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1.
J Chromatogr A ; 1627: 461399, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823104

RESUMO

Citrinin is a toxic small organic molecule produced as a secondary metabolite by fungi types Penicillium, Monascus and Aspergillus and is known to contaminate various food commodities during postharvest stages of food production. During the last 10 years, most reported methods for citrinin analysis employed enzyme-linked immunosorbent assays or high-performance liquid chromatography. Over this same time period, liquid extraction, solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS were the most cited sample preparation and clean-up methods. In this review the advantages and disadvantages of the various sample preparation, separation and detection methods for citrinin analysis over the last decade are evaluated. Furthermore, current trends, emerging technologies and the future prospects of these methods are discussed.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citrinina/análise , Espectrometria de Massas em Tandem/métodos , Aspergillus/metabolismo , Citrinina/isolamento & purificação , Citrinina/urina , Ensaio de Imunoadsorção Enzimática , Contaminação de Alimentos/análise , Humanos , Microextração em Fase Líquida , Monascus/metabolismo , Extração em Fase Sólida
2.
Food Chem ; 331: 127281, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32559596

RESUMO

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.


Assuntos
Curcuma/química , Diarileptanoides/metabolismo , Alimentos e Bebidas Fermentados/análise , Metabolômica/métodos , Disponibilidade Biológica , Curcuma/metabolismo , Curcuma/microbiologia , Curcumina/química , Curcumina/farmacocinética , Diarileptanoides/farmacocinética , Eurotium/metabolismo , Fermentação , Espectrometria de Massas , Monascus/metabolismo , Extratos Vegetais/química , Software
3.
J Food Prot ; 83(4): 702-709, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32221575

RESUMO

ABSTRACT: Absent, small, or homeotic discs 2 (Ash2), a histone H3K4 methyltransferase complex, has been implicated in the control of hyphal development and secondary metabolism in many kinds of filamentous fungi. We constructed an Ash2 deletion mutant (ΔAsh2) by using an Agrobacterium-mediated gene knockout method to investigate the function of the Ash2 gene in the mold Monascus purpureus. Lack of the Ash2 gene resulted in the formation of a lower colony phenotype with fluffy aerial hyphae that autolyzed as the colony grew on potato dextrose agar at 30°C. The production of pigments and the number of conidia were significantly lower in the ΔAsh2 than in the wild type. Citrinin production by the ΔAsh2 was not detected during 15 days of fermentation. Relative expression levels of secondary metabolite regulatory genes PigR and CTNR, secondary metabolite synthesizing genes PKSPT and CTN, key genes of mitogen-activated protein kinase pathway Spk1 and its downstream gene mam2, the conidium development control gene BrlA, and global regulatory genes LaeA and VeA were detected by the quantitative real-time PCR. These results indicate that the Ash2 gene is involved in conidial germination, pigment production, and citrinin production and plays a key role in development and secondary metabolism in M. purpureus.


Assuntos
Citrinina , Monascus , Citrinina/biossíntese , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Histona Metiltransferases/genética , Histona Metiltransferases/metabolismo , Histonas , Monascus/genética , Monascus/metabolismo , Pigmentos Biológicos
4.
Food Chem ; 316: 126243, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32036177

RESUMO

Okara dietary fiber was prepared by liquid fermentation with Monascus anka (M. anka). Infrared spectra results indicated that there were more oligosaccharides because of the hydrogen bond cleavage of the polysaccharides in okara Monascus dietary fiber (OMDF). Scanning electron microscopy and X-ray analyses showed that the structures of OMDF were altered as compared to that of the control. The UV-visible spectrum of the M. anka seed broth (MSB) contained three absorption peaks corresponding to red, orange, and yellow pigments, which were present in equal quantities. The concentration of citrinin in MSB and Monascus okara fermentation broth was 0.980 ppm and 0.940 ppm, respectively. After fermentation, the soluble OMDF content in OMDF was 7.7 g/100 g, which was 1.79 times of that in the control. Further, the water holding capacity, oil holding capacity, and swelling capacity of OMDF increased significantly, while the water retaining capacity decreased slightly. HYPOTHESIS: This study was aimed at investigating the effect of liquid fermentation of M. anka on okara. After fermentation, the dietary fiber structure may change and the functional properties may be improved.


