Extremolytes: natural compounds from extremophiles for versatile applications

Abstract

Extremophilic microorganisms have adopted a variety of ingenious strategies for survival under high or low temperature, extreme pressure, and drastic salt concentrations. A novel application area for extremophiles is the use of "extremolytes," organic osmolytes from extremophilic microorganisms, to protect biological macromolecules and cells from damage by external stresses. In extremophiles, these low molecular weight compounds are accumulated in response to increased extracellular salt concentrations, but also as a response to other environmental changes, e.g., increased temperature. Extremolytes minimize the denaturation of biopolymers that usually occurs under conditions of water stress and are compatible with the intracellular machinery at high (>1 M) concentrations. The ectoines, as the first extremolytes that are produced in a large scale, have already found application as cell protectants in skin care and as protein-free stabilizers of proteins and cells in life sciences. In addition to ectoines, a range of extremolytes with heterogenous chemical structures like the polyol phosphates di-myoinositol-1,1'-phosphate, cyclic 2,3-diphosphoglycerate, and alpha-diglycerol phosphate and the mannose derivatives mannosylglycerate (firoin) and mannosylglyceramide (firoin-A) were characterized and were shown to have protective properties toward proteins and cells. A range of new applications, all based on the adaptation to stress conditions conferred by extremolytes, is in development.

A Specialized Aspartokinase Enhances the Biosynthesis of the Osmoprotectants Ectoine and Hydroxyectoine in Pseudomonas stutzeriA1501

“…Ectoine and hydroxyectoine have attracted considerable biotechnological attention, since these compatible solutes possess excellent stabilizing properties for proteins, cell membranes, nucleic acids, and even entire cells (19,23,34,38,45). They have therefore found versatile uses as in vivo protein-folding catalysts, as in vitro protein stabilizers, as PCR enhancers, as cytoprotectants, and, foremost, as skin care products in cos-metics (19,38,45).…”

In vitro evaluation of glyceric acid and its glucosyl derivative, α-glucosylglyceric acid, as cell proliferation inducers and protective solutes

“…14) The in vitro functions of compatible solutes in terms of protecting biological molecules are another important aspect. 15,16) Ectoine, a commercially available compound produced by bacterial fermentation, exhibits broad-spectrum protection of biological molecules, cells, and skin, such as enzyme-stabilizing effects against heat and freeze-thawing, 17) inhibition of insulin amyloid formation, 18) and prevention of UVA-induced photoaging. 19) Mannosylglycerate is a commercial product that protects proteins.…”

“…The protective effect against DNA scission by the hydroxyl radical was determined in water with a hydroxyl radical-generation system that uses H 2 O 2 , FeCl 3 , and ascorbic acid. 15) pUC118 (Takara, Otsu, Shiga) was used as the DNA source. The reaction was incubated at 37°C for 30 min and then subjected to 1% agarose electrophoresis.…”

A Comparative Metabolomics Analysis ofSaccharopolyspora spinosaWT, WH124, and LU104 Revealed Metabolic Mechanisms Correlated with Increases in Spinosad Yield

“…Highly osmotic pressure can induce the ectoine synthesis. 39,40) The high concentration of ectoine in WH124 suggests that the degradation of the macromolecules proceeded more rapidly in WH124.…”