Isolation and characterization of solvent-tolerant Pseudomonas putida strain T-57, and its application to biotransformation of toluene to cresol in a two-phase (organic-aqueous) system.
Pseudomonas putida T-57 was isolated from an activated sludge sample after enrichment on mineral salts basal medium with toluene as a sole source of carbon. P. putida T-57 utilizes n-butanol, toluene, styrene, m-xylene, ethylbenzene, n-hexane, and propylbenzene as growth substrates. The strain was able to grow on toluene when liquid toluene was added to mineral salts basal medium at 10-90% (v/v), and was tolerant to organic solvents whose log P(ow) (1-octanol/water partition coefficient) was higher than 2.5. Enzymatic and genetic analysis revealed that P. putida T-57 used the toluene dioxygenase pathway to catabolize toluene. A cis-toluene dihydrodiol dehydrogenase gene (todD) mutant of T-57 was constructed using a gene replacement technique. The todD mutant accumulated o-cresol (maximum 1.7 g/L in the aqueous phase) when cultivated in minimal salts basal medium supplemented with 3% (v/v) toluene and 7% (v/v) 1-octanol. Thus, T-57 is thought to be a good candidate host strain for bioconversion of hydrophobic substrates in two-phase (organic-aqueous) systems.
Faizal
Irvan
I
Department of Molecular Biotechnology, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
Dozen
Kana
K
Hong
Chang Soo
CS
Kuroda
Akio
A
Takiguchi
Noboru
N
Ohtake
Hisao
H
Takeda
Koji
K
Tsunekawa
Hiroshi
H
Kato
Junichi
J
D001709:Biotechnology / Q000379:methods*; D003408:Cresols / Q000378:metabolism*; D003470:Culture Media; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D018274:Electroporation; D008969:Molecular Sequence Data; D009154:Mutation; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism*; D016958:Pseudomonas putida / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D012997:Solvents / Q000378:metabolism; D014050:Toluene / Q000378:metabolism*; D014169:Transformation, Bacterial; D014867:Water
D003408:Cresols; D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012722:Sewage; D012997:Solvents; D014867:Water; D014050:Toluene; D010105:Oxygenases; C023172:toluene dioxygenase; C077977:cresol