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Studies in Mycology Sep 2018has long-been used as a model organism to gain insights into the genetic basis of asexual and sexual developmental processes both in other members of the genus , and...
has long-been used as a model organism to gain insights into the genetic basis of asexual and sexual developmental processes both in other members of the genus , and filamentous fungi in general. Paradigms have been established concerning the regulatory mechanisms of conidial development. However, recent studies have shown considerable genome divergence in the fungal kingdom, questioning the general applicability of findings from , and certain longstanding evolutionary theories have been questioned. The phylogenetic distribution of key regulatory elements of asexual reproduction in was investigated in a broad taxonomic range of fungi. This revealed that some proteins were well conserved in the ( AbaA, FlbA, FluG, NsdD, MedA, and some velvet proteins), suggesting similar developmental roles. However, other elements ( BrlA) had a more restricted distribution solely in the , and it appears that the genetic control of sporulation seems to be more complex in the aspergilli than in some other taxonomic groups of the . The evolution of the velvet protein family is discussed based on the history of expansion and contraction events in the early divergent fungi. Heterologous expression of the gene in failed to induce development of complete conidiophores as seen in the aspergilli, but did result in increased conidial production. The absence of many components of the asexual developmental pathway from members of the supports the hypothesis that differences in the complexity of their spore formation is due in part to the increased diversity of the sporulation machinery evident in the Pezizomycotina. Investigations were also made into the evolution of sex and sexuality in the aspergilli. loci were identified from the heterothallic () and () and the homothallic (=). A consistent architecture of the locus was seen in these and other heterothallic aspergilli whereas much variation was seen in the arrangement of loci in homothallic aspergilli. This suggested that it is most likely that the common ancestor of the aspergilli exhibited a heterothallic breeding system. Finally, the supposed prevalence of asexuality in the aspergilli was examined. Investigations were made using as a representative 'asexual' species. It was possible to induce a sexual cycle in given the correct and partners and environmental conditions, with recombination confirmed utilising molecular markers. This indicated that sexual reproduction might be possible in many supposedly asexual aspergilli and beyond, providing general insights into the nature of asexuality in fungi.
PubMed: 30425416
DOI: 10.1016/j.simyco.2018.10.002 -
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 -
Chembiochem : a European Journal of... Nov 2021Azaphilones are a family of polyketide-based fungal natural products that exhibit interesting and useful bioactivities. This minireview explores the literature on... (Review)
Review
Azaphilones are a family of polyketide-based fungal natural products that exhibit interesting and useful bioactivities. This minireview explores the literature on various characterised azaphilone biosynthetic pathways, which allows for a proposed consensus scheme for the production of the core azaphilone structure, as well as identifying early diversification steps during azaphilone biosynthesis. A consensus understanding of the core enzymatic steps towards a particular family of fungal natural products can aid in genome-mining experiments. Genome mining for novel fungal natural products is a powerful technique for both exploring chemical space and providing new insights into fungal natural product pathways.
Topics: Benzopyrans; Biological Products; Molecular Structure; Monascus; Pigments, Biological
PubMed: 34190382
DOI: 10.1002/cbic.202100240 -
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 -
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 -
AMB Express Mar 2022Monacolin K is one of the bioactive substances produced by Monascus ruber during fermentation. The multi-factors and their interactions on the effect of solid-state...
Monacolin K is one of the bioactive substances produced by Monascus ruber during fermentation. The multi-factors and their interactions on the effect of solid-state fermentation of Monascus for high yield of monacolin K were attractive to industrial production. A detailed study of 7 single-factor experiments and a series of experiments with Plackette-Burman and Box-Benhnken design, data fitting and modeling, and analyzing the visual 3D response surface plots for investigation of the key factors for Monacolin K production. The results showed that initial moisture (50 ~ 55%) and bran content (4.5 ~ 5.5%) as the key factors of transport for nutrients and oxygen during the solid-state fermentation (SSF) process of Monascus. Under the optimal conditions, a temperature shifting of the SSF with a higher Monacolin K yield of 14.53 ± 0.16 mg·g compared with the content of monacolin K in the commercially available functional red yeast rice of 8 mg g.
PubMed: 35239075
DOI: 10.1186/s13568-022-01368-z -
Frontiers in Microbiology 2019Ypts (east rotein ransport),also called as as-ssociated inding GTPases (Rab), are the largest group of the small GTPases family, which have been extensively studied in...
