MtTRC-1, a Novel Transcription Factor, Regulates Cellulase Production via Directly Modulating the Genes Expression of the Mthac-1 and Mtcbh-1 in Myceliophthora Thermophila
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ABSTRACT:
ORGANISM(S): Thermothelomyces thermophilus
PROVIDER: GSE205182 | GEO | 2022/09/21
REPOSITORIES: GEO
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Project description:Thermophilic fungus Myceliophthora thermophila with great capacity for polysaccharides degradation is attractive to be engineered into a cell factory to produce chemicals and biofuels directly from renewable polysaccharides such as starch. Understanding the molecular mechanism of starch degradation of the fungi would be helpful. To date, there has been no transcriptome analysis on starch in thermophilic fungi. In this study, we performed the transcriptomic profile of M. thermophila responding to soluble starch, and a 342-gene set was identified as “starch regulon”, including the major amylolytic enzyme (Mycth_72393), which was verified thereafter as the most important such hydrolase for starch degradation in this fungus. Moreover, the function of key amylolytic enzyme regulator AmyR in M. thermophila was evaluated by analyzing the performance of its deletion mutant using our CRISPR/Cas9 system, which showed significantly decreased amylase activity and poor growth on starch. Additionally, deletion of amyR led to resistance to carbon catabolite repression (CCR) and enhanced cellulases production. Our study provides an insight into understanding the molecular basis of starch degradation in this thermophilic fungus, and will accelerate the fungal strain rational engineering for starch-based biochemical production.
2021-02-02 | GSE110062 | GEO
Project description:BackgroundFilamentous fungi with the ability to use complex carbon sources has been developed as platforms for biochemicals production. Myceliophthora thermophila has been developed as the cell factory to produce lignocellulolytic enzymes and plant biomass-based biofuels and biochemicals in biorefinery. However, low fungal growth rate and cellulose utilization efficiency are significant barriers to the satisfactory yield and productivity of target products, which needs our further exploration and improvement.ResultsIn this study, we comprehensively explored the roles of the putative methyltransferase LaeA in regulating mycelium growth, sugar consumption, and cellulases expression. Deletion of laeA in thermophile fungus Myceliophthora thermophila enhanced mycelium growth and glucose consumption significantly. Further exploration of LaeA regulatory network indicated that multiple growth regulatory factors (GRF) Cre-1, Grf-1, Grf-2, and Grf-3, which act as negative repressors of carbon metabolism, were regulated by LaeA in this fungus. We also determined that phosphoenolpyruvate carboxykinase (PCK) is the core node of the metabolic network related to fungal vegetative growth, of which enhancement partially contributed to the elevated sugar consumption and fungal growth of mutant ΔlaeA. Noteworthily, LaeA participated in regulating the expression of cellulase genes and their transcription regulator. ΔlaeA exhibited 30.6% and 5.5% increases in the peak values of extracellular protein and endo-glucanase activity, respectively, as compared to the WT strain. Furthermore, the global histone methylation assays indicated that LaeA is associated with modulating H3K9 methylation levels. The normal function of LaeA on regulating fungal physiology is dependent on methyltransferase activity.ConclusionsThe research presented in this study clarified the function and elucidated the regulatory network of LaeA in the regulation of fungal growth and cellulase production, which will significantly deepen our understanding about the regulation mechanism of LaeA in filamentous fungi and provides the new strategy for improvement the fermentation properties of industrial fungal strain by metabolic engineering.
| S-EPMC10071736 | biostudies-literature
Project description:The thermophilic filamentous fungi Myceliophthora thermophila (Sporotrichum thermophile) has an ability to decompose cellulolytic biomass. To identify the genes and proteins involved in this process, we explored the transcriptomes of M. thermophila grown at 45 °C on different agricultural straws (oat, triticale, canola, flax straws).
