Bidirectional fermentation of Monascus and Mulberry leaves enhances GABA and pigment contents: establishment of strategy, studies of bioactivity and mechanistic.

Bidirectional fermentation is a technology that utilizes fungi to ferment medicinal edible substrates, with synergistic and complementary advantages. In this work, a fermentation strategy was established to produce a high yield of γ-aminobutyric acid (GABA) and Monascus pigments (MPs) using Monascus and mulberry leaves (MLs). Firstly, the basic fermentation parameters were determined using single-factor experiments, followed by Plackett-Burman (PB) experimental design to identify MLs, glucose, peptone, and temperature as significant influencing factors. The fermentation parameters were optimized using an artificial neural network (ANN). Finally, the effects of bidirectional fermentation of MLs and Monascus were investigated by bioactivity analysis, microstructure observation, and RT-qPCR. The outcomes showed that the bidirectional fermentation significantly increased the bioactive content and promoted the secondary metabolism of Monascus. The established fermentation conditions were 44.2 g/L of MLs, 57 g/L of glucose, 15 g/L of peptone, 1 g/L of MgSO4, 2 g/L of KH2PO4, 8% (v/v) of inoculum, 180 rpm, initial pH 6, 32 °C and 8 days. The content of GABA reached 13.95 g/L and the color value of MPs reached 408.07 U/mL. This study demonstrated the feasibility of bidirectional fermentation of MLs and Monascus, providing a new idea for the application of MLs and Monascus.

An efficient method for improving the stability of Monascus pigments using ionic gelation.

BACKGROUND: Monascus pigments (Mps) are easily impacted by heating, pH and light, resulting in degradation. In this study, Mps were encapsulated by the ionic gelation method with sodium alginate (SA) and sodium caseinate (SC), as well as CaCl2 as a crosslinker. The encapsulated Mps SA/SC in four proportions (SA/SC: 1/4, 2/3, 3/2, 4/1, w/w). Then, the encapsulation efficiency and particle size of the SA/SC-Mps system were evaluated to obtain the optimal embedding conditions. Finally, the effects of heating, pH, light and storage on the stability of non-capsulated Mps and encapsulated Mps were assessed. RESULTS: SA/SC = 2/3 (AC2) had higher encapsulation efficiency (74.30%) of Mps and relatively small particle size (2.02 mm). The AC2 gel beads were chosen for further investigating the stability of encapsulated Mps to heating, pH, light and storage. Heat stability experiments showed that the degradation of Mps followed first-order kinetics, and the encapsulated Mps had lower degradation rates than non-capsulated Mps. Encapsulation could reduce the effect of pH on Mps. The effects of ultraviolet light on the stability of Mps were considered, and showed that the retention efficiency of encapsulated Mps was 22.01% higher than that of non-capsulated Mps on the seventh day. Finally, storage stability was also evaluated under dark refrigerated conditions for 30 days, and the results indicated that encapsulation could reduce the degradation of Mps. CONCLUSION: This study has proved that AC2 gel beads can improve the stability of Mps. Thus, the ionic gelation method is a promising encapsulation method to improve the stability of Mps. © 2023 Society of Chemical Industry.

Secondary Metabolites with Antifungal Activities from Mangrove Derived Fungus Monascus purpureus WMD2424.

The mold Monascus, also called red yeast rice, anka, or koji, has been used as the natural food coloring agent and food additives for more than 1000 years in Asian countries. It has also been used in Chinese herbology and traditional Chinese medicine due to its easing digestion and antiseptic effects. However, under different culture conditions, the ingredients in Monascus-fermented products may be changed. Therefore, an in-depth understanding of the ingredients, as well as the bioactivities of Monascus-derived natural products, is important. Here, through the thorough investigation into the chemical constituents of M. purpureus wmd2424, five previously undescribed compounds, monascuspurins A-E (1-5), were isolated from the EtOAc extract of mangrove-derived fungus Monascus purpureus wmd2424 cultured in RGY medium. All the constituents were confirmed via HRESIMS and 1D- and 2D-NMR spectroscopy. Their antifungal activity was also evaluated. Our results showed that four constituents (compounds 3-5) possessed mild antifungal activity against Aspergillus niger, Penicillium italicum, Candida albicans, and Saccharomyces cerevisiae. It is worth mentioning that the chemical composition of the type strain Monascus purpureus wmd2424 has never been studied.

