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To avoid the unreasonable use of chemical fertilizer, an environmentally friendly means of improving soil fertility is required. This study explored the role of the plant growth-promoting rhizosphere bacteria (PGPR) strain Bacillus velezensis SAAS-63 in improving nutrient stress in lettuce. Compared with no inoculation, B. velezensis SAAS-63 inoculants exhibited significantly increased fresh weight, root length, and shoot height under nutrient deficiency, as well as improved antioxidant activities and proline contents. The exogenous addition of B. velezensis SAAS-63 also significantly increased the accumulation of macroelements and micronutrients in lettuce. To elucidate the resistance mechanisms induced by B. velezensis SAAS-63 under nutrient stress, high-throughput sequencing and multi-omics analysis were performed. Inoculation with B. velezensis SAAS-63 altered the microbial community of the rhizosphere and increased the relative abundances of Streptomyces, Actinoallomurus, Verrucomicrobia, and Chloroflexi. It is worth noting that the inoculant SAAS-63 can affect plant rhizosphere metabolism. The inoculant changed the metabolic flow of phenylpropanoid metabolic pathway under nutrient deficiency and promoted phenylalanine to participate more in the synthesis of lignin precursors and coumarin substances by inhibiting the synthesis of flavone and isoflavone, thus improving plant resistance. This study showed that the addition of inoculant SAAS-63 could help plants recruit microorganisms to decompose and utilize trehalose and re-established the carbon metabolism of the plant rhizosphere. Additionally, microbes were found to be closely related to the accumulation of metabolites based on correlation analysis. The results indicated that the addition of PGPRs has an important role in regulating soil rhizosphere microbes and metabolism, providing valuable information for understanding how PGPRs affect complex biological processes and enhance plant adaptation to nutrient deficiency. KEY POINTS: ⢠Inoculation with SAAS-63 significantly promoted plant growth under nutrient-deficient conditions ⢠Inoculation with SAAS-63 affected rhizosphere microbial diversity and community structure ⢠Inoculation with SAAS-63 affected plant rhizosphere metabolism and induced plants to synthesize substances that resist stress.
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Bacillus , Lactuca , Nutrientes , Rizosfera , Microbiologia do Solo , Estresse Fisiológico , Bacillus/metabolismo , Bacillus/genética , Lactuca/microbiologia , Lactuca/crescimento & desenvolvimento , Nutrientes/metabolismo , Raízes de Plantas/microbiologia , Microbiota , MultiômicaRESUMO
High mobility group protein 1 (HMGB1) plays a complex role in tumor biology. When released into the extracellular space, it binds to the receptor for advanced glycation end products (RAGE) located on the cell membrane, playing an important role in tumor development by regulating a number of biological processes and signal pathways. In this review, we outline the multifaceted functions of the HMGB1/RAGE axis, which encompasses tumor cell proliferation, apoptosis, autophagy, metastasis, and angiogenesis. This axis is instrumental in tumor progression, promoting tumor cell proliferation, autophagy, metastasis, and angiogenesis while inhibiting apoptosis, through pivotal signaling pathways, including MAPK, NF-κB, PI3K/AKT, ERK, and STAT3. Notably, small molecules, such as miRNA-218, ethyl pyruvate (EP), and glycyrrhizin exhibit the ability to inhibit the HMGB1/RAGE axis, restraining tumor development. Therefore, a deeper understanding of the mechanisms of the HMGB1/RAGE axis in tumors is of great importance, and the development of inhibitors targeting this axis warrants further exploration.
