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Fusheng Chen - One of the best experts on this subject based on the ideXlab platform.

  • an integrated approach to determine the boundaries of the azaphilone pigment biosynthetic gene cluster of Monascus ruber m7 grown on potato dextrose agar
    Frontiers in Microbiology, 2021
    Co-Authors: Qingpei Liu, Fusheng Chen, Siyu Zhong, Xinrui Wang, Shuaibiao Gao, Xiaolong Yang, Istvan Molnar
    Abstract:

    Monascus-type azaphilone pigments (MonAzPs) are produced in multi-thousand ton quantities each year and used as food colorants and nutraceuticals in East Asia. Several groups, including ours, described MonAzPs biosynthesis as a highly complex pathway with many branch points, affording more than 110 MonAzP congeners in a small group of fungi in the Eurotiales order. MonAzPs biosynthetic gene clusters (BGCs) are also very complex and mosaic-like, with some genes involved in more than one pathway, while other genes playing no apparent role in MonAzPs production. Due to this complexity, MonAzPs BGCs have been delimited differently in various fungi. Since most of these predictions rely primarily on bioinformatic analyses, it is possible that genes immediately outside the currently predicted BGC borders are also involved, especially those whose function cannot be predicted from sequence similarities alone. Conversely, some peripheral genes presumed to be part of the BGC may in fact lay outside the boundaries. This study uses a combination of computational and transcriptional analyses to predict the extent of the MonAzPs BGC in Monascus ruber M7. Gene knockouts and analysis of MonAzPs production of the mutants are then used to validate the prediction, revealing that the BGC consists of 16 genes, extending from mrpigA to mrpigP. We further predict that two strains of Talaromyces marneffei, ATCC 18224 and PM1, encode an orthologous but non-syntenic MonAzPs BGC with 14 genes. This work highlights the need to use comprehensive, integrated approaches for the more precise determination of secondary metabolite BGC boundaries.

  • characterization of the asexual developmental genes brla and weta in Monascus ruber m7
    Fungal Genetics and Biology, 2021
    Co-Authors: Lili Jia, Fusheng Chen, Wanping Chen
    Abstract:

    Abstract Monascus spp. are widely used in the production of monacolin K and food- grade pigments in East Asia. In Aspergillus species, the three transcription factors BrlA → AbaA → WetA sequentially function as the central activators of asexual development (conidiation), leading to the formation of conidiophores. Unlike their close relative Aspergillus spp., Monascus spp. produce basipetospora-type asexual spores (conidia), and their genomes contain homologs of brlA and wetA but not abaA. In the present study, to investigate their roles in Monascus conidiation, MrbrlA and MrwetA were functionally characterized by gene knockout and overexpression in Monascus ruber M7. The results revealed that the deletion and overexpression of MrbrlA and/or MrwetA caused no apparent changes in the morphology, size, number, structure, or germination of conidia. However, deletion and overexpression of MrwetA severely repressed sexual development and affected the production of secondary metabolites. Taken together, these results suggest that the well-established central regulatory model of conidiation in Aspergillus is not applicable in their Monascus relatives. The results of the present study could enrich our understanding of the asexual development regulatory networks in filamentous fungi.

  • effect of static magnetic field on Monascus ruber m7 based on transcriptome analysis
    Journal of Fungi, 2021
    Co-Authors: Shuyan Yang, Hongyi Zhou, Weihua Dai, Juan Xiong, Fusheng Chen
    Abstract:

    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.

  • effects of mrpigg on development and secondary metabolism of Monascus ruber m7
    Journal of Fungi, 2020
    Co-Authors: Fusheng Chen
    Abstract:

    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.

  • genetic modification of mfst gene stimulating the putative penicillin production in Monascus ruber m7 and exhibiting the sensitivity towards precursor amino acids of penicillin pathway
    Microorganisms, 2019
    Co-Authors: Rabia Ramzan, Muhammad Safiullah Virk, Zafarullah Muhammad, Amani Mohedein Mohammed Ahmed, Xi Yuan, Fusheng Chen
    Abstract:

