Poly(3-Hydroxyvalerate) Depolymerase of
            <i>Pseudomonas lemoignei</i>

Schöber, Ute; Thiel, Christian; Jendrossek, Dieter

doi:10.1128/aem.66.4.1385-1392.2000

Cited by 50 publications

(21 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…NRRL B-14911 to form a clearing zone on an opaque plate. It has been noted that the PhaZs of Alcaligenes faecalis AE122, Ralstonia pickettii T1, and Pseudomonas stutzeri, which contain type 1 catalytic domains, could degrade dPHB to produce a mixture of 3HB oligomers and monomers, whereas those PhaZs from Acidovorax sp., Comamonas sp., C. acidovorans, C. testosteroni, and Streptomyces exfoliates, which contain type 2 catalytic domains, could yield 3HB monomer as a main product (32). However, the PhaZs from Bacillus sp.…”

Section: Discussionmentioning

confidence: 99%

Identification and Characterization of a Novel Class of Extracellular Poly(3-Hydroxybutyrate) Depolymerase from Bacillus sp. Strain NRRL B-14911

Ma¹,

Lin²,

Chen³

et al. 2011

Appl Environ Microbiol

View full text Add to dashboard Cite

The catalytic, linker, and denatured poly(3-hydroxybutyrate) (dPHB)-binding domains of bacterial extracellular PHB depolymerases (PhaZs) are classified into several different types. We now report a novel class of extracellular PHB depolymerase from Bacillus sp. strain NRRL B-14911. Its catalytic domain belongs to type 1, whereas its putative linker region neither possesses the sequence features of the three known types of linker domains nor exhibits significant amino acid sequence similarity to them. Instead, this putative linker region can be divided into two distinct linker domains of novel types: LD1 and LD2. LD1 shows significant amino acid sequence similarity to certain regions of a large group of PHB depolymerase-unrelated proteins. LD2 and its homologs are present in a small group of PhaZs. The remaining C-terminal portion of this PhaZ can be further divided into two distinct domains: SBD1 and SBD2. Each domain showed strong binding to dPHB, and there is no significant sequence similarity between them. Each domain neither possesses the sequence features of the two known types of dPHBbinding domains nor shows significant amino acid sequence similarity to them. These unique features indicate the presence of two novel and distinct types of dPHB-binding domains. Homologs of these novel domains also are present in the extracellular PhaZ of Bacillus megaterium and the putative extracellular PhaZs of Bacillus pseudofirmus and Bacillus sp. strain SG-1. The Bacillus sp. NRRL B-14911 PhaZ appears to be a representative of a novel class of extracellular PHB depolymerases.Poly(3-hydroxybutyrate) (PHB) is synthesized and accumulated intracellularly as a carbon and energy storage material by a wide variety of bacteria (14,28,29). When nutrient availability is restricted or unbalanced, the accumulated PHB is subject to degradation by the intracellular PHB depolymerase(s) (PhaZ) to produce 3-hydroxybutyrate (3HB) oligomers and/or monomers. These products subsequently are metabolized by the intracellular 3HB-oligomer hydrolase and/or the 3HB dehydrogenase as carbon and energy sources (21,22,30,36,38). The intracellular PHB exists in an amorphous state. When the amorphous PHB is subjected to solvent extraction or exposed to the extracellular environment due to cell death or lysis, the amorphous PHB is transformed into denatured semicrystalline PHB (dPHB) (13, 16).A wide variety of bacteria can produce and secrete extracellular PHB depolymerases for the specific degradation of dPHB (12,16,40), with some exceptions. One exception is the extracellular PHB depolymerase PhaZ7 of Paucimonas lemoignei, which can only degrade amorphous PHB (7). Another known exception is the periplasm-located PHB depolymerase of Rhodospirillum rubrum, which shows substrate specificity for amorphous PHB (8). Like intracellular PHB depolymerases, extracellular PHB depolymerases can degrade PHB into 3HB oligomers and/or monomers. The produced 3HB oligomers can be further degraded by extracellular 3HB-oligomer hydrolases into 3HB monomers or degraded ...

show abstract

Section: Discussionmentioning

confidence: 99%

Identification and Characterization of a Novel Class of Extracellular Poly(3-Hydroxybutyrate) Depolymerase from Bacillus sp. Strain NRRL B-14911

Ma¹,

Lin²,

Chen³

et al. 2011

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…This method is practicable when the degradation of macroscopically visible specimens of polymer samples (e.g., PHB films) is determined over a time scale of many hours. For short assays of PHB depolymerase activity, most laboratories determine the rate of clearing of a turbid suspension of nPHB or dPHB granules for (1,13,22,24,28,32,45,46). However, this method is limited principally to very diluted suspensions of PHB granules.…”

