results revealed the critical roles of HAT Rtt109 in Monascus, and enriched our current knowledge of the development and regulation of secondary metabolism in fungi, throwing light on restraining or eliminating citrinin in the development and industrial applications of Monascus. [ABSTRACT FROM AUTHOR]

Monascus red pigments (MRPs) are mainly used as natural food colorants; however, their application is limited due to their poor stability. To expand their areas of application, we investigated the binding constants and capacity of MRPs to whey protein isolate (WPI) and whey protein hydrolysate (WPH) and calculated the surface hydrophobicities of WPI and WPH. MRPs were combined with WPI and WPH at a hydrolysis degree (DH) of 0.5% to form the complexes (DH = 0.0%) and (DH = 0.5%), respectively. Subsequently, the structural characteristics of complex (DH = 0.5%) and WPI were characterized and the color retention rates of both complexes and MRPs were investigated under different pretreatment conditions. The results showed that the maximum binding constant of WPI with MRPs was 0.670 ± 0.06 U−1 and the maximum binding capacity was 180 U/g. Furthermore, the thermal degradation of complex (DH = 0.0%), complex (DH = 0.5%), and MRPs in a water bath at 50–100 °C followed a first-order kinetic model. Thus, the interaction of WPI with MRPs could alter the protein conformation of WPI and effectively protect the stability of MRPs. [ABSTRACT FROM AUTHOR]

Food acceptability and appeal are significantly influenced by colour. Harmful effects associated with synthetic colorants are well established, and research is currently focused on developing natural, synthetic chemical-free substitutes from fungal sources, with broad applications in food, medicine, textiles and agriculture. Additionally, the market's dearth of natural red colour substitutes requires the creation of novel red pigment alternatives from secure and scalable sources. The goal of the current research was to establish new endophytic marine fungi that are naturally occurring bio-sources of the red pigment. Based on its profuse extracellular red pigment-producing capacity, the fungus CPEF02 was selected and identified as Monascus purpureus CPEF02 via internal transcribed spacer (ITS) sequences and phylogenetic analysis. The chemical moieties of the pigmented extracts were identified by liquid chromatography-high resolution mass spectrometry (LC-HRMS). The optimal culture conditions for maximum pigment production were investigated by surveying various media compositions. The methanolic fungal colourant extract was shown to have substantial antibacterial and antifungal activities against anthropogenic pathogens, Staphylococcus aureus (MTCC 1430), methicillin-resistant Staphylococcus aureus (ATCCBAA811), Salmonella typhimurium (MTCC 3241) and Vibrio cholerae (N16961) at a 100 µg/mL concentration and at a 1 mg/mL concentration for Alternaria solani (ITCC 4632) and Rhizoctonia solani (AG1-IA). This extract also exhibited antioxidant activity against the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical with an IC50 of 14.42 µg/mL and a Trolox equivalent antioxidant capacity of 0.571 µM Trolox/µg of the methanolic colourant extract. The findings suggested that M. purpureus's pigment could be a source of an industrially useful natural red colourant. [ABSTRACT FROM AUTHOR]

Exopolysaccharides are important metabolites of Monascus with healthy activities. However, the low production level limits their applications. Hence, the aim of this work was to increase the yield of exopolysaccharides (EPS) and optimize liquid fermentation by adding flavonoids. The EPS yield was optimized via both medium composition and culture conditions. The optional fermentation conditions achieved for EPS production of 7.018 g/L were 50 g/L sucrose, 3.5 g/L yeast extract, 1.0 g/L MgSO4·7H2O, 0.9 g/L KH2PO4, 1.8 g/L K2HPO4·3H2O, 1 g/L quercetin, and 2 mL/L Tween-80, with pH 5.5, inoculum size 9%, seed age 52 h, shaking speed 180 rpm, and fermentation culture 100 h, respectively. Furthermore, the addition of quercetin increased EPS production by 11.66%. The results also showed little citrinin residue in the EPS. The exopolysaccharides' composition and antioxidant capacity of quercetin-modified exopolysaccharides were then preliminarily investigated. The addition of quercetin changed the composition of the exopolysaccharides and the molecular weight (Mw). In addition, the antioxidant activity of Monascus exopolysaccharides was monitored using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS+), and -OH. Monascus exopolysaccharides have good scavenging ability of DPPH and -OH. Furthermore, quercetin increased the scavenging ABTS+ ability. Overall, these findings provide a potential rationale for the application of quercetin in improving the EPS yield. [ABSTRACT FROM AUTHOR]