    : The biosynthesis of penicillin G (PG) is compartmentalized, which forces penicillin and its intermediates to cross the membrane barriers. Although many aspects around the penicillin intermediates traffic system remain unclosed, the transmembrane transporter protein involvement has been only predicted. In the present work, detection of PG and isopenicillin N (IPN) in Monascus ruber M7 was performed and functions of mfst gene as a transporter were investigated by the combination of gene deletion (Δmfst) complementation (ΔmfsT::mfsT) and overexpression (M7::PtrpC-mfsT). While, the feeding of PG pathway precursor side chain and amino acids, i.e., phenylacetic acid, D-valine, and L-cysteine was performed for the interpretation of mfsT gene role as an intermediate transporter. The results showed that, the feeding of phenylacetic acid, D-valine, and L-cysteine possessed a significant effect on morphologies, secondary metabolites (SMs) production of all above-mentioned strains including M. ruber M7. The results of UPLC-MS/MS revealed that, ΔmfsT interrupt the penicillin G (PG) production in M. ruber M7 by blocking the IPN transportation, while PG and IPN produced by the ΔmfsT::mfsT have been recovered the similar levels to those of M. ruber M7. Conclusively, these findings suggest that the M. ruber M7 is, not only a PG producer, but also, indicate that the mfsT gene is supposed to play a key role in IPN intermediate compound transportation during the PG production in M. ruber M7.

Gong Chen - One of the best experts on this subject based on the ideXlab platform.

  • evaluating antitumor and antioxidant activities of yellow Monascus pigments from Monascus ruber fermentation
    Molecules, 2018
    Co-Authors: Hailing Tan, Gong Chen, Ziyi Xing, Xiaofei Tian
    Abstract:

    Yellow Monascus pigments can be of two kinds: Natural and reduced, in which natural yellow Monascus pigments (NYMPs) attract widespread attention for their bioactivities. In this study, the antioxidative and antibreast cancer effects of the water-soluble NYMPs fermented by Monascus ruber CGMCC 10910 were evaluated. Results showed that water-soluble NYMPs had a significantly improved antioxidative activities compared to the reduced yellow Monascus pigments (RYMPs) that were chemically derived from orange or red Monascus pigments. Furthermore, NYMPs exhibited a concentration-dependent inhibition activity on MCF-7 cell growth (p < 0.001). After a 48-h incubation, a 26.52% inhibition yield was determined with 32 μg/mL of NYMPs. NYMPs also significantly inhibited the migration and invasion of MCF-7 cells. Mechanisms of the activities were associated with a down-regulation of the expression of matrix metalloproteinases and vascular endothelial growth factor. Rather than being alternatively used as natural colorants or antioxidants, this work suggested that NYMPs could be selected as potential functional additives in further test of breast cancer prevention and adjuvant therapy.

  • changing oxidoreduction potential to improve water soluble yellow pigment production with Monascus ruber cgmcc 10910
    Microbial Cell Factories, 2017
    Co-Authors: Tao Huang, Hailing Tan, Gong Chen
    Abstract:

    Monascus pigments are widely used in the food and pharmaceutical industries due to their safety to human health. Our previous study found that glucose concentration induced extracellular oxidoreduction potential (ORP) changes could influence extracellular water-soluble yellow pigment production by Monascus ruber CGMCC 10910 in submerged fermentation. In this study, H2O2 and dithiothreitol (DTT) were used to change the oxidoreduction potential for investigating the effects of oxidative or reductive substances on Monascus yellow pigment production by Monascus ruber CGMCC 10910. The extracellular ORP could be controlled by H2O2 and DTT. Both cell growth and extracellular water-soluble yellow pigment production were enhanced under H2O2-induced oxidative (HIO) conditions and were inhibited under dithiothreitol-induced reductive conditions. By optimizing the amount of H2O2 added and the timing of the addition, the yield of extracellular water-soluble yellow pigments significantly increased and reached a maximum of 209 AU, when 10 mM H2O2 was added on the 3rd day of fermentation with M. ruber CGMCC 10910. Under HIO conditions, the ratio of NADH/NAD+ was much lower than that in the control group, and the expression levels of relative pigment biosynthesis genes were up-regulated; moreover, the activity of glucose-6-phosphate dehydrogenase (G6PDH) was increased while 6-phosphofructokinase (PFK) activity was inhibited. Oxidative conditions induced by H2O2 increased water-soluble yellow pigment accumulation via up-regulation of the expression levels of relative genes and by increasing the precursors of pigment biosynthesis through redirection of metabolic flux. In contrast, reductive conditions induced by dithiothreitol inhibited yellow pigment accumulation. This experiment provides a potential strategy for improving the production of Monascus yellow pigments.