Supplementary effect of whey components on the monascin productivity of Monascus sp.

BACKGROUND: Monascus sp. has been used in fermented foods for centuries. It can synthesize yellow, red, and orange pigments as secondary metabolites. Here, we focused on yellow pigment monascin, responsible for anti-inflammation and antidiabetic effects, and investigated whether whey could be a suitable substrate with or without rice powder for monascin production using M. purpureus AHU 9085, M. pilosus NBRC 4520 and M. ruber NBRC 32318. RESULTS: The growth and monascin production of the three Monascus strains were dependent on three liquid media consisting of whey and/or rice. All strains showed the best growth in a rice and whey mixed medium, in which M. ruber NBRC 32318 exhibited the highest total monascin production. Subsequent investigation of the effects of whey components indicated that a mineral cocktail in whey was particularly effective in stimulating the monascin production efficiency of M. ruber NBRC 32318. However, this recipe exhibited less stimulation, or even inhibition, for M. pilosus NBRC 4520 and M. purpureus AHU 9085, respectively. In terms of total monascin production, rice with whey provided the highest amount due to growth promotion along with relatively high production efficiency. CONCLUSION: The effect of whey on growth and monascin production was strongly dependent on the Monascus strains. Even a mineral cocktail in whey could regulate monascin productivity in a strain-specific manner. Further studies are needed to elucidate the mechanism behind the diverse responses by the minerals in the production of monascin from Monascus. © 2023 Society of Chemical Industry.

A new endophyte Monascus ruber SRZ112 as an efficient production platform of natural pigments using agro-industrial wastes.

A number of biopigment applications in various industrial sectors are gaining importance due to the growing consumer interest in their natural origin. Thus, this work was conducted to valorize endophytic fungi as an efficient production platform for natural pigments. A promising strain isolated from leaves of Origanum majorana was identified as Monascus ruber SRZ112 produced several types of pigments. The nature of the pigments, mainly rubropunctamine, monascin, ankaflavin, rubropunctatin, and monascorubrin in the fungal extract was studied by LC/ESI-MS/MS analyses. As a first step towards developing an efficient production of red pigments, the suitability of seven types of agro-industrial waste was evaluated. The highest yield of red pigments was obtained using potato peel moistened with mineral salt broth as a culture medium. To increase yield of red pigments, favourable culture conditions including incubation temperature, incubation period, pH of moistening agent, inoculum concentration, substrate weight and moisture level were evaluated. Additionally, yield of red pigments was intensified after the exposure of M. ruber SRZ112 spores to 1.00 KGy gamma rays. The final yield was improved by a 22.12-fold increase from 23.55 to 3351.87 AU g-1. The anticancer and antioxidant properties of the pigment's extract from the fungal culture were also studied. The obtained data indicated activity of the extract against human breast cancer cell lines with no significant cytotoxicity against normal cell lines. The extract also showed a free radical scavenging potential. This is the first report, to our knowledge, on the isolation of the endophytic M. ruber SRZ112 strain with the successful production of natural pigments under solid-state fermentation using potato peel as a substrate.

Antioxidative, anti-inflammatory, and anticancer properties of the red biopigment extract from Monascus purpureus (MTCC 369).