2016-11-28 | GSE57235 | GEO
Project description:Myceliophthora thermophila is a thermophilic fungus with great biotechnological characteristics for industrial applications, which can degrade and utilize all major polysaccharides in plant biomass. Nowadays, it has been developing into a platform for production of enzyme, commodity chemicals and biofuels. Therefore, an accurate genome-scale metabolic model would be an accelerator for this fungus becoming a universal chassis for biomanufacturing. Here we present a genome-scale metabolic model for M. thermophila constructed using an auto-generating pipeline with consequent thorough manual curation. Temperature plays a basic and critical role for the microbe growth. we are particularly interested in the genome wide response at metabolic layer of M. thermophilia as it is a thermophlic fungus. To study the effects of temperature on metabolic characteristics of M. thermophila growth, the fungus was cultivated under different temperature. The metabolic rearrangement predicted using context-specific GEMs integrating transcriptome data.The developed model provides new insights into thermophilic fungi metabolism and highlights model-driven strain design to improve biotechnological applications of this thermophilic lignocellulosic fungus.
2022-09-14 | GSE184074 | GEO
Project description:Myceliophthora thermophila (ATCC 42464) is a thermophilic fungus that produces cellulolytic enzymes with high thermal stability. Unlike its mesophile counterparts, study on gene expression regulation of cellulolytic enzymes in M. thermophila is inadequate. This work identified the function of MHR1, a putative transcription regulator of cellulolytic enzymes in M. thermophila that was found through RNA-Seq based gene expression profile analysis. RNA interference was used to study the role of MHR1. A recombinant plasmid, pUC19-Ppdc-mhr1-Tpdc, which contained the RNAi sequence for mhr1 was constructed and transformed into M. thermophila. One of the transformants, MtR5, in which the RNA interference efficiency was the highest, was used for the following studies. In the mhr1-silenced strain MtR5, the filter paper hydrolyzing activity was 1.33-fold; β-1, 4-endoglucanase activity was 1.65-fold; and xylanase activity was 1.48-fold higher than those of the parental strain after induction, respectively, by wheat straw powder. qRT-PCR showed that gene expression of cbh1, cbh2, egl3 and xyr1 were 9.56-, 37.36-, 56.14- and 28.30-fold higher in MtR5 than in wild type, respectively. Our findings suggest that the transcription factor MHR1 of M. thermophila can repress cellulase and xylanase activities. Silenced mhr1 results in increased expression not only of the main cellulase genes, but also of the positive regulatory gene xyr1. This work is relevant to the development of M. thermophila as an industrial production host for cellulolytic and hemicellulolytic enzymes, which could be used to degrade a wide range of different biomass, converting lignocellulosic feedstock into sugar precursors for biofuels.
| S-EPMC5835483 | biostudies-literature
Project description:Fungi secrete many different enzymes to deconstruct lignocellulosic biomass, including several families of hydrolases, oxidative enzymes, and many uncharacterized proteins. Here we describe the isolation, characterization, and primary sequence analysis of an extracellular aldonolactonase from the thermophilic fungus Myceliophthora thermophila (synonym Sporotrichum thermophile). The lactonase is a 48-kDa glycoprotein with a broad pH optimum. The enzyme catalyzes the hydrolysis of glucono-δ-lactone and cellobiono-δ-lactone with an apparent second-order rate constant, k(cat)/K(m), of ~1 × 10(6) M(-1) s(-1) at pH 5.0 and 25°C but is unable to hydrolyze xylono-γ-lactone or arabino-γ-lactone. Sequence analyses of the lactonase show that it has distant homology to cis-carboxy-muconate lactonizing enzymes (CMLE) as well as 6-phosphogluconolactonases present in some bacteria. The M. thermophila genome contains two predicted extracellular lactonase genes, and expression of both genes is induced by the presence of pure cellulose. Homologues of the M. thermophila lactonase, which are also predicted to be extracellular, are present in nearly all known cellulolytic ascomycetes.
