Search Results (9)

Monascus pigments (MPs) are the most valuable secondary metabolites of Monascus. To improve the production of MPs is of great importance to food processing. Currently, studies using rice bran as the substrate to produce MPs are rare. In this study, rice bran with different carbon sources and cellulase hydrolysis conditions were explored in Monascus purpureus M9 in this study. Through single-factor experiments and Box–Behnken response surface optimization, we demonstrated that mannitol supplementation combined with cellulase treatment of substrate significantly enhanced the yields of MPs. The optimal conditions (4.00% mannitol, cellulase hydrolysis at 60 °C for 2 h) achieved a maximum color value of 3538 U/g. Furthermore, comparative evaluation under different culture conditions, including only rice bran (RB), cellulase hydrolysis of rice bran (Cel), rice bran supplemented with mannitol (Man), mannitol supplementation combined with cellulase pretreatment of substrate (Opti), and only rice (Rice), confirmed the effectiveness of the optimized treatment. The color value of the Opti group was 27.95 times more than that of the RB group and reached 80.96% of the counterpart of the Rice group. The Opti group also significantly enhanced the yields of two orange pigments (Monascorubrin and Rubropunctatin), induced more sexual spore formation, and exhibited the maximum biomass and colony diameter among different groups. The hyphae of the Man and Opti groups were full, intact, and tubular. The citrinin content in the Opti group was under the limit standard of China. The data provides a theoretical basis reference for improving the yields of MPs with RB as the substrate. Full article

In this study, wheat bran was used to prepare dietary fiber by Monascus anka in liquid fermentation. The structural and functional characteristics of wheat bran dietary fiber were analyzed. Scanning electron microscopy and X-ray diffraction analysis indicated that the insoluble dietary fiber matrix was disrupted during the liquid fermentation. Infrared spectroscopy and differential scanning calorimetry analysis demonstrated that intramolecular hydrogen bonds were broken and the oligosaccharides increased. The soluble dietary fiber content increased from 10.7 g/100 g to 16.5 g/100 g, which contributed to improvements in the water-holding capacity, oil-holding capacity, and swelling capacity of wheat bran dietary fiber. UV–Vis spectroscopy analysis demonstrated that the M. anka wheat bran fermentation broth (MWFB) mainly contained yellow pigments (236.6 μ mL⁻¹). HPLC-MS spectrometry further showed MWFB contained three known Monascus pigments: monasine (observed. m/z 359.1853 [M+H]+), ankaflavin (observed. m/z 387.2151 [M+H]+), and monascorubrin (observed. m/z 382.2007 [M+H]+). In conclusion, M. anka can make the most use of wheat bran and improve the structure and function of dietary fiber, thereby expanding its application potential in functional food additives, gut microbiota modulation, and low-calorie baked goods. Full article

During the ongoing studies designed to examine the fungal diversity present within the abandoned and flooded Escádia Grande gold mine (Góis, Portugal), we repeatedly isolated several specimens belonging to a Penicillium species. Molecular phylogenetic analysis, coupled with morphological observations, positioned this fungus within subgen. Penicillium sect. Paradoxa, series Atramentosa, pinpointing its identity as Penicillium mexicanum (the first record for mining soils and the country). Given the limited research conducted on Penicillia isolated from similar environments, the species genome was sequenced utilizing the Oxford Nanopore^® MinION^™ methodology and studied through bioinformatic analysis. The obtained genome has a size of 29.62 Mb, containing a 47.72% GC content, 10,156 genes, with 44 rRNAs and 178 tRNAs/tmRNAs, providing the first genomic resource for this microorganism. Bioinformatic analysis allowed us to identify multiple genomic traits that can contribute towards this species survival in these extreme environments, including the presence of high levels of major facilitator transporters (MFS), Zn (2)-C6 fungal-type DNA-binding domains, P-loop containing nucleoside triphosphate hydrolases, specific fungal transcription factors and sugar transporters. Furthermore, putative advantageous metabolic traits, such as methylotrophy, assimilatory nitrate and sulfate reduction abilities, were also detected. In addition, the results also highlighted a strong genomic and metabolic organization and investment towards arsenic detoxification (transport and oxidation). Lastly, thirty-two putative biosynthetic gene clusters were predicted, including some with high similarity values to monascorubrin, nidulanin A, histidyltryptophanyldiketopiperazine/dehydrohistidyltryptophanyldiketopiperazine/roquefortine D/roquefortine C/glandicoline A/glandicoline B/meleagrine, YWA1 and choline. Overall, this study expands the current Penicillia knowledge from mining environments while also enhancing our understanding regarding fungal arsenic resistance. Full article

To explore the application of forward osmosis (FO) technology in the organic solvent recovery field, we prepared a new solvent-resistant triple layer thin film composite (TFC) membrane on the PI (polyimide) substrate. The deep eutectic supramolecular polymers (DESPs) interlayer was constructed on the substrate to improve the separation performance and solvent resistance. DESPs interlayer was formed by mixing and heating with cyclodextrin as the hydrogen bond acceptor and L-malic acid as the hydrogen bond donor. The chemical changes, surface property and morphology of the composite membrane with DESPs interlayer were characterized. The separation performance and stability of the triple layer composite membrane in organic solvent FO were studied. For the monascorubrin-ethanol system, the permeation flux of TFC/DESPs5-PI membrane could reach 9.51 LMH while the rejection rate of monascorubrin was 98.4% (1.0 M LiCl/ethanol as draw solution), which was better than the pristine membrane. Therefore, this solvent-resistant triple layer composite FO membrane has good potential for the recovery of organic solvents. Full article

