Carbon source and pH-dependent transcriptional regulation of cellulase genes of Humicola grisea var. thermoidea grown on sugarcane bagasse

Mello-de-Sousa, Thiago M.; Silva-Pereira, Ildinete; Poças-Fonseca, Marcio José

doi:10.1016/j.enzmictec.2010.08.007

Cited by 24 publications

(29 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The promoter of pacC contains PacC binding sites confirming that PacC autoregulates, with higher abundance of pacC transcripts found at alkaline pH [111,113]. A study using the thermophilic ascomycete Humicola grisea investigated the pH-dependent transcriptional regulation of CAZymeencoding genes with sugarcane bagasse as the substrate [113]. Here the transcript level of cbh1.1, cbh2.2, egl1, egl2, bgl4 and xyn1 increased at alkaline pH (pH8) and Mello-de-Sousa et al [113] identified one or multiple PacC binding sites in the promoters of these genes.…”

Section: Ph Regulation Of Cazyme-encoding Gene Expressionmentioning

confidence: 93%

“…A study using the thermophilic ascomycete Humicola grisea investigated the pH-dependent transcriptional regulation of CAZymeencoding genes with sugarcane bagasse as the substrate [113]. Here the transcript level of cbh1.1, cbh2.2, egl1, egl2, bgl4 and xyn1 increased at alkaline pH (pH8) and Mello-de-Sousa et al [113] identified one or multiple PacC binding sites in the promoters of these genes. Other CAZyme-encoding genes regulated by PacC include the A. nidulans xylanase genes (xlnA and xlnB) [114] and alpha-Larabinofuranosidase gene (abfB) [115].…”

Section: Ph Regulation Of Cazyme-encoding Gene Expressionmentioning

confidence: 99%

Section: Ph Regulation Of Cazyme-encoding Gene Expressionmentioning

confidence: 99%

See 2 more Smart Citations

Transcriptional Regulation and Responses in Filamentous Fungi Exposed to Lignocellulose

2015

Mycology: Current and Future Developments

View full text Add to dashboard Cite

Biofuels derived from lignocellulose are attractive alternative fuels but their production suffers from a costly and inefficient saccharification step that uses fungal enzymes. One route to improve this efficiency is to understand better the transcriptional regulation and responses of filamentous fungi to lignocellulose. Sensing and initial contact of the fungus with lignocellulose is an important aspect. Differences and similarities in the responses of fungi to different lignocellulosic substrates can partly be explained with existing understanding of several key regulators and their mode of action, as will be demonstrated for Trichoderma reesei, Neurospora crassa and Aspergillus spp. The regulation of genes encoding Carbohydrate Active enZymes (CAZymes) is influenced by the presence of carbohydrate monomers and short oligosaccharides, as well as the external stimuli of pH and light. We explore several important aspects of the response to lignocellulose that are not related to genes encoding CAZymes, namely the regulation of transporters, accessory proteins and stress responses. The regulation of gene expression is examined from the perspective of mixed cultures and models are presented for the nature of the transcriptional basis for any beneficial effects of such mixed cultures. Various applications in biofuel technology are based on manipulating transcriptional regulation and learning from fungal responses to lignocelluloses. Here we critically access the application of fungal transcriptional responses to industrial saccharification reactions. As part of this chapter, selected regulatory mechanisms are also explored in more detail.

show abstract

Section: Ph Regulation Of Cazyme-encoding Gene Expressionmentioning

confidence: 93%

Section: Ph Regulation Of Cazyme-encoding Gene Expressionmentioning

confidence: 99%

Section: Ph Regulation Of Cazyme-encoding Gene Expressionmentioning

confidence: 99%

See 1 more Smart Citation

Transcriptional Regulation and Responses in Filamentous Fungi Exposed to Lignocellulose

2015

Mycology: Current and Future Developments

View full text Add to dashboard Cite

show abstract

“…Subsequently, it was shown that H. grisea CBH genes are differentially expressed according to the carbon source in which the fungus is grown (Poças-Fonseca et al 2000). Mello-de-Sousa et al (2011) have recently demonstrated that H. grisea cbh1.2 gene expression, as well as the expression of several other genes of this fungal cellulolytic system, is regulated through a crosstalk between carbon source-and pH-dependent regulatory mechanisms.…”

Section: Introductionmentioning

confidence: 98%

“…thermoidea is an efficient producer of several thermostable hydrolases, thus presenting potential for biotechnological applications as recently reviewed by Mello-de-Sousa et al (2011). When cultivated on lignocellulosic materials such as sugarcane bagasse, H. grisea major secreted protein is cellobiohydrolase I.2 (CBH1.2) of about 47 kDa (De Paula et al 2003).…”

Section: Introductionmentioning

confidence: 99%

An alkaline thermostable recombinant Humicola grisea var. thermoidea cellobiohydrolase presents bifunctional (endo/exoglucanase) activity on cellulosic substrates

Oliveira

Ulhôa

Silveira

et al. 2012

World J Microbiol Biotechnol

View full text Add to dashboard Cite

Humicola grisea var. thermoidea is a deuteromycete which secretes a large spectrum of hydrolytic enzymes when grown on lignocellulosic residues. This study focused on the heterologous expression and recombinant enzyme analysis of the major secreted cellulase when the fungus is grown on sugarcane bagasse as the sole carbon source. Cellobiohydrolase 1.2 (CBH 1.2) cDNA was cloned in Pichia pastoris under control of the AOX1 promoter. Recombinant protein (rCBH1.2) was efficiently produced and secreted as a functional enzyme, presenting a molecular mass of 47 kDa. Maximum enzyme production was achieved at 96 h, in culture medium supplemented with 1.34 % urea and 1 % yeast extract and upon induction with 1 % methanol. Recombinant enzyme exhibited optimum activity at 60 °C and pH 8, and presented a remarkable thermostability, particularly at alkaline pH. Activity was evaluated on different cellulosic substrates (carboxymethyl cellulose, filter paper, microcrystalline cellulose and 4-para-nitrophenyl β-D-glucopyranoside). Interestingly, rCBH1.2 presented both exoglucanase and endoglucanase activities and mechanical agitation increased substrate hydrolysis. Results indicate that rCBH1.2 is a potential biocatalyst for applications in the textile industry or detergent formulation.

show abstract

Microbial Metabolic Pathways in the Production of Valued‐added Products

Pereira

Finco

Letti

et al. 2018

Microbial Sensing in Fermentation

View full text Add to dashboard Cite

Carbon source and pH-dependent transcriptional regulation of cellulase genes of Humicola grisea var. thermoidea grown on sugarcane bagasse

Cited by 24 publications

References 48 publications

Transcriptional Regulation and Responses in Filamentous Fungi Exposed to Lignocellulose

Transcriptional Regulation and Responses in Filamentous Fungi Exposed to Lignocellulose

An alkaline thermostable recombinant Humicola grisea var. thermoidea cellobiohydrolase presents bifunctional (endo/exoglucanase) activity on cellulosic substrates

Microbial Metabolic Pathways in the Production of Valued‐added Products

Contact Info

Product

Resources

About