Metabolic Engineering of Trichoderma reesei for l-Malic Acid Production

Abstract

L-Malic acid has various applications in the chemical and food industries. The filamentous fungus Trichoderma reesei is known to be an efficient enzyme producer. Here, through metabolic engineering, T. reesei was constructed for the first time as an excellent cell factory for L-malic acid production. The heterologous overexpression of genes encoding the C4-dicarboxylate transporter from Aspergillus oryzae and Schizosaccharomyces pombe initiated L-malic acid production. The overexpression of pyruvate carboxylase from A. oryzae in the reductive tricarboxylic acid pathway further increased both the titer and yield of L-malic acid, resulting in the highest titer reported in a shake-flask culture. Furthermore, the deletion of malate thiokinase blocked L-malic acid degradation. Finally, the engineered T. reesei strain produced 220.5 g/L of L-malic acid in a 5 L fed-batch culture (productivity of 1.15 g/L/h). A T. reesei cell factory was created for the efficient production of L-malic acid.

Simultaneous Production of Cellulase and β-Carotene in the Filamentous Fungus Trichoderma reesei

“…These results are consistent with those of previous studies that T. reesei can tolerate a high glucose environment, which facilitates the production of primary metabolites, while a moderate nitrogen source is suitable for the accumulation of terpenoids such as β-carotene. , …”

“…We found that providing a high glucose concentration and a modest tryptone concentration in the medium is conducive to enhancing the production and proportion of β-carotene in the modified strains. These results are consistent with those of previous studies that T. reesei can tolerate a high glucose environment, which facilitates the production of primary metabolites, 48 while a moderate nitrogen source is suitable for the accumulation of terpenoids such as β-carotene. 17,28 3.4.…”

High-Density Au Anchored to Ti3C2-Based Colorimetric-Fluorescence Dual-Mode Lateral Flow Immunoassay for All-Domain-Enhanced Performance and Signal Intercalibration

“…The quenching ability of the fluorescence quencher is one of the chief parameters determining the sensitivity of fluorescence quenching LFIA. 25 An equal volume of Ti 3 C 2 @Au or AuNP was mixed with 0.04 mg/mL TRFM for quenching and the fluorescence quenching efficiency was determined by the formula 26 :…”

Enhancing l-Malic Acid Production in Aspergillus niger via Natural Activation of sthA Gene Expression

“…Employing the microbial reductive TCA (rTCA) pathway under aerobic conditions essentially entails competition with the tricarboxylic acid (TCA) cycle for pyruvic acid. Researchers have explored enhancing the rTCA pathway by overexpressing Pyc and Mdh using different constitutive promoters in various microorganisms. ,,,, However, simply increasing the intracellular enzyme content represents a basic strategy. Reaching the theoretical limit of enzyme-catalyzed reactions frequently demands a sufficient supply of cofactors, encompassing biotin, FAD­(H2), NAD­(H), NADP­(H), and metal ions. − These cofactors perform specific functions, including activation, hydrogen transfer, electron transfer, and chemical group transfer.…”

“…Researchers have explored enhancing the rTCA pathway by overexpressing Pyc and Mdh using different constitutive promoters in various microorganisms. 10,11,17,22,23 However, simply increasing the intracellular enzyme content represents a basic strategy. Reaching the theoretical limit of enzyme-catalyzed reactions frequently demands a sufficient supply of cofactors, encompassing biotin, FAD(H2), NAD(H), NADP(H), and metal ions.…”