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Light, magnetic field, and methylation affected the growth and secondary metabolism of fungi. The regulation effect of the three factors on the growth and Monascus pigments (MPs) synthesis of Monascus purpureus was investigated in this study. 5-azacytidine (5-AzaC), DNA methylation inhibitor, was used to treat M. purpureus (wild-type, WT). Twenty micromolar 5-AzaC significantly promoted the growth, development, and MPs yield. Moreover, 250 lux red light and red light coupled magnetic field (RLCMF) significantly promoted the biomass. For WT, red light, and RLCMF significantly promoted MPs yield. But compared with red light treatment, only 0.2 mT RLCMF promoted the alcohol-soluble MPs yield. For histone H3K4 methyltransferase complex subunit Ash2 gene knockout strain (ΔAsh2), only 0.2 mT RLCMF significantly promoted water-soluble MPs yield. Yet red light, 1.0 and 0.2 mT RLCMF significantly promoted alcohol-soluble MPs yield. This indicated that methylation affected the MPs biosynthesis. Red light and weaker MF had a synergistic effect on the growth and MPs synthesis of ΔAsh2. This result was further confirmed by the expression of related genes. Therefore, histone H3K4 methyltransferase was involved in the regulation of the growth, development, and MPs synthesis of M. purpureus by the RLCMF.
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Monascus , Pigmentos Biológicos , Pigmentos Biológicos/metabolismo , Monascus/genética , Monascus/metabolismo , Luz Vermelha , Histonas/metabolismo , Histona Metiltransferases/metabolismo , Campos MagnéticosRESUMO
Red Monascus pigments (MPs) are a large group of polyketides from the fungus Monascus which have been widely used as food colorants. In this study, a variety of red MPs congeners were prepared to explore promising water-soluble candidates for application in liquid food formulations. The results showed that by combining the two-stage, low-pH fermentation strategy with a downstream purification step of fractional crystallization, precursors of red MPs, namely monascorubrin and rubropunctatin, were obtained with a purity of 91.9%. Then, via the azaphilic addition reaction, 18 types of red MPs congeners carrying different amino acid moieties (MPs-aa) were semi-synthesized. Compared to rubropunctamine and monascorubramine, the water solubility, pH and thermal stability of MPs-aa were improved greatly. MPs-His, MPs-Phe, MPs-Tyr and MPs-Trp were identified to be the most resistant to pasteurization. These findings provide water-soluble red MPs candidates with high thermal stability and an attractive approach for their large scale production.
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Tremella sanguinea is a traditional Chinese medicinal and edible mushroom. Polysaccharides from Tremella mushrooms have received increasing amounts of research attention due to their diverse pharmacological activities. In this study, via the incubation of basidiospores collected from fresh artificially cultivated basidiocarps of T. sanguinea, a haploid yeast strain of T. sanguinea was obtained, and it was found to be a typical loose-slime-forming yeast capable of producing a large amount of exopolysaccharides (EPS). Using DEAE-52 cellulose column chromatography and Sephadex G-100 gel permeation chromatography, the major polysaccharide, named TSPS-1, was separated and purified from the EPS produced by the haploid yeast strain of T. sanguinea. TSPS-1 was a homogeneous polysaccharide with a molecular weight of 2.5 × 103 kDa and consisted of rhamnose, glucose, xylose, mannose and glucuronic acid at a molar ratio of 1: 0.7: 62.2: 24.6: 11.5. The bioactivity of the TSPS-1 polysaccharide was evaluated. The results show that TSPS-1 exhibited noticeable antioxidant activity by scavenging hydroxyl radicals (EC50 = 1.92 mg/mL) and superoxide radicals (EC50 = 1.33 mg/mL), and prebiotic activity by promoting the growth of different probiotic strains in the genus Lactobacillus and Bifidobacterium. These results suggest that the cultivation of the haploid yeast strain can be a promising alternative for the efficient production of valuable T. sanguinea polysaccharides with antioxidant and prebiotic potential.
