Metagenomic analysis revealing the metabolic role of microbial communities in the free amino acid biosynthesis of Monascus rice vinegar during fermentation

Free amino acid(FAA)is the important component of vinegar that infl uences quality perception and consumer acceptance.FAA is one of the major metabolites produced by microorganisms;however,the microbial metabolic network on FAA biosynthesis remains unclear.Through metagenomic analysis,this work aimed to elucidate the roles of microbes in FAA biosynthesis during Monascus rice vinegar fermentation.Taxonomic profiles from functional analyses showed 14 dominant genera with high contributions to the metabolism pathways.The metabolic network for FAA biosynthesis was then constructed,and the microbial distribution in different metabolic pathways was illuminated.The results revealed that 5 functional genera were closely involved in FAA biosynthesis.This study illuminated the metabolic roles of microorganisms in FAA biosynthesis and provided crucial insights into the functional attributes of microbiota in vinegar fermentation.

N^+离子注入选育色素产生菌Monascus的研究

应用 1 0keV的N+离子注入,对产红色素红曲菌进行了诱变选育。在确定最佳注入剂量后,经过两轮离子注入诱变筛选,选育出 1株高产突变株,红色素色价提高 3 8.1 %,且色调适宜。经传代培养,其高产性状能稳定遗传。对该菌株的发酵特性也进行了研究。

氨基酸对于Monascus ruber生物合成Monacolin K影响的研究

在Monacolin K发酵中添加氨基酸后发现较高质量浓度的氨基酸高度抑制了Monacolin K的产量。0.1 g.L-1的D-甲硫氨酸在发酵第4 d添加可以提高产量30%以上,而L-甲硫氨酸则没有此功能,D,L-甲硫氨酸因D-甲硫氨酸的关系也有一定的增产效果。以甲硫氨酸代替蛋白胨作为主要氮源,则抑制了polyketide途径的前期步骤,因此严重抑制了色素及Monacolin K的生产。另外,发现1 g.L-1的L-苯丙氨酸的添加时间越早越有利于Monacolin K的生产,在起始时添加发酵单位可达135.9 mg.L-1,可能是因为L-苯丙氨酸经过脱氨后,可以进入polyketide途径从而促进了Monacolin K的生产。

产红色素真菌Monascus sanguineus的分离及其色素提取条件研究

采用组织块分离法首次从药用植物地黄中分离出一株产红色素内生真菌RJL03,根据形态学特征和r DNA ITS1-5.8S-ITS2序列分析的手段鉴定为Monascus sanguineus。采用响应面法(RSM)对菌株RJL03中红色素提取工艺条件进行研究。在单因素实验的基础上,以提取液OD值为指标,利用Box-Behnken中心组合实验设计原理(BBD)优化菌株中红色素的有机溶剂超声波辅助浸提(UAE)工艺。结果显示,该色素提取液在515 nm处有最大吸收波长,最佳提取工艺为温度70℃、提取时间34 min、乙醇浓度50%。在此条件下提取菌株中的红色素,得到的提取液OD值为2.587,可比优化前提高约1.5倍。

产红色素真菌Monascus sanguineus的液态发酵条件研究

从药用植物地黄中分离出一株产红色素内生真菌RJL03(Monascus sanguineus),为进一步提高菌株RJL03的红色素产量,采用响应面法(RSM)对其液态摇瓶发酵条件进行研究。在单因素实验的基础上,以发酵液OD值为指标,利用Box-Behnken中心组合实验设计原理(BBD)优化菌株液态发酵产红色素的工艺条件。结果显示,该色素发酵液在474 nm处有最大吸收波长,最佳发酵工艺为温度30℃、装瓶量67%、初始p H自然(7)。在此条件下液态发酵菌株,显著提高了菌株RJL03的红色素产量。

Monascus pilosus-fermented black soybean inhibits lipid accumulation in adipocytes and in high-fat diet-induced obese mice

Objective:To explore the anti-obesity effects and the mechanism of action of Monascus pilosus(M.pilosus)-fermented black soybean(MFBS)extracts(MFBSE)and MFBS powders(MFBSP)in adipocytes and high-fat diet(HFD)-induced obese mice,respectively.Methods:Black soybean was fermented with M.pilosus,and the main constituents in MFBS were analyzed by HPLC analysis.In vitro,MFBSE were examined for anti-adipogenic effects using Oil-Red O staining.In vivo,mice were fed a normal-fat diet(NFD)control,HFD control or HFD containing 1 g/kg MFBSP for 12 weeks,and then body weight gain and tissues weight measured.Real-time PCR and western blot assay were used to determine the mechanism of anti-adipogenic effects.Results:MFBSE inhibited lipid accumulation in 3T3-L1 adipocytes without exerting cell cytotoxicity.MFBSP treatment in HFD-fed mice significantly decreased the body weight gain compared with the HFD control mice.MFBSE and MFBSP treatment resulted in significantly lower mRNA levels of adipogenesis-related genes,such as peroxisome proliferator-activated receptorγ(PPARγ),fatty acid-binding protein 4(FABP4),and fatty acid synthase(FAS),in adipocytes and in white adipose tissue(WAT)of HFD-induced obese mice.Conclusions:These results suggest that the anti-obesity effects of MFBS are elicited by regulating the expression of adipogenesis-related genes in adipocytes and WAT of HFDinduced obese mice.