  • rising temperature stimulates the biosynthesis of water soluble fluorescent yellow pigments and gene expression in Monascus ruber cgmcc10910
    AMB Express, 2017
    Co-Authors: Tao Huang, Hailing Tan, Gong Chen, Lu Wang
    Abstract:

    Monascus species can produce secondary metabolites that have a polyketide structure. In this study, four types of extracellular water-soluble yellow pigments (Y1–Y4) were generated by submerged fermentation with Monascus ruber CGMCC 10910, of which Y3 and Y4 had strong yellow fluorescence. The composition of the pigment mixtures was closely related to the fermentation temperature. The dominating pigments changed from Y1 to Y3 and Y4 when fermentation temperature increased from 30 to 35 °C. Increasing the temperature to 35 °C changed the metabolic pathways of the pigments, which inhibited the biosynthesis of Y1 and enhanced the biosynthesis of Y3 and Y4. Moreover, the yield of Y1 reduced insignificantly, while the yields of Y3 and Y4 increased by 98.21 and 79.31% respectively under two-stage temperature fermentation condition. The expression levels of the relative pigment biosynthetic genes, such as MpFasA2, MpFasB2, MpPKS5, mppR1, mppB, and mppE, were up-regulated at 35 °C. The two-stage temperature strategy is a potential method for producing water-soluble Monascus yellow pigments with strong yellow fluorescence.

  • metabolism and secretion of yellow pigment under high glucose stress with Monascus ruber
    AMB Express, 2017
    Co-Authors: Tao Huang, Gong Chen, Meihua Wang, Kan Shi, Xiaofei Tian
    Abstract:

    The biosynthesis of microbial secondary metabolites is induced by a wide range of environmental stresses. In this study, submerged fermentation of Monascus yellow pigments by Monascus ruber CGMCC 10910 under high glucose stress was investigated. The increase of lipid content was the major contributor to the increase of dry cell weight (DCW), and the lipid-free DCW was only slightly changed under high glucose stress, which benefited the accumulation of intracellular hydrophobic pigments. The fatty acid composition analysis in Monascus cell membranes showed that high glucose stress significantly increased the ratio of unsaturated/saturated fatty acid and the index of unsaturated fatty acid (IUFA) value, which would improve the fluidity and permeability of the cell membrane. As a consequence, high glucose stress increased extracellular yellow pigments production by enhancing secretion and trans-membrane conversion of intracellular pigments to the broth. The total yield of extracellular and intracellular yellow pigments per unit of lipid-free DCW increased by 94.86 and 26.31% under high glucose stress compared to conventional fermentation, respectively. A real-time quantitative PCR analysis revealed that the expression of the pigment biosynthetic gene cluster was up-regulated under high glucose stress. The gene mppE, which is associated with yellow pigment biosynthesis, was significantly up-regulated. These results  indicated that high glucose stress can shift the Monascus pigment biosynthesis pathway to accumulate yellow pigments and lead to a high yield of both extracellular and intracellular yellow pigments. These findings have potential application in commercial Monascus yellow pigment production.

  • production of water soluble yellow pigments via high glucose stress fermentation of Monascus ruber cgmcc 10910
    Applied Microbiology and Biotechnology, 2017
    Co-Authors: Meihua Wang, Tao Huang, Gong Chen
    Abstract:

    Monascus pigments are secondary metabolites of Monascus species and are mainly composed of yellow pigments, orange pigments and red pigments. In this study, a larger proportion of Monascus yellow pigments could be obtained through the selection of the carbon source. Hydrophilic yellow pigments can be largely produced extracellularly by Monascus ruber CGMCC 10910 under conditions of high glucose fermentation with low oxidoreduction potential (ORP). However, keeping high glucose levels later in the culture causes translation or a reduction of yellow pigment. We presume that the mechanism behind this phenomenon may be attributed to the redox level of the culture broth and the high glucose stress reaction of M. ruber CGMCC 10910 during high glucose fermentation. These yellow pigments were produced via high glucose bio-fermentation without citrinin. Therefore, these pigments can act as natural pigments for applications as food additives.

Francielo Vendruscolo - One of the best experts on this subject based on the ideXlab platform.