In this study, the Monascus purpureus (MTCC 369) extracted biopigment produced by solid-state fermentation was evaluated for its therapeutic potential using human prostate LNCaP cells. Antioxidant efficacy of the red biopigment determined using 2,2 diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, and ferric reducing antioxidant power assays was found to be 53.16%, 86.27%, and 13.83%, respectively. In addition, expression studies of target gene superoxide dismutase 2 (SOD-2) showed that increasing concentrations (10-50 µg/ml) of the biopigment enhanced its expression from 0.91- to 1.905-fold. An inhibitory effect of 0.424-0.627-fold was observed in the expression of glutathione peroxidase (GPX) with a similar increase in biopigment concentration. Addition of quercetin (positive control) at 50 µg/ml led to 0.295-fold decrease in GPX expression. In contrast, the expression of SOD-2 increased by 1.026-fold in the presence of quercetin. The biopigment also showed an increased serological IL-10 expression (an anti-inflammatory agent) ranging from 1034.58 to 4657.89 pg/ml. Treatment of LNCaP cells with the red biopigment (10-100 µg/ml) resulted in significant (p < .05) reduction (upto 79.86%) in viability and 51.79%-89.86% reduction in cell metabolic activity. Fluorescent microscopy examination of red biopigment-treated cells showed significant inhibition of normal cellular morphology including condensed nuclei, membrane blebbing, and apoptotic bodies, thus confirming its cytotoxic potential. Results of this study revealed that the red biopigment has the potential to modulate the expression of antioxidative and anti-inflammatory markers in addition to being cytotoxic to the LNCaP cancer cells. PRACTICAL APPLICATIONS: These findings indicate that cell treatment with red biopigment has the potential to modulate anti-oxidative, pro-inflammatory and anti-inflammatory genes for therapeutic effects, which is further enhanced by its cytotoxic activity against cancer cells. Considering these cell-based observations, Monascus red biopigment has ample potential as a useful supplement to formulate therapeutic products that delay the development of inflammatory-related diseases and associated complications.

Hypoglycemic and Hypolipogenic Action of Acetic Acid and Monascus-Fermented Grain Vinegar: A Comparative Study.

Acetic acid has been proposed to improve lifestyle-related diseases, including hyperlipidemia and hyperglycemia. This study compared the hypoglycemic and hypolipogenic effects of acetic acid vinegar (AV, contains only 4% acetic acid) and Monascus-fermented grain vinegar (MV) containing various bioactive compounds in 3T3L1 cells and C57BL/KsJ-db/db mice (DB). The DB were divided randomly into three treatment groups containing nine mice each; DB-, AV-, and MV-groups were orally administered 1 mL/kg/day of distilled water, acetic acid vinegar, and Monascus vinegar, respectively, for 8 weeks. Exposure to AV and MV inhibited the adipogenic differentiation of 3T3L1 preadipocytes and lipid accumulation during differentiation. Oral administration of AV or MV to the mice resulted in a marked reduction in the body weight, liver weight, and hepatic triglyceride content compared to the control DB-group. Moreover, treatment with AV and MV clearly increased the expression of cyclic adenosine monophosphate (cAMP) and AMP-activated protein kinase (AMPK) and suppressed the expression of fatty acid synthetase in liver tissues of DB. Significantly, lower levels of fasting blood glucose, insulin, leptin, and the glycosylated hemoglobin (HbA1c) as well as higher levels of the skeletal muscle GLUT4 expression were obtained in the AV- or MV-groups than levels determined in the control DB-group (P < .05). Although MV has the potential to be a natural alternative treatment for obesity-associated type 2 diabetes, this study suggests that acetic acid is the central ingredient in MV responsible for the hypoglycemic and hypolipogenic effects in the DB mice.

Highland barley Monascus purpureus Went extract ameliorates high-fat, high-fructose, high-cholesterol diet induced nonalcoholic fatty liver disease by regulating lipid metabolism in golden hamsters.

ETHNOPHARMACOLOGICAL RELEVANCE: Hepatocyte lipid accumulation is the main feature in the early stage of nonalcoholic fatty liver disease (NAFLD). Highland barley Monascus purpureus Went (HBMPW), a fermentation product of Hordeum vulgare Linn. var. nudum Hook. f. has traditionally been used as fermented foods in Tibet with the effect of reducing blood lipid in folk medicine. AIM OF THE STUDY: This study investigated the protective effects and molecular mechanism of highland barley Monascus purpureus Went extract (HBMPWE) on NAFLD in syrian golden hamster fed with high-fat, high-fructose, high-cholesterol diet (HFFCD). MATERIALS AND METHODS: HFFCD-induced NAFLD golden hamster model was established and treated with HBMPWE. Liver index, biochemical index, and hematoxylin and eosin (HE) staining were observed. Liver metabolomics and western blot analysis were employed. RESULTS: Our study found that HBMPWE ameliorated HFFCD induced dyslipidemia, weight gain and elevated the liver index. In addition, HBMPWE treatment significantly attenuated lipid accumulation in the liver and modulated lipid metabolism (sphingolipid, glycerophospholipid). Our data demonstrated that HBMPWE not only regulated the expression of proteins related to fatty acid synthesis and decomposition (SREBP-1/ACC/FAS/AceS1, PPARα/ACSL/CPT1/ACOX1), but also regulated the expression of proteins related to cholesterol synthesis and clearance (HMGCR, LDLR, CYP7A1). CONCLUSIONS: HBMPWE improved NAFLD through multiple pathways and multiple targets in body metabolism and could be used as a functional food to treat NAFLD and other lipid metabolic disorders.