| S-EPMC3020561 | biostudies-literature
Project description:Transcriptional landscape of MyceliopTranscriptional profiling of Myceliophthora thermophila on galactose and metabolic engineering for improved galactose utilization thora thermophila responding to soluble starch and the role of regulator AmyR on polysaccharide degradation Efficient biological conversion of all sugars from lignocellulosic biomass is necessary for cost-effective production of biofuels and commodity chemicals. Galactose is the next most abundant sugar in many hemicelluloses and it will be important to capture this carbon for an efficient bioconversion process of plant biomass. Thermophilic fugus Myceliophthora thermophila has been used as cell factory to produce biochemicals directly from renewable polysaccharides. This study determined the transcriptomic profiles of M. thermophila responding to galactose and identified the gene involved in the oxido-reductive pathway for galactose degradation, of which hexokinase might be the rate-limiting enzyme in this thermophilic fungus. Galactokinase was necessary for high induction of galactose transporter and disruption of galK resulted in decreased galactose utilization. Both of galactokinase deletion and sugar transporter overexpression could further activate the oxido-reductive pathway and led to improved galactose utilization. In addition, disruption of the Leloir pathway brought about reduced tolerance to cell wall perturbation, oxidative stress and high osmolality. In order to accelerate galactose consumption, the third galactose-degradation pathway- De Ley-Doudoroff pathway was successfully integrated into M. thermophila and the consumption rate of galactose was increased by 57%. This study will be benefit for the rational design of fungal strains to produce biofuels and biochemical from plant biomass, especially, marine plant biomass with the abundant of galactose, such as red seaweed and molasses.
2021-02-05 | GSE165516 | GEO
Project description:Purpose: To explore the pathway cross-talk of endoplasmic reticulum (ER) stress response and cellulases synthesis in Neurospora crassa. Methods: To identify ER stress response targets(ESRTs), conidial suspensions of WT were obtained and 1 x 10^6 cells/ml incubated in cellulases induction medium (1x vogel’s salts , 1% w/v crystalline cellulose (Avicel PH-101; Sigma-Aldrich), 0.2% w/v NH4NO3 ,pH 7.0 )for 36 hours (25ºC, 200 rpm, constant light) followed by the addition of dithiothreitol (DTT, final concentration of 0.1mM for mild stress level while 5mM for acute stress level) or tunicamycin (TM, final concentration of 5ug/mL for mild stress level while 40ug/mL for acute stress level) and growth for 1 more hour.To identify which ESRTs regulated by IRE-1/Hac-1 mediated UPR pathway,conidial suspensions of the Ire-1 and Hac-1 KO mutants as well as their parental strains (FGSC#2489 and FGSC#9720, respectively) were obtained and 1 x 10^6 cells/ml incubated in minimal medium containing 2% sucrose for 16 hours, then young hyphae was harvested and transferred into cellulases induction medium as mentioned above culture for 4 hours followed by the addition of DTT (final concentration of 5mM)(or H2O as mock)and growth for 1 more hour.For Hac-1 KO mutant and FGSC#9720,cultures were plus with final concentration of 100ug/ml L-histidine.To explore the function of transcription factors RES-1, RES-2 and RRG-2 in response to ER stress and cellulases synthesis, each conidial suspension of the three strains was obtained and 1 x 10^6 cells/ml incubated in cellulases induction medium for 36 hours followed by the addition of dithiothreitol (DTT, final concentration of 5mM ) (or H2O as mock)and growth for 1 more hour.Cells were harvested by vacuum filtration with Whatman filter paper, frozen immediately in liquid nitrogen. Total RNA was isolated by the Trizol-Phenol-Chloroform method. An additional clean-up including the on-column DNase I treatment was performed by using the RNeasy mini kit (Qiagen).The thirteen 49-nt single-end RNA-seq libraries were generated commercially at Beijing Genomics Institute (BGI, Shenzhen, China) while eight 90-nt paired-end RNA-seq libraries were generated at Genewiz Co. Ltd (Suzhou) by using the HiSeq™ platform.Sequencing data was handled essentially with Bowtie2, Tophat2, NOIseq. Expression levels are presented as Reads Per Kilobase of transcript per Million mapped reads (RPKM). Results: Transcriptional profiling of ER stress during cellulase synthesis in N.crassa uncovered a set of 766 genes was identified as the ER stress response target genes (ESRTs). Of these 766 genes, canonical UPR components IRE-1 and HAC-1 regulated 223 and 186 genes, respectively. In screening 527 available ESRT mutants, we found 249 that exhibited DTT sensibility, including 100 targets with unknown function. Disruption of ire-1 or hac-1 renders N. crassa cells seriously deficient in cellulase secretion. Further investigation of the 39 transcription factors (TFs) that showed differential expression under ER stress uncovered three novel TFs (RES-1, RES-2, RRG-2) that markedly affected cellulase secretion. Conclusions: Here, we determined the transcriptional scope of the ER stress response during lignocellulase synthesis in the model cellulolytic fungus N. crassa. Through genome-wide mutant screening and analysis, dozens of novel genes were discovered to be involved in the process. The findings of this work will be useful for strain improvement to facilitate lignocellulase and biomass-based chemical production.
