Comparative genomic analysis of the thermophilic biomass-degrading fungi Myceliophthora thermophila and Thielavia terrestris

Abstract

Thermostable enzymes and thermophilic cell factories may afford economic advantages inFurthermore, we present evidence suggesting that aside from representing a potential 9 reservoir of thermostable enzymes, thermophilic fungi are amenable to manipulation using 10 classical and molecular genetics. 11Rapid, efficient and robust enzymatic degradation of biomass-derived polysaccharides is 12 currently a major challenge for biofuel production. A prerequisite is the availability of enzymes 13 that hydrolyze cellulose, hemicellulose and other polysaccharides into fermentable sugars at 14 conditions suitable for industrial use. The best studied and most widely used cellulases and to overcome these obstacles is to raise the reaction temperature, thereby increasing hydrolytic 20 rates and reducing contamination risks. AT-rich repetitive regions (Fig. 1) To examine the strategy used by these thermophiles for decomposition of plant cell wall 9 polysaccharides, we used RNA-Seq to compare transcript profiles during growth on barley straw 10 or alfalfa straw to growth on glucose. Alfalfa was chosen to represent dicotyledonous plants, 11 whereas barley was used to represent monocotyledon plants. The major difference between these 12 materials is that the carbohydrates from barley cell wall are mainly cellulose and hemicellulose 13 with a negligible amount of pectin 11 , whereas alfalfa cell wall contains pectin and xylan in 14 roughly similar proportions, each consisting of 15-20% of total carbohydrates 12, . 15 We observed notable differences between the transcriptional profiles of genes encoding conditions. For example, the orthologs in Clades A, B, E, G and P of GH61 are upregulated 8 under growth in complex substrates for both thermophiles (Fig. 2b). An even more striking 9 correlation between transcript levels and orthologs is evident for the GH6 and GH7 cellulases 10 ( Supplementary Fig. 7) where the transcript profiles for the orthologs of the two organisms are Table 7). Thermophilic fungi are major components of the microflora in self-heating composts. They 9 break down cellulose at a faster rate than prodigious, mesophilic cellulase producers such as T. Tables 11-14). On the basis of 24 our comparative analyses of the genomes from two thermophilic fungi, we conclude that their 25 nucleotide and protein features are different from those observed in thermophilic prokaryotes. 26 We also investigated the possibility that thermophilic fungi possess major differences in 27 processes mediating thermophily including heat shock, oxidative stress, membrane biosynthesis, 28 chromatin structure and modification, and fungal cell wall metabolism. We compared the 29 proteins predicted to be involved in these processes in C. globosum, M. thermophila and T. 30 terrestris, but were unable to find differences that can convincingly be interpreted as the Fig. 9). Within the Sordiariales, thermophily 6 is restricted to subgroups of the family Chaetomiaceae. Among fungi more broadly, thermophily 7 also exists in the Zygomycota, but it ...

Evidence for Transceptor Function of Cellodextrin Transporters in Neurospora crassa

“…7) (43, 44). Given the widespread presence of cellodextrin transporters in diverse fungi (22), such signaling networks may also function in a wide range of filamentous fungi of ecological or industrial interest for biofuels applications, such as the related thermotolerant fungus Myceliophthora thermophila (45,46).…”

Enhancing xylanase production in the thermophilic fungus Myceliophthora thermophila by homologous overexpression of Mtxyr1

“…Myceliophthora thermophila is a mild thermophilic fungus which can grow in temperatures between 25 and 55 °C. The genome of M. thermophila has been analyzed [6]. Genomic data analysis reveals that this fungus has the potential to produce more than 200 kinds of glucoside hydrolases and a large number of accessory proteins related with cellulase and hemicellulase degradation and has fine application prospects in the biorefinery industry [12,14].…”

WITHDRAWN: Identification of an endogenous redox partner for lytic polysaccharide monooxygenase-based oxidative cleavage of polysaccharides

“…As earlier studies have shown that the genomes of biomass degrading fungi encode a plethora of LPMOs, several of which are upregulated when grown on biomass substrates (20,22,(25)(26)(27). We aimed at identification of cellulose inducible LPMOs from B. cinerea.…”