Advances in exopolysaccharide production from marine bacteria

Abstract

Over the last two decades, a wealth of novel marine exopolysaccharides (EPS) from bacteria have been found to possess many potential applications in industrial, medical, and environmental applications due to their chemical structure, which determines their functional properties. Marine bacteria communities rely on EPS to endure the extremes of temperature, salinity, and nutrient availability found in this ecosystem. Bacterial EPS are biodegradable, generally not toxic, and renewable with potential applications in many fields. However, the major challenge faced by marine bacteria EPS for commercial application is the high production cost that limits downstream processes. Therefore, the optimization of the fermentation parameters has been researched to achieve large‐scale production. This review summarize the characteristics and properties of marine bacterial EPS and evaluate some of the most important findings in the development of fermentation strategies that have shown promising results in terms of productivity improvement. © 2022 Society of Chemical Industry (SCI).

Production of exopolysaccharides with a high emulsifying activity using an Idiomarina strain under different conditions of oxygen transfer and temperature

“…For the cultures at 4.2 and 6.1 mmol L −1 h −1 , the highest EPS at the same culture time was 1.71 ± 0.17 and 2.44 ± 0.11 g L −1 , respectively. These results suggest that at the highest value of OTR max evaluated, the carbon and nitrogen sources are mainly diverted into EPS biosynthesis under both incubation temperatures, supporting the fact that EPS biosynthesis is an energy‐demanding process 5,36 . It is well documented that EPS production is a common adaptation in marine organisms to withstand low temperatures and high salinities 37,38 .…”

“…In general, there is a positive effect of q O 2 on biomass and EPS production, as well as EPS volumetric productivity where the increase in oxygen consumption favors cell growth and biosynthesis of EPS. It is known that exopolymer production may require an energy expenditure of up to 70%, 5 which amounts to a significant carbon and energy investment from cellular respiration to produce energy storage molecules to be used in the biosynthesis of EPS and synthesize building blocks for cell generation. However, more studies are needed on other parameters of information about the phenomenon of cellular respiration, such as the carbon dioxide transfer rate, the respiration quotient (RQ), and the yield coefficient of biomass on oxygen ( Y XO ).…”

“…These results suggest that at the highest value of OTR max evaluated, the carbon and nitrogen sources are mainly diverted into EPS biosynthesis under both incubation temperatures, supporting the fact that EPS biosynthesis is an energydemanding process. 5,36 It is well documented that EPS production is a common adaptation in marine organisms to withstand low temperatures and high salinities. 37,38 However, no significant differences were found in the maximal EPS production achieved at higher OTR max under the different incubation temperatures evaluated.…”

“…This chemical heterogeneity confers properties to EPS such as mechanical strength, metal‐complexing ability, emulsifying properties, and adhesion for important biological functions such as biofilm formation for protection against harsh environmental conditions, biotic interactions, and toxic metal tolerance. Due to biocompatibility and biodegradability, as well as their use as emulsifiers, stabilizers, and foaming agents, EPS have several industrial applications in many fields depending on their nature, composition, and structure, such as medicine and pharmaceuticals, food and cosmetics additives, bioremediation, source of sugar monomers to produce biofuels and biochemicals, paper and textile industries, among other applications 4‐8 …”

“…Due to biocompatibility and biodegradability, as well as their use as emulsifiers, stabilizers, and foaming agents, EPS have several industrial applications in many fields depending on their nature, composition, and structure, such as medicine and pharmaceuticals, food and cosmetics additives, bioremediation, source of sugar monomers to produce biofuels and biochemicals, paper and textile industries, among other applications. [4][5][6][7][8] Emulsifiers enable two usually non-mixable ingredients to mix; these are adsorbed at the interface between the dispersed and continuous phases to stabilize the dispersed particles by means of functional groups, spatial and hydrophobic interactions, and hydrogen bonds. For instance, Boujida et al 9 reported an interesting exopolymer produced by Marinobacter sp.…”