Biobased pigments are environmentally friendly alternatives to synthetic variants with an increased market demand. Production of pigments via fermentation is a promising process, yet optimization of the production yield and rate is crucial. Herein, we evaluated the potential of Penicillium purpurogenum to produce biobased pigments. Optimum sugar concentration was 30 g/L and optimum C:N ratio was 36:1 resulting in the production of 4.1–4.5 AU (namely Pigment Complex A). Supplementation with ammonium nitrate resulted in the production of 4.1–4.9 AU (namely Pigment Complex B). Pigments showed excellent pH stability. The major biopigments in Pigment Complex A were N-threonyl-rubropunctamin or the acid form of PP-R (red pigment), N-GABA-PP-V (violet pigment), PP-O (orange pigment) and monascorubrin. In Pigment Complex B, a novel biopigment annotated as N-GLA-PP-V was identified. Its basic structure contains a polyketide azaphilone with the same carboxyl-monascorubramine base structure as PP-V (violet pigment) and γ-carboxyglutamic acid (GLA). The pigments were not cytotoxic up to 250 μg/mL. Full article

In this study, the physicochemical properties, pharmacokinetics properties, and drug-likeness of pigments from Monascus-fermented rice (Monascus pigments, MPs) were predicted in silico using SwissADME tool. In silico prediction of physicochemical properties showed that MPs had desirable lipophilic drug-like physicochemical properties including molecular weight (236 to 543), TPSA (44.76 to 179.77), lipophilicity (−0.81 to 4.14), and water solubility (−4.94 to −0.77). The pharmacokinetic properties of MPs (i.e., GIA, P-glycoprotein substrate, and CYP3A4 inhibitor) illustrated that most MPs had high intestinal absorption and bioavailability, but some MPs might cause pharmacokinetics-related drug–drug interactions. Following this, six main well-known MPs (monascin, ankaflavin, rubropunctatin, monascorubrin, rubropunctamine, monascorubramine) were selected for molecular docking with some enzyme receptors. The docking results were shown with the best molecular docking poses, and the interacting residues, number and distance of hydrogen bonds of the MPs and monacolin K (for docking with 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMG-CoA reductase)), or MPs and oleic acid (for docking with lipase). Dissociation constants showed that MPs had lower inhibitory potential for HMGR (compared with Monacolin K), and higher inhibitory potential for lipase. Individual pigments from Monascus-fermented rice, therefore, have the potential to be developed as drug candidates for controlling hyperlipidemia. Full article

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. Full article

Monascus species have been used for the production of many industrially and medically important metabolites, most of which are polyketides produced by the action of polyketide synthases that use acetyl-CoA and malonyl-CoA as precursors, and some of them are derived from acetate. In this study the effects of acetic acid, and two kinds of acetates, sodium acetate and ammonium acetate at different concentrations (0.1%, 0.25% and 0.5%) on the morphologies, biomasses, and six major Monascus pigments (MPs) of M. ruber M7 were investigated when M7 strain was cultured on potato dextrose agar (PDA) at 28 °C for 4, 8, 12 days. The results showed that all of the added acetate species significantly affected eight above-mentioned parameters. In regard to morphologies, generally the colonies transformed from a big orange fleecy ones to a small compact reddish ones, or a tightly-packed orange ones without dispersed mycelia with the increase of additives concentration. About the biomass, addition of ammonium acetate at 0.1% increased the biomass of M. ruber M7. With respect to six MPs, all acetate species can enhance pigment production, and ammonium acetate has the most significant impacts. Production of monascin and ankaflavin had the highest increase of 11.7-fold and 14.2-fold in extracellular contents at the 8th day when 0.1% ammonium acetate was supplemented into PDA. Intracellular rubropunctatin and monascorubrin contents gained 9.6 and 6.46-fold at the 8th day, when 0.1% ammonium acetate was added into PDA. And the extracellular contents of rubropunctamine and monascorubramine were raised by 1865 and 4100-fold at the 4th day when M7 grew on PDA with 0.5% ammonium acetate. Full article

Penicillium marneffei (synonym: Talaromyces marneffei) is the most important pathogenic thermally dimorphic fungus in China and Southeastern Asia. The HIV/AIDS pandemic, particularly in China and other Southeast Asian countries, has led to the emergence of P. marneffei infection as an important AIDS-defining condition. Recently, we published the genome sequence of P. marneffei. In the P. marneffei genome, 23 polyketide synthase genes and two polyketide synthase-non-ribosomal peptide synthase hybrid genes were identified. This number is much higher than those of Coccidioides immitis and Histoplasma capsulatum, important pathogenic thermally dimorphic fungi in the Western world. Phylogenetically, these polyketide synthase genes were distributed evenly with their counterparts found in Aspergillus species and other fungi, suggesting that polyketide synthases in P. marneffei did not diverge from lineage-specific gene duplication through a recent expansion. Gene knockdown experiments and ultra-high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry analysis confirmed that at least four of the polyketide synthase genes were involved in the biosynthesis of various pigments in P. marneffei, including melanin, mitorubrinic acid, mitorubrinol, monascorubrin, rubropunctatin, citrinin and ankaflavin, some of which were mycotoxins and virulence factors of the fungus. Full article