Monascus vinegar alleviates high-fat-diet-induced inflammation in rats by regulating the NF-κB and PI3K/AKT/mTOR pathways

Monascus vinegar(MV) is a typical fermented food with various health-promoting effects. This study aimed to evaluate the role of MV in alleviating high-fat-diet-induced inflammation in rats with hyperlipidemia and elucidate the possible regulatory mechanisms. In the study, serum lipid profiles, liver pathology and liver inflammatory cytokines were analyzed in hyperlipidemia rats with MV(0.5 mL/kg mb, 2 mL/kg mb). Results showed that the administration of MV alleviated dyslipidemia by decreasing the serum and liver levels of triglyceride and total cholesterol. Increase in hepatic lipase and carnitine palmitoyl transferase 1(CPT-1)levels and decrease in hepatocyte steatosis, nephritis, and intestinal tissue injury in the HD group showed that high-dose MV can significantly suppress hepatic lipid accumulation and steatosis. In addition, compared with the model(MOD) group, the HD group showed significantly down-regulated the level of serum or hepatic alanine aminotransferase(ALT), aspartate aminotransferase(AST), CPT-1, interleukin(IL)-2, IL-6, IL-12,and tumor necrosis factor α(TNF-α). Moreover, the HD group showed repressed hepatic nuclear factor κB(NF-κB) pathway and inactivated phosphatidylinositol 3-kinase(PI3K)/protein kinase B(Akt)/mammalian target of rapamycin(mTOR) pathway mitigated liver inflammation. Similar results were obtained from cell experiments. Collectively, these findings revealed that MV might attenuate high-fat-diet-induced inflammation by inhibiting the NF-κB and PI3K/Akt/mTOR pathways.

Separation and Purification of Monascus Pigments from Red Yeast Rice

It is difficult to extract beneficial components from Monascus pigments due to their complex composition. The low purity of Monascus pigment preparations limits their further application in research and production. Therefore, this study was conducted to optimize the conditions for extraction and isolation of Monascus pigments from red yeast rice, to improve the purity of Monascus pigment preparations. Three fractions were isolated using column chromatography from red yeast rice, they were red, orange and yellow respectively. Then, the three fractions were analyzed for composition and purity using thin layer chromatography and liquid chromatography-mass spectrometry(LC-MS). The chromatograms revealed that the yellow and orange fractions had complex compositions that were difficult to be separated, while the red fraction consisted of fewer components. Finally, a single component was isolated from the red fraction using a thin layer chromatography plate, identified as monascorubramine according to its molecular mass.

Process Optimization on Monascus Pigment Produced by Monascus

[Objective] This study was conducted to optimize rice making process and improve the content of Monascus pigment. [Method]Selecting water addition( A),sterilization temperature( B),sterilization time( C),soaking time( D) as experimental factors,L_9( 3~4) orthogonal test was carried out to optimize rice making process. [Result] The four factors all had very significant effect on the yield of Monascus pigment,the optimal combination was A_1B_2C_2D_2,namely water addition of 30 ml,sterilization temperature at 121 ℃,sterilization time of 23 min,and soaking time of 24 h. The level of Monascus reached 2 884 U/g under this condition. [Conclusion] The study has great practical significance to Monascus rice production enterprises.

