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Journal of Fungi (Basel, Switzerland) May 2024, one of the conidiation center regulatory genes in many filamentous fungi, plays an important role in promoting asexual spores (conidia) maturation. Our recent research...
, one of the conidiation center regulatory genes in many filamentous fungi, plays an important role in promoting asexual spores (conidia) maturation. Our recent research has found that knocking out or overexpressing (a homolog of ) in M7 does not affect the development of its asexual spores like other fungi, but both repress the development of its sexual spores (ascospores). However, the mechanism remains unclear. In this study, the function of on sexual reproduction and secondary metabolism in M7 was confirmed by a complementary experiment. Moreover, the regulatory roles of in modulating the expression of genes involved in sexual reproduction, meiosis, and biosynthesis of pigment and citrinin were analyzed based on the transcriptional data. These results not only contribute to clarifying the regulation of the reproduction and secondary metabolism of spp., but also to enriching the regulation molecular mechanism of reproduction in filamentous fungi.
PubMed: 38786694
DOI: 10.3390/jof10050338 -
Journal of Fungi (Basel, Switzerland) Dec 2023Citrinin (CIT), a secondary metabolite produced by the filamentous fungi species, exhibits nephrotoxic, hepatotoxic, and carcinogenic effects in mammals, remarkably...
Citrinin (CIT), a secondary metabolite produced by the filamentous fungi species, exhibits nephrotoxic, hepatotoxic, and carcinogenic effects in mammals, remarkably restricting the utilization of -derived products. CIT synthesis is mediated through the gene and modified by multiple genetic factors. Here, the regulatory effects of two transcripts, α, and β, generated via pre-mRNA alternative splicing (AS), were investigated using hairpin RNA (ihpRNA) interference, and their impact on CIT biosynthesis and the underlying mechanisms were assessed through chemical biology and transcriptome analyses. The CIT yield in ihpRNA-pksCTα and ihpRNA-pksCT (α + β) transformants decreased from 7.2 μg/mL in the wild-type strain to 3.8 μg/mL and 0.08 μg/mL, respectively. Notably, several genes in the CIT biosynthetic gene cluster, specifically , , and in the ihpRNA-pksCT (α + β) transformant, were downregulated. Transcriptome results revealed that silencing has a great impact on carbohydrate metabolism, amino acid metabolism, lipid metabolism, and AS events. The key enzymes in the citrate cycle (TCA cycle) and glycolysis were significantly inhibited in the transformants, leading to a decrease in the production of biosynthetic precursors, such as acetyl-coenzyme-A (acetyl-coA) and malonyl-coenzyme-A (malonyl-coA). Furthermore, the reduction of CIT has a regulatory effect on lipid metabolism via redirecting acetyl-coA from CIT biosynthesis towards lipid biosynthesis. These findings offer insights into the mechanisms underlying CIT biosynthesis and AS in , thus providing a foundation for future research.
PubMed: 38132775
DOI: 10.3390/jof9121174 -
Microbiology Resource Announcements Jan 2024In China, certain strains are traditionally used as edible fungi. We sequenced the genome of FM39-7 strain, an isolate from fermented rice. The genome is 25.89 Mb with...
In China, certain strains are traditionally used as edible fungi. We sequenced the genome of FM39-7 strain, an isolate from fermented rice. The genome is 25.89 Mb with a G + C content of 48.86%, containing 8485 annotated genes.
PubMed: 38099680
DOI: 10.1128/mra.00805-23 -
Journal of Food and Drug Analysis Mar 2023Red mold rice (RMR) is a traditional Chinese medicine prepared using Monascus fermentation. Monascus ruber ( pilosus) and Monascus purpureus have a long history of use...
Red mold rice (RMR) is a traditional Chinese medicine prepared using Monascus fermentation. Monascus ruber ( pilosus) and Monascus purpureus have a long history of use as food and medicine. As an economically important starter culture, the relationship between the taxonomy of Monascus and production capabilities of secondary metabolites is crucial for the Monascus food industry. In this study, monacolin K, monascin, ankaflavin, and citrinin production by M. purpureus and M. ruber were genomically and chemically investigated. Our findings suggest that M. purpureus can produce monascin and ankaflavin in a correlated manner, whereas M. ruber produces monascin with minimum ankaflavin. M. purpureus is capable of producing citrinin; however, it is unlikely able to produce monacolin K. In contrast, M. ruber produces monacolin K, but not citrinin. We suggest that the current monacolin K content-related regulation of Monascus food should be revised, and labeling of Monascus species should be considered.
