title: Enhancement of nuclease P1 production by Penicillium citrinum YL104 immobilized on activated carbon filter sponge.
abstract: The efficiency of current methods for industrial production of the enzyme nuclease P1 is limited. In this study, we sought to improve fermentation methods for the production of nuclease P1. An immobilized fermentation system using an activated carbon filter sponge as a carrier was used for the production of nuclease P1. In an airlift internal loop reactor (ALR), the fermentation performance of three different fermentation modes, including free-cell fermentation, repeated-batch fermentation, and semi-continuous immobilized fermentation, were compared. The fermentation kinetics in the fermentation broth of the three fermentation modes, including dissolved oxygen (DO), pH value, cell concentration, residual sugar concentration, and enzyme activity, were tested. The productivity of semi-continuous immobilized fermentation reached 8.76 U/mL/h, which was 33.3 and 80.2% higher than that of repeated-batch fermentation and free-cell fermentation, respectively. The sugar consumption of free-cell, repeated-batch, and semi-continuous immobilized fermentations was 41.2, 30.8, and 25.9 g/L, respectively. These results showed that immobilized-cell fermentation by using Penicillium citrinum with activated carbon filter sponge in an ALR was advantageous for nuclease P1 production, especially in the semi-continuous immobilized fermentation mode. In spite of the significant improvement in nuclease P1 production in semi-continuous immobilized fermentation mode, the specific activity of nuclease P1 was almost equal among the three fermentation modes.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, 210009, People's Republic of China.
authors.forename: Nan
authors.initials: N
authors.lastname: Zhao
authors.forename: Hengfei
authors.initials: H
authors.lastname: Ren
authors.forename: Zhenjian
authors.initials: Z
authors.lastname: Li
authors.forename: Ting
authors.initials: T
authors.lastname: Zhao
authors.forename: Xinchi
authors.initials: X
authors.lastname: Shi
authors.forename: Hao
authors.initials: H
authors.lastname: Cheng
authors.forename: Wei
authors.initials: W
authors.lastname: Zhuang
authors.forename: Yong
authors.initials: Y
authors.lastname: Chen
authors.forename: Hanjie
authors.initials: H
authors.lastname: Ying
mesh_terms: D019149:Bioreactors / Q000382:microbiology; D002241:Carbohydrates / Q000032:analysis; D018914:Cells, Immobilized / Q000201:enzymology / Q000378:metabolism; D002606:Charcoal; D003470:Culture Media / Q000737:chemistry; D005285:Fermentation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000032:analysis; D010407:Penicillium / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000235:genetics / Q000378:metabolism*
chemical_list: D002241:Carbohydrates; D003470:Culture Media; D005656:Fungal Proteins; D002606:Charcoal; C526100:Nuclease P1, Penicillium citrinum; D015719:Single-Strand Specific DNA and RNA Endonucleases; D010100:Oxygen