Assuntos
Fibras na Dieta , Fermentação , Monascus/metabolismo , Soja/química , Citrinina/biossíntese , Água/química
5.
mBio ; 11(1)2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-32019788

RESUMO

Despite the important biological activities of natural product naphthoquinones, the biosynthetic pathways of and resistance mechanisms against such compounds remain poorly understood in fungi. Here, we report that the genes responsible for the biosynthesis of Monascus naphthoquinones (monasones) reside within the gene cluster for Monascus azaphilone pigments (MonAzPs). We elucidate the biosynthetic pathway of monasones by a combination of comparative genome analysis, gene knockouts, heterologous coexpression, and in vivo and in vitro enzymatic reactions to show that this pathway branches from the first polyketide intermediate of MonAzPs. Furthermore, we propose that the monasone subset of biosynthetic genes also encodes a two-tiered resistance strategy in which an inducible monasone-specific exporter expels monasones from the mycelia, while residual intracellular monasones may be rendered nontoxic through a multistep reduction cascade.IMPORTANCE The genes for Monascus naphthoquinone (monasone) biosynthesis are embedded in and form a composite supercluster with the Monascus azaphilone pigment biosynthetic gene cluster. Early biosynthetic intermediates are shared by the two pathways. Some enzymes encoded by the supercluster play double duty in contributing to both pathways, while others are specific for one or the other pathway. The monasone subcluster is independently regulated and inducible by elicitation with competing microorganisms. This study illustrates genomic and biosynthetic parsimony in fungi and proposes a potential path for the evolution of the mosaic-like azaphilone-naphthoquinone supercluster. The monasone subcluster also encodes a two-tiered self-resistance mechanism that models resistance determinants that may transfer to target microorganisms or emerge in cancer cells in case of naphthoquinone-type cytotoxic agents.


Assuntos
Monascus/efeitos dos fármacos , Monascus/genética , Família Multigênica , Naftoquinonas/metabolismo , Naftoquinonas/farmacologia , Vias Biossintéticas , Farmacorresistência Fúngica/genética , Monascus/metabolismo
6.
J Biosci Bioeng ; 129(2): 229-236, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31500988

RESUMO

Monascus pigments (MPs), the secondary metabolites produced by the fungal strains of Monascus spp., hold commercial importance in not only the food and meat industries, but also therapeutic, cosmetic, and textile industries. To reduce the cost of MPs production, the utilization of rice straw hydrolysate as a substrate in submerged fermentation was investigated. The atmospheric and room temperature plasma (ARTP) mutation system was employed to develop a mutant strain Monascus purpureus M630, with high total extracellular Monascus pigments (exMPs) production of 34.12 U/mL in submerged fermentation with glucose-based medium. The results revealed that M. purpureus M630 produces 8.61 U/mL and 20.86 U/mL of exMPs in rice straw hydrolysate alone or in combination with glucose fermentation medium, respectively. Furfural (Fur) and 5'-hydroxymethyl furfural (5'-HMF), produced during pretreatment and hydrolysis of rice straw; are generally inhibitory for microbial growth and fermentation. Our findings revealed that M. purpureus M630 develops the tolerance and adaptation mechanisms in response to 5'-HMF and Fur during growth and MPs biosynthesis in rice straw hydrolysate. In conclusion, we report that rice straw hydrolysate can serve as an efficient and low-cost substitute for the MP production through submerged fermentation by Monascus spp.


Assuntos
Monascus/metabolismo , Oryza/metabolismo , Pigmentos Biológicos/biossíntese , Análise Custo-Benefício , Fermentação , Glucose/metabolismo , Hidrólise , Pigmentos Biológicos/economia , Especificidade por Substrato
7.
J Agric Food Chem ; 68(3): 808-817, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31870144

RESUMO

Various Monascus bioactive metabolites used as food or food additives in Asia for centuries are subjected to constant physical and chemical changes and different Monascus genus. With the aim to identify enzymes that participate in or indirectly regulate the pigments and citrinin biosynthesis pathways of Monascus purpureus cultured under high ammonium chloride, the changes of the proteome profile were examined using sequential window acquisition of all theoretical mass spectra-mass spectrometry-based quantitative proteomics approach in combination with bioinformatics analysis. A total of 292 proteins were confidently detected and quantified in each sample, including 163 that increased and 129 that decreased (t-tests, p ≤ 0.05). Pathway analysis indicated that high ammonium chloride in the present study accelerates the carbon substrate utilization and promotes the activity of key enzymes in glycolysis and ß-oxidation of fatty acid catabolism to generate sufficient acetyl-CoA. However, the synthesis of the monascus pigments and citrinin was not enhanced because of inhibition of the polyketide synthase activity. All results demonstrated that the cause of initiation of pigments and citrinin synthesis is mainly due to the apparent inhibition of acyl and acetyl transfer by some acyltransferase and acetyltransferase, likely malony-CoA:ACP transacylase.