  • enhancement of microbial pigment production from Monascus ruber by sodium octanoate addition
    Acta Scientiarum Polonorum Technologia Alimentaria, 2020
    Co-Authors: Taynara Alvares Martins, Francielo Vendruscolo
    Abstract:

    Background The addition of fatty acids and other molecules to culture media may intensify the production of biomolecules, such as Monascus pigments, however, few studies of this have been developed. Thus, the objective of the present study was to investigate the effects of adding sodium octanoate to the culture medium, with a view to increasing the synthesis and production of the pigments produced by Monascus ruber CCT 3802 on solid and submerged cultivations. Methods Monacus ruber CCT 3802 was cultivated on solid and submerged media supplemented with different concentrations of sodium octanoate. The radial growth rate of the colonies was obtained from the declivity of the linear regression of the radius of the colonies as a function of cultivation time and the kinetics of submerged cultivations were performed. The filtrate obtained was submitted to scanning spectrophotometry at a range from 350 to 550 nm and the color parameters were determined by using the CIELAB color system. The data were submitted to a univariate analysis of variance (ANOVA) and the means obtained for each treatment submitted to Tukey's test using Statistica version 5.0 software at a 5% level of significance. Results Sodium octanoate exerted a strong influence on growth and pigment production in solid and submerged cultivations. The values for L*, a* and b* were positive for pigments produced, with regards to colors close to red and yellow. In the media supplemented with 1.0 mM and 1.5 mM of sodium octanoate, the production of red pigments became expressive from 48 hours-cultivation, increasing considerably from the second to the fourth days. This shows that supplementation with sodium octanoate provides a greater production of pigments in a shorter time interval than the control culture, which required 144 hours of cultivation to present a higher value for AU510nm, which directly influenced pigment productivity. Conclusions The addition of sodium octanoate exerted a significant influence on both microbial growth and pigment production in both solid and submerged cultivations. The supplementation of the submerged cultures with sodium octanoate was responsible for an expressive production of pigments in just 48 hours, whereas 144 hours were necessary in the absence of sodium octanoate. These results are promising for increasing the productivity of pigment production, including possibilities for application on an industrial scale.

  • Monascus ruber cct 3802 e soro de queijo estudo do efeito da intensidade luminosa no crescimento radial Monascus ruber cct 3802 and cheese serum study of the effect of light intensity on radial growth
    Brazilian Journal of Animal and Environmental Research, 2019
    Co-Authors: Thais Neves Dos Santos, Taynara Alvares Martins, Jaquelinne Pires Vital Da Costa, Celso Jose De Moura, Francielo Vendruscolo
    Abstract:

    Este trabalho teve como objetivo estudar o aproveitamento do soro de queijo como substrato para o crescimento e a producao de pigmentos microbianos Monascus ruber em placas de Petri com agar dextrose de batata suplementado com soro de queijo, revestidos com filmes azul, amarelo, vermelho, verde, preto e transparente sob efeito de intensidade luminosa. Os resultados apontam elevado crescimento micelial nos meios de cultivos suplementados com soro de queijo, onde as maiores velocidades de crescimento radial das colonias foram verificadas quando as placas foram revestidas com filme verde e preto, atingindo valores de 0,190 e 0,178 mm h -1 , respectivamente. Este estudo sugere que o crescimento microbiano em completa escuridao, ou com a aplicacao de luz verde, e acelerado quando comparado com as demais intensidades coloridas absorvidas, tornando assim favoravel a producao de pigmentos por Monascus ruber .

  • efeito do ph e da concentracao de soro de queijo na producao de pigmentos por Monascus ruber em cultivo solido effect of ph and serum concentration of cheese on the production of pigments by Monascus ruber in solid culture
    Brazilian Journal of Animal and Environmental Research, 2019
    Co-Authors: Jaquelinne Pires Vital Da Costa, Camila Fernanda Dias De Oliveira, Welker Denner Bernardes De Araujo, Francielo Vendruscolo
    Abstract:

    E de amplo conhecimento que o soro de queijo e o mais importante subproduto da industria de laticinios. assim, este estudo buscou evidenciar o soro de queijo como substrato sob diferentes condicoes de ph para a producao de pigmentos naturais, a partir da determinacao da velocidade de crescimento radial pelo fungo filamentoso Monascus ruber cct 3802 em cultivo solido. em diferentes valores de ph e a uma concentracao de 20 g l -1 de soro de queijo (o que corresponde a 6,4 g l -1 de lactose como fonte de carbono), as colonias de Monascus apresentaram crescimento e coloracoes diferentes. a maior velocidade de crescimento foi verificada em ph 6,0, o que correspondeu a um crescimento medio de 0,1340±0,0075 mm h -1 e colocaracao vermelha intensa. em valores de ph extremos, como ph 2,0 e 8,0, o crescimento do fungo apresentou inibicao e o aspecto visual diferiu-se, apresentando coloracao amarela e vermelha, respectivamente. a velocidade de crescimento em ph 3,0, 4,0 e 5,0 nao diferiu significativamente (p ≤ 0,05), porem, observou-se que em diferentes valores de ph, houve producao de pigmentos laranja e vermelho, o que demonstra a clara influencia do ph na producao de pigmentos produzidos por Monascus ruber.  evidencia-se, portanto, o soro de queijo como alternativa viavel, barata e rentavel a producao de biopigmentos produzidos por Monascus ruber, haja vista o alto teor de nutrientes deste subproduto e o elevado crescimento do fungo nesse meio quando em condicoes adequadas de ph e concentracao.