Microbial fermentation with immobilized cells possesses many advantages. However, this fermentation mode is restricted to the production of extracellular products. Our previous study demonstrated that the extractive fermentation of Monascus spp. in nonionic surfactant micelle aqueous solution can export Monascus pigments that are supposed to be mainly intracellular products to extracellular culture broth and, in the meantime, extracellularly enhance the production of yellow pigments at a low pH condition; consequently, this makes the continuous production of yellow pigments with immobilized Monascus cells feasible. In this study, immobilized-cell fermentation and extractive fermentation in Triton X-100 micelle aqueous solution were successfully combined to continuously produce Monascus yellow pigments extracellularly. We examined the effects of cell immobilization and Triton X-100 on cell growth, pigment production, and pigment composition. In the repeated-batch extractive fermentation with immobilized cells, the biomass in Ca-alginate gel beads continued to grow and reached 21.2 g/L after seven batches, and dominant yellow pigments were produced extracellularly and stable for each batch. The mean productivity of the extracellular yellow pigments reached up to 22.31 AU410 nm/day within the first four batches (13 days) and 19.7 AU410 nm/day within the first seven batches (25 days). The results also provide a new strategy for producing such intracellular products continuously and extracellularly. [ABSTRACT FROM AUTHOR]

Fungi of the Monascus species are used in Asia for the production of fermented foods, mainly due to the ability of these fungi to produce secondary metabolites such as pigments. Due to the growing discussion about the use of synthetic dyes and the fact that their ingestion is associated with harm to human health, studies have sought to replace these dyes using natural pigments, and new alternatives for the production of these natural pigments have been presented. In this context, Monascus pigments are a viable alternative for application in the food industry. This study aimed to evaluate different main carbon sources and pH conditions in the red pigment production of Monascus sp. We found that mannitol, when used as the only carbon source, stimulated the production of extracellular red pigment, reaching a concentration of 8.36 AU in 48 h, while glucose and sucrose reached concentrations of 1.08 and 1.34 AU, respectively. Cultivation in a bioreactor using mannitol showed great potential for optimizing pigment production and obtaining a high concentration of extracellular pigment in a short time, reaching a concentration of 25 AU in 60 h of cultivation. The change in pH altered the production of extracellular red pigment in a culture medium containing mannitol as a carbon source, demonstrating less potential than the use of static pH during cultivation in a bioreactor. Mannitol proved to be an efficient carbon source for M. pupureus under static pH conditions for both flask and benchtop bioreactor cultivation. [ABSTRACT FROM AUTHOR]

Monascus red pigments (MRPs), which are a kind of natural colorant produced by Monascus spp., are widely used in the food and health supplements industry but are not very stable during processing and storage. Thus, MRPs were embedded into liposome membranes using a thin-film ultrasonic method to improve stability in this study. Monascus red pigments liposomes (MRPL) exhibited spherical unilamellar vesicles (UV) with particle size, polydispersity indexes (PDI), and zeta potential of 20–200 nm, 0.362 ± 0.023, and −42.37 ± 0.21 mV, respectively. pH, thermal, light, metal ion, storage, and in vitro simulated gastrointestinal digestion stability revealed that, compared with free MRPs, liposomes embedding significantly enhanced the stability of MRPs when exposed to adverse environmental conditions. Furthermore, anticancer assay suggested that MRPL exhibited a stronger inhibitory effect on MKN-28 cells by damaging the integrity of cells, with the IC50 value at 0.57 mg/mL. Overall, MRPLs possess stronger stability in external environment and in vitro simulated digestion with greater anticancer activity, indicating that MRPLs have the potential for promising application in the functional foods and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Monascus-fermented cheese (MC) is a new type of mold-ripened cheese that combines a traditional Chinese fermentation fungus, Monascus purpureus M1, with Western cheese fermentation techniques. In this study, the compositions of the volatile aroma compounds in MC were analyzed during a 30-day ripening period using SPME-Arrow and GC-O-MS. The activity of esterase in MC, which is a key enzyme catalyzing esterification reaction, was determined and compared with the control group (CC). Next, sensory analysis was conducted via quantitative descriptive analysis followed by Pearson correlation analysis between esterase activity and the key flavor compounds. A total of 76 compounds were detected. Thirty-three of these compounds could be smelled at the sniffing port and were identified as the key aroma compounds. The esterase activity in MC was found to be 1.24~1.33 times that of the CC. Moreover, the key odor features of ripened MC were alcohol and fruity flavors, considerably deviating from the sour and cheesy features found for the ripened CC. Furthermore, correlation analysis showed that esterase activity was strongly correlated (|r|> 0.75, p < 0.05) with various acids such as pentanoic and nonanoic acids and several aromatic esters, namely, octanoic acid ethyl ester and decanoic acid ethyl ester, revealing the key role that esterases play in developing the typical aroma of ripened MC. [ABSTRACT FROM AUTHOR]