Section: Discussionmentioning

confidence: 99%

Assay of Poly(3-Hydroxybutyrate) Depolymerase Activity and Product Determination

Gebauer

Jendrossek

2006

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

Two methods for accurate poly(3-hydroxybutyrate) (PHB) depolymerase activity determination and quantitative and qualitative hydrolysis product determination are described. The first method is based on online determination of NaOH consumption rates necessary to neutralize 3-hydroxybutyric acid (3HB) and/or 3HB oligomers produced during the hydrolysis reaction and requires a pH-stat apparatus equipped with a softwarecontrolled microliter pump for rapid and accurate titration. The method is universally suitable for hydrolysis of any type of polyhydroxyalkanoate or other molecules with hydrolyzable ester bonds, allows the determination of hydrolysis rates of as low as 1 nmol/min, and has a dynamic capacity of at least 6 orders of magnitude. By applying this method, specific hydrolysis rates of native PHB granules isolated from Ralstonia eutropha H16 were determined for the first time. The second method was developed for hydrolysis product identification and is based on the derivatization of 3HB oligomers into bromophenacyl derivates and separation by highperformance liquid chromatography. The method allows the separation and quantification of 3HB and 3HB oligomers up to the octamer. The two methods were applied to investigate the hydrolysis of different types of PHB by selected PHB depolymerases.Polyhydroxyalkanoates (PHAs) are typical storage compounds of carbon and energy and are widely found in prokaryotes. The most common PHA is poly(3-hydroxybutyrate) (PHB), and this polymer can be accumulated at up to 90% of the cellular dry weight during unbalanced growth in some bacteria (2a, 37, 49). PHAs are thermoplasts, and despite the relatively high production costs, PHB and copolymers of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate are industrially produced on a scale of a few hundred tons per year.One reason for the interest in biologically produced PHAs lies in the environmentally friendly production from renewable resources and in the biodegradability of PHAs. The ester bonds of the PHAs are the Achilles' heel of the polymer that can be hydrolyzed by a large variety of hydrolytic enzymes (PHA depolymerases). In vivo, PHAs can be hydrolyzed by the accumulating strain itself during periods of starvation (intracellular PHA hydrolysis by intracellular PHA depolymerases) (41). PHAs that were produced by humans or that were released from PHA-accumulating microorganisms (e.g., after death) can be cleaved by extracellular PHB depolymerases, and many examples of extracellular PHA depolymerases were described during the last two decades (14, 21). A differentiation of extracellular degradation from intracellular degradation is necessary because PHA exists in two biophysical conformations: in vivo, PHB is completely amorphous (native) and is covered by a surface layer that is about half the size of a cytoplasmic membrane (4, 5, 31) but apparently consists mainly of proteins, so-called phasins (48). After the release of the polymer from the cell (e.g., after cell lysis or by solvent extraction) or after damage of the surface l...

show abstract

“…GjC content 59p2 mol %. Abilities to produce several extracellular polyhydroxyalkanoate depolymerase isoenzymes and to utilize PHB, PHV, related oligomers and\or polymers for growth (Scho$ ber et al, 2000) are characteristic for Paucimonas lemoignei. Utilization of polyesters is visible by clearing zone formation of opaque polyhydroxyalkanoate-containing solid media .…”

Section: Description Of Paucimonas Lemoignei Comb Novmentioning

confidence: 99%

Transfer of [Pseudomonas] lemoignei, a gram-negative rod with restricted catabolic capacity, to Paucimonas gen. nov. with one species, Paucimonas lemoignei comb. nov.

Jendrossek¹

2001

International Journal of Systematic and Evolutionary Microbiology

View full text Add to dashboard Cite

show abstract

Poly(3-Hydroxyvalerate) Depolymerase of Pseudomonas lemoignei

Cited by 50 publications

References 29 publications

Identification and Characterization of a Novel Class of Extracellular Poly(3-Hydroxybutyrate) Depolymerase from Bacillus sp. Strain NRRL B-14911

Identification and Characterization of a Novel Class of Extracellular Poly(3-Hydroxybutyrate) Depolymerase from Bacillus sp. Strain NRRL B-14911

Assay of Poly(3-Hydroxybutyrate) Depolymerase Activity and Product Determination

Transfer of [Pseudomonas] lemoignei, a gram-negative rod with restricted catabolic capacity, to Paucimonas gen. nov. with one species, Paucimonas lemoignei comb. nov.

Contact Info

Product

Resources

About