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Agaricales , Antioxidantes , Antioxidantes/química , Saccharomyces cerevisiae , Haploidia , Polissacarídeos/químicaRESUMO
Fos-related antigen 1 (Fra-1) is a nuclear transcription factor that regulates cell growth, differentiation, and apoptosis. It is involved in the proliferation, invasion, apoptosis and epithelial mesenchymal transformation of malignant tumor cells. Fra-1 is highly expressed in gastric cancer (GC), affects the cycle distribution and apoptosis of GC cells, and participates in GC occurrence and development. However, the detailed mechanism of Fra-1 in GC is unclear, such as the identification of Fra-1-interacting proteins and their role in GC pathogenesis. In this study, we identified tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein eta (YWHAH) as a Fra-1-interacting protein in GC cells using co-immunoprecipitation combined with liquid chromatography-tandem mass spectrometry. Experiments showed that YWHAH positively regulated Fra-1 mRNA and protein expression, and affected GC cell proliferation. Whole proteome analysis showed that Fra-1 affected the activity of the high mobility group AT-hook 1 (HMGA1)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway in GC cells. Western blotting and flow cytometry confirmed that YWHAH activated HMGA1/PI3K/AKT/mTOR signaling pathway by positively regulating Fra-1 to affect GC cell proliferation. These results will help to discover new molecular targets for the early diagnosis, treatment, and prognosis prediction of GC.
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Proteínas Proto-Oncogênicas c-akt , Neoplasias Gástricas , Humanos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Neoplasias Gástricas/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteína HMGA1a/genética , Linhagem Celular Tumoral , Transdução de Sinais , Proteínas Proto-Oncogênicas c-fos/genética , Serina-Treonina Quinases TOR/metabolismo , Proliferação de Células/genética , Apoptose/genética , Regulação Neoplásica da Expressão Gênica , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismoRESUMO
Fibroblasts are highly heterogeneous mesenchymal stromal cells, and different fibroblast subpopulations play different roles. A subpopulation of fibroblasts expressing CD90, a 25-37 kDa glycosylphosphatidylinositol anchored protein, plays a dominant role in the fibrotic and pro-inflammatory state. In this review, we focused on CD90+ fibroblasts, and their roles and possible mechanisms in disease processes. First, the main biological functions of CD90+ fibroblasts in inducing angiogenesis and maintaining tissue homeostasis are described. Second, the role and possible mechanism of CD90+ fibroblasts in inducing pulmonary fibrosis, inflammatory arthritis, inflammatory skin diseases, and scar formation are introduced, and we discuss how CD90+ cancer-associated fibroblasts might serve as promising cancer biomarkers. Finally, we propose future research directions related to CD90+ fibroblasts. This review will provide a theoretical basis for the diagnosis and treatment CD90+ fibroblast-related disease.
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Células-Tronco Mesenquimais , Neoplasias , Humanos , Neoplasias/metabolismo , Fibroblastos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Biomarcadores Tumorais/metabolismoRESUMO
Tartary buckwheat was hydrolyzed with α-amylase, pullulanase, α-amylase and pullulanase double enzymes and fermented by Monascus. The fermentation products were named as enzymolysis-Monascus-fermented tartary buckwheat (EMFTB). The composition and content of volatile flavor compounds in EMFTB were investigated. The results showed that α-amylase and pullulanase hydrolysis reduced starch content and raised protein, flavonoids, Monacolin K and Monascus pigments content of EMFTB. Meanwhile, double enzyme hydrolysis significantly changed the principal components of volatile substances and affected the varieties and content of volatile organic substances in EMFTB using electronic nose and headspace gas chromatography-ion mobility chromatography (HS-GC-IMS). The volatile organic substances and main aroma components increased significantly in EMFTB, including 2-heptanone, 3-methyl-1-butanol, butan-1-ol, 2-methyl-1-propanol and other substances. These results indicate that the amylase hydrolysis plays an important role in improving the flavor quality of EMFTB.