Triton X-100 supplementation regulates growth and secondary metabolite biosynthesis during in-depth extractive fermentation of Monascus purpureus.

Extractive fermentation has been proven to be efficient in enhancing the secretion and production of secondary metabolites in submerged fermentation by Monascus spp., owing to increased cell membrane permeability and resolved product inhibition. In this study, we investigated the regulation effect of Triton X-100 on cell growth and secondary metabolite biosynthesis in submerged fermentation of M. purpureus DK. The results show that the maximum monascus pigments (MPs), citrinin (CIT) production, and specific growth rate are 136.86 U/mL, 4.57 mg/L, and 0.04 h-1, respectively, when 3 g/L of Triton X-100 is supplemented after fermentation for 10 d, and the extracellular MPs and CIT increased by 127.48% and 288.57%, respectively. RT-qPCR shows that the expression levels of MPs and CIT biosynthesis gene clusters are significantly upregulated, whereas those of glycolysis, tricarboxylic acid cycle, respiratory chains, and ATP synthase are downregulated. This study provides a vital strategy for extractive fermentation under extreme environmental conditions for further enhancing MP production.

Evaluation of Chemical Compositions, Antioxidant Capacity and Intracellular Antioxidant Action in Fish Bone Fermented with Monascus purpureus.

Fish bones (FBs) are aquatic by-products that are sources of antioxidant-active peptides, calcium dietary supplements, and biomedical materials. Usually, fermentation of these by-products via microorganisms brings desirable changes, enhancing their value. This study investigates the value addition of FB when fermented with Monascus purpureus (MP) for different time intervals, such as 3 days (F3) and 6 days (F6). The results indicate that the soluble protein, peptide, amino acid and total phenol content, as well as the antioxidant capacity (DPPH, ABTS+ radical scavenging activity, and relative reducing power), of F3 and F6 were significantly increased after fermentation. Furthermore, the ROS contents of F3 and F6 were reduced to a greater extent than that of hydrogen peroxide (H2O2) in Clone-9 cells. The MMP integrity, as well as the SOD, CAT, and GPx activity, of F3 and F6 were also increased significantly compared to the H2O2 in Clone-9 cells. Notably, F3 and F6 displayed significant reductions in ROS content, as well as elevate, SOD activity and MMP integrity in Clone-9 cells, when compared with the native FB. These results indicate that the FBs fermented with MP for 3 days (F3), and 6 days (F6) have antioxidant capacity, with possible applications as natural food supplements.

Different types of components obtained from Monascus purpureus with neuroprotective and anti-inflammatory potentials.

The mold Monascus has been used as a natural food coloring agent and food additive for more than 1000 years in Asian countries. In Chinese herbology, it was also used for easing digestion and antiseptic effects. Through a thorough investigation of a citrinin-free strain: M. purpureus BCRC 38110, four azaphilones, three benzenoids, one benzofuranone, one 5',6'-dihydrospiro[isochromane-1,2'-pyran]-4'(3'H)-one derivative, two steroids, and six tetralones have been successfully identified. Among them, monapyridine A (1), monatetralones A-E (2-6), and monabenzofuranone (7) were first reported. Their structures were characterized by 1D and 2D NMR, UV, IR, and HRESIMS analyses. With a series of bioactivity screening, monascuspirolide B (14) and ergosterol peroxide (16) exhibited concentration-dependent attenuation of the paclitaxel-induced neurite damage of mouse dorsal root ganglion neurons. The interleukin (IL)-1ß-induced release of inflammatory cytokines IL-8 and tumor necrosis factor (TNF)-α in human chondrosarcoma cells was inhibited by monapurpureusone (8) and monascuspirolide B (14). Altogether, M. purpureus BCRC 38110 possessed potentials as natural therapeutics against inflammatory osteoarthritis and paclitaxel-induced neurotoxicity.

