• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.1
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• pp.21-25
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• 2002

To maximize and sustain the productivity of Monascus pigments, various environmental and nutritional parameters, such as the initial moisture content, pH, inoculum size, sample size, and nutrient supplement, that influence pigment production were evaluated in solid-state cultures as follows: initial moisture content, $50\%;$ pH, 6.0; inoculum size $1\;\times\;10^4$ spore cells $(grams\;of\;dry\;solid\;substrate)^{-1};$ sample size, 300 g. All supplementary nutrients (carbon, nitrogen, and mineral sources) added has inhibitory effects on the cell growth and red pigment production. In open tray culture the maximum biomass yield and specific productivity of red pigments were 223 mg DCW $(grams\;of\;initial\;dry\;substrate)^{-1}$ and, $47.6\;OD_{500}\;(DCW\;grams)^{-1}h^h{-1}$ respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1047-1052
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• 2001

The pigment content in meju fermented by a Monascus species with different materials was studied. The relations between growth of M. pilosus and pigment production were positive and the correlation coefficient associated with this relationship was determined to be : r = 0.9879. Pigments produced by M. purpureus and M. pilosus were composed of 9 and 8 bands, respectively. One kind of them was yellowish, whereas the others were reddish. Total pigment levels in rice meju fermented by M. purpureus and M. pilosus were 335.25 and 1428.90$\mu\textrm{g}$/g, respectively. Pigment levels in the mejus fermented at 3$0^{\circ}C$ showed higher than those at 20 and 4$0^{\circ}C$. The order of pigment content in meju was polished rice > germinated brown rice > wheat > brown rice > waxy brown rice > germinated waxy brown rice. Pigment production by M. pilosus was higher than that of M. purpureus. Pigment content in rice meju prepared by adding 10% seed culture was highest, and pigment content of granulated rice was higher than that of powdered rice. Pigment production was not desirable in soybean meju fermented by seed culture, whereas the pigment levels in meju by adding 10% powdered rice and 10% powdered rice seed meju increased by 23.0 ~75.0 $\mu\textrm{g}$/g.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.249-256
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• 2017

The Monascus azaphilone (MAz) pigment is a well-known food colorant that has yellow, orange and red components. The structures of the yellow and orange MAz differ by two hydride reductions, with yellow MAz being the reduced form. Orange MAz can be non-enzymatically converted to red MAz in the presence of amine derivatives. It was previously demonstrated that mppE and mppG are involved in the biosynthesis of yellow and orange MAz, respectively. However, ${\Delta}mppE$ and ${\Delta}mppG$ knockout mutants maintained residual production of yellow and orange MAz, respectively. In this study, we deleted the region encompassing mppD, mppE and mppG in M. purpureus and compared the phenotype of the resulting mutant (${\Delta}mppDEG$) with that of an mppD knockout mutant (${\Delta}mppD$). It was previously reported that the ${\Delta}mppD$ strain retained the ability to produce MAz but at approximately 10% of the level observed in the wildtype strain. A chemical analysis demonstrated that the ${\Delta}mppDEG$ strain was still capable of producing both yellow and orange MAz, suggesting the presence of minor MAz route(s) not involving mppE or mppG. Unexpectedly, the ${\Delta}mppDEG$ strain was observed to accumulate fast-eluting pigments in a reverse phase high-performance liquid chromatography analysis. A LC-MS analysis identified these pigments as ethanolamine derivatives of red MAz, which had been previously identified in an mppE knockout mutant that produces high amounts of orange MAz. Although the underlying mechanism is largely unknown, this study has yielded an M. purpureus strain that selectively accumulates red MAz.