  • xarope de maltose como potencial substrato para o crescimento de Monascus ruber
    UNICIÊNCIAS, 2019
    Co-Authors: Camila Fernanda Dias De Oliveira, Welker Denner Bernardes De Araujo, Francielo Vendruscolo
    Abstract:

    Diversas fontes de carbono vem sendo utilizadas como substrato para o crescimento do Monascus ruber , as mais usuais sao glicose, sacarose, amido e o arroz, tem sido amplamente consumido na China, Japao, Asia, Indonesia e paises do Sudeste Asiatico. E o xarope de maltose apresenta-se como um substrato potencial alternativo para o fungo Monascus , bem interessante por ser um subproduto da industria de alimentos. Deste modo, o objetivo deste trabalho foi avaliar o reaproveitamento do residuo agroindustrial xarope de maltose como um potencial para fabricacao de pigmentos, determinando a velocidade de crescimento radial pelo fungo Monascus ruber CCT 3802, em cultivo solido sob diferentes concentracoes de substrato. As analises de velocidade de crescimento radial foram realizadas em meio agar dextrose de batata (PDA) sob diferentes concentracoes de xarope de maltose (5, 20, 50, 80 e 95 g/L), alem da placa padrao contendo apenas PDA. Diante dos resultados pode-se observar que o micro-organismo cultivado no meio contendo 50 g/L de xarope de maltose obteve crescimento de 0,0607 mm h -1 , ou seja, 1,4568 mm dia -1 representando maior velocidade de crescimento radial quando comparado com as demais concentracoes. Portanto, a utilizacao do xarope de maltose como substrato para o Monascus ruber e promissor observando que as diferentes concentracoes obtiveram influencia em seu crescimento. Palavras-chave: Crescimento Radial. Fermentacao Solida. Xarope de Maltose. Abstract Several sources of carbon have been used as a substrate for the growth of Monascus ruber , the most common of which are glucose, sucrose, starch and rice, have been widely consumed in China, Japan, Asia, Indonesia and Southeast Asian countries. And maltose syrup presents itself as an alternative potential substrate for the Monascus fungus, quite interesting as it is a by-product of the food industry. Thus, the objective of this work was to evaluate the reuse of the agro - industrial maltose syrup residue as a potential for pigment manufacture, determining the radial growth rate by the Monascus ruber CCT 3802 fungus in solid culture under different substrate concentrations. Radial growth rate analyzes were performed on potato dextrose agar (PDA) under different concentrations of maltose syrup (5, 20, 50, 80 and 95 g/L), in addition to the standard plate containing only PDA. In view of the results, it can be observed that the microorganism cultured in the medium containing 50 g/L of maltose syrup obtained growth of 0.0607 mm h -1 , that is, 1.4568 mm day -1 representing higher speed of radial growth when compared to the other concentrations. Therefore, the use of maltose syrup as a substrate for Monascus ruber is promising by observing that the different concentrations have influenced its growth. Keywords : Radial Growth. Solid Fermentation. Maltose Syrup.

  • production of red pigments by Monascus ruber cct 3802 using lactose as a substrate
    Biocatalysis and agricultural biotechnology, 2017
    Co-Authors: Jaquelinne Pires Vital Da Costa, Francielo Vendruscolo
    Abstract:

    Abstract The use of lactose as a carbon source for the production of pigments by Monascus ruber was the aim of this study. 500-mL Erlenmeyer flasks containing 160 mL of culture medium with different substrates (glucose, lactose and hydrolyzed lactose) were incubated at 30 °C in shaker for 7 days. Production of pigment andl biomass in the three culture media was observed; however, the consumption of reducing sugars and biomass production for culture containing only lactose were inhibited, with a decline in pigment production after 72 h of cultivation. In medium containing hydrolyzed lactose, there was maximum pigment production of 7.58 AU 510 , exceeding culture containing glucose which presented 7.36 AU 510 . The average production of red pigment was higher in glucose media (0.072 AU 510  h −1 ), followed by medium containing hydrolyzed lactose (0.059 AU 510  h −1 ). However, the average production of yellow and orange pigments was higher for hydrolyzed lactose media (0.043 AU 400  h −1 and 0.053 AU 470  h −1 , respectively). Pigment produced in hydrolyzed lactose media appeared lighter but redder and more yellow than in glucose media. The Hue angle values for the glucose and hydrolyzed lactose media showed that both tended to redness. These results evidenced the importance of this study for the use of lactose in the production of biopigments by M. ruber , since it is present in agro-industrial residues of great relevance, as is the case of cheese whey.

