Cysteine-Mediated Cyclic Metabolism Drives the Microbial Degradation of Keratin

TY - JOUR

T1 - Cysteine-Mediated Cyclic Metabolism Drives the Microbial Degradation of Keratin

AU - Peng, Zheng

AU - Xu, Peng

AU - Song, Yang

AU - Du, Guocheng

AU - Zhang, Juan

AU - Chen, Jian

PY - 2021/7/14

Y1 - 2021/7/14

N2 - Keratinase is a key enzyme to degrade keratin. However, the extremely low efficiency of keratinase hydrolyzing keratin after being separated from living cells is still the bottleneck of its application. Living cells seem to provide synergistic factors for the efficient catalysis of keratinase. To this end, we analyzed the role of the metabolic activity of living cells in the hydrolysis of feather keratin by keratinase. Here, studies have shown that sulfite is the key to switch on the catalytic procedure of keratinase, and cysteine is the bridge for living cells to control this process. Cysteine catabolism mediated by an intracellular detoxification mechanism produces sulfite and is secreted to promote the hydrolysis of keratin by keratinase. Then, the cysteine released by keratin hydrolysis will enter the cell and continue to be converted into sulfite through catabolism. These two processes form a perpetual chain reaction for the adequate hydrolysis of keratin. Furthermore, we confirmed that loading this self-circulation synergistic catalysis system into keratinase-secreting cells can significantly enhance their keratin hydrolysis capacity. This work demonstrated the missing link of keratinase-catalyzed keratin hydrolysis and obtained engineered strains with improved hydrolysis capacity.

AB - Keratinase is a key enzyme to degrade keratin. However, the extremely low efficiency of keratinase hydrolyzing keratin after being separated from living cells is still the bottleneck of its application. Living cells seem to provide synergistic factors for the efficient catalysis of keratinase. To this end, we analyzed the role of the metabolic activity of living cells in the hydrolysis of feather keratin by keratinase. Here, studies have shown that sulfite is the key to switch on the catalytic procedure of keratinase, and cysteine is the bridge for living cells to control this process. Cysteine catabolism mediated by an intracellular detoxification mechanism produces sulfite and is secreted to promote the hydrolysis of keratin by keratinase. Then, the cysteine released by keratin hydrolysis will enter the cell and continue to be converted into sulfite through catabolism. These two processes form a perpetual chain reaction for the adequate hydrolysis of keratin. Furthermore, we confirmed that loading this self-circulation synergistic catalysis system into keratinase-secreting cells can significantly enhance their keratin hydrolysis capacity. This work demonstrated the missing link of keratinase-catalyzed keratin hydrolysis and obtained engineered strains with improved hydrolysis capacity.

KW - Keratin

KW - Bioconversion

KW - Bacillus

KW - Cysteine metabolism

KW - Sulfite

KW - Keratinase

U2 - 10.1021/acssuschemeng.1c02627

DO - 10.1021/acssuschemeng.1c02627

M3 - 文章

SN - 2168-0485

JO - ACS Sustainable Chemistry and Engineering

JF - ACS Sustainable Chemistry and Engineering

ER -