Structural insight into a glucomannan-type extracellular polysaccharide produced by a marine Bacillus altitudinis SORB11 from Southern Ocean

Abstract

Extracellular polysaccharide (EPS) produced by a deep-sea, psychrotolerant Bacillus altitudinis SORB11 was evaluated by considering physiochemical nature and structural constituents. The productivity of crude EPS was measured ~ 13.17 g L−1. The surface topography of the crude EPS showed a porous, webbed structure along with a branched coil-like configuration. The crystalline crude EPS contained a high amount of sulfur. Further, the crude EPS was subjected for purification. The molecular weight of purified EPS was determined ~ 9.8 × 104 Da. The purified EPS was appeared to show glucomannan-like configuration that is composed of → 4)-β-Manp-(1 → and → 4)-β-Glcp-(1 → residues. So, this polysaccharide was comparable to the structure of plant-derived glucomannan. Subsequently, EPS biosynthesis protein clusters like EpsC, EpsD, EpsE, and glycosyltransferase family proteins were predicted from the genome of strain SORB11, which may provide an insight into the production of glucomannan-type of polysaccharide. This low molecular weight linear form of glucomannan-type EPS might be involved to form a network-like unattached aggregation, and helps in cell-to-cell interaction in deep-sea microbial species.

Exopolysaccharide Production from Marine-Derived Brevundimonas huaxiensis Obtained from Estremadura Spur Pockmarks Sediments Revealing Potential for Circular Economy

“…SPUR-55 revealed 100% identity with four different strains of the Bacillus genera (Figure 3). Bacillus aerius ATHM35, a salt-tolerant EPS producer, was isolated from hypersaline soils [41], and the deep sea psychrotolerant B. altitudinis SORB11 produced EPS with a glucomannan-like configuration, composed of → 4)-β-Manp-(1 → and → 4)-β-Glcp-(1 → residues) [42]. In another study, B. altitudinis MSH2014, isolated from mangrove trees in Ras Mohamed, Red Sea Coast, Sinai Peninsula, Egypt, produced EPS containing mannouronic acid, glucose, and sulfate, [38].…”

“…There have been reports of EPS Brevundimonas producers isolated from saline environments [36][37][38]. Although EPS production was previously described for a B. vesicularis strain isolated from a paper mill [39] and for B. nasdae residues) [42]. In another study, B. altitudinis MSH2014, isolated from mangrove trees in Ras Mohamed, Red Sea Coast, Sinai Peninsula, Egypt, produced EPS containing mannouronic acid, glucose, and sulfate, [38].…”