Tao Huang - One of the best experts on this subject based on the ideXlab platform.

  • changing oxidoreduction potential to improve water soluble yellow pigment production with Monascus ruber cgmcc 10910
    Microbial Cell Factories, 2017
    Co-Authors: Tao Huang, Hailing Tan, Gong Chen
    Abstract:

    Monascus pigments are widely used in the food and pharmaceutical industries due to their safety to human health. Our previous study found that glucose concentration induced extracellular oxidoreduction potential (ORP) changes could influence extracellular water-soluble yellow pigment production by Monascus ruber CGMCC 10910 in submerged fermentation. In this study, H2O2 and dithiothreitol (DTT) were used to change the oxidoreduction potential for investigating the effects of oxidative or reductive substances on Monascus yellow pigment production by Monascus ruber CGMCC 10910. The extracellular ORP could be controlled by H2O2 and DTT. Both cell growth and extracellular water-soluble yellow pigment production were enhanced under H2O2-induced oxidative (HIO) conditions and were inhibited under dithiothreitol-induced reductive conditions. By optimizing the amount of H2O2 added and the timing of the addition, the yield of extracellular water-soluble yellow pigments significantly increased and reached a maximum of 209 AU, when 10 mM H2O2 was added on the 3rd day of fermentation with M. ruber CGMCC 10910. Under HIO conditions, the ratio of NADH/NAD+ was much lower than that in the control group, and the expression levels of relative pigment biosynthesis genes were up-regulated; moreover, the activity of glucose-6-phosphate dehydrogenase (G6PDH) was increased while 6-phosphofructokinase (PFK) activity was inhibited. Oxidative conditions induced by H2O2 increased water-soluble yellow pigment accumulation via up-regulation of the expression levels of relative genes and by increasing the precursors of pigment biosynthesis through redirection of metabolic flux. In contrast, reductive conditions induced by dithiothreitol inhibited yellow pigment accumulation. This experiment provides a potential strategy for improving the production of Monascus yellow pigments.

  • rising temperature stimulates the biosynthesis of water soluble fluorescent yellow pigments and gene expression in Monascus ruber cgmcc10910
    AMB Express, 2017
    Co-Authors: Tao Huang, Hailing Tan, Gong Chen, Lu Wang
    Abstract:

    Monascus species can produce secondary metabolites that have a polyketide structure. In this study, four types of extracellular water-soluble yellow pigments (Y1–Y4) were generated by submerged fermentation with Monascus ruber CGMCC 10910, of which Y3 and Y4 had strong yellow fluorescence. The composition of the pigment mixtures was closely related to the fermentation temperature. The dominating pigments changed from Y1 to Y3 and Y4 when fermentation temperature increased from 30 to 35 °C. Increasing the temperature to 35 °C changed the metabolic pathways of the pigments, which inhibited the biosynthesis of Y1 and enhanced the biosynthesis of Y3 and Y4. Moreover, the yield of Y1 reduced insignificantly, while the yields of Y3 and Y4 increased by 98.21 and 79.31% respectively under two-stage temperature fermentation condition. The expression levels of the relative pigment biosynthetic genes, such as MpFasA2, MpFasB2, MpPKS5, mppR1, mppB, and mppE, were up-regulated at 35 °C. The two-stage temperature strategy is a potential method for producing water-soluble Monascus yellow pigments with strong yellow fluorescence.