Topics: Monascus; Fermentation; Lovastatin; Oryza
PubMed: 37224553
DOI: 10.38212/2224-6614.3438 -
Frontiers in Microbiology 2022spp. are traditional medicinal and edible filamentous fungi in China, and can produce various secondary metabolites, such as pigments (MPs) and citrinin (CIT). Genetic...
spp. are traditional medicinal and edible filamentous fungi in China, and can produce various secondary metabolites, such as pigments (MPs) and citrinin (CIT). Genetic modification methods, such as gene knock-out, complementation, and overexpression, have been used extensively to investigate the function of related genes in spp.. However, the resistance selection genes that can have been used for genetic modification in spp. are limited, and the gene replacement frequency (GRF) is usually <5%. Therefore, we are committed to construct a highly efficient gene editing system without resistance selection marker gene. In this study, using M7 as the starting strain, we successfully constructed a so-called markerlessly and highly genetic modification system including the mutants ΔΔ and ΔΔ::, in which we used the endogenous gene from M7 instead of the resistance marker gene as the screening marker, and simultaneously deleted related to non-homologous end joining in M7. Then, the morphology, the growth rate, the production of MPs and CIT of the mutants were analyzed. And the results show that the mutant strains have normal mycelia, cleistothecia and conidia on PDA+Uridine(U) plate, the biomass of each mutant is also no different from M7. However, the U addition also has a certain effect on the orange and red pigments yield of M7, which needs our further study. Finally, we applied the system to delete multiple genes from M7 separately or continuously without any resistance marker gene, and found that the average GRF of ΔΔ was about 18 times of that of M7. The markerlessly and highly genetic modification system constructed in current study not only will be used for multi-gene simultaneous modification in spp., and also lays a foundation for investigating the effects of multi-genes modification on spp..
PubMed: 35979480
DOI: 10.3389/fmicb.2022.952323 -
Frontiers in Microbiology 2022The biosynthesis of penicillin G (PG) is compartmentalized, and the transportation of the end and intermediate products, and substrates (precursors) such as L-cysteine...
The biosynthesis of penicillin G (PG) is compartmentalized, and the transportation of the end and intermediate products, and substrates (precursors) such as L-cysteine (L-Cys), L-valine (L-Val) and phenylacetic acid (PAA) requires traversing membrane barriers. However, the transportation system of PAA as a side chain of PG are unclear yet. To discover ABC transporters (ABCTs) involved in the transportation of PAA, the expression levels of 38 ABCT genes in the genome of M7, culturing with and without PAA, were examined, and found that one gene, namely 31, was considerably up-regulated with PAA, indicating that 31 may be relative with PAA transportation. Furthermore the disruption of 31 was carried out, and the effects of two PG substrate's amino acids (L-Cys and L-Val), PAA and some other weak acids on the morphologies and production of secondary metabolites (SMs) of Δ31 and M7, were performed through feeding experiments. The results revealed that L-Cys, L-Val and PAA substantially impacted the morphologies and SMs production of Δ31 and M7. The UPLC-MS/MS analysis findings demonstrated that Δ31 did not interrupt the synthesis of PG in M7. According to the results, it suggests that 31 is involved in the resistance and detoxification of the weak acids, including the PAA in M7.
PubMed: 35966689
DOI: 10.3389/fmicb.2022.915721 -
3 Biotech Sep 2022In this study, the whole genome of KACC 46666 was generated using the PacBio RSII sequencer with high-quality de novo assembly to obtain trustworthy assembly and...
In this study, the whole genome of KACC 46666 was generated using the PacBio RSII sequencer with high-quality de novo assembly to obtain trustworthy assembly and annotation using genome assemblies with long reads from PacBio single-molecule real-time sequencing. The whole genome of has a total length of 25.9 Mb, divided in 13 contigs with 9639 genes. The functions of genes involved in secondary metabolite production were further analyzed. Gene clusters involved in the production of pigment, monacolin K, and mycotoxin citrinin were identified. Notably, most of the citrinin gene cluster was lost, as confirmed via high-performance liquid chromatography analysis. This genome-level safety evaluation of industrially important strains will provide valuable information for genome-based microbial engineering of natural food colorants and production of commercially important secondary metabolites such as monacolin K.
PubMed: 35959167
DOI: 10.1007/s13205-022-03287-z -
Scientific Reports Jul 2022A number of biopigment applications in various industrial sectors are gaining importance due to the growing consumer interest in their natural origin. Thus, this work...
A number of biopigment applications in various industrial sectors are gaining importance due to the growing consumer interest in their natural origin. Thus, this work was conducted to valorize endophytic fungi as an efficient production platform for natural pigments. A promising strain isolated from leaves of Origanum majorana was identified as Monascus ruber SRZ112 produced several types of pigments. The nature of the pigments, mainly rubropunctamine, monascin, ankaflavin, rubropunctatin, and monascorubrin in the fungal extract was studied by LC/ESI-MS/MS analyses. As a first step towards developing an efficient production of red pigments, the suitability of seven types of agro-industrial waste was evaluated. The highest yield of red pigments was obtained using potato peel moistened with mineral salt broth as a culture medium. To increase yield of red pigments, favourable culture conditions including incubation temperature, incubation period, pH of moistening agent, inoculum concentration, substrate weight and moisture level were evaluated. Additionally, yield of red pigments was intensified after the exposure of M. ruber SRZ112 spores to 1.00 KGy gamma rays. The final yield was improved by a 22.12-fold increase from 23.55 to 3351.87 AU g. The anticancer and antioxidant properties of the pigment's extract from the fungal culture were also studied. The obtained data indicated activity of the extract against human breast cancer cell lines with no significant cytotoxicity against normal cell lines. The extract also showed a free radical scavenging potential. This is the first report, to our knowledge, on the isolation of the endophytic M. ruber SRZ112 strain with the successful production of natural pigments under solid-state fermentation using potato peel as a substrate.