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are the core components that mediate vesicle fusion, and they play an important role in secondary metabolism of filamentous fungi. However, in Monascus spp., one of the traditional medicinal and edible filamentous fungi, the members and function of SNAREs remain unknown. Here, twenty SNAREs in M. ruber M7 were systematically identified based on the gene structure, amino acid structure and phylogenetic analysis and were classified into four subfamilies. We also compared the expression profiles of twenty MrSNAREs in M. ruber M7 and its deletion mutants, ΔmrpigA and ΔpksCT, which could not produce Monascus pigment and citrinin, respectively. The results indicated that these MrSNAREs showed distinct expression patterns in the three strains. Compared to M. ruber M7, the expression levels of Mrtlg2, Mrbet1, Mrgos1 and Mrsec22 remained higher in ΔmrpigA but lower in ΔpksCT, which could be reason to consider them as potential candidate genes involved in secondary metabolism for further functional characterization. Further, the significant upregulation of Mrpep12 and Mrvtil in ΔpksCT is worthy of attention for further research. Our results provide systematic identification and expression profiling of the SNARE family in Monascus and imply that the functions of MrSNAREs are specific to different secondary metabolic processes. [ABSTRACT FROM AUTHOR]

Monascus pigments (MPs) are natural edible pigments with high safety and strong function, which have been widely used in food and health products. In this study, different types of tea extracts (rich in polyphenols) were used to regulate the biosynthesis of MPs. The results showed that 15% ethanol extract of pu-erh tea (T11) could significantly increase MPs production in liquid fermentation of Monaco's purpureus M3. Comparative transcriptomic and metabolomic analyses combined with reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were used to further explore the regulatory mechanism of T11 on the biosynthesis of MPs. Comparative transcriptomic analysis showed that there were 1503 differentially expressed genes (DEGs) between the Con group and the T11 group, which were mainly distributed in carbohydrate metabolism, amino acid metabolism, energy metabolism, lipid metabolism, metabolism of terpenoids and polyketides, etc. A total of 115 differential metabolites (DMs) identified by metabolomics between the Con and T11 groups were mainly enriched in glutathione metabolism, starch and sucrose metabolism, alanine, aspartic acid and glutamate metabolism and glycine, serine and threonine metabolism, etc. The results of metabolomics were basically consistent with those of gene transcriptomics, indicating that the regulatory effect of T11 on the biosynthesis of MPs is mainly achieved through affecting the primary metabolic pathway, providing sufficient energy and more biosynthetic precursors for secondary metabolism. In this study, tea extracts with low economic value and easy access were used as promoters of MPs biosynthesis, which may be conducive to the application of MPs in large-scale industrial production. At the same time, a more systematic understanding of the molecular regulatory mechanism of Monascus metabolism was obtained through multi-omics analysis. [ABSTRACT FROM AUTHOR]

