Function Enhancement of a Metabolic Module via Endogenous Promoter Replacement for Pseudomonas sp. JY-Q to Degrade Nicotine in Tobacco Waste Treatment

• Published in: Applied biochemistry and biotechnology Vol. 193; no. 9; pp. 2793 - 2805
• Main Authors: Li, Jun, Yi, Fengmei, Chen, Guoqing, Pan, Fanda, Yang, Yang, Shu, Ming, Chen, Zeyu, Zhang, Zeling, Mei, Xiaotong, Zhong, Weihong
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-09-2021; Springer Nature B.V
• Subjects: Biochemistry; Biodegradation; Biodegradation, Environmental; Biotechnology; Chemistry; Chemistry and Materials Science; Combinatorial analysis; Genomics; Homology; Metabolic Networks and Pathways; Metabolic pathways; Metabolism; Microorganisms, Genetically-Modified - genetics; Microorganisms, Genetically-Modified - metabolism; Modules; Nicotiana - chemistry; Nicotine; Nicotine - chemistry; Nicotine - metabolism; Nicotine dehydrogenase; Original Article; Promoter Regions, Genetic; Promoters; Pseudomonas; Pseudomonas - genetics; Pseudomonas - metabolism; Solid Waste; Tobacco; Transcription; Waste treatment; Biodegradation; Dehydrogenase promoter; Function enhancement; Nicotine; Pseudomonas
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-021-03566-0

Nicotine-degrading
Pseudomonas
sp. JY-Q is a preferred strain utilized in reconstituted tobacco process for tobacco waste treatment. However, its efficiency of nicotine metabolism still requires to be improved via genomic technology such as promoter engineering based on genomic information. Concerning upstream module of nicotine metabolic pathway, we found that two homologous genes of nicotine dehydrogenase (
nicA2
and
nox
) coexisted in strain JY-Q. However, the transcriptional amount of
nox
was 20-fold higher than that of
nicA2.
Thus, the
nicA2
expression required improvement. Combinatorial displacement was accomplished for two predicted endogenous promoters, named as
PnicA2
and
Pnox
for
nicA2
and
nox
, respectively. The mutant with
Pnox
as the promoters for both
nicA2
and
nox
exhibited the best nicotine metabolic capacity which increased by 66% compared to the wild type. These results suggested that endogenous promoter replacement is also feasible for function improvement of metabolic modules and strain enhancement of biodegradation capacity to meet real environment demand.