Precision Engineering of the Transcription Factor Cre1 in () for Efficient Cellulase Production in the Presence of Glucose.

In , carbon catabolite repression (CCR) significantly downregulates the transcription of cellulolytic enzymes, which is usually mediated by the zinc finger protein Cre1. It was found that there is a conserved region at the C-terminus of Cre1/CreA in several cellulase-producing fungi that contains up to three continuous S/T phosphorylation sites. Here, S387, S388, T389, and T390 at the C-terminus of Cre1 in were mutated to valine for mimicking an unphosphorylated state, thereby generating the transformants _Cre1, _Cre1, _Cre1, and _Cre1, respectively.

Redesigning transcription factor Cre1 for alleviating carbon catabolite repression in .

Carbon catabolite repression (CCR), which is mainly mediated by Cre1 and triggered by glucose, leads to a decrease in cellulase production in . Many studies have focused on modifying Cre1 for alleviating CCR. Based on the homologous alignment of CreA from wild-type 114-2 (Po-0) and cellulase hyperproducer JUA10-1(Po-1), we constructed a C-terminus substitution strain-Po-2-with decreased transcriptional levels of cellulase and enhanced CCR.

Rewiring central carbon metabolism for tyrosol and salidroside production in Saccharomyces cerevisiae.

Metabolic engineering of Saccharomyces cerevisiae for high-level production of aromatic chemicals has received increasing attention in recent years. Tyrosol production from glucose by S. cerevisiae is considered an environmentally sustainable and safe approach.

Identification and Characterization of an Efficient d-Xylose Transporter in .

d-Xylose is the most abundant hemicellulosic monomer on earth, but wild-type has very limited d-xylose uptake capacity. We conducted bioprospecting for new sugar transporters from the d-xylose-consuming filamentous fungus and identified three candidates belonging to the major facilitator superfamily. When they were expressed in yeast and assayed for d-xylose uptake, one of them, Xltr1p, had d-xylose transport activity that was more efficient than that of Gal2p, an endogenous yeast transporter.

Rational Engineering of Chorismate-Related Pathways in for Improving Tyrosol Production.

Tyrosol is extensively used in the pharmaceutical industry as an important natural product from plants. In this study, an exogenous pathway involved in catalyzing tyrosine to tyrosol was introduced into . Furthermore, The pyruvate decarboxylase gene was deleted to redirect the flux distribution at the pyruvate node, and a bifunctional NAD-dependent fused chorismate mutase/prephenate dehydrogenase from (TyrA) and its' tyrosine inhibition resistant mutant (TyrA) were heterologously expression in to tuning up the chorismate metabolism effectively directed the metabolic flux toward tyrosol production.

Identification of a thermostable fungal lytic polysaccharide monooxygenase and evaluation of its effect on lignocellulosic degradation.

Auxiliary activity family 9 (AA9) lytic polysaccharide monooxygenases (LPMOs) show significant synergism with cellulase in cellulose degradation. In recent years, there have been many reports on AA9 LPMOs; however, the identification of efficient and thermostable AA9 LPMOs with broad potential for industrial applications remains necessary. In this study, a new AA9 LPMO from Talaromyces cellulolyticus, named TcAA9A, was identified.

Factors involved in the response to change of agitation rate during cellulase production from Penicillium decumbens JUA10-1.

Improvement of agitation is a commonly used approach for the optimization of fermentation processes. In this report, the response to improving agitation rate from 150 to 250 rpm on cellulase production from Penicillium decumbens JUA10-1 was investigated. It was shown that the production of all the major components of the cellulase mixture increased following improved agitation.

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time.