Assuntos
Cloreto de Amônio/metabolismo , Citrinina/biossíntese , Monascus/metabolismo , Pigmentos Biológicos/metabolismo , Acetiltransferases/metabolismo , Aciltransferases/metabolismo , Citrinina/química , Proteínas Fúngicas/metabolismo , Espectrometria de Massas , Monascus/química , Pigmentos Biológicos/química , Proteômica
8.
Mater Sci Eng C Mater Biol Appl ; 107: 110318, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761250

RESUMO

Cobalt ferrite nanoparticles were successfully synthesized using the fungus Monascus purpureus ATCC16436 as a potentially low-cost, eco-friendly and easy to produce method. Fourier transform infrared spectroscopy confirmed the functional groups present in the prepared samples. X-ray diffraction pattern of the synthesized nanoparticles revealed a single-phase crystalline structure. Transmission electron microscope studies showed the spherical shape with a mean particle size of 6.50 nm. Vibrating sample magnetometer analyses revealed that the synthesized nanoparticles have a superparamagnetic behavior. In addition, the antioxidant, anticancer and antimicrobial activities of the synthesized nanoparticles were evaluated. The synthesized nanoparticles exhibited antioxidant potential as compared by ascorbic acid with 50% inhibitory concentration of 100.25 µg mL-1. Based on the MTT assay, the synthesized nanoparticles significantly inhibited the proliferation of two different human cancer cell lines (breast and liver) and normal human melanocytes. The recorded 50% inhibitory concentrations of the respective cell lines were 45.21, 61.86 and 200.15 µg mL-1. The synthesized nanoparticles showed potent antibacterial and antifungal activities against all the tested plant and human microbial pathogens with minimal inhibitory concentration range 250-500 µg mL-1. Moreover, the feasibility of production enhancement of the synthesized nanoparticles using the fungal culture as affected by gamma irradiation was also adopted. Gamma irradiation at 1000 Gy dramatically intensified the yield of nanoparticles to 24.87 g L-1. Accordingly, these findings suggest a new and alternate approach with the excellent biotechnological potentiality for the nanoparticles production that will open up the way for the industrial manufacture of nanomaterials.


Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Cobalto/química , Compostos Férricos/química , Nanopartículas Metálicas/química , Monascus/metabolismo , Anti-Infecciosos/química , Antineoplásicos/química , Antioxidantes/química , Linhagem Celular Tumoral , Cobalto/metabolismo , Compostos Férricos/metabolismo , Raios gama , Humanos , Células MCF-7 , Melanócitos/efeitos dos fármacos , Nanopartículas Metálicas/uso terapêutico , Testes de Sensibilidade Microbiana , Monascus/efeitos da radiação , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
J Agric Food Chem ; 67(49): 13673-13683, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31617717

RESUMO

Because Monascus pigments (MPs) predominantly accumulate in the cytoplasm during submerged fermentation, many biotechnologies are applied to enhance the production of extracellular MPs (exMPs) to reduce the downstream processing costs. In this study, the genes monascus_7017 and monascus_8018, identified as ERG4 genes, were knocked out to disrupt the ergosterol biosynthetic pathway and enhance the production of exMPs in Monascus purpureus LQ-6. Double-deletion of EGR4 in M. purpureus LQ-6 reduced ergosterol concentration by 57.14% and enhanced exMP production 2.06-fold. In addition, integrated transcriptomic and proteomic analyses were performed to elucidate the transmembrane secretion mechanism of exMPs based on the relationship between ergosterol synthesis and membrane permeability, which revealed that several metabolic pathways were noticeably dynamic, including fatty acid degradation, amino acid metabolism, energy metabolism, carbohydrate metabolism, and transport. These findings therefore clarified the secretion mechanism of exMPs and provide a novel strategy for further enhancement of exMP production in submerged fermentation.


