Biotechnology Bulletin ›› 2025, Vol. 41 ›› Issue (5): 267-279.doi: 10.13560/j.cnki.biotech.bull.1985.2024-1053

Previous Articles    

Identification, Enzymatic Characteristics, and Genomic Analysis of Strain D2 from Ancient Tea Forest

YE Liu-jian1(), MENG Jian-zong2(), QIN Fu-fang3, HE Shuang1, ZHU Qi-xia1, WANG Xiao-hu1, WEI Sheng-bo1, ZHOU Li-qin1()   

  1. 1.Institute of Biological Sciences and Technology, National Key Laboratory of Non-Food Biomass Energy Technology, Guangxi Academy of Sciences, Nanning 530007
    2.Institute of Food & Pharmaceutical Science, Guangxi Vocational University of Agriculture, Nanning 530007
    3.Guangxi Guangming Investment Co. , Ltd. , Baise 533000
  • Received:2024-10-28 Online:2025-05-26 Published:2025-06-05
  • Contact: MENG Jian-zong, ZHOU Li-qin E-mail:yeliujian2022@126.com;meng_jz@163.com;gxkxyzlq@126.com

Abstract:

Objective Identify a high-yield protease-producing strain D2 in the rhizosphere of a wild ancient tea forest in Baise, and analyze the enzymatic characteristics and genome of strain D2, and provide a basis for further application of strain D2 in the development of functional fertilizers for agricultural purposes. Method Based on 16S rRNA amplification technology and colony morphology identification of strain D2, the enzyme activity of protease was determined by the Folin method, and the genome of strain D2 was sequenced and subjected to bioinformatics analysis using next-generation sequencing technology. Result The strain D2 with high protease production in the rhizosphere of wild ancient tea forests in Baise was identified as a new species of Stenotrophomonas genus, with the closest genetic relationship to Stenotrophomonas maltophilia. Strain D2 produced 255.73 U/mL neutral protease and 282.12 U/mL alkaline protease after 24 h of fermentation, with a total protease activity of 544.60 U/mL. The optimal temperature and pH for the protease catalyzed reaction of strain D2 are 50 ℃ and 8, respectively. High temperature has a significant impact on enzyme activity, while pH and organic solvents have relatively small effects. Treatment with organic solvent DMSO can also enhance enzyme activity. The full-length genome of strain D2 is 4 599 465 bp, with a GC content of 66.77%. It contains 4 176 CDS, 71 tRNA, 5 rRNA genes, and 1 ncRNA. The genome of strain D2 also contains abundant carbohydrate active enzyme genes and heavy metal resistance genes, with 11 Saccharide synthesis gene clusters (accounting for 57.89% of the total gene clusters), which interact with 38 plant pathogens. Conclusion The strain D2 from the ancient tea forest has been identified as a new species of Stenotrophomonas genus, with high protease activity and good enzymatic properties. The genome contains abundant gene clusters for carbohydrate active enzymes, resistance to heavy metal, secondary metabolite synthesis, and plant pathogen resistance.

Key words: Stenotrophomonas maltophilia, wild ancient tea forest, rhizosphere microorganisms, neutral protease, alkaline protease, enzymatic characteristics, genomics