  • metabolism and secretion of yellow pigment under high glucose stress with Monascus ruber
    AMB Express, 2017
    Co-Authors: Tao Huang, Gong Chen, Meihua Wang, Kan Shi, Xiaofei Tian
    Abstract:

    The biosynthesis of microbial secondary metabolites is induced by a wide range of environmental stresses. In this study, submerged fermentation of Monascus yellow pigments by Monascus ruber CGMCC 10910 under high glucose stress was investigated. The increase of lipid content was the major contributor to the increase of dry cell weight (DCW), and the lipid-free DCW was only slightly changed under high glucose stress, which benefited the accumulation of intracellular hydrophobic pigments. The fatty acid composition analysis in Monascus cell membranes showed that high glucose stress significantly increased the ratio of unsaturated/saturated fatty acid and the index of unsaturated fatty acid (IUFA) value, which would improve the fluidity and permeability of the cell membrane. As a consequence, high glucose stress increased extracellular yellow pigments production by enhancing secretion and trans-membrane conversion of intracellular pigments to the broth. The total yield of extracellular and intracellular yellow pigments per unit of lipid-free DCW increased by 94.86 and 26.31% under high glucose stress compared to conventional fermentation, respectively. A real-time quantitative PCR analysis revealed that the expression of the pigment biosynthetic gene cluster was up-regulated under high glucose stress. The gene mppE, which is associated with yellow pigment biosynthesis, was significantly up-regulated. These results  indicated that high glucose stress can shift the Monascus pigment biosynthesis pathway to accumulate yellow pigments and lead to a high yield of both extracellular and intracellular yellow pigments. These findings have potential application in commercial Monascus yellow pigment production.

  • production of water soluble yellow pigments via high glucose stress fermentation of Monascus ruber cgmcc 10910
    Applied Microbiology and Biotechnology, 2017
    Co-Authors: Meihua Wang, Tao Huang, Gong Chen
    Abstract:

    Monascus pigments are secondary metabolites of Monascus species and are mainly composed of yellow pigments, orange pigments and red pigments. In this study, a larger proportion of Monascus yellow pigments could be obtained through the selection of the carbon source. Hydrophilic yellow pigments can be largely produced extracellularly by Monascus ruber CGMCC 10910 under conditions of high glucose fermentation with low oxidoreduction potential (ORP). However, keeping high glucose levels later in the culture causes translation or a reduction of yellow pigment. We presume that the mechanism behind this phenomenon may be attributed to the redox level of the culture broth and the high glucose stress reaction of M. ruber CGMCC 10910 during high glucose fermentation. These yellow pigments were produced via high glucose bio-fermentation without citrinin. Therefore, these pigments can act as natural pigments for applications as food additives.

Yanchun Shao - One of the best experts on this subject based on the ideXlab platform.

  • effects of different g protein α subunits on growth development and secondary metabolism of Monascus ruber m7
    Frontiers in Microbiology, 2019
    Co-Authors: Ming Lei, Yanchun Shao, Jiao Liu, Yang Fang, Fusheng Chen
    Abstract:

    Strains of Monascus filamentous fungal species have been used to produce fermented foods in Asian countries, such as China, Japan, and The Korean Peninsula, for nearly 2,000 years. At present, their fermented products are widely used as food additives and nutraceutical supplements worldwide owing to their production of beneficial secondary metabolites. Heterotrimeric G-protein signaling pathways participate in regulating multiple biological processes in fungi. Previously, we identified three Monascus ruber M7 G-protein α subunits (Mga1-3) and demonstrated that Mga1 can regulate growth, reproduction and some secondary metabolites' production. Here, we systematically analyzed and compared the roles of mga1-3 by combining single- and double-gene(s) knockouts and their transcriptomic data. First, mga2 and mga3 knock-out mutants and pairwise combinations of mga1-3 deletion strains were generated. Then the changes in growth, development and the main secondary metabolites, Monascus pigments and citrinin, in these mutants were systematically compared with M. ruber M7. Moreover, RNA-Seq analyses of these mutants were performed. All three Gα subunits worked together to regulate biological processes in M. ruber M7, with Mga1 playing a major role, while Mga2 and Mga3 playing supplemental roles. According to the existing literatures which we can find, gene knock-out mutants of the pairwise combination of mga1-3 and their transcriptome analysis are first reported in this study. The current results have clearly demonstrated the functional division of Mga1-3 in M. ruber M7, and could provide a deeper understanding of the effects of different Gα subunits on growth, development and secondary metabolism in other filamentous fungi.

  • effects of an alternative oxidase gene on conidia viability under external stresses in Monascus ruber m7
    Journal of Basic Microbiology, 2017
    Co-Authors: Yanchun Shao, Youxiang Zhou, Fusheng Chen
    Abstract:

    Monascus species can produce natural edible pigments and many other bioactive metabolites. In this study, mraox gene (Monascus ruber alternative oxidase) was isolated, sequenced, and replaced in order to investigate the function in resistance of conidia to stressful conditions. The derived protein of the mraox gene consisted of 350 amino acids with a conserved ferritin-like diiron-binding domain at the C-terminus, sharing a high homolog with alternative oxidase proteins in other filamentous fungi. Deletion of mraox gene repressed the conidia germination rate (CGR) when conidia were exposed to H2 O2 , high temperature (40 and 50 °C) and alkerline buffer (pH8.0), but CGR of mraox-deleted strain was not decreased when the conidia were treated with NaCl, acid buffer (citric acid-dibasic sodium phosphate buffer, pH3) compared to that of the wild-type strain, suggesting that mraox gene is partially responsible for the resistance of conidia to stressful conditions in M. ruber.

