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). one PL3 and two GH28). Pectin lyases are most active at neutral to alkaline pH whereas GH28 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 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 Table 7). 14 Secretomes and exo-proteomes 15In addition to extracellular CAZymes involved in digestion of polysaccharide nutrients, the 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. Fig. 8 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. 30terrestris, but were unable to find differences that can convincingly be interpreted as the Fig. 9) Thermophilic fungi are ubiquitous organisms commonly found in decomposing organic matter. 25The biotechnological utility of these fungi has been recognized for many years. enzymes from the thermophiles exhibit higher hydrolytic capacity than their counterparts from 6 mesophiles at temperatures ranging from 30 °C to 60 °C (Fig. 3). One explanation is that the 7 enzymes from the thermophiles possess higher specific activity toward lignocellulosic biomass.8

Fungal communities in pressmud composting harbour beneficial and detrimental fungi for human welfare

“…Furthermore, the genomic study of M. thermophila and Thielavia terrestris suggested that they were capable of hydrolyzing all the major polysaccharides present in the plant biomass (Berka et al, 2011). M. thermophila has the largest number of hemicellulolytic enzymes and accessory enzymes observed to date; it contains eight genes encoding endoglucanases, seven cellobiohydrolases, nine b-glucosidases, 25 lytic polysaccharide monooxygenases (LPMOs), and other enzymes of the group including xylanase, arabinases, mannanase, pectinases and esterases (Karnaouri et al, 2014).…”

A family of starch-active polysaccharide monooxygenases

“…copper enzymes | oxygen activation | CBM20 P olysaccharide monooxygenases (PMOs) are enzymes secreted by a variety of fungal and bacterial species (1)(2)(3)(4)(5). They have recently been found to oxidatively degrade chitin (6)(7)(8) and cellulose (8)(9)(10)(11)(12)(13)(14).…”

Caldicellulosiruptor Core and Pangenomes Reveal Determinants for Noncellulosomal Thermophilic Deconstruction of Plant Biomass

“…As members of the phylum Firmicutes, Caldicellulosiruptor species are distinct from the thermophilic, anaerobic clostridia in that they secrete free and S-layer-bound cellulases and hemicellulases (9,23,24,43,44,58,60,63,75,84,89,90) that are not assembled into cellulosomes (85,89). In this respect, their strategy for crystalline cellulose deconstruction is similar to that for noncellulosomal biomass-degrading aerobic fungi, such as Trichoderma reesei, (54), the thermophilic fungi Myceliophthora thermophila and Thielavia terrestris (7), or the thermophilic aerobe Thermobifida fusca (48).…”