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Fagopyrum , Monascus , Fagopyrum/química , Hidrólise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Mobilidade Iônica , alfa-AmilasesRESUMO
Nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) is an evolutionarily conserved nicotinamide adenine dinucleotide (NAD+) synthase located in the cytoplasm and Golgi apparatus. NMNAT2 has an important role in neurodegenerative diseases, malignant tumors, and other diseases that seriously endanger human health. NMNAT2 exerts a neuroprotective function through its NAD synthase activity and chaperone function. Among them, the NMNAT2-NAD+-Sterile alpha and Toll/interleukin-1 receptor motif-containing 1 (SARM1) axis is closely related to Wallerian degeneration. Physical injury or pathological stimulation will cause a decrease in NMNAT2, which activates SARM1, leading to axonal degeneration and the occurrence of amyotrophic lateral sclerosis (ALS), Alzheimer's disease, peripheral neuropathy, and other neurodegenerative diseases. In addition, NMNAT2 exerts a cancer-promoting role in solid tumors, including colorectal cancer, lung cancer, ovarian cancer, and glioma, and is closely related to tumor occurrence and development. This paper reviews the chromosomal and subcellular localization of NMNAT2 and its basic biological functions. We also summarize the NMNAT2-related signal transduction pathway and the role of NMNAT2 in diseases. We aimed to provide a new perspective to comprehensively understand the relationship between NMNAT2 and its associated diseases.
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Doenças Neurodegenerativas , Nicotinamida-Nucleotídeo Adenililtransferase , Humanos , Axônios , NAD/metabolismo , Degeneração Walleriana/metabolismo , Degeneração Walleriana/patologia , Doenças Neurodegenerativas/patologia , Progressão da Doença , Nicotinamida-Nucleotídeo Adenililtransferase/genética , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismoRESUMO
Fermentation strains play a key role in the quality of bread. The combination of yeast and lactic acid bacteria (LAB) may effectively improve the function and nutritional properties of bread. In this study, the dough was fermented to make bread by using single strain (Saccharomyces cerevisiae, mode A), the combination of two strains (S. cerevisiae and Lactiplantibacillus plantarum, mode B; S. cerevisiae and Lactobacillus delbrueckii, mode C), or three strains (S. cerevisiae, L. plantarum, and L. delbrueckii, mode D). The specific volume, texture, and aroma substances of bread were evaluated. The possibility of mixed fermentation of selected yeast and LAB to replace natural fermentation dough was evaluated. The results showed that the specific volume of bread in mode B was 15.2% higher than that of mode A. The structure was softer and the taste was more vigorous in mode B bread. The content of volatile compounds was highest in mode B bread among the four mode bread. The characteristic flavors were ethyl 2-hydroxypropionate and z-3-hexenol. The cofermentation in mode B made the bread aroma richer and gave better aroma characteristics to bread. Therefore, the fermentation of S. cerevisiae and L. plantarum can be recommended to replace naturally fermented dough to improve the quality of bread. PRACTICAL APPLICATION: L. plantarum and L. delbrueckii, separately or together, assisted in yeast fermentation to make bread. The specific volume, texture, and aroma substances of bread were evaluated to replace natural fermented dough with mixed fermentation. L. plantarum-assisted yeast fermentation improved the specific volume, texture, and aroma of bread. The characteristic flavors were ethyl 2-hydroxypropionate and z-3-hexenol in bread. Therefore, the fermentation of S. cerevisiae and L. plantarum could replace naturally fermented dough to improve the quality of bread.
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Lactobacillales , Lactobacillus delbrueckii , Pão/microbiologia , Fermentação , Saccharomyces cerevisiaeRESUMO
The yellow Monascus pigments (YMPs) named monascin and ankaflavin and the orange Monascus pigments (OMPs) named rubropunctatin and monascorubrin are two groups of bioactive components in a mixture state in the Monascus fermented products. In order to separate these two groups of bioactive pigments, a facile macroporous resin-based method was developed. The weak-polar resin CAD-40 was selected from the seven tested macroporous resins as it revealed better properties for the adsorption and desorption of the YMPs and OMPs. Then, CAD-40 resin was used for column-chromatographic separation. After eluted by 4 bed volumes of ethanol, the yellow group (monascin and ankaflavin) and the orange group (rubropunctatin and monascorubrin) were successfully separated and purified, with an increased content from 49.3% and 44.2% in the crude pigment extract to 85.2% and 83.0% in the final products, respectively. This method would be helpful for the large-scale separation and purification of Monascus pigment products with specific bioactivity.
