Pseudomonas strains using

By screening 53 Rhodococcus and Pseudomonas strains, an NHase-amidase biocatalyst system was identified for the production of the 2,2-dimethylcyclopropane carboxylic acid precursor of the dehydropeptidase inhibitor Cilastatin, which is used to prolong the antibacterial effect of Imipenem. A systematic study of the most selective of these strains, Rhodococcus erythropolis ATCC25 544, revealed that maximal product formation occurs at pH 8.0 but that ee decreased above pH 7.0. In addition, significant enantioselectivity decreases were observed above 20 °C. A survey of organic solvent effects identified methanol (10% v/v) as the... 

Many Pseudomonas strains accumulate MCL-PHAs from alkane, alkene, al-kanoate, alkenoate, or alkanol [5,6,14,96]. The composition of the PHAs formed by the pseudomonads of the rRNA homology group I is directly related to the structure of the carbon substrate used [6]. These results suggested that MCL-PHAs are synthesized from the intermediates of the fatty acid oxidation pathway. In almost all pseudomonads belonging to the rRNA homology group I except Pseudomonas oleovorans, MCL-PHA can also be synthesized from acetyl-CoA through de novo fatty acid synthetic pathway [97]. The -oxidation pathway and de novo fatty acid synthetic pathway function independently in PHA biosynthesis. 

Desulfurization of other diesel feedstocks from Total Raffinage was also reported by EBC. In these studies, different engineered biocatalysts were used. Two different middle distillate fractions, one containing 1850 ppm sulfur and other containing 650 ppm sulfur, were tested. R. erythropolis sp. RA-18 was used in one experiment and was reported to desulfurize the diesel from 1850 to < 1200ppm sulfur within 24 hours. On the other hand, it removed sulfur from a middle distillate with 650ppm sulfur to below 200 ppm sulfur [222], Various Pseudomonas strains were also tested in this study and reported to remove less amounts of sulfur. A favorable characteristic of the Pseudomonas strains is their inability to form stable emulsions, which can be useful trait for product recovery. 

A strain of Pseudomonas sp. uses 2,6-dinitrophenol as a nitrogen source for growth by first cleaving the nitro groups to free nitrite which, presumably after reduction to NH3, sustains replication of the bacteria. 

Biological. A Pseudomonas strain P6, isolated from a Matapeake silt loam, was grown using a yeast extract. After 8 d, 4-nitroaniline degraded completely to carbon dioxide (Zeyer and Kearney, 1983). In activated sludge inoculum, following a 20-d adaptation period, no degradation... 

Pyoverdin-like siderophores with other chromophores have also been observed (see Fig. 1) (45). The 5,6-dihydropyoverdins (Chra without the 5,6-double bond) and the ferribactins (Chrc) are considered to be biogenetic precursors of the pyoverdins 318) (the term ferribactin was originally used for the Fe " complex 221) and later for the free ligand). An azotobactin chromophore (Chrd, see also below Sect. 2.2) is occasionally found in Pseudomonas isolates e.g. 146)). Siderophores produced by a specific Pseudomonas strain but differing in the chromophore always have identical peptide chains. 

Biomacromolecules and biopolymers have also been put to use as templates for the synthesis of new materials, or models for the study of molecular mechanisms in nature. Exanq>Ies are nucleic acid synthetic alternatives (Eschenmoser 1999), P- and y-peptide synthetic analoguesofnatural a-peptides (Seebach 2001), and analogues ofpoly-(i )-3-hydroxybutanoic acid. The latter can be obtained from chemical synthesis (Seebach 2001) or the culture of engineered Pseudomonas strains (Kessler 2001). 

A similar addition of a catabolic plasmid was used to construct a Pseudomonas strain capable of utilizing 2,4,6-trinitrotoluene (TNT) as a carbon and energy source (Duque et al., 1993). Pseudomonas sp. clone A utilizes the nitro-groups of TNT as the sole source of nitrogen while growing with fructose as the carbon source. Toluene is produced as a consequence of this activity, which cannot be metabolized by clone A. Introduction ofTOLallowed complete utilization of TNT without the need for an ancillary source of carbon and energy. 

While atrazine degradation to hydroxyatrazine was enhanced by the addition of ammonium sulfate in anaerobic wetland sediments (Chung et al., 1995), the addition of 2.0g/L of ammonium nitrate into aerobic wetland water sample reactors clearly inhibited atrazine degradation (Ro and Chung, 1995). In 15N tracer studies done with Pseudomonas strain ADP (which can use all five N atoms of atrazine as a sole N source), Bichat et al. (1997) indicated that while organic N sources had little effect on atrazine degradation, nitrate and ammonium delayed atrazine degradation. 

Using an enzymatic resolution process, chiral alcohol A-(+)-(43) was also prepared by the lipase-catalyzed stereoselective acetylation of racemic (43) in organic solvent [74], We evaluated various lipases, among which lipase PS-30 and BMS lipase (produced by fermentation of Pseudomonas strain SC 13856)... 

The inherent substrate specificities of Pseudomonas sp. 61-3 PHA synthases (PhaClPs and PhaC2Ps) are rather low toward 3HB monomer (17,18), and the fad mutant E. coli strain used in our study cannot generate enough 3HB monomers from the (3-oxidation pathway (21,26). Therefore, we introduced the R. eutropha phaABRe genes to generate enough more 3HB... 

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