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 1993.05a
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• pp.149-159
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• 1993

The concept of Solid-State Fermentation is briefly explained in comparison to other fermentation principles, and several types of fermenters are presented. A recently developed "Swing Reactor" for SSF is shown. When inoculated on rice, the mould Monascus purpureus forms red pigments, Which can be used as food colors (Ang-kak, Red Rice). By Response Surface Methodology, serveral factors have been optimized for maximal red colour formation. Showing that presoaking time of rice, pH of soaking water, age of preculture and inoculum size were not of importance within the observed limits. For a fermentation time of 7 days, start humidity is optimal at 34% and temperature is optimal at 28.8 C. These results of small scale fermentation could be transferred to the Swing Reactor.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.5
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• pp.341-346
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• 2001

For the purpose of mass producing Monascus red pigments optimum medium composition and environmental conditions were investigated in submerged flask cultures. The optimum carbon and nitrogen sources were determined to be 30g/L of glucose and 1.5 g/L of monosodium glutamate (MSG). Of the three metals examined, Fe$\^$2+/ showed the strongest stimulatory effect on pigment production and some stimulatory effect was also found in Mn$\^$2+/. Optimum pH and agitation speed were determined to be 6.5 and 700 rpm, respectively. Under the optimum culture conditions batch fermentation showed that the maximum biomass yield and specific productivity of red pigments were 0.20 g DCW/g glucose and, 32.5 OD$\sub$500/g DCW$\^$-1/h$\^$-1/, respectively.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.83-91
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• 2018

Advances in bacterial and fungal genome mining uncover a plethora of cryptic secondary metabolite biosynthetic gene clusters. Guided by the genome information, targeted transcriptional derepression could be employed to determine the product of a cryptic gene cluster and to explore its biological role. Monascus spp. are food grade filamentous fungi popular in eastern Asia and several genome data belong to them are now available. We achieved transcription activation of a cryptic fungal polyketide synthase-nonribosomal peptide synthase gene Mpfus1 in Monascus purpureus ${\Delta}MpPKS5$ by inserting Aspergillus gpdA promoter at the upstream of Mpfus1 through double crossover gene replacement. The gene cluster with Mpfus1 show a high similarity to those for the biosynthesis of conjugated polyene derivatives with 2-pyrrolidone ring and the mycotoxin fusarin is the representative member of this group. The ${\Delta}MpPKS5$ is incapable of producing azaphilone pigment, providing an excellent background to identify chromogenic and UV-absorbing compounds. Activation of Mpfus1 resulted in a yellow hue on mycelia and its methanol extract exhibit a maximum absorption at 365 nm. HPLC analysis of the organic extracts indicated the presence of a variety of yellow compounds in the extract. This implies that the product of MpFus1 is metabolically or chemically unstable. LC-MS analysis guided us to predict the MpFus1 product and to propose that the Mpfus1-containing gene cluster encode the biosynthesis of a desmethyl analogue of fusarin. This study showcases the genome mining in Monascus and the possibility to unveil new biological activities embedded in it.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.933-941
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• 2008

An extracellular $\beta$-glucosidase produced by Monascus purpureus NRRL1992 in submerged cultivation was purified by acetone precipitation, gel filtration, and hydrophobic interaction chromatography, resulting in a purification factor of 92-fold. A $2^2$ central-composite design (CCD) was performed to find the best temperature and pH conditions for enzyme activity. Maximum activity was observed in a wide range of temperature and pH values, with optimal conditions set at $50^{\circ}C$ and pH 5.5. The $\beta$-glucosidase showed moderate thermostability, was inhibited by $HgCl_2$, $K_2Cr_O_4$, and $K_2Cr_2O_7$, whereas other reagents including $\beta$-mercaptoethanol, SDS, and EDTA showed no effect. Activity was slightly stimulated by low concentrations of ethanol and methanol. Hydrolysis of p-nitrophenyl-$\beta$-D-glucopyranoside (pNPG), cellobiose, salicin, n-octyl-$\beta$-D-glucopyranoside, and maltose indicates that the $\beta$-glucosidase has broad substrate specificity. Apparently, glucosyl residues were removed from the nonreducing end of p-nitrophenyl-$\beta$-D-cellobiose. $\beta$-Glucosidase affinity and hydrolytic efficiency were higher for pNPG, followed by maltose and cellobiose. Glucose and cellobiose competitively inhibited pNPG hydrolysis.

