Engineering of solvent-tolerant Pseudomonas putida S12 for bioproduction of phenol from glucose.
Appl Environ Microbiol
; 71(12): 8221-7, 2005 Dec.
Article
in En
| MEDLINE
| ID: mdl-16332806
ABSTRACT
Efficient bioconversion of glucose to phenol via the central metabolite tyrosine was achieved in the solvent-tolerant strain Pseudomonas putida S12. The tpl gene from Pantoea agglomerans, encoding tyrosine phenol lyase, was introduced into P. putida S12 to enable phenol production. Tyrosine availability was a bottleneck for efficient production. The production host was optimized by overexpressing the aroF-1 gene, which codes for the first enzyme in the tyrosine biosynthetic pathway, and by random mutagenesis procedures involving selection with the toxic antimetabolites m-fluoro-dl-phenylalanine and m-fluoro-l-tyrosine. High-throughput screening of analogue-resistant mutants obtained in this way yielded a P. putida S12 derivative capable of producing 1.5 mM phenol in a shake flask culture with a yield of 6.7% (mol/mol). In a fed-batch process, the productivity was limited by accumulation of 5 mM phenol in the medium. This toxicity was overcome by use of octanol as an extractant for phenol in a biphasic medium-octanol system. This approach resulted in accumulation of 58 mM phenol in the octanol phase, and there was a twofold increase in the overall production compared to a single-phase fed batch.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pseudomonas putida
/
Phenol
/
Glucose
Language:
En
Journal:
Appl Environ Microbiol
Year:
2005
Document type:
Article
Affiliation country:
Netherlands