The structure of the exopolysaccharide produced by the halophilic Archaeon Haloferax mediterranei strain R4 (ATCC 33500)

Parolis, Haralambos; Parolis, Lesley A.S.; Boán, Isabel F.; Rodrı́guez-Valera, Francisco; Widmalm, Göran; Manca, Maria; Jansson, Per‐Erik; Sutherland, Ian W.

doi:10.1016/s0008-6215(96)90134-2

Cited by 76 publications

(45 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Higher viscosity causes difficulties in oxygen input during the aerobic process, and higher performance and energy demands for the stirring system of the bioreactor. As elucidated by Parolis et al 41 who used a smart combination of glycolysis, methylation, sulfate analysis, periodate oxidation, and NMR analysis, this EPS constitutes a sulfated (hence anionic) polysaccharide, consisting of a regular trisaccharide repeating unit of one mannose (Man) and two 2-acetamido-2-deoxyglucuronic acid (GlcNAcA) moieties; one sulfate ester bond is present per trisaccharide unit on carbon number 3 of the second GlcNAcA unit. Structure and linkage between the building blocks are illustrated in Fig.…”

Section: Pha and Eps From H Mediterraneimentioning

confidence: 99%

Study on the Production and Re-use of Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) and Extracellular Polysaccharide by the Archaeon Haloferax mediterranei Strain DSM 1411

Koller

Chiellini

Braunegg

2015

Chem.Biochem.Eng.Q.

View full text Add to dashboard Cite

The halobacterium Haloferax mediterranei was used to study the production of two types of biopolymers: The biopolyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was accumulated as intracellular granules, whereas an extracelluar polysaccharide was excreted in parallel to biopolyester synthesis.After production, microbial re-use and degradation of these polymers under different conditions were investigated to assess the requirements for handling the product-rich fermentation broth prior to the downstream processing for product recovery. Degradation kinetics of the polymers and the impact of different storage conditions on molar mass of PHBV were studied.It turned out that the biotechnological fermentation process can be run without any sterility precautions. No major product losses were observed without pasteurization of fermentation broth after the stop of fermentation. In addition, neither PHBV nor EPS are re-utilized by the cells for biomass formation even if the culture is maintained under conditions of carbon starvation for an extended time.

show abstract

Section: Pha and Eps From H Mediterraneimentioning

confidence: 99%

Study on the Production and Re-use of Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) and Extracellular Polysaccharide by the Archaeon Haloferax mediterranei Strain DSM 1411

Koller

Chiellini

Braunegg

2015

Chem.Biochem.Eng.Q.

View full text Add to dashboard Cite

show abstract

“…The quest for both Gram-positive and Gram-negative microbial species to be used as extremophile cellular PHA-bio polyester factories started in the middle of the 1980ies by the discovery of the high PHA accumulation potential of the extremely osmophilic Archaeon Hfx. mediterannei, a versatile PHA- [33], pigment- [34], halocin- [35], and polysaccharide [36,37] producer from the haloachaeal group of extremophiles [38]. Pigment-(C50 carotenoids) and extracellular polysaccharide (EPS) production provides cultures of these organisms a typical reddish and mucous character, as illustrated in Figure 3.…”

Section: Introductionmentioning

confidence: 99%

Production of Polyhydroxyalkanoate (PHA) Biopolyesters by Extremophiles?

Koller¹

2017

MOJPS

View full text Add to dashboard Cite

The article reviews the current state of knowledge of the production of polyhydroxyalkanoate (PHA) biopolyesters under extreme environmental conditions.Although PHA production by extremophiles is not realized yet at industrial scale, significant PHA accumulation under high salinity or extreme pH-or temperature conditions was reported for diverse representatives of the microbial domains of both Archaea and Bacteria. Several mechanisms were proposed to explain the mechanistic role of PHA and their monomers as microbial cell-and enzyme protective chaperons and the factors boosting PHA biosynthesis under environmental stress conditions. The potential of selected extremophile strains, isolated from extreme environments like glaciers, hot springs, saline brines, or from habitats highly polluted with heavy metals or solvents, for efficient future PHA production on an industrially relevant scale is assessed based on the basic data available in the scientific literature. The article reveals that, beside the needed optimization of other cost-decisive factors like inexpensive raw materials or efficient downstream processing, the application of extremophile production strains can drastically safe energy costs, are easily accessible towards long-term cultivation in chemostat processes, and therefore might pave the way towards cost-efficient PHA production, even combined with safe disposal of industrial waste streams. However, further challenges have still to be overcome in terms of strain improvement and process engineering aspects.

show abstract

“…Anton et al 67 were the first to report the production of EPS by an archaebacterium, Haloferax mediterranei (ATCC 33500). The structure of the neutral extracellular polysaccharides of Haloferax gibbonsii (ATCC 33959) has been determined by Paramonov et al 68 while, Parolis et al 69 elucidated the structure of In a screening program, Nicolaus et al 70 isolated three obligatory halophilic microorganisms (T5, T6, and T7) from an unexplored site in Tunisia. These strains produced sulfated extracellular polysaccharides in a minimal medium containing glucose as sole carbon source with EPS yields ranging from 35 to 370 mg/L.…”

Section: -51mentioning

confidence: 99%

Untitled

2017

BIJ

View full text Add to dashboard Cite

Halophilic microorganisms derived from diverse thalassohaline and athalassohaline environments including marine estuaries, saline and soda lakes, inland solar salterns and acidic habitats are categorized as slight-, moderate-and extreme halophiles according to their NaCl requirements. Taxonomic studies with culturable diversities of halophiles revealed that they belong to both Archaea and Bacteria representing the families Halobacteriaceae, Methanosarcinaceae and the class Gammaproteobacteria. As adaptive strategies against harsh salt stresses, majority of halophiles often synthesize and accumulate extracellular polysaccharides (EPS) which differ significantly in terms of their physical, chemical and material properties. So far the novelty in structure and functions of exopolysaccharides are concerned, producer strains belonging to the genera Halomonas and Haloferax have attracted the main attention. However, EPS producing strains belonging to the genera Idiomarina, Salipiger and Alteromonas are not uncommon. Through process optimization and metabolic regulation a number of potent halophilic strains have been found to produce copious amount of EPS indicating its commercial viability. Moreover, the significance of production, physico-chemical and biological properties along with the possible applications of halophilic EPS in industry and biotechnology have also been highlighted..

show abstract

The structure of the exopolysaccharide produced by the halophilic Archaeon Haloferax mediterranei strain R4 (ATCC 33500)

Cited by 76 publications

References 14 publications

Study on the Production and Re-use of Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) and Extracellular Polysaccharide by the Archaeon Haloferax mediterranei Strain DSM 1411

Study on the Production and Re-use of Poly(3-hydroxybutyrate-co-3- hydroxyvalerate) and Extracellular Polysaccharide by the Archaeon Haloferax mediterranei Strain DSM 1411

Production of Polyhydroxyalkanoate (PHA) Biopolyesters by Extremophiles?

Untitled

Contact Info

Product

Resources

About