Martina Macková

PCB metabolism by Pseudomonas sp. P2

Abstract The degradation of Delor 103, a mixture of polychlorinated biphenyl (PCB) congeners, by Pseudomonas sp. P2, an indigenous soil bacterium was studied. In mineral medium with biphenyl as sole carbon source the extent of PCB degradation monitored by GC exceeded 70%. The efficiency of Delor 103 degradation by strain P2 was compared with that of Ralstonia eutropha H850. The addition of saccharose or agar improved PCB degradation, whereas the addition of glycerol or pyruvate substantially reduced the degradation efficiency. The presence of an amino acid mixture enhanced PCB degradation. The following chlorobenzoic acids (CBA): 2,5 CBA, 2,4 CBA, 4 CBA, 2 CBA and 2,5-diCBA were detected as metabolites of Delor 103, with 2,5-diCBA as the major product. Although 2,5-diCBA inhibited the growth of Pseudomonas sp. P2 the degradation of 2,5-diCBA was unaffected for upto 14 days.

Application of selectively acylated glycosides for the alpha-galactosidase-catalyzed synthesis of disaccharides

Abstract4-Nitrophenyl α-d-galactopyranosyl-(1→3)-6-O-acetyl-α-d-galactopyranoside was prepared in a transglycosylation reaction catalyzed by α-d-galactosidase fromTalaromyces flavus using 4-nitrophenyl α-d-galactopyranoside as a glycosyl donor and 4-nitrophenyl 6-O-acetyl-α-d-galactopyranoside as an acceptor. 4-Nitrophenyl 6-O-acetyl-α-d-galactopyranoside and 4-nitrophenyl 6-O-acetyl-β-d-galactopyranoside were prepared in a regioselective enzymic transesterification in pyridine-acetone catalyzed by the lipase PS fromBurkholderia cepacia. A series of water-miscible organic solvents (acetone, acetonitrile, dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, 2-methoxyethanol, pyridine, 2-methylpropan-2-ol, tetrahydrofuran, propargyl alcohol) were used as co-solvents in this enzymic reaction. Their influence on the activity and stability of the α-galactosidase fromT. flavus was established. 2-Methylpropan-2-ol and acetone (increasing the solubility of the modified substrate acceptors and displaying the minimum impairment of the activity and stability of the enzyme) were used as co-solvents in transglycosylation reactions.

Biotransformation of ergot alkaloids by plant cell cultures with high peroxidase activity

Ergot alkaloids agroclavine and elymoclavine have been modified using plant cell cultures exhibiting high peroxidase activity. Setoclavine and isosetoclavine have been isolated from media after transformation of agroclavine on a semipreparative scale. 10-Hydroxyelymoclavine resulted from similar treatment of elymoclavine.

Alkane assimilation ability of Pseudomonas C12B originally isolated for degradation of alkyl sulfate surfactants

SummaryPseudomonas C12B (NCIMB 11753) is able to utilize a broad range of alkyl sulfates. The growth on n-alkanes of different chain lenght (C6–C16) was tested. Pseudomonas C12B assimilated hydrocarbons from C9–C16. Growth rate on n-decane (1%) that was chosen as the typical sole source of carbon and energy depended on oxygen supply. The addition of surfactants (Triton X-100 and Tween-80) in a nontoxic concentrations resulted in increased biomass yield. Under optimal growth conditions Pseudomonas C12B exhibited the maximal growth rate and yield with C11 as the sole carbon source.