''Paucimonas lemoignei'', formerly 'Pseudomonas lemoignei'' is a

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

soil bacterium. It is

aerobic Aerobic means "requiring air," in which "air" usually means oxygen. Aerobic may also refer to * Aerobic exercise, prolonged exercise of moderate intensity * Aerobics, a form of aerobic exercise * Aerobic respiration, the aerobic process of cellu ...

, motile, and

rod-shaped Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archae ...

Basic Information

* Straight to slightly curved rods. Motile by a single polar flagellum. Endospores not found. * The only known habitat is soil, particularly the

rhizosphere The rhizosphere is the narrow region of soil or Substrate (biology), substrate that is directly influenced by root secretions and associated soil microorganisms known as the root microbiome. Pore space in soil, Soil pores in the rhizosphere can ...

, but not associated with plants. * Obligate

Chemoorganotrophic Primary nutritional groups are groups of organisms, divided in relation to the nutrition mode according to the sources of energy and carbon, needed for living, growth and reproduction. The sources of energy can be light or chemical compounds; the ...

. Characterized by restricted metabolism. * Most strains are able to fix nitrogen. * Grows between pH 5.5 and 9.0. Optimum temperature is near 30 °C, but no growth is observed above 41 °C. * Colonies are circular, small, white to beige, and adherent to the agar.

Taxonomy

''P. lemoignei'' is established by Delafield ''et al.'' in 1965, and transferred by Jendrossek in 2001 after reevaluating its 16S rDNA sequence. This is a big shift from one class to another. ''P. lemoignei'' is so far the only species under the genus ''Paucimonas.'' "''Paucus''" means little or few. "''Paucimonas''" refers to bacterium with restricted catabolic capacities. ''P. lemoignei'' is named after the French microbiologist Maurice Lemoigne who first described

poly-3-hydroxybutyrate Polyhydroxybutyrate (PHB) is a polyhydroxyalkanoate (PHA), a polymer belonging to the polyesters class that are of interest as bio-derived and biodegradable plastics. The poly-3-hydroxybutyrate (P3HB) form of PHB is probably the most common typ ...

(PHB) as a constituent of bacterial cells.

Metabolic Properties

''P. lemoignei'' are originally isolated from soil rich in

(PHB). There are only 10 known substrates, mostly organic acids, that can be used for ''P. lemoignei'' as a sole carbon source. Sugars, sugar acids, alcohols, polyalcohols, amino acids, polypeptides, and polyols do not support its growth. Preferred carbon sources include: acetate, pyruvate, succinate,

butyrate The conjugate acids are in :Carboxylic acids. {{Commons category, Carboxylate ions, Carboxylate anions Carbon compounds Anions ...

, 3-hydroxybutyrate,

valerate Valeric acid or pentanoic acid is a straight-chain alkyl carboxylic acid with the chemical formula . Like other low-molecular-weight carboxylic acids, it has an unpleasant odor. It is found in the perennial flowering plant '' Valeriana officin ...

and 3-hydroxyvalerate.

Application

Polyhydroxyalkanoates Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugars or lipids. When produced by bacteria they serve as both a source of energy and as a carbon store. Mor ...

(PHA) are polyesters that can be used to make biodegradable and biocompatible thermoplastics, attracting commercial interests with the growing awareness of sustainability. PHA-degrading bacteria are mainly proteobacteria. ''(Note: PHB and PHV mentioned above are two types belonging to the PHA family.)'' ''P. lemoignei'' can encode five kinds of extracellular PHA depolymerase, all of which hydrolyze PHB at high specific activities. It hydrolyzes the 3-hydroxybutyrate dimer with the highest specific activity of any of the enzymes reported so far. In addition, the purified enzymes are remarkably stable and active at high temperature (60 °C), high pH (up to 12.0), low ionic strength (distilled water), and in solvents (''e.g. n''-propyl alcohol). The PHA depolymerases of ''P. lemoignei'' demonstrate a stable expression and secretion in recombinant ''

Escherichia coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus '' Escherichia'' that is commonly fo ...

''. The processing sites of the precursors in ''E. coli'' were the same as that in ''P. lemoignei'', and similar substrate specificities were determined for the wild-type and the recombinant proteins. This lays the foundation for streamlined production of extracellular PHA depolymerases.

References

External links

J.P. Euzéby: Listf Prokaryotic names with Standng in NomenclatureType strain of ''Paucimonas lemoignei'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{DEFAULTSORT:Paucimonas Lemoignei Burkholderiaceae Gram-negative bacteria