Monascus-fermented red mold rice (RMR) has excellent physiological efficacy on lipid metabolism and liver function. This study investigated the ameliorative effects of monascuspiloin (MP) from RMR on alcoholic liver injury in mice, and further clarified its mechanism of action. Results showed that MP intervention obviously ameliorated lipid metabolism and liver function in mice with over-drinking. In addition, dietary MP intervention reduced liver MDA levels and increased liver CAT, SOD, and GSH levels, thus alleviating liver oxidative stress induced by excessive drinking. 16S rRNA amplicon sequencing showed that MP intervention was beneficial to ameliorate intestinal microbiota dysbiosis by elevating the proportion of norank_f_Lachnospiraceae, Lachnoclostridium, Alistipes, Roseburia, Vagococcus, etc., but decreasing the proportion of Staphylococcus, norank_f_Desulfovibrionaceae, Lachnospiraceae_UCG-001, Helicobacter, norank_f_Muribaculaceae, unclassified_f_Ruminococcaceae, etc. Additionally, correlation network analysis indicated that the key intestinal bacterial taxa intervened by MP were closely related to some biochemical parameters of lipid metabolism, liver function, and oxidative stress. Moreover, liver metabolomics analysis revealed that dietary MP supplementation significantly regulated the levels of 75 metabolites in the liver, which were involved in the synthesis and degradation of ketone bodies, taurine, and hypotaurine metabolism, and other metabolic pathways. Furthermore, dietary MP intervention regulated gene transcription and protein expression associated with hepatic lipid metabolism and oxidative stress. In short, these findings suggest that MP mitigates alcohol-induced liver injury by regulating the intestinal microbiome and liver metabolic pathway, and thus can serve as a functional component to prevent liver disease. [ABSTRACT FROM AUTHOR]

Monascus azaphilones pigments (MonAzPs) produced by microbial fermentation are widely used as food chemicals for coloring and supplying beneficial biological attributes. In this study, a fermentation perturbation strategy was implemented by separately adding different amino acids, and detecting the intracellular metabolome via UHPLC-Q-Orbitrap HRMS. With the aid of weighted gene co-expression network analysis, two metabolic intermediates, fumarate and malate, involved in the tricarboxylic acid cycle, were identified as the hub metabolites. Moreover, exogenous addition of fumarate or malate significantly promoted red pigment production, and reduced orange/yellow pigment production. The importance of the tricarboxylic acid cycle was further emphasized by detecting intracellular levels of ATP, NAD(P)H, and expression of oxidoreductase-coding genes located in the MonAzPs synthetic gene cluster, suggesting a considerable effect of the energy supply on MonAzPs synthesis. Collectively, metabolomics is a powerful approach to position the crucial metabolic regulatory factors, and facilitate the development of engineering strategies for targeted regulation, lower trial-and-error cost, and advance safe and controllable processes for fermented food chemistry industries. [ABSTRACT FROM AUTHOR]

In order to improve the flavor and taste of Camembert cheese, the use of Monascus as an adjunct starter for the production of Camembert-type cheese was studied to investigate its effect on the proteolysis, lipolysis, and volatile compounds during ripening for 40 days. The Camembert cheese without Monascus was used as a control. The results showed that proteolytic and lipolytic activities increased to a certain extent. The addition of Monascus promoted primary and secondary proteolysis, due to the release of some proteases by Monascus. Aspartic, Threonine, Glutamic, Glycine, Methione, Isoleucine, Phenyalanine, and Lysine contents in experimental group (R) cheese were significantly higher than those in control group (W) cheeses. In addition, the free amino acid and fatty acid contents were also affected. The identification of flavor components using gas-mass spectrometry (GC-MS) showed that 2-undecone, 2-tridecanone, phenylethyl alcohol, butanediol (responsible for the production of flowery and honey-like aroma), ethyl hexanoate, ethyl octanoate, and ethyl citrate (fruit-like aroma) were significantly higher (p < 0.05) in the experimental cheeses than in the control. The contents of 2-nonanone, 2-octanone and 2-decanone (showing milky flavor), and 1-octene-3 alcohol with typical mushroom-like flavor were lower than the control. [ABSTRACT FROM AUTHOR]