Assuntos
Membrana Celular/metabolismo , Ergosterol/biossíntese , Monascus/metabolismo , Pigmentos Biológicos/biossíntese , Vias Biossintéticas , Membrana Celular/genética , Permeabilidade da Membrana Celular , Fermentação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Monascus/genética
10.
Appl Microbiol Biotechnol ; 103(21-22): 8863-8874, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31659421

RESUMO

Although the potential of heterotrophic microalgae served as a sustainable source for lutein, it was still crucial to formulate a suitable medium to offset the cost involved in algal biomass cultivation while improve inherent lutein productivity. The objective of this study was to investigate the feasibilities of waste Monascus fermentation broth medium (MFBM) toward heterotrophic Chlorella protothecoides-enriched lutein. The results indicated that C. protothecoides subjected to MFBM batch feeding achieved 7.1 g/L biomass and 7.27 mg/g lutein. The resulting lutein productivity (7.34 mg/L/day) represented 1.54-fold more than that of frequently used Basal medium. Concurrently, the effective metabolism and absorption of carbon, nitrogen, and phosphorus in MFBM by C. subellipsoidea cultivation make it easily complied with the permissible dischargeable limits for fermentation broth. When response to fed-batch culture mode, the biomass and lutein productivity peaked 20.4 g/L and 9.11 mg/L/day with concentrated MFBM feeding. Transcriptomics data hinted that MFBM feeding manipulated lutein biosynthesis key checkpoints (e.g., lycopene ß-cyclase and lycopene ε-cyclase) while accelerated energy pathways (e.g., glycolysis and TCA cycle) to contribute such high lutein productivity in C. protothecoides. These encouraging findings not only provided indications in applying nutrient-rich fermentation broth for affordable microalgae cultivation but also presented possibilities in linking algal high value-added products like lutein with high-efficient biological nutrition removal from industrial fermentation processing.


Assuntos
Chlorella/metabolismo , Luteína/biossíntese , Microalgas/metabolismo , Monascus/metabolismo , Biocombustíveis/microbiologia , Biomassa , Reatores Biológicos/microbiologia , Chlorella/crescimento & desenvolvimento , Fermentação
11.
Appl Microbiol Biotechnol ; 103(20): 8393-8402, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31501941

RESUMO

The influence of pH on the biosynthesis of orange Monascus pigments (OMPs) in Monascus ruber M7 was investigated. Under acidic fermentation conditions, pigment mixtures predominantly rich in OMPs were obtained. HPLC analysis revealed the presence of four orange components (O1-O4) and four yellow components (Y1-Y4) in the mixtures, and the dominant ones were O1 and O3, which accounted for 56.0% to 75.9% of the total pigments in the pH range 3-6. Subsequently, O1 and O3 were identified by LC-DAD-ESI/MS as Rubropunctatin and Monascorubrin, respectively. The yield of OMPs was observed to be inversely dependent on pH. At pH 3, large amounts of OMPs with high purity (79.1%) were accumulated. A real-time quantitative PCR analysis revealed that the expression of genes related to the biosynthesis of OMPs in M. ruber M7 was upregulated at acidic pH as compared to neutral pH, and the variation in the level of expression of these genes with pH was consistent with the production of OMPs. These results indicated that the large accumulation of OMPs under acidic condition involved the acidic pH-induced transcription of genes related to the biosynthesis of OMPs. These results would contribute towards the development of an efficient technology for large-scale production of OMPs.


Assuntos
Meios de Cultura/química , Monascus/crescimento & desenvolvimento , Monascus/metabolismo , Pigmentos Biológicos/metabolismo , Cromatografia Líquida , Fermentação , Concentração de Íons de Hidrogênio , Pigmentos Biológicos/química , Pigmentos Biológicos/classificação , Espectrometria de Massas por Ionização por Electrospray
12.
World J Microbiol Biotechnol ; 35(9): 138, 2019 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-31451937

RESUMO

Monascus azaphilone pigments, including red, orange, and yellow, are world-famous food colorants. However, the pigments produced by different Monascus species vary in yields and compositions. The underlying mechanism is unclear. In this study, four wild-type Monascus strains, namely M. anka M7, M. purpureus M9, M. ruber C100, and M. aurantiacus M15, were selected as research objects according to the diversification of their pigments fermented in the same mediums and conditions. Twenty-three 3 kbp segments (300 bp overlap with adjacent segments) of the pigment gene cluster were amplified, sequenced, and assembled into the DNA sequences of the clusters. The DNA sequences of pigment biosynthetic gene clusters of the four strains showed 99.94% similarity according to the results of multiple alignment. The expression levels of 17 pigment biosynthetic genes of four strains were determined by using real-time quantitative PCR. The transcriptional regulation contributed more than the DNA sequence variation in Monascus pigments metabolism. Our result gives insight into the study of Monascus pigment biosynthesis.


