Genome analysis, protease characterization, and enzyme production optimization of Chryseobacterium sp. ZHDP1

Abstract:

[Background] Characterizing the protease activity is essential for revealing the potential ecological roles, industrial values, and pathogenic mechanism of Chryseobacterium. [Objective] This paper aims to analyze the genome sequence, characterize the protease, and optimize the enzyme production conditions of a novel Chryseobacterium strain, thereby providing the data support for subsequent research. [Methods] The genome sequence of the strain was obtained by high-throughput sequencing technology, and the conditions of protease activity and enzyme production were optimized by single factor tests. [Results] A strain, Chryseobacterium sp. ZHDP1, was isolated in this work. The genome of this strain had a length of 4 917 748 bp and the GC content of 35.95%. The average nucleotide identity (ANI) and DNA-DNA hybridization (DDH) indexes of the genome were 91.39 and 47.8, respectively. More than 20 protease genes were identified in the genome, and protease activity was detected in the supernatant of the fermentation broth. The protease had the optimum performance at 50 ℃ and pH 7.0 and was strongly inhibited by Zn²⁺, Mn²⁺, and Cr₂O₇^2-. The optimal conditions for the protease production of Chryseobacterium sp. ZHDP1 were as follows: culture temperature of 35 ℃, culture time of 35 h, inoculum amount of 4%, carbon source and nitrogen source of corn flour, and shaking speed of 100 r/min. [Conclusion] This study reveals the full-length genome sequence and the protease characteristics of Chryseobacterium sp. ZHDP1, which lays a foundation for the in-depth study of this strain.