The effects of a static magnetic field (SMF) on Monascus ruber M7 (M. ruber M7) cultured on potato dextrose agar (PDA) plates under SMF treatment at different intensities (5, 10, and 30 mT) were investigated in this paper. The results revealed that, compared with the control (CK, no SMF treatment), the SMF at all tested intensities did not significantly influence the morphological characteristics of M. ruber M7, while the intracellular and extracellular Monascus pigments (MPs) and extracellular citrinin (CIT) of M. ruber M7 were increased at 10 and 30 mT SMF but there was no impact on the MPs and CIT at 5 mT SMF. The transcriptome data of M. ruber M7 cultured at 30 mT SMF on PDA for 3 and 7 d showed that the SMF could increase the transcriptional levels of some relative genes with the primary metabolism, including the carbohydrate metabolism, amino acid metabolism, and lipid metabolism, especially in the early growing period (3 d). SMF could also affect the transcriptional levels of the related genes to the biosynthetic pathways of MPs, CIT, and ergosterol, and improve the transcription of the relative genes in the mitogen-activated protein kinase (MAPK) signaling pathway of M. ruber M7. These findings provide insights into a comprehensive understanding of the effects of SMF on filamentous fungi. [ABSTRACT FROM AUTHOR]

The color of food is a critical factor influencing its general acceptance. Owing to the effects of chemical colorants on health, current research is directly aimed at producing natural and healthy food colorants from microbial sources. A pigment-producing fungal isolate, obtained from soil samples and selected based on its rapidity and efficiency in producing red pigments, was identified as Monascus ruber OMNRC45. The culture conditions were optimized to enhance pigment production under submerged fermentation. The optimal temperature and pH for the highest red pigment yield were 30 °C and 6.5, respectively. The optimum carbon and nitrogen sources were rice and peptone, respectively. The usefulness of the pigment produced as a food colorant was evaluated by testing for contamination by the harmful mycotoxin citrinin and assessing its biosafety in mice. In addition, sensory evaluation tests were performed to evaluate the overall acceptance of the pigment as a food colorant. The results showed that M. ruber OMNRC45 was able to rapidly and effectively produce dense natural red pigment under the conditions of submerged fermentation without citrinin production. The findings of the sensory and biosafety assessments indicated the biosafety and applicability of the red Monascus pigment as a food colorant. [ABSTRACT FROM AUTHOR]

Monascus pigments (MPs) have been used as food colorants for several centuries in Asian countries and are now used throughout the world via Asian catering. The MP biosynthetic pathway has been well-illustrated, but the functions of a few genes, including mrpigG, in the MP gene cluster are still unclear. In the current study, in order to investigate the function of mrpigG in M. ruber M7, gene deletion (ΔmrpigG), complementation (ΔmrpigG::mrpigG) and overexpression (M7::PtrpC-mrpigG) mutants were successfully obtained. The morphologies and biomasses, as well as the MP and citrinin production, of these mutants were analyzed. The results revealed that the disruption, complementation and overexpression of mrpigG showed no apparent defects in morphology, biomass or citrinin production (except MP production) in ΔmrpigG compared with M. ruber M7. Although the MP profiles of ΔmrpigG and M. ruber M7 were almost the same—with both having four yellow pigments, two orange pigments (OPs) and two red pigments (RPs)—their yields were decreased in ΔmrpigG to a certain extent. Particularly, the content of rubropunctatin (an OP) and its derivative rubropunctamine (an RP) in ΔmrpigG, both of which have a five-carbon side chain, accounted for 57.7%, and 22.3% of those in M. ruber M7. On the other hand, monascorubrin (an OP) and its derivative monascorubramine (an RP), both of which have a seven-carbon side chain, were increased by 1.15 and 2.55 times, respectively, in ΔmrpigG compared with M. ruber M7. These results suggest that the MrPigG protein may preferentially catalyze the biosynthesis of MPs with a five-carbon side chain. [ABSTRACT FROM AUTHOR]