Assuntos
Monascus/genética , Monascus/metabolismo , Pigmentos Biológicos/biossíntese , Transcrição Genética , Sequência de Aminoácidos , Sequência de Bases , Cor , DNA Fúngico/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Variação Genética , Monascus/química , Monascus/classificação , Família Multigênica , Filogenia , Pigmentos Biológicos/química
13.
Appl Microbiol Biotechnol ; 103(13): 5301-5310, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31049618

RESUMO

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.


Assuntos
Ácido Glutâmico/farmacologia , Lovastatina/biossíntese , Monascus/efeitos dos fármacos , Monascus/metabolismo , Meios de Cultura/química , Fermentação , Proteínas Fúngicas/genética , Expressão Gênica , Microbiologia Industrial , Microscopia Eletrônica de Varredura , Micélio/ultraestrutura , Reação em Cadeia da Polimerase em Tempo Real
14.
J Microbiol Biotechnol ; 29(6): 897-904, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31091861

RESUMO

Monascus purpureus recombinant mppC and mpp7 knockout strains were subjected to extractive fermentation in the context of azaphilone pigment production. Inclusion of Diaion HP-20 resin resulted in the selective production of unreduced azaphilone congeners, in addition to the early intermediate FK17-P2a, from ∆mppC and ∆mpp7 strains that would otherwise mainly produce reduced congeners. Structural determination of two novel unreduced azaphilones from the ∆mpp7 strain was accomplished. The unreduced azaphilone compound was converted into the cognate reduced congener in recombinant M. purpureus strains, demonstrating its intermediate role in azaphilone biosynthesis. This study demonstrates the possibility that extractive fermentation with Diaion HP-20 resin can be used to obtain cryptic azaphilone metabolites.


Assuntos
Benzopiranos/metabolismo , Microbiologia Industrial/métodos , Monascus/genética , Monascus/metabolismo , Pigmentos Biológicos/metabolismo , Poliestirenos/metabolismo , Benzopiranos/química , Vias Biossintéticas , Fermentação , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Deleção de Genes , Oxirredução , Pigmentos Biológicos/química
15.
J Ethnopharmacol ; 238: 111879, 2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-30991138

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Monascus-fermented rice product (MFRP) has been regarded as a dietary supplement and traditional medicine with circulation-promoting effects in China and other countries for centuries. AIM OF THE STUDY: This study was carried out to profile the chemical components in MFRP, and provide available information for elucidating the potential lipid-lowering compounds other than monacolins. MATERIALS AND METHODS: High-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS) and gas chromatography coupled with mass spectrometry (GC-MS) methods were applied to comprehensive analysis of chemical components in MFRP. Potential small molecules were identified by comparing with reference standards, or tentatively characterized by comparing their retention time and high-resolution mass spectral data with previous literature. The lipid-lowering properties of ten major non-monacolin compounds were evaluated in cholesterol-fed zebrafish larvae. And one with optimum lipid-lowering activity was subsequently evaluated in high fat diet-fed C57BL/6 J mice, with the dyslipidemia and ectopic lipid deposition being investigated. RESULTS: A total of 99 compounds were characterized in MFRP, including 38 monacolins, 5 decalins, 6 isoflavones, 13 pigments, 8 azaphilonoids, 11 amino acids, 4 nucleosides, 9 lipid acids, 4 phytosterols and glycerol. The preliminary screening showed that ergosterol remarkably reduced cholesterol levels in zebrafish larvae. Moreover, ergosterol delayed body weight gain and decreased circulating total cholesterol, triglyceride, low density lipoprotein cholesterol levels in high fat diet-fed mice. Ectopic lipid accumulation was also ameliorated in the liver and heart of obese mice. CONCLUSION: Global analysis of chemical components and screening of lipid-lowering non-monacolin compounds in MFRP have improved our understanding of its therapeutic material basis.