Monascus ruber fermented Panax ginseng ameliorates lipid metabolism disorders and modulate gut microbiota in rats fed a high-fat diet.

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng Meyer) is rich in a variety of biologically active ingredients, which shows good effect in the treatment of metabolic diseases. Monascus has lipid-lowering activity and one of its metabolites, lovastatin, is widely used in clinical practice. AIM OF THE STUDY: The main purpose of this study was to clarify the effects of fermented Panax ginseng by Monascus ruber (PM) on lipid metabolism and gut microbiota in rats fed a high-fat diet. MATERIALS AND METHODS: SPF Sprague-Dawley rats were randomly divided into 5 groups, the therapeutic effect of PM on HFD-induced obesity, hyperlipidemia, hepatic steatosis, and disordered gut microbiota were determined in rats. RESULTS: PM could attenuate features of obesity in rats, decrease serum TC, LDL-C and IgA levels, increase excretion of bile acids in feces. Hepatic histopathologic analysis revealed that PM decrease lipid accumulation in hepatocytes. Consistently, mRNA expression levels of cholesterol metabolism-related genes were regulated in the livers of HFD-fed rats administered with PM. In addition, PM could enhance the diversity and relative abundance of gut microbiota, reduce the Firmicutes/Bacteroidetes (F/B) ratio, increase significantly the relative abundance of Prevotella_9, and decrease these of Muribaculaceae. CONCLUSIONS: PM could regulate lipid metabolism and the structure of the gut microbiota in the HFD rats. Our findings provide valuable experience for the development of ginseng. PM could be a potentially effective strategy to prevent and treat metabolic diseases and alleviate the gut microbiota disturbance caused by it.

Process optimization in ginseng fermentation by Monascus ruber and study on bile acid-binding ability of fermentation products in vitro.

Ginseng (Panax ginseng C. A. Meyer) is a famous Traditional Chinese Medicine, which is widely used to treat cardiovascular disease. Monascus ruber (M. ruber) is a fungus used in food and medicine fermentation, and lovastatin, its metabolite, is used extensively in the treatment of dyslipidemia. In this study, ginseng has been fermented by M. ruber, and the response surface methodology (RSM) was applied to optimize fermentation parameters to obtain optimal fermentation system, with further exploring to lipid-lowering activity of P. ginseng C. A. Meyer-M. ruber fermentation products (PM). The concentration of ginseng, temperature, and rotating speed were set as variables and the lovastatin yield was optimized by a Box-Behnken design (BBD) analyzed by RSM. The binding capacity of PM for sodium taurocholate and sodium cholate was assayed by UV spectrophotometry. The highest content of lovastatin production (85.53 µg g-1) was obtained at a ginseng concentration of 1.96%, temperature of 30.11 °C, and a rotating speed of 160.47 rpm. PM exhibited bile acid binding capacity, which was stronger than unfermented ginseng. The RSM can be used to optimize the fermentation system to obtain the best fermentation process. In addition, the fermentation of ginseng by M. ruber can enhance the lipid-lowering effect.

Identification of potential modulators of osteosarcoma metastasis by high-throughput cellular screening of natural products.

A high-throughput screening assay was developed and applied to a large library of natural product extract samples, in order to identify compounds which preferentially inhibited the in vitro 2D growth of a highly metastatic osteosarcoma cell line (MG63.3) compared to a cognate parental cell line (MG63) with low metastatic potential. Evaluation of differentially active natural product extracts with bioassay-guided fractionation led to the identification of lovastatin (IC50  = 11 µm) and the limonoid toosendanin (IC50  = 26 nm). Other statins and limonoids were then tested, and cerivastatin was identified as a particularly potent (IC50  < 0.1 µm) and selective agent. These compounds potently and selectively induced apoptosis in MG63.3 cells, but not MG63. Assays with other cell pairs were used to examine the generality of these results. Statins and limonoids may represent unexplored opportunities for development of modulators of osteosarcoma metastasis. As cerivastatin was previously approved for clinical use, it could be considered for repurposing in osteosarcoma, pending validation in further models.