Background: Several traditional medicines have been developed among communities as part of the efforts to improve thrombocytopenia in patients with Dengue virus infection (DVI). Among those efforts is the administration of Monascus jmbA rice (MJR), which is rice fermented with Monascus purpureus. The administration of MJR is believed to increase the platelet count in patients with DVI. Aim: The objective of this study is to elucidate the mechanism of the effects of MJR on increased levels of platelets in DVI serotype 3 through changes in IL-3, IL-6, IL-11 and TNF-a. Methods: It was a true experimental laboratory study using the randomized posttest only control group design. The study compared between groups of wistar rats were being treated only with group IVD wistar rats who experienced treatment followed by administration of MJR as well as groups of wistar rats without any treatment as a control group. Results: The increase in platelet count in the group treated with DVI + MJR was higher than that treated with only DVI and the difference was a significant (P<0.05). Increased levels of TNF-a in the group treated with DVI + MJR were lower than that treated with only DVI and the difference was significant (P<0.05). The significant levels of the causal relationship of TNF-a with IL-6, TNF-a with IL-11 and IL- 6 with platelets were 0.044 (P<0.05), 0.029 (P<0.05) and 0.041 (P<0.05), respectively. Conclusion: MJR is capable of increasing platelet count through the role of TNF- a and IL-6 in Wistar rats infected with DVI serotype 3. [ABSTRACT FROM AUTHOR]

The effect of light on Monascus and the underlying mechanism have received a great deal of interest for the industrial application of Monascus pigments. In this study, we have examined the effects of blue light on the culture morphology, mycelium growth, pigments, and citrinin yield of Monascus in liquid-state and oscillation fermentation, and explored the mechanism at a physiological level. It was found that blue light affected the colony morphology, the composition (chitin content), and permeability of the Monascus mycelium cell wall in static liquid culture, which indicates blue light benefits pigments secreting from aerial mycelium to culture medium. In liquid oscillation fermentation, the yields of Monascus pigments in fermentation broth (darkness 1741 U/g, blue light 2206 U/g) and mycelium (darkness 2442 U/g, blue light 1900 U/g) cultured under blue light and darkness are different. The total pigments produced per gram of Monascus mycelium under blue light was also higher (4663 U/g) than that in darkness (4352 U/g). However, the production of citrinin (88 μg/g) under blue light was evidently lower than that in darkness (150 μg/g). According to the degradation of citrinin caused by blue light and hydrogen peroxide, it can be concluded that blue light could degrade citrinin and inhibit the catalase activity of Monascus mycelium, subsequently suppressing the decomposition of hydrogen peroxide, which is the active species that degrades citrinin. [ABSTRACT FROM AUTHOR]

Fish bone fermented using Monascus purpureus (FBF) has total phenols and functional amino acids that contribute to its anti-oxidant and anti-inflammatory properties. Colorectal cancer, one of the most prevalent cancers and the third largest cause of death worldwide, has become a serious threat to global health. This study investigates the anti-cancer effects of FBF (1, 2.5 or 5 mg/mL) on the cell growth and molecular mechanism of HCT-116 cells. The HCT-116 cell treatment with 2.5 or 5 mg/mL of FBF for 24 h significantly decreased cell viability ( p < 0.05). The S and G2/M phases significantly increased by 88-105% and 25-43%, respectively ( p < 0.05). Additionally, FBF increased the mRNA expression of caspase 8 (38-77%), protein expression of caspase 3 (34-94%), poly (ADP-ribose) polymerase (PARP) (31-34%) and induced apoptosis (236-773%) of HCT-116 cells ( p < 0.05). FBF also increased microtubule-associated protein 1B light chain 3 (LC3) (38-48%) and phosphoinositide 3 kinase class III (PI3K III) (32-53%) protein expression, thereby inducing autophagy (26-52%) of HCT-116 cells ( p < 0.05). These results showed that FBF could inhibit HCT-116 cell growth by inducing S and G2/M phase arrest of the cell cycle, apoptosis and autophagy. Thus, FBF has the potential to treat colorectal cancer.

Deep ocean water (DOW) obtained from a depth of more than 200 m includes abundant nutrients and minerals. DOW was proven to positively increase monascin (MS) and ankaflavin (AK) production and the anti-adipogenesis effect of Monascus-fermented red mold dioscorea (RMD). However, the influences that the major metals in DOW have on Monascus secondary metabolite biosynthesis and anti-adipogenesis remain unknown. Therefore, the major metals in DOW were used as the culture water to produce RMD. The secondary metabolites production and anti-adipogenesis effect of RMD cultured with various individual metal waters were investigated. In the results, the addition of water with Mg, Ca, Zn, and Fe increased MS and AK production and inhibited mycotoxin citrinin (CT). However, the positive influence may be contributed to the regulation of pigment biosynthesis. Furthermore, in the results of cell testing, higher lipogenesis inhibition was seen in the treatments of various ethanol extracts of RMD cultured with water containing Mg, K, Zn, and Fe than in those of RMD cultured with ultra-pure water. In conclusion, various individual metals resulted in different effects on MS and AK productions as well as the anti-adipogenesis effect of RMD, but the specific metals contained in DOW may cause synergistic or comprehensive effects that increase the significantly positive influence. [ABSTRACT FROM AUTHOR]