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Light or low frequency magnetic field (LF-MF) as one of the cultivation environments affects secondary metabolites (SMs) production of M. purpureus. Phytochrome (Phy) is a hybrid histidine kinase possessing dual properties of photoreceptor and kinase to sense red and far-red light. The interaction effects of LF-MF and light on SMs of M. purpureus was investigated by knocking out the Phy-like gene in M. purpureus (MpPhy) by homologous recombination. A MpPhy-deletion (ΔMpPhy) strain produced less Monascus pigments (MPs) and monacolin K (mon K) than the wild-type (WT) strain and reduced citrinin production by 78.3% on 10th day but didn't affect the biomass. These results indicated that the MpPhy gene is involved in SMs biosynthesis of M. purpureus. MPs production in WT was decreased significantly when the inoculum was exposed to white/blue/green/red light (500 Lux). But it in ΔMpPhy was no significant difference when exposed to white/red light. The colony size of ΔMpPhy was smaller on potato dextrose agar media containing 0.01% SDS. These results indicated that the deletion of MpPhy gene affected the aerial hyphae and increased sensitivity to cell membrane stress but decreased sensitivity to red light. The inoculum of both WT and ΔMpPhy was exposure to the LF-MF (50 Hz). The accumulation of WT secondary metabolites was not changed, while SMs production of ΔMpPhy was significantly enhanced under exposed to 2.0 mT LF-MF. This indicated that the decrease of SMs caused by the deletion of MpPhy gene was restored by LF-MF. It revealed that there is a crosstalk between magnetoreception and photosensitivity.
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Luz , Monascus/metabolismo , Fitocromo/genética , Metabolismo Secundário/efeitos da radiação , Biomassa , Citrinina/biossíntese , Meios de Cultura/química , Lovastatina/biossíntese , Monascus/citologia , Monascus/crescimento & desenvolvimento , Mutagênese , Fitocromo/metabolismo , Pigmentos Biológicos/metabolismoRESUMO
The oncogenesis of cervical cancer is a multi-factor and multi-step process, and major risk factors include oncogene activation with tumor suppressor gene inactivation, viral factors, and immune factors. For example, the human papillomavirus (HPV) has been linked to the occurrence of cervical cancer. At present, the pathogenesis of cervical cancer remains unclear. Fra-1 (Fos-related antigen 1, also known as FOSL1) is a member of the Fos family and an important nuclear transcription factor that regulates normal cell growth, differentiation, and apoptosis. In the present study, we found that Fra-1 inhibited the proliferation of cervical cancer cells while also promoting apoptosis and affecting cell cycle distribution. Moreover, Fra-1 up-regulated STAT1 expression and modulated p53 signal pathway activity in cervical cancer cells. Overexpression of Fra-1 inhibited cell senescence by altering sirtuin 1 (SIRT1) expression in HeLa cells, and Fra-1 overexpression restored mitochondrial disorder and suppressed metabolic reprogramming in HeLa cells. Silencing of STAT1 impaired the inhibitory effect of Fra-1 on cervical cancer cell growth, while knock-down of STAT1 reversed the effect on cell senescence and mitochondrial dysfunction caused by Fra-1 in HeLa cells. Silencing of STAT1 also recovered metabolic reprogramming in cervical cancer cells. In summary, our results show that Fra-1 inhibited cervical cancer cell growth and the Warburg effect via STAT1-mediated regulation of the p53 signaling pathway.
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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.