Effects of the extract from peanut meal fermented with Bacillus natto and Monascus on lipid metabolism and intestinal barrier function of hyperlipidemic mice.

BACKGROUND: Hyperlipidemia is one of the metabolic disorders that poses a great threat to human health. This study is aimed at investigating the potential hypolipidemic properties of extract from peanut meal fermented with Bacillus natto and Monascus in mice fed with a high-fat diet. Herein, 60 male C57BL/6J mice were randomly divided into six groups: four control groups, comprised of a normal group, a model (M) group, a positive control group (atorvastatin 10 mg kg-1 ), and a nonfermented peanut meal extract group (150 mg kg-1 ), and two experimental groups, comprised of a fermented peanut meal extract low-dose group (50 mg kg-1 ) and a fermented peanut meal extract high-dose group (FH, 150 mg kg-1 ). RESULTS: Body weight (P = 0.001) and levels of serum total cholesterol (P = 0.007), triacylglycerol (P = 0.040), low-density lipoprotein cholesterol (P < 0.001), and leptin (P < 0.001) were remarkably decreased in the FH group, whereas the serum high-density lipoprotein cholesterol levels were increased (P < 0.001) by 78.3% compared with the M group. Ileum tissue stained with hematoxylin and eosin showed that the ileal villus detachments in mice were improved, and the villus height was increased by supplementation with extract from fermented peanut meal. Moreover, the expressions of intestinal ZO-1 (P = 0.003) and occludin (P = 0.013) were elevated in the FH group, compared with the M group. CONCLUSION: Extract of peanut meal fermented by B. natto and Monascus can effectively improve hyperlipidemia caused by a high-fat diet in mice, via regulating leptin and blood lipid levels, and protect the intestinal mucosal barrier, which provides evidence for its anti-hyperlipidemia effects and is a research basis for potential industrial development. © 2020 Society of Chemical Industry.

Protective effect and mechanism of Monascus-fermented red yeast rice against colitis caused by Salmonella enterica serotype Typhimurium ATCC 14028.

Red yeast rice (RYR), a traditional Chinese fermented food, has the effect of lowering blood lipid and cholesterol, but little information is available about whether RYR can inhibit pathogenic bacterial infection in vivo. The present study explored the effect of RYR on Salmonella enterica-induced intestinal inflammation and gut microbiota dysbiosis in mice as well as the underlying anti-inflammatory mechanism. Results showed that RYR can alleviate S. enterica infection in vivo and Monascus pigments are the main functional components. The analysis of microbiota, gene expression profile and serological immunology revealed that RYR can regulate the intestinal flora and increase the relative abundance of beneficial bacteria such as Lactobacillus and Akkermansia. Meanwhile, RYR is also found to regulate the expression of pro-inflammatory factors and tight junction-related genes to inhibit the NO and NF-κB-mediated inflammatory response and maintain the integrity of the intestinal barrier. This study provides a new dietary intervention strategy for the prevention of pathogenic bacterial infection.

A novel predict-verify strategy for targeted metabolomics: Comparison of the curcuminoids between crude and fermented turmeric.

Curcuminoids are the major bioactive constituents of turmeric, the application of which are limited by the poor bioavailability. In this study, turmeric was fermented by the Monascus purpureus and Eurotium cristatum fungi to enhance its bioavailability. To explore the variations in the curcuminoids contents in fermented turmeric, a targeted predict-verify strategy was established. For targeted analysis of curcuminoids, a compound library containing all possible curcuminoids based on their structural skeleton was predicted and built for targeted scanning. Then, the MS data were automatically matched with the predicted library to verify the corresponding curcuminoids. As a result, 115 curcuminoids (48 novel compounds and 14 compounds reported in turmeric for the first time) were fully characterized in crude and fermented turmeric. Among these curcuminoids, 31 were newly generated in fermented turmeric. The established predict-verify strategy allows for an efficient and automatic metabolomic analysis to screen for curcuminoids with potentially better bioavailability.