Deep ocean water (DOW) has, in previous studies, been found to be a novel anti-obesity drink and useful in raising Monascus-produced monascin and ankaflavin levels. This may resolve the limited anti-obesity ability of red mold dioscorea (RMD) known as the Monascus purpureus-fermented Disocorea batatas. This study aims to compare the anti-obesity effect of DOW-cultured RMD (DOW-RMD) and ultra-pure water-cultured RMD (UPW-RMD) in rats fed on a high fat diet. Moreover, the effect of ions composition of DOW and DOW-influenced functional metabolites change of RMD on the differentiation and lipogenesis regulation were investigated using 3T3-L1 pre-adipocytes. In the animal test, compared to UPW-RMD, DOW-RMD possessed better ability to inhibit increases in weight gain, and better feed efficiency, body-fat pad and cross-sectional area of adipocytes. In the cell test, the anti-obesity abilities of DOW-RMD in inhibiting PPAR? and C/EBPa expression in differentiation and lipoprotein lipase activity in lipogenesis were contributed to by the DOW-increased monascin and ankaflavin levels and the ions of DOW, respectively. [ABSTRACT FROM AUTHOR]

A new azaphilonidal derivative, monapurpyridine A (MPA), has recently been isolated from the fermented products of Monascus purpureus NTU 568. The structure of MPA was elucidated by nuclear magnetic resonance (1H-NMR, 13C-NMR, COSY, HMQC, and HMBC) and other spectroscopic analyses. Biological evaluation revealed that MPA could induce cell death in human breast adenocarcinoma cells MCF-7, and it has no significant toxicity to normal mammary epithelial cells M10. The MTT assay and flow cytometric analysis were employed to investigate cell viability and cell cycle influenced by MPA. Moreover, we used Western blot and caspase activity assay to demonstrate the activation of caspase-3, -8 and -9 resulted from MPA. All evidence supported that MPA was suitable for developing into a chemotherapeutic or chemopreventive agent against breast cancer. [ABSTRACT FROM AUTHOR]

Four new pyridine derivatives, monasnicotinates A-D (1-4) were isolated from the red yeast rice of Monascus pilosus BCRC 38093. Their structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, and high-resolution mass spectrometry. Their inhibitory effects on NO production was also evaluated. [ABSTRACT FROM AUTHOR]

Monascus pigments (MPs) have been used as food colorants for several centuries in Asian countries and are currently used around the world via Asian catering. The MPs biosynthetic pathway has been well-illustrated; however, the functions of a few genes including mrpigH in the MPs gene cluster of M. ruber M7 are still unclear. In the current study, mrpigH was disrupted in Δmrlig4ΔmrpyrG, a highly efficient gene modification system, using mrpyrG as a selection marker, and ΔmrpigHΔmrlig4ΔmrpyrG::mrpyrG and ΔmrpigHΔmrlig4ΔmrpyrG have been obtained. Subsequently, their morphologies, biomasses, MPs and citrinin (CIT) production were analyzed, respectively. These results have revealed that the deletion of mrpigH has significant effects on the morphology and growth of M. ruber M7. Moreover, compared with M. ruber M7, the yields of MPs and CIT were drastically increased and decreased in mrpigH mutants, respectively. [ABSTRACT FROM AUTHOR]

Citrinin (CIT) is secondary metabolite of filamentous molds. This mycotoxin has nephrotoxic, hepatotoxic, embryocidal, and fetotoxic properties. It is also produced by several species of the three genera Penicillium spp., Aspergillus spp., and Monascus spp., which are used to make red yeast rice (RYR). The material for this study consisted of 15 dietary supplements containing an extract of fermented red rice, available on the Polish market. Samples were extracted using a MeOH–H2O mixture, cleaned-up with an immunoaffinity CitriTest HPLC column, and quantified by HPLC–FLD. None of the analyzed samples contained CIT above the established limit of detection (LOD). Studies on the presence of toxic metabolites in red yeast rice show the importance of regulating this product and of clear information on the label regarding the standardized amounts of monacolin. [ABSTRACT FROM AUTHOR]

