A Novel Cellobiohydrolase I (CBHI) from Penicillium digitatum: Production, Purification, and Characterization.

A Novel Cellobiohydrolase I (CBHI) from Penicillium digitatum: Production, Purification, and Characterization. Appl Biochem Biotechnol. 2020 May 06;: Authors: Dos Santos FC, de Oliveira MAS, Seixas FAV, Barbosa-Tessmann IP Abstract A new cellulase producer strain of Penicillium digitatum (RV 06) was previously obtained from rotten maize grains. This work aim was to optimize the production and characterize this microorganism produced cellulase. A CMCase maximum production (1.6 U/mL) was obtained in stationary liquid culture, with an initial pH of 5.0, at 25 °C, with 1% lactose as carbon source, and cultured for 5 days. The produced enzyme was purified by ammonium sulfate precipitation and exclusion chromatography. The purified enzyme optimal temperature and pH were 60 °C and 5.2, respectively. The experimental Tm of thermal inactivation was 63.68 °C, and full activity was recovered after incubation of 7 h at 50 °C. The purified 74 kDa CMCase presented KM for CMC of 11.2 mg/mL, Vmax of 0.13 μmol/min, kcat of 52 s-1, and kcat/KM of 4.7 (mg/mL)-1 s-1. The purified enzyme had a high specificity for CMC and p-nitrophenyl cellobioside and released glucose and cellobiose as final products of the CMC hydrolysis. The enzyme trypsin digestion produced peptides whose masses were obtained by MALDI-TOF/TOF mass spectrometry, which was also used to obtain two peptide sequences. These peptide sequences and the mass peak profile retr...
Source: Applied Biochemistry and Biotechnology - Category: Biochemistry Authors: Tags: Appl Biochem Biotechnol Source Type: research