Low-Frequency Magnetic Field of Appropriate Strengths Changed Secondary Metabolite Production and Na+ Concentration of Intracellular and Extracellular Monascus purpureus.

Monascus purpureus is used to yield edible pigments accompanied by mycotoxin-citrinin. A low-frequency (<300 Hz) magnetic field (LF-MF) affects microbial metabolism. The link of LF-MF with secondary metabolites and intracellular and extracellular Na+ levels in M. purpureus was determined. The fermentation broth was exposed to LF-MF during the first 2 days of fermentation and continuously cultured at 30°C and 200 rpm until the 8th day of fermentation. Results showed that LF-MF treatments didn't affect the growth of M. purpureus in liquid-state fermentation. Compared with the control, citrinin production showed a decrease of 45.0%, while yellow, red, and orange pigment production showed an increase of 72.9, 73.9, and 40.1%, respectively, with LF-MF treatment of 1.6 mT. This was in agreement with downregulation of pksCT and ctnA, and upregulation of pksPT, pigR, veA, and laeA at the transcriptional level. Moreover, 1.6 mT LF-MF exposure caused the transfer of Na+ from extracellular to intracellular, which was validated through the upregulation of transmembrane sensor synthesis genes and the changes in the relative expression levels of the P-type ATPase and protein phosphatase genes. This study established that LF-MF could inhibit citrinin and stimulate pigment production and change intracellular and extracellular Na+ concentrations. Bioelectromagnetics. 2020;41:289-297 © 2020 Bioelectromagnetics Society.

Development of an Improved Menopausal Symptom-Alleviating Licorice (Glycyrrhiza uralensis) by Biotransformation Using Monascus albidulus.

Licorice (Glycyrrhiza uralensis) contains several compounds that have been reported to alleviate menopausal symptoms via interacting with estrogen receptors (ERs). The compounds exist mainly in the form of glycosides, which exhibit low bioavailability and function. To bioconvert liquiritin and isoliquiritin, the major estrogenic compounds, to the corresponding deglycosylated liquiritigenin and isoliquiritigenin, respectively, licorice was fermented with Monascus, which has been demonstrated to deglycosylate other substances. The contents of liquiritigenin and isoliquiritigenin in Monascus-fermented licorice increased by 10.46-fold (from 38.03 µM to 379.75 µM) and 12.50-fold (from 5.53 µM to 69.14 µM), respectively, compared with their contents in non-fermented licorice. Monascus-fermented licorice exhibited 82.5% of the ERß binding activity of that observed in the positive control (17 ß-estradiol), whereas the non-fermented licorice exhibited 54.1% of the binding activity in an in vivo ER binding assay. The increase in the ERß binding activity was associated with increases in liquiritigenin and isoliquiritigenin contents. Liquiritigenin acts as a selective ligand for ERß, which alleviates menopausal symptoms with fewer side effects, such as heart disease and hypertension, compared with a ligand for ERα. In addition, Monascus-fermented licorice contained 731 mg/kg of monacolin K, one of the metabolites produced by Monascus that reduces serum cholesterol. Therefore, Monascus-fermented licorice is a promising material for the prevention and treatment of menopausal syndrome with fewer side effects.

Effects of glutamic acid on the production of monacolin K in four high-yield monacolin K strains in Monascus.

Monascus purpureus is a traditional Chinese microbe that can be used as a medicinal herb and is edible. To improve the yield of monacolin K, we optimized the medium of M. purpureus with high-yield monacolin K strains. When high-yield strains C8, D8, E3, and I1 were grown in glutamic medium instead of the original medium, monacolin K production was increased. Among these strains, C8 exhibited the highest monacolin K production in glutamic acid medium, with levels increased 4.80-fold. RT-qPCR demonstrated that glutamic acid enhanced the expression of mokC and mokG. Observation of Monascus mycelium morphology using SEM showed that mycelia exhibited more folds, swelling, curves, and fractures. Thus, glutamic acid may promote the growth of the mycelium and appeared to increase the permeability of the cell membrane. This lays a foundation for research on the regulatory effect of glutamic acid and provides a theoretical basis for the industrialization and commercialization of Monascus.