Assuntos
Alimentos e Bebidas Fermentados , Lipídeos/sangue , Monascus/metabolismo , Naftalenos/química , Naftalenos/farmacologia , Oryza , Animais , Suplementos Nutricionais , Análise de Alimentos , Hipolipemiantes/química , Hipolipemiantes/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Peixe-Zebra
16.
J Sci Food Agric ; 99(10): 4772-4780, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-30953365

RESUMO

BACKGROUND: Monascus, a filamentous fungus, produces many bioactive substances. However, in the process of fermentation, Monascus also produces the mycotoxin citrinin. Owing to the presence of citrinin, the safety of Monascus products has been questioned and their wide application limited. Using soybean isoflavones (SI) as exogenous additives, alterations in citrinin production by Monascus aurantiacus Li AS3.4384 (MALA) in different media used for liquid state fermentation were investigated. RESULTS: Results showed that the citrinin concentration was 95.98% lower than that of the control group after 16-days fermentation when 20.0 g L-1 SI were added to rice powder and inorganic salt medium. Citrinin production was reduced by 97.24% after 12-days fermentation with 10.0 g L-1 SI in starch inorganic salt medium; 82.52% after 20-days fermentation with 20.0 g L-1 SI in starch peptone medium with high starch content; 45.07% after 14-days fermentation with 5.0 g L-1 SI in starch peptone medium with low starch content; and 82.21% after 14-days fermentation with 20.0 g L-1 SI in yeast extract sucrose medium. CONCLUSION: The developed method of removing citrinin is simple, safe, and effective, and it can be applied to reduce the citrinin content of Monascus products. © 2019 Society of Chemical Industry.


Assuntos
Citrinina/metabolismo , Meios de Cultura/metabolismo , Microbiologia de Alimentos/métodos , Isoflavonas/metabolismo , Monascus/metabolismo , Soja/metabolismo , Citrinina/análise , Meios de Cultura/química , Fermentação , Oryza/química , Oryza/metabolismo , Soja/química
17.
J Sci Food Agric ; 99(9): 4439-4444, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30866050

RESUMO

BACKGROUND: Today, there is an increasing concern about the consumption of synthetic colorants in food because of their possible health hazards. Monascus purpureus has attracted a great deal of attention as it produces various coloured pigments with high chemical stability, but it also produces citrinin, a secondary toxic metabolite, along with the pigments. This study aims to investigate the amount of pigment and citrinin reduction by different treatments with Saccharomyces cerevisiae such as heat treatment and suspension concentration. RESULTS: The results indicated that the ability of S. cerevisiae regarding citrinin adsorption increased with increase of temperature and yeast concentration. The maximum extent of citrinin adsorption was related to heat treatment at 121 °C and a yeast concentration of 105 cells mL-1 , for which citrinin reduced from 4.43 mg L-1 in control to 0.1 mg L-1 . Heat treatment of 103 cells mL-1 suspension of S. cerevisiae cells at 50 °C, with 0.56 mg L-1 citrinin remaining in the medium, showed the lowest ability for citrinin binding. The optimum absorbance of all red, orange and yellow pigments was observed for the heat treatment at 50 °C and yeast concentrations of 103 and 104 cells mL-1 which was greater than that for the control. CONCLUSIONS: We can conclude from this study that heat treatment with S. cerevisiae can be a useful way to reduce citrinin to below the standard limits. © 2019 Society of Chemical Industry.


Assuntos
Citrinina/metabolismo , Monascus/metabolismo , Pigmentos Biológicos/metabolismo , Saccharomyces cerevisiae/metabolismo , Citrinina/toxicidade , Temperatura Alta , Concentração de Íons de Hidrogênio , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/crescimento & desenvolvimento
18.
Food Chem ; 284: 205-212, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-30744847

RESUMO

The mycotoxin citrinin is often produced during fermentation of Monascus products. We studied the effects of flavonoids on citrinin production by Monascus aurantiacus Li AS3.4384 (MALA) by adding rutin, α-glucosylrutin, or troxerutin to the fermentation medium, in a first-of-its-kind study. Appropriate amounts of rutin, α-glucosylrutin, or troxerutin did not affect normal mycelial growth. Addition of 5.0 g/l of rutin only weakly reduced (29.2%) citrinin production, relative to inhibition by 5 g/l α-glucosylrutin or troxerutin (by 54.7% and 40.6%, respectively). In starch inorganic liquid culture media, addition of 20.0 g/l of troxerutin, followed by fermentation for 12 days, reduced citrinin yield by 75.26%. Addition of 15.0 g/l of troxerutin to low-starch peptone liquid fermentation media reduced citrinin yield by 87.9% after 14 days of fermentation, and addition of 30.0 g/l troxerutin to yeast extract sucrose liquid media for 12 days reduced citrinin yield by 53.7%.