2015-03-25 | GSE61949 | GEO
Project description:The xylanases with high specific activity and resistance to harsh conditions are of high practical value for biomass utilization. In the present study, two new GH11 xylanase genes, MYCTH_56237 and MYCTH_49824, have been cloned from thermophilic fungus Myceliophthora thermophila and expressed in Pichia pastoris. The specific activities of purified xylanases reach approximately 1,533.7 and 1,412.5 U/mg, respectively. Based on multiple template-based homology modeling, the structures of their catalytic domains are predicted. Enzyme activity was more effective in 7.5 L fermentor, yielding 2,010.4 and 2,004.2 U/mL, respectively. Both enzymes exhibit optimal activity at 60°C with pH of 6.0 and 7.0, respectively. Their activities are not affected by EDTA and an array of metal ions. The kinetic constants have been determined for MYCTH_56237 (Km = 8.80 mg/mL, Vmax = 2,380 U/mg) and MYCTH_49824 (Km = 5.67 mg/mL, Vmax = 1,750 U/mg). More importantly, both xylanases significantly cooperate with the commercial cellulase Celluclast 1.5 L in terms of the saccharification efficiency. All these biochemical properties of the xylanases offer practical potential for future applications.
| S-EPMC5817056 | biostudies-literature
Project description:Plant biomass holds tremendous potential as a renewable feedstock in the production of biofuels and biochemicals. The effective co-utilization of the main components cellulose and hemicellulose in plant lignocellulose is critical to the economic viability of lignocellulosic biorefineries. Here, we found that the thermophilic cellulolytic fungi Myceliophthora thermophila can utilize cellulose and hemicellulose synchronously. To investigate the underlying molecular mechanisms, we firstly checked the soluble carbohydrate of the culture using plant biomass (corncob) as sole carbon source and revealed the presence of various oligosaccharides including cellodextrin and xylodextrin, both intracellularly and extracellularly in the cultures, in addition to glucose or xylose. Based on these, intracellular oligosaccharide metabolism was proposed and confirmed by identification of cellodextrin and xylodextrin metabolism pathway. Furthermore, sugar consumption assay showed that contrasting with synchronous utilization of mixed cello-/xylo-dextrin, the inhibition effect of glucose for the metabolism of xylose and cello-/xylo-dextrin exists in this fungus, suggesting Carbon Catabolite Repression (CCR) is largely avoided at the form of oligosaccharides. Transporter MtCDT-2 showing preference to xylobiose and the tolerance of cellobiose inhibition also helps to bypass metabolic inhibition. Finally, the expression of cellulase and hemicellulase genes, were found orthogonal induction by cellobiose/Avicel and xylobiose/xylan, which conferred the ability of the strain to synchronously utilize cellulose and hemicellulose. Taken together, the orthogonal oligosaccharide catabolic pathway in this fungus establishes the molecular basis for the synchronous utilization of cellulose and hemicellulose, which sheds new light on understanding the plant biomass degradation by fungi and provides alternative paradigm for development of lignocellulose biorefinery such as consolidated bioprocessing in the future.
2024-02-28 | GSE222371 | GEO