Ypts (east rotein ransport),also called as as-ssociated inding GTPases (Rab), are the largest group of the small GTPases family, which have been extensively studied in model eukaryotic cells and play a pivotal role in membane trafficking, while this study showed potential regulation role of Ypts in fungi. One of Ypts, Ypt7 may be involved in fungal development and secondary metabolism, but the exact mechanism still exists a controversy. In current study, the functions of a homologous gene (7) from M7 was investigated by combination of gene-deletion (Δ7), overexpression (M7::-7) and transcriptome analysis. Results showed that the radial growth rate of Δ7 was significantly slower than M7, little conidia and ascospores can be observed in Δ7, but the yield of intracellular secondary metabolites was dramatically increased. Simultaneously, the 7 overexpression strain possessed similar capacity for sporulation and secondary metabolism observed in M7. Transcriptome results further illustrated that 7 could coordinate with numerous genes involved in the vegetative growth, conidiogenesis, secondary metabolism biosynthesis and transportation of M7. Combined with the similar effect of Ypt7 homologs on other fungi, we propose that Ypt7 works more like a global regulatory factor in fungi. To our knowledge, it is the first time to investigate Ypt7 functions in . It could also improve the understanding of Ypt7 functions in fungi.
PubMed: 30936855
DOI: 10.3389/fmicb.2019.00452 -
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 -
Toxins Aug 2015Ruminant diets include cereals, protein feeds, their by-products as well as hay and grass, grass/legume, whole-crop maize, small grain or sorghum silages. Furthermore,... (Review)
Review
Review on Mycotoxin Issues in Ruminants: Occurrence in Forages, Effects of Mycotoxin Ingestion on Health Status and Animal Performance and Practical Strategies to Counteract Their Negative Effects.
Ruminant diets include cereals, protein feeds, their by-products as well as hay and grass, grass/legume, whole-crop maize, small grain or sorghum silages. Furthermore, ruminants are annually or seasonally fed with grazed forage in many parts of the World. All these forages could be contaminated by several exometabolites of mycotoxigenic fungi that increase and diversify the risk of mycotoxin exposure in ruminants compared to swine and poultry that have less varied diets. Evidence suggests the greatest exposure for ruminants to some regulated mycotoxins (aflatoxins, trichothecenes, ochratoxin A, fumonisins and zearalenone) and to many other secondary metabolites produced by different species of Alternaria spp. (e.g., AAL toxins, alternariols, tenuazonic acid or 4Z-infectopyrone), Aspergillus flavus (e.g., kojic acid, cyclopiazonic acid or β-nitropropionic acid), Aspergillus fuminatus (e.g., gliotoxin, agroclavine, festuclavines or fumagillin), Penicillium roqueforti and P. paneum (e.g., mycophenolic acid, roquefortines, PR toxin or marcfortines) or Monascus ruber (citrinin and monacolins) could be mainly related to forage contamination. This review includes the knowledge of mycotoxin occurrence reported in the last 15 years, with special emphasis on mycotoxins detected in forages, and animal toxicological issues due to their ingestion. Strategies for preventing the problem of mycotoxin feed contamination under farm conditions are discussed.
Topics: Agriculture; Animal Feed; Animals; Food Contamination; Mycotoxins; Ruminants
PubMed: 26274974
DOI: 10.3390/toxins7083057 -
Chemical Science Mar 2016The individual steps of citrinin biosynthesis in M7 were determined by a combination of targeted gene knockout and heterologous gene expression in . The pathway...
The individual steps of citrinin biosynthesis in M7 were determined by a combination of targeted gene knockout and heterologous gene expression in . The pathway involves the synthesis of an unreduced trimethylated pentaketide by a non-reducing polyketide synthase (nrPKS) known as CitS. Reductive release yields the keto-aldehyde as the first enzyme-free intermediate. The nrPKS appears to be assisted by an as-yet cryptic hydrolysis step catalysed by CitA which was previously wrongly annotated as an oxidase. CitB is a non-heme iron oxidase which oxidises the 12-methyl of to an alcohol. Subsequent steps are catalysed by CitC which oxidises the 12-alcohol to an aldehyde and CitD which converts the 12-aldehyde to a carboxylic acid. Final reduction of C-3 by CitE yields citrinin. The pathway rules out alternatives involving intramolecular rearrangements, and fully defines the molecular steps for the first time and corrects previous errors in the literature. The activity of CitB links the pathway to fungal tropolone biosynthesis and the observation of aminated shunt products links the pathway to azaphilone biosynthesis. Production of citrinin by coordinated production of CitS + CitA-CitE in the heterologous host , in which each gene was driven by a constitutive promoter, was achieved in high yield.
PubMed: 29899939
DOI: 10.1039/c5sc04027b