Topics: Endophytes; Fermentation; Humans; Industrial Waste; Monascus; Pigments, Biological; Plant Extracts; Tandem Mass Spectrometry
PubMed: 35871189
DOI: 10.1038/s41598-022-16269-1 -
Botanical Studies Jul 2022Medical plants confer various benefits to human health and their bioconversion through microbial fermentation can increase efficacy, reduce toxicity, conserve resources...
BACKGROUND
Medical plants confer various benefits to human health and their bioconversion through microbial fermentation can increase efficacy, reduce toxicity, conserve resources and produce new chemical components. In this study, the cholesterol-lowering monacolin K genes and content produced by Monascus species were identified. The high-yield monacolin K strain further fermented with various medicinal plants. The antioxidant and anti-inflammatory activities, red pigment and monacolin K content, total phenolic content, and metabolites in the fermented products were analyzed.
RESULTS
Monacolin K was detected in Monascus pilosus (BCRC 38072), and Monascus ruber (BCRC 31533, 31523, 31534, 31535, and 33323). It responded to the highly homologous mokA and mokE genes encoding polyketide synthase and dehydrogenase. The high-yield monacolin K strain, M. ruber BCRC 31535, was used for fermentation with various medicinal plants. A positive relationship between the antioxidant capacity and total phenol content of the fermented products was observed after 60 days of fermentation, and both declined after 120 days of fermentation. By contrast, red pigment and monacolin K accumulated over time during fermentation, and the highest monacolin K content was observed in the fermentation of Glycyrrhiza uralensis, as confirmed by RT-qPCR. Moreover, Monascus-fermented medicinal plants including Paeonia lactiflora, Alpinia oxyphylla, G. uralensis, and rice were not cytotoxic. Only the product of Monascus-fermented G. uralensis significantly exhibited the anti-inflammatory capacity in a dose-dependent manner in lipopolysaccharide-induced Raw264.7 cells. The metabolites of G. uralensis with and without fermentation (60 days) were compared by LC/MS. 2,3-Dihydroxybenzoic acid, 3,4-dihydroxyphenylglycol, and 3-amino-4-hydroxybenzoate were considered to enhance the antioxidant and anti-inflammatory ability.
CONCLUSIONS
Given that highly homologous monacolin K and citrinin genes can be observed in Monascus spp., monacolin K produced by Monascus species without citrinin genes can be detected through the complementary methods of PCR and HPLC. In addition, the optimal fermentation time was important to the acquisition of antioxidants, red pigment and monacolin K. These bioactive substances were significantly affected by medicinal plants over fermentation time. Consequently, Monascus-fermented G. uralensis had a broad spectrum of biological activities.
PubMed: 35779152
DOI: 10.1186/s40529-022-00351-y -
Mycotoxin Research May 2022Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method,...
Fungi and mycotoxins in silage can have detrimental consequences for both cattle and human health. This pilot study identified, via the routinary direct plating method, the dominant cultivable fungi in mouldy grass silages (GS) (n = 19) and maize silages (MS) (n = 28) from Austria. The profiles of regulated, modified, and emerging mycotoxins together with other fungal metabolites were analysed via LC-(ESI)MS/MS. Penicillium roqueforti, Saccharomyces spp., Geotrichum candidum, Aspergillus fumigatus and Monascus ruber were the most frequent fungal organisms identified. Other species including Mucor circinelloides, Fusarium spp. and Paecilomyces niveus were detected at lower frequencies. The presence of complex mixtures of toxic and potentially toxic compounds was evidenced by high levels and occurrences (≥ 50%) of Penicillium-produced compounds such as mycophenolic acid (MPA), roquefortines (ROCs), andrastins (ANDs) and marcfortine A. Mouldy silages contained toxins commonly produced by genus Fusarium (e.g. zearalenone (ZEN) and trichothecenes), Alternaria (like tenuazonic acid (TeA) and alternariol (AHO)) and Aspergillus (such as sterigmatocystin (STC)). Compared to those in GS, mouldy spots in MS presented significantly higher fungal counts and more diverse toxin profiles, in addition to superior levels of Fusarium spp., Penicillium spp. and total fungal metabolites. Generally, no correlation between mould counts and corresponding metabolites was detected, except for the counts of P. roqueforti, which were positively correlated with Penicillium spp. metabolites in mouldy MS. This study represents a first assessment of the fungal diversity in mouldy silage in Austria and highlights its potential role as a substantial contributor to contamination with complex mycotoxin mixtures in cattle diets.
Topics: Alternaria; Animals; Austria; Cattle; Food Contamination; Fusarium; Mycotoxins; Pilot Projects; Poaceae; Silage; Tandem Mass Spectrometry; Zea mays
PubMed: 35347677
DOI: 10.1007/s12550-022-00453-3