Effect of <i>Monascus</i>Fermentation on Aroma Patterns of Semi-Dried Grass Carp

The aim of the present study is to investigate the effects of Monascus fermentation on the aroma pattern of semi-dried grass carp. Semi-dried fish was fermented using Monascus purpureus GDMCC3.439. The volatile flavor substances present in fresh fish, semi-dry fish and Monascus fermented semi-dried fish were compared by simultaneous distillation and extraction combined with gas chromatograph-mass spectrometer (GC-MS). The results showed that alcohols, aldehydes and ketones were the main components of the flavor of the unfermented and fermented semi-dried grass crap. Monascus fermentation could significantly affect the volatile flavor substances of semi-dried grass carp. Moreover, the processing of semi-dried fish fermented by Monascus could not only effectively improve the fishy smell of fresh fish, but also make up for the defect of the pickled flavor of semi-dried fish. Eighteen of the main volatile components in semi-dried fish fermented by Monascus were identified by relative odor activity value (ROAV), as follows: 1-octene-3-ol, phenylethanol, hexanal, heptanal, nonanal, (E)-2-octenal, 3-Methyl-1-butanal, benzaldehyde, (E)-2-nonenal, (E,E)-2,4-heptadienal, (E)-2-Decenal, phenylacetaldehyde, (E,E)-2.4-decadienal, tetradecanal, 2,3-butanone, 2,3-octanedione, alpha-pinene, 2-pentane furan.

Ecological Dyeing of Polyamide 6, 6(PA66) Fabrics with Monascus Pigments in Decamethylcyclopentasiloxane(D5) Solvent

Synthetic dyes in the aqueous media have been commonly used for textile dyeing, resulting in resource and environmental pressure arising from consumption of water and environmentally unfriendly chemicals. In this study, an eco-friendly process of dyeing polyamide 6, 6(PA66) fabrics with natural Monascus pigments in decamethylcyclopentasiloxane(D5) solvent has been developed to minimize water consumption and effluent generation. The influence of processing parameters including dyeing temperature, dyebath pH and dyeing time on dyeing effects was explored. It was shown that color strength and color fastness of the samples dyed in D5 media were higher than those of the samples dyed in the aqueous media. Moreover, PA66 fabrics exhibited the highest color strength, good color fastness and a bacteriostatic rate of 53.6% against Staphylococcus aureus when it was dyed at pH of 3.5 and temperature of 80 ℃ for 30 min.

Transportation of citrinin is regulated by the CtnC gene in the medicinal fungus Monascus purpureus

Monascus is one of the most essential microbial resources in China,with thousands of years of history.Modern science has proved that Monascus can produce pigment,ergosterol,monacolin K,-aminobutyric acid,and other functionally active substances.Currently,Monascus is used to produce a variety of foods,health products,and pharmaceuticals,and its pigments are widely used as food additives.However,Monascus also makes a harmful polyketide component called citrinin in the fermentation process;citrinin has toxic effects on the kidneys such as teratogenicity,carcinogenicity,and mutagenicity(Gong et al.,2019).The presence of citrinin renders Monascus and its products potentially hazardous,which has led many countries to set limits and standards on citrinin content.

Biotransformation of quinoa phenolic compounds with Monascus anka to enhance the antioxidant capacity and digestive enzyme inhibitory activity

This research aims to change the phenolic fractions and the bioactivities of quinoa by solid-state fermentation(SSF)with the edible fungus Monascus anka(M.anka).The contents of protein and fat increased in the fermented product,while the carbohydrate decreased.After 6-day fermentation with M.anka,the amount of phenolic compound reached the highest level.The majority of phenolic forms in fermented quinoa were phenolic acids,mainly ferulic acid,protocatechuic acid and p-hydroxybenzoic acid.Ultrahigh-performance liquid chromatography-mass spectrometry(UHPLC-MS)results showed that SSF was an effective method to transform quinoa phenolic compounds.Free fractions could be rapidly absorbed in the small intestine,suggesting that SSF with M.anka was a useful method to enhance bioavailable antioxidants.Antioxidant ability in vitro results showed that phenolic fractions from fermented quinoa were greater than the unfermented quinoa,and a significant cellular antioxidant activity(CAA)increment of 135%was obtained in the free phenolic fraction of fermented quinoa.Moreover,α-amylase andα-glucosidase inhibition activities were enhanced with fermentation.Correlation matrix analysis revealed that most of the free phenolic compounds showed strong positive correlations with antioxidant activities and digestive enzyme activities.Consequently,fermentation with M.anka was a particularly promising method to enhance the bioactivity of quinoa.

Effect of fermentation with Monascus pilosus on the antioxidant activities and phenolic acid contents of adzuki bean(Vigna angularis)

