INFLUENCE OF THE TACA TRANSCRIPTION FACTOR KNOCKOUT ON THE TRANSCRIPTION AND EXPRESSION OF THE CBHI GENE IN THE PENICILLIUM VERRUCULOSUM STRAIN

Abstract

The tacA gene, encoding the TacA repressor protein, was cloned by “walking the uncloned DNA” method from the genomic DNA of the fungus Penicillium verruculosum B1-221-151. Knockout of the tacA and niaD genes by the CRIS-PR/CAS9 led to the production of a new host strain P. verruculosum ΔniaDΔtacA, characterized by a higher rate of extracellular protein biosynthesis. Analysis of the transcription and expression of the cbhI gene in the original P. verruculosum B1-221-151 strain and in the P. verruculosum ΔniaDΔtacA strain showed a sharp increase in the level of cbhI gene transcription 2 h after the start of induction with cellobiose, cellotriose, gentiobiose, and a mixture of di- and trisaccharides in comparison with the transcription of the cbhI gene in the original strain. The speci c activity of cellobiohydrolase I, the main enzyme of the cellulolytic complex of the fungus P. verruculosum, by 96 h of fermentation of the ΔtacA strain increased 3 times compared to the original strain.