Exopolysaccharide biosynthesis and biodegradation by a marine hydrothermal Alteromonas sp. strain

Abstract

Alteromonas macleodii subsp. fijiensis biovar deepsane is a deep-sea ecotype exopolysaccharide-producing bacteria isolated from the polychaete annelid Alvinella pompejana. The high molecular weight biopolymer HYD657 produced by this strain, is the first marine exopolysaccharide (EPS) to be commercialized for cosmetic use. Depolymerization methods are necessary to elucidate the complete structure of this EPS and to generate potentially bioactive oligosaccharides. Enzymatic methods are useful for elucidating polysaccharide structure because they specifically cleave glycosidic bonds and do not require harsh chemical conditions. The HYD657 EPS is structurally complex and no commercially available enzymes are able to effectively degrade it. Here, we present the first results on the endogenous enzymatic depolymerization of a marine EPS of biotechnological interest by the producing strain. Enzymatic activity was detected in the bacterial lysate and was able to decrease the apparent molecular size of the EPS, releasing mainly oligosaccharides. The reduced form of the native polysaccharide showed a slightly modified osidic composition, particularly in terms of molar ratio. Several exoglycosidase activities were measured in the bacterial lysate using paranitrophenyl-osides.

Enzymatic depolymerization of the GY785 exopolysaccharide produced by the deep-sea hydrothermal bacterium Alteromonas infernus : Structural study and enzyme activity assessment

“…2D). These observations emphasize that enzymes responsible for the EPS depolymerization are only present in bacterial cells; a part of them may be bound to (Lelchat et al, 2015).…”

“…No LMW bands It was then assumed that A. infernus strain could produce by itself enzymes able to degrade its own EPS. The presence of polysaccharidases and polysaccharide lyases degrading the EPS synthesized by the same bacteria has already been reported for few other EPS producing bacterial strains (Sutherland 1995(Sutherland , 1999Lelchat et al, 2015). To explore this hypothesis, three protein extracts were prepared and tested on the GY785 EPS: the culture supernatant (S), the soluble lysate (L) and the insoluble cell debris (D), obtained both after bacterial cell membrane lysis.…”

“…Indeed, several bacteria excreting EPS of peculiar structures have already been described, among which Alteromonas macleodii subsp. fijiensis biovar deepsane producing the bioactive HYD657 EPS (Cambon-Bonavita, Raguenes, Jean, Vincent, & Guézennec, 2002;Le Costaouëc et al, 2012;Lelchat et al, 2015), Vibrio diabolicus secreting HE800 EPS displaying some biological activities in skin and bone regeneration (Rougeaux, Kervarec, Pichon, & Guezennec, 1999;Zanchetta, Lagarde, & Guezennec, 2003;Senni et al, 2013), and Alteromonas infernus synthesizing GY785 EPS (Raguénès et al, 1997;Roger, Kervarec, Ratiskol, Colliec-Jouault, & Chevolot, 2004). Low molecular weight (LMW) oversulfated derivatives of GY785 EPS have shown some biological properties close to glycosaminoglycans (GAG).…”

The promise of marine molecules as cosmetic active ingredients

“…Two oligosaccharides within the EPS were found to protect epidermal keratinocytes and Langerhans cells from inflammatory mediators, including UVR [30]. Deepsane has been marketed as Abyssine â by Lucas Meyers as the first commercialized marine EPS [12,31]. The chemical structure of this unusual polysaccharide has also been reported [32].…”

Recent Advances in the Study of Marine Microbial Biofilm: From the Involvement of Quorum Sensing in Its Production up to Biotechnological Application of the Polysaccharide Fractions

“…A. macleodii subsp. fijiensis bacterium produces a high molecular weight (1.5ˆ10 6 Da) polymer, i.e., HYD657, that is commercially available with the name Abyssine ® (Patent PCT 94907582-4) for the protection of sensitive skin against chemical, mechanical and UVB aggressions [45]. Its main chemical features are shown in Table 1.…”