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Citrinina , Monascus , Citrinina/biossíntese , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Histona Metiltransferases/genética , Histona Metiltransferases/metabolismo , Histonas , Monascus/genética , Monascus/metabolismo , Pigmentos BiológicosRESUMO
Monascus purpureus is used to yield edible pigments accompanied by mycotoxin-citrinin. A low-frequency (<300 Hz) magnetic field (LF-MF) affects microbial metabolism. The link of LF-MF with secondary metabolites and intracellular and extracellular Na+ levels in M. purpureus was determined. The fermentation broth was exposed to LF-MF during the first 2 days of fermentation and continuously cultured at 30°C and 200 rpm until the 8th day of fermentation. Results showed that LF-MF treatments didn't affect the growth of M. purpureus in liquid-state fermentation. Compared with the control, citrinin production showed a decrease of 45.0%, while yellow, red, and orange pigment production showed an increase of 72.9, 73.9, and 40.1%, respectively, with LF-MF treatment of 1.6 mT. This was in agreement with downregulation of pksCT and ctnA, and upregulation of pksPT, pigR, veA, and laeA at the transcriptional level. Moreover, 1.6 mT LF-MF exposure caused the transfer of Na+ from extracellular to intracellular, which was validated through the upregulation of transmembrane sensor synthesis genes and the changes in the relative expression levels of the P-type ATPase and protein phosphatase genes. This study established that LF-MF could inhibit citrinin and stimulate pigment production and change intracellular and extracellular Na+ concentrations. Bioelectromagnetics. 2020;41:289-297 © 2020 Bioelectromagnetics Society.
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Citrinina/biossíntese , Campos Magnéticos , Monascus/metabolismo , Sódio/metabolismo , Fermentação , Regulação Fúngica da Expressão Gênica , Monascus/genética , Pigmentos Biológicos/genética , Pigmentos Biológicos/metabolismo , Metabolismo SecundárioRESUMO
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.
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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 ElectrosprayRESUMO
The authors wish to make the following correction to their paper [...].
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We report a broadband photonic-based microwave hybrid combiner (PMHC) using a dual-polarization dual-parallel Mach-Zehnder modulator. The broadband PMHC with arbitrarily tunable phase shift and power combining ratio can overcome several limitations of conventional microwave combiners in terms of tunability and bandwidth. By simply adjusting the biases of the modulator, the phase shift and power ratio of the two combined microwave signals are independently, continuously, and freely tunable. The proposed PMHC is theoretically analyzed and experimentally verified. In a proof-of-concept experiment, two sinusoidal microwave waveforms are successfully combined to form rectangular and triangular waveforms, respectively.
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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.
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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/metabolismoRESUMO
Cooking oil fumes as an important source of volatile organic compounds in metropolitan areas are poisonous to the environment and human health. In this study, the removal of hexanal (a representative of cooking fume) using "storage-plasma catalytic oxidation" at ambient conditions has been investigated. Alkali-modified Co-Mn catalysts were synthesized by coprecipitation method and further characterized by XRD, SEM, N2 adsorption-desorption, H2-TPR, O2-TPD and XPS techniques. It was clearly shown that the Na modification afforded a remarkable enhancement in the hexanal storage capacity, which is ascribed to the formation of surface hydroxyls that resulted in the chemical adsorption. Moreover, the plasma-catalytic oxidation results showed 99.4% hexanal removal and 85.7% CO2 selectivity at a GHSV of 47700 h-1. XPS results revealed that Na modification promoted the formation of more abundant Co3+, Mn3+ cations and surface adsorbed oxygen species, thus facilitated the oxidation process. In-situ FTIR results revealed that Na modification could trigger disproportionation reaction, resulting in the transformation of adsorbed hexanal into alcohol and carboxylic acid thus further speeds up the oxidation rate. This work provides a low-cost, highly efficient and energy-consuming approach for the removal of gaseous cooking fume by storage and plasma catalytic oxidation cycle at room temperature.