• Journal of Life Science
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• v.31 no.2
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• pp.192-198
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• 2021

Red yeast rice has been extensively used as food and traditional medicine for thousands of years in East Asian countries. It is produced by the fermentation of a particular yeast (in general, Monascus purpureus) as rice and various cereals (barley, soybean, etc.). Monascus sp. produces many secondary metabolites during its growth, including pigments, monacolins, and γ-aminobutyric acid. Some metabolites―specifically, monacolin K, γ-aminobutyric acid, dimerumic acid, and monascus pigments―have been reported to lower cholesterol and blood pressure while showing anti-obesity effects. In this study, we investigated the anti-obesity effect of ethanol extract from red yeast barley (RYB) fermented with Monascus sp. BHN-MK 2 on 3T3-L1 cells. The anti-obesity effects of RYB extract were examined: its lipid accumulation inhibitory effect was tested by Oil Red O staining, and obesity-related mRNA expression levels were tested by real-time RT-PCR in MDI stimulated 3T3-L1 cells. The intracellular lipid content of MDI-stimulated 3T3-L1 cells decreased significantly to 5.04%, 12.24%, and 23.52% in response to 200, 400, and 800 ㎍/ml RYB, respectively. Moreovers, we evaluated that RYB extract significantly downregulated the expression of C/EBPα, SREBP-1, and PPAR-γ gene in a dose-dependent manner. As a result, red yeast barley ethanol extracts exerted the strongest anti-obesity effects. Also, the results indicate that red yeast barley could be used as a functional anti-obesity food material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.711-715
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• 2004

The stability of 80% ethanol-soluble pigments from Monasus purpureus CBS 281.34 was investigated according to storage temperature, pH and addition of organic acid. Also, the stability of ethanol-soluble pigment in aqueous system was examined after the addition of distilled water in the range of 0∼80% during the storage at 1$0^{\circ}C$ and 2$0^{\circ}C$ for 4 weeks with water soluble pigment. The heat stability was the highest (9.74%) when the 80% ethanol-soluble pigments were stored at 1$0^{\circ}C$ for 4 weeks. However, the 80% ethanol-soluble pigments stored at 6$0^{\circ}C$ and 8$0^{\circ}C$ for 24 h and 12 h greatly decreased by 23.06% and 30.36%, respectively. Although the 80% ethanol-soluble pigments were stable in the range of pH 4∼8, the degradation rate of pigment increased at pH 2 and PH 10.80% ethanol extract was adjusted to PH 4 by adding organic acids. The rate of pigment degradation was not different from control for 4 weeks. Red pigment was stable in the treatment of organic acids. And the stability of ethanol-soluble pigment in aqueous system was gradually decreased as the pigment content and storage time increased. Additionally, the stability of ethanol-soluble pigment was higher at 1$0^{\circ}C$ than at 2$0^{\circ}C$.

• Journal of Life Science
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• v.15 no.4 s.71
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• pp.536-541
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• 2005

Obesity is emerging as one of the major risk factors of death in Korea as well as western societies. This study was performed to investigate the effect of kimchi with Monascus purpureus (Hongkuk) on liver function, plasma lipid composition of rats fed high fat diet for four weeks in rats. Rats were divided into the following 6 groups; I group (normal diet), II group (normal diet with $1\%$ kimchi powder using $5.0\%$ Hongkuk), III group (high fat diet), IV group (high fat diet with $1\%$ kimchi powder), V group (hish fat diet with $1\%$ kimchi powder using $2.5\%$ Hongkuk), and VI group (high fat diet with $1\%$ kimchi powder using $5\%$ Hongkuk). Weight gains showed to decrease in group IV, V, VI. Food intake and food efficiency ratio were no significantly different among the groups. Plasma total cholesterol showed to decrease with kimchi using Hongkuk. LDL-cholesterol levels were lower in kimchi using Hongkuk than that of control group. These results demonstrated that the kimchi and kimchi using Monascus purpureus(Hongkuk) decreased weight gains and lowered serum cholesterol levels in rat.