Heterologous Expression and Characterization of a Novel Exo-Polygalacturonase from Aspergillus fumigatus Af293 and Its Application in Juice Extraction.
J Microbiol Biotechnol
; 33(4): 533-542, 2023 Apr 28.
Article
em En
| MEDLINE
| ID: mdl-36788465
ABSTRACT
Exo-polygalacturonase (exo-PG) hydrolyzes pectin acids and liberates mono-galacturonate, which plays an important role in juice extraction, and has rarely been reported. Exo-PG (AfumExoPG28A) from Aspergillus fumigatus belongs to the glycoside hydrolase 28 family. In this study, its gene was cloned and the protein was expressed and secreted in Pichia pastoris with a maximal activity of 4.44 U/ml. The optimal temperature and pH of AfumExoPG28A were 55°C and 4.0, respectively. The enzyme exhibited activity over almost the entire acidic pH range (>20.0% activity at pH 2.5-6.5) and remained stable at pH 2.5-10.0 for 24 h. The Km and Vmax values of AfumExoPG28A were calculated by the substrate of polygalacturonic acid as 25.4 mg/ml and 23.6 U/mg, respectively. Addition of AfumExoPG28A (0.8 U/mg) increased the light transmittance and juice yield of plantain pulp by 11.7% and 9%, respectively. Combining AfumExoPG28A (0.8 U/mg) with an endo-PG (0.8 U/mg) from our laboratory, the enzymes increased the light transmittance and juice yield of plantain pulp by 45.7% and 10%, respectively. Thus, the enzyme's potential value in juice production was revealed by the remarkable acidic properties and catalytic activity in fruit pulp.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poligalacturonase
/
Aspergillus fumigatus
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article