  • effects of light intensity and color on the biomass extracellular red pigment and citrinin production of Monascus ruber
    Journal of Agricultural and Food Chemistry, 2016
    Co-Authors: Liling Wang, Yanchun Shao, Wanping Chen, Yang Dai, Fusheng Chen
    Abstract:

    Light is a crucial environmental signal for fungi. In this work, the effects of different light intensities and colors on biomass, Monascus pigments (MPs) and citrinin production of Monascus ruber M7 were investigated. We have demonstrated that low intensity of blue light (500 lx) decreased Monascus biomass, increased MPs accumulation via upregulation of MpigA, MpigB, and MpigJ genes expression, but had no significant influence on citrinin production. High intensity of blue light (1500 lx) decreased citrinin accumulation but had no significant influence on biomass and MPs production after 14 days cultivation. Low intensity of green light (500 lx) stimulated citrinin production via upregulation of pksCT, mrl1, mrl2, and ctnA genes expression. One putative red light photoreceptor and two putative green light photoreceptors were identified in M. ruber M7. These observations will not only guide the practical production of Monascus but also contribute to our understanding light effects on Monascus.

  • mrskn7 a putative response regulator gene of Monascus ruber m7 is involved in oxidative stress response development and mycotoxin production
    Mycologia, 2016
    Co-Authors: Yanchun Shao, Youxiang Zhou, Sha Yang, Zhouwei Zhang, Fusheng Chen
    Abstract:

    Skn7, a response regulator (RR), is associated with oxidative stress adaptation, hypo-osmotic stress response, fungicide sensitivity, cell wall biosynthesis, cell cycle regulation, sexual mating, and sporulation in many filamentous fungi and yeasts. In this study a Skn7-like protein gene mrskn7 (Monascus ruber skn7) was isolated, sequenced, and disrupted to investigate its function in M. ruber Bioinformatics predicted that the deduced protein encoded by mrskn7 contained the conserved DNA-binding and signal-receiver domains similar to the Skn7-like protein structure in other filamentous fungi. The Δmrskn7 strain produced fewer conidia and less mycotoxin, demonstrated increased sensitivity to peroxide but the same level of osmotic resistance to NaCl and glycerol with the wild-type. Additionally, cleistothecia observed at different time point showed a different morphology between the wild-type and the Δmrskn7 strain, suggesting the involvement of mrskn7 in sexual development of M. ruber These results indicated that mrskn7 plays important roles in asexual and sexual development, the production of mycotoxin as well as regulation of oxidative stress signal in M. ruber.

  • cloning expression and characterization of a novel cold active and organic solvent tolerant esterase from Monascus ruber m7
    Extremophiles, 2016
    Co-Authors: Hailun Guo, Yanchun Shao, Wanping Chen, Yan Zhang, Fusheng Chen
    Abstract:

    Cold active esterases are a class of important biocatalysts that exhibit high activity at low temperatures. In this study, a search for putative cold-active esterase encoding genes from Monascus ruber M7 was performed. A cold-active esterase, named Lip10, was isolated, cloned, purified, and characterized. Amino acid sequence analysis reveals that Lip10 contained a conserved sequence motif Gly173-Xaa-Ser175-Xaa-Gly177 that is also present in the majority of esterases and lipases. Phylogenetic analysis indicated that Lip10 was a novel microbial esterase. The lip10 gene was cloned and heterologously expressed in Escherichia coli BL21(DE3), resulting in the expression of an active and soluble protein that constituted 40 % of the total cell protein content. Lip10 maintained almost 50 % of its maximal activity at 4–10 °C, with optimal activity at 40 °C. Furthermore, Lip10 retained 184–216 % of its original activity, after incubation in 50 % (v/v) hydrophobic organic solvents for 24 h. The enzyme also exhibited high activity under alkaline conditions and good tolerance to metal ions in the reaction mixture. These results indicate that Lip10 may have potential uses in chemical synthesis and food processing industrial applications as an esterase.