Objective:To enhance physiological activities of adzuki bean(Vigna angularis)via fermentation with Monascus pilosus(M.pilosus).Methods:The adzuki bean fermentation conditions with M.pilosus were optimized,and the effect of Monascus-fermentation on the antioxidant capacity and phenolic acid contents of adzuki bean was investigated.Results:Optimal fermentation conditions were determined by the production of monacolin K.The highest monacolin K production was observed in 5%inoculum sized on day 15 in fermentation.Free and bound phenolic acids were isolated from native and fermented adzuki bean.A 1.9-fold decrease was observed in bound p-coumaric acid content,whereas the contents of bound ferulic and sinapic acids were increased by 28-and 1.7-fold,respectively.However,the contents of free phenolic acids such as p-coumaric,ferulic,and sinapic acids were increased by 2.6-,5.2-,and 7.2-fold,respectively.The fermentation of adzuki bean by M.pilosus enhanced the activities of DPPH■radical scavenging,ferrous ion-chelating,nitric oxide scavenging,and ferric antioxidant reducing activities 2.2-,1.7-,1.2-,and 1.8-fold,respectively.Conclusions:Results from our study suggest that the contents of p-coumaric,ferulic,and sinapic acids in adzuki bean were highly increased by fermentation with M.pilosus,resulting in enhanced various antioxidant activities.

通过红曲霉-土曲霉属间原生质体融合提高Monacolin K产量

为获得高产Monacolin K的红曲霉菌株，将高产Monacolin K的土曲霉Aspergillus terreus CA99与低产Monacolin K的红曲霉Monascus anka M-3进行原生质体融合．生长24h的A．terrus CA99和M．anka M-3菌株用0．5％溶壁酶、0．3％蜗牛酶和0．3％纤维素酶混合酶液分别在34℃和30℃下处理5h和3．5h，原生质体的形成率分别为1．76×10^7／mI。和1．68×10^7／mL．两种原生质体分别置于30W的紫外灯下，距离30cm照射3min灭活，等浓度混合后用浓度为30％的PEG 6000融合15min．再生平板上共选取363株融合子，从中筛选得到多株Monacolin K产量高于出发菌株的高产融合子，其中有10株产量的提高幅度超过60％，有2株融合子（F49和F104）产量提高了将近一倍，分别为460μg／mL。和457μg／mL。对F49的发酵培养基进行优化，Monacolin K发酵单位达到了1216μg／mL。

REMI介导红曲霉遗传转化条件的优化

为了构建限制性内切酶介导的整合(REMI)技术介导的红曲霉(Monascus anka)遗传转化系统,以潮霉素B作为抗性筛选标记,pBC-Hygro、pCB1003、pAN7-1作为转化质粒,采用REMI技术转化红曲霉。结果表明,用REMI技术介导红曲霉转化时,质粒pBC-Hygro和pCB1003适合于红曲霉的转化。环状质粒与线性质粒的转化率无显著差别;在用REMI技术介导转化时添加酶切缓冲液不利于转化;原生质体浓度为1×107～1×108个/mL时,每微克质粒可获得的潮霉素B抗性转化子为2800～3200个;HindⅢ介导转化时的最佳酶用量为105～120U;在质粒用量为8μg/100μL时转化率最高。

红曲霉与红花双向发酵体系的初步研究

以红曲霉(Monascus)作为发酵菌株,中药红花(Carthamus tinctorius)作为发酵基质进行了双向发酵试验。结果表明,红花对于红曲霉的生长和次级代谢产物莫那可林K(Monacolin K)的积累具有促进作用,同时基质中红花黄色素提取率也得到了提高,经过对发酵条件的优化,双向发酵的最佳工艺条件为红曲霉接种量6%,红花添加量3%,葡萄糖添加量6%,发酵温度28℃,发酵11 d。在此工艺条件下,Monacolin K的产量达到25.23 mg/L,比未加红花的对照提高了32.6%;红花黄色素提取率为5.18%,比未加红曲霉的对照提高了8.1%。

高产红曲色素菌株的复合诱变选育

以红曲霉MAC-8(Monascusanka)为出发菌株,经紫外线(UV)、亚硝基胍(NTG)和60Co多重复合诱变,选育到一株生产特性有明显改善的变异菌株MACF6。发酵试验表明,菌株MACF6发酵液色阶平均达到242U.mL-1,菌丝体色阶达1.09ⅹ104U.g-1,分别比出发菌株MAC-8提高了22.8%和19.8%。连续传代试验表明该菌株在遗传上是稳定的。

红曲霉发酵不同底物产色素的研究进展

红曲色素是由红曲霉发酵产生的天然色素。传统上红曲霉都是发酵大米生产红曲色素,近些年,随着研究的深入,小米、玉米、木薯、菠萝蜜籽等谷物及农工业废弃物都被用于红曲色素生产。文章简述了红曲色素的性质,对红曲霉发酵不同底物生产色素的研究进行了综述。

红曲霉代谢产物及其调控方法的研究进展

系统介绍了红曲霉(Monascus spp.)及其主要代谢产物的性质和调控红曲霉代谢产物的方法,提出了物理场辅助发酵法具有选择性好、周期短、应用潜力大的特点,将有望成为调控红曲霉代谢的一项重要的手段。