Monascus pilosus strains are widely applied to yield a cholesterol synthesis inhibitor monacolin K (MK), also called lovastatin (LOV). However, the mechanism of MK production by M. pilosus strains is still unclear. In this study, we firstly confirmed four Monascus strains, MS-1, YDJ-1, YDJ-2, and K104061, isolated from commercial MK products as M. pilosus and compared their abilities to produce MK in solid-state and liquid-state cultures. Then, we sequenced and analyzed their genomes and MK biosynthetic gene clusters (BGCs). The results revealed that the MK yields of MS-1, YDJ-1, YDJ-2, and K104061 in solid-state cultures at 14 days were 6.13, 2.03, 1.72, and 0.76 mg/g, respectively; the intracellular and extracellular MK contents of MS-1, YDJ-1, YDJ-2, and K104061 in liquid-state cultures at 14 days reached 0.9 and 1.8 mg/g, 0.38 and 0.43 mg/g, 0.30 and 0.42 mg/g, and 0.31 and 0.76 mg/g, respectively. The genome sizes of the four M. pilosus strains were about 26 Mb, containing about 7000–8000 coding genes and one MK gene cluster. The MK BGCs of MS-1, YDJ-2, and K104061 contained 11 genes, and the MK BGC of YDJ-1 contained 9 genes. According to the literature search, there are few comparisons of gene clusters and related genes responsible for the synthesis of LOV and MK. We also compared the LOV BGC in A. terreus with the MK BGCs in different species of Monascus spp., and the results revealed that although LOV and MK were the same substance, the genes responsible for the synthesis of MK were much less than those for LOV synthesis, and the gene functions were quite different. The current results laid a foundation to explore the mechanism of MK produced by Monascus spp. and compare the synthesis of LOV and MK. [ABSTRACT FROM AUTHOR]

Monascus vinegar (MV), during whose brewing process Monascus spp. and polished rice (PR) are normally used as the starter and the raw material, respectively, is one of the traditional vinegars in China. In this study, the effects of three raw materials, including PR, unhusked rice (UR), and germinated UR (GR), on MV volatile compounds have been investigated. The results revealed that MV of GR (GMV), and its intermediate Monascus wine (GMW), exhibited the highest amount of aroma, not only in the concentrations but also in the varieties of the aromatic compounds mainly contributing to the final fragrance. Especially after three years of aging, the contents of benzaldehyde and furfural in GMV could reach to 13.93% and 0.57%, respectively, both of which can coordinate synergistically on enhancing the aroma. We also found that the filtering efficiency was significantly improved when UR and GR were applied as the raw materials, respectively. Therefore, GR might be more suitable raw materials for MV. [ABSTRACT FROM AUTHOR]

A dye exclusion test (DET) was performed to determine the viability of human breast cancer cells MCF-7, using natural food pigments as compared with trypan blue (TB), a typical synthetic dye for DET known to exhibit teratogenicity and cytotoxicity. We demonstrated that Monascus pigment (MP) is noninvasive to living cells and can effectively stain only dead cells. This study is the first verification of the applicability of MP to cancer cells. The appropriate MP concentration was 0.4% (0.02% as the concentration of pure MP) and all the dead cells were stained within 10 min. We found that the cell proliferation or the reduced nicotinamide adenine dinucleotide (NADH) activity of living cells was maintained over 48 h. Although 0.1% TB did not show an increase in dead cells, a marked decrease in NADH activity was confirmed. In addition, even when MP coexisted with cisplatin, staining of dead cells was maintained for 47 h, indicating stability to drugs (reagents). The cost of MP is estimated to be about 1/10 of TB. The fact that MP can be used as a cell viability determination reagent for Euglena and Paramecium, as shown in preceding papers, and also for MCF-7, as shown in this paper, indicates the possibility of application in more cells of different species. [ABSTRACT FROM AUTHOR]