Mineralization of phenol and its derivatives by Pseudomonas sp. strain CP4

Abstract

A Pseudomonas sp. strain, CP4, was isolated that used phenol up to 1.5 g/l as sole source of carbon and energy. Optimal growth on 1.5 g phenol/l was at pH 6.5 to 7.0 and 30°C. Unadapted cells needed 72 h to decrease the chemical oxygen demand (COD) of about 2000 mg/l (from 1 g phenol/l) to about 200 mg/l. Adapted cells, pregrown on phenol, required only 65 h to decrease the COD level to below 100 mg/l. Adaptation of cells to phenol also improved the degradation of cresols. Cell-free extracts of strain CP4 grown on phenol or o-, m- or p-cresol had sp. act. of 0.82, 0.35, 0.54 and 0.32 units of catechol 2,3-dioxygenase and 0.06, 0.05, 0.05 and 0.03 units of catechol 1,2-dioxygenase, respectively. Cells grown on glucose or succinate had neither activity. Benzoate and all isomers of cresol, creosote, hydroxybenzoates, catechol and methyl catechol were utilized by strain CP4. No chloroaromatic was degraded, either as sole substrate or as co-substrate.

Simultaneous degradation of phenol and 3-chlorobenzoate by a mixture of separately immobilized cells of two strainsof Pseudomonas – A preliminary study

“…Strain CP4 could effectively mineralize all 3 isomers of cresol, creosote, aniline, benzoate, 3-hydroxy and 4-hydroxybenzoates, catechol, 4-methyl catechol, gentisate, protocatechuate etc. besides degrading phenol at high concentrations (Babu et al, 1995a;1995b;Ahamad and Kunhi, 1999;Ahamad et al, 2001, Ahamad andKunhi, 2011). Strain 3mT is capable of degrading various aromatic compounds such as benzoates, 3-and 4-hydroxybenzoates, catechol, 3-and 4-CC etc.…”

“…CP4 (Babu et al, 1995b;Ahamad and Kunhi, 1999;Ahamad et al, 2001) and Pseudomonas aeruginosa 3mT (Babu et al, 1995a;Ajith-Kumar and Kunhi, 2000;Jayachandran and Kunhi, 2009) used in this study were the ones isolated in the laboratory previously.…”

“…Cell biomass of strain CP4 was prepared by growing it in a 10 L fermenter ("Digi-Ferm fermenter", locally fabricated) as described previously (Ahamad and Kunhi, 2011) in a mineral medium (M3 medium) (Babu et al, 1995b) containing 500 mg/L of phenol. M3 medium contained: (g/L) KH2PO4, 2.72; Na2HPO4, 5.0; NH4NO3, 0.5; MgS04· 7H2O, 0.2; Ca(NO3)2, 0.1; trace minerals solution, 1.0 mL [consisting of (g/L) FeSO4· 7H2O, 1.0; MnSO4·H 2O, 1.0; Na2MoO4·H 2O, 0.25; H3BO3, 0.1; CuCl2· 2H2O].…”

“…This mixed culture contained Pseudomonas sp. strain CP4 (CP4), which could degrade up to 1.5 g/L of phenol (Babu et al, 1995b) and up to 2.0 g/L of cresols (Ahamad and Kunhi, 1999;Ahamad et al, 2001) through meta-cleavage pathways and P. aeruginosa strain 3mT (3mT) capable of degrading 8.0 g/L of 3-CBA and 12 g/L of 4-chlorobenzoate (4-CBA) via a modified ortho-pathway (Ajith-Kumar and Kunhi, 2000). A mixed culture of the strain 3mT and an ortho-pathway-following phenol degrader, Pseudomonas stutzeri strain SPC-2 (Ahamad and Kunhi, 1996) also degraded 3-CBA-phenol mixtures efficiently when used as free suspended cells in shake flasks (Jayachandran and Kunhi, 2009).…”

Degradation of 3-chlorobenzoate and phenol singly and in mixture by a mixed culture of two ortho-pathway-following Pseudomonas strains

“…Generally, chlorocatechols are cleaved through a modiWed ortho-mode by pyrocatechase II (catechol 1,2-dioxygenase, C12D) [6,16,20,34,36], although a few exceptions have been reported [8,23,25,27]. Non-haloaromatics such as, phenol, benzoate, cresols, methyl benzoates, and so on, on the other hand, are usually degraded by bacteria through a meta-Wssion pathway involving meta-pyrocatechase (catechol 2,3-dioxygenase, C23D) [4,11,13,17,18,24,31,32] although there have been several reports, in recent years, on the involvement of C12D in the catabolism of non-haloaromatics [1,15].…”