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Telechelic Polyhydroxyalkanoates/Polyhydroxybutyrates (PHAs/PHBs)
Published in Sophie M. Guillaume, Handbook of Telechelic Polyesters, Polycarbonates, and Polyethers, 2017
Abdulkadir Alli, Baki Hazer, Grażyna Adamus, Marek Kowalczuk
PHAs can be sorted out into three types according to the length of the side chain. One family is including short-chain-length PHAs (sclPHAs) containing 3–5 carbon atoms that are produced by Ralstonia eutropha (also referred to as Watersia eutropha, Alcaligenes eutrophus) [1]. The second group is including medium-chain-length PHAs (mclPHAs) containing 6–14 carbon atoms that are produced from Pseudomonas oleovorans and other Pseudomonads sensu strictu [18]. The last type is including PHAs larger than 14 carbon atoms, which are named long-chain-length PHAs (lclPHAs). Pseudomonas oleovorans is a very multifaceted microorganism for PHA production to generate mclPHAs and lclPHAs from a wide range of carbon substrates. Poly(3-hydroxybutyrate) (PHB), poly(3-hydroxyvalerate) (PHV), and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), copolymer, are typical members of sclPHAs. Poly(3-hydroxyoctanoate) (PHO) and poly(3-hydroxynonanoate) (PHN), which are mostly formed as copolymers of 3-hydroxyoctanoate or 3-hydroxynonanoate together with 3-hydroxyhexanoate (HHx), 3-hydroxyheptanoate, and/or 3-hydroxydecanoate, are typical members of mclPHAs [19]. These types of PHAs are gathered in Table 3.1.
RR1 Consortium for Soil Decontamination: its Preparation and Use
Published in Donald L. Wise, Debra J. Trantolo, Edward J. Cichon, Hilary I. Inyang, Ulrich Stottmeister, Remediation Engineering of Contaminated Soils, 2000
Dana M. V. Horáková, Miroslav Nemec
The 1980 s were a period of rapid advances in the knowledge of genetics and molecular biology of bacterial degradation of different hydrocarbons, and of renewed interest in microbial ecology of pollution-stressed environments. From the genetic point of view it is clear that the ability of a major proportion of microorganisms to degrade oil hydrocarbons is partly controlled by plasmids. Many microorganisms, including several pseudo-monads, are able to use linear alkanes as their sole source of carbon and energy (5). The OCT-plasmid of Pseudomonas oleovorans contains two operons, alkBFGHJKL and alkST, which encode all proteins necessary for the degradation of n-octane and other 5- to 12 -carbon linear alkanes. Branched isomers, such as isooctane, are less susceptible to biodegradation than n-octane (6). The conversion of linear alkanes to the corresponding alcohols is catalyzed by a group of proteins collectively referred to as the "alkane hydroxylase system." It has three main components: alkane 1-monooxygenase, and two soluble proteins, rubredoxin and rubredoxin reductase. Rubredoxin reductase transfers electrons from NADH to rubredoxin. This protein then passes electrons to alkane 1-monooxygenase, which is an enzyme localized in the cytoplasmatic membrane. The final product of this pathway, alkanoyl-CoA, enters the beta-oxidation cycle and is used as a carbon and energy source (5). The proof of the transfer of plasmid has made it possible to explain the rapid increase of the number of microorganisms with degrading ability.
Amphiphiles from Poly(3-hydroxyalkanoates)
Published in Martin Koller, The Handbook of Polyhydroxyalkanoates, 2020
Double bond functionality is readily open for the modification reactions. Therefore, the first step was the production of unsaturated mcl-PHA by Lenz’s group. In an early experiment, Pseudomonas oleovorans was grown separately on 3-hydroxy-6-octenoic acid and 3-hydroxy-7-octenoic acid as the only carbon source and under ammonium nutrient-limiting conditions to produce storage polyesters. The polyesters produced contained mainly unsaturated C8 units [27].
Biodegradation of mixed polycyclic aromatic hydrocarbons by Pseudomonas sp. isolated from estuarine sediment
Published in Bioremediation Journal, 2023
Vasudha C. Bhatawadekar, Samir R. Damare, Anita Garg
Many Pseudomonas species have been reported to degrade PAHs (Nwinyi, Ajayi, and Amund 2016; Gupta, Kumar, and Pal 2019; Oyehan and Al-Thukair 2017). Pseudomonas pachastrellae was reported to degrade petroleum hydrocarbon, along with other bacterial strains like Rhodococcus sp., Acinetobacter sp., etc. (Kostka et al. 2011; Perdigão et al. 2020). Pseudomonas oleovorans has been reported for polyhydroxyalkanoate (PHA) production using n-octane as a carbon source (Santhanam and Sasidharan 2010) and for biodegradation of Tetrahydro-furan and BTEX (Zhou et al. 2011; Chen et al. 2013). However, Pseudomonas pachastrellae and Pseudomonas oleovorans are not reported for degradation of Phe, Flt and Pyr. The results of this study reveal that Pseudomonas oleovorans and Pseudomonas pachastrellae could be efficiently used for bioremediation of sites contaminated with Phe, Flt, and Pyr.