Assuntos
Citrinina/biossíntese , Monascus/efeitos dos fármacos , Monascus/metabolismo , Rutina/farmacologia , Meios de Cultura/química , Meios de Cultura/farmacologia , Fermentação , Hidroxietilrutosídeo/análogos & derivados , Hidroxietilrutosídeo/farmacologia , Monascus/crescimento & desenvolvimento , Rutina/análogos & derivados , Trissacarídeos
19.
Toxins (Basel) ; 11(2)2019 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-30769930

RESUMO

Applications of beneficial secondary metabolites produced by Monascus purpureus (M. purpureus) could be greatly limited for citrinin, a kidney toxin. The link of NaCl with cell growth and secondary metabolites in M. purpureus was analyzed with supplementations of different concentrations of NaCl in medium. The content of citrinin was reduced by 48.0% but the yellow, orange, red pigments and monacolin K productions were enhanced by 1.7, 1.4, 1.4 and 1.4 times, respectively, compared with those in the control using NaCl at 0.02 M at the 10th day of cultivation. NaCl didn't affect the cell growth of M. purpureus. This was verified through the transcriptional up-regulation of citrinin synthesis genes (pksCT and ctnA) and the down-regulation of the Monascus pigments (MPs) synthesis genes (pksPT and pigR). Moreover, the reactive oxygen species (ROS) levels were promoted by NaCl at the 2nd day of cultivation, and then inhibited remarkably with the extension of fermentation time. Meanwhile, the activities of superoxide dismutase (SOD) and catalase (CAT), and the contents of total glutathione (T-GSH) were significantly enhanced in the middle and late stages of cultivation. The inhibition effect on colony size and the growth of aerial mycelia was more obvious with an increased NaCl concentration. Acid and alkaline phosphatase (ACP and AKP) activities dramatically increased in NaCl treatments. NaCl could participate in secondary metabolites synthesis and cell growth in M. purpureus.


Assuntos
Citrinina/antagonistas & inibidores , Lovastatina/metabolismo , Monascus/efeitos dos fármacos , Pigmentos Biológicos/metabolismo , Cloreto de Sódio/farmacologia , Fosfatase Ácida/metabolismo , Fosfatase Alcalina/metabolismo , Catalase/metabolismo , Citrinina/metabolismo , Fermentação , Glutationa/metabolismo , Monascus/crescimento & desenvolvimento , Monascus/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Metabolismo Secundário/efeitos dos fármacos , Superóxido Dismutase/metabolismo
20.
J Agric Food Chem ; 67(9): 2563-2569, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30734557

RESUMO

Monascus purpureus is an important food and drug microbial resource through the production of a variety of secondary metabolites, including monacolin K, a well-recognized cholesterol-lowering agent. However, the high production costs and naturally low contents of monacolin K have restricted its large-scale production. Thus, in this study we sought to improve the production of monacolin K in M. purpureus through overexpression of four genes ( mokC, mokD, mokE, and mokI). Four overexpression strains were successfully constructed by protoplast electric shock conversion, which resulted in a 234.3%, 220.8%, 89.5%, and 10% increase in the yield of monacolin K, respectively. The overexpression strains showed clear changes to the mycelium surface with obvious folds and the spores with depressions, whereas the pBC5 mycelium had a fuller structure with a flatter surface. Further investigation of these strains can provide the theoretical basis and technical support for the development of functional Monascus varieties.


Assuntos
Benzopiranos/metabolismo , Lovastatina/biossíntese , Lovastatina/genética , Monascus/genética , Pigmentos Biológicos/metabolismo , Policetídeos/metabolismo , Expressão Gênica , Engenharia Genética/métodos , Monascus/metabolismo
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