Lessons from nature: the role of sugars in anhydrobiosis

https://doi.org/10.1016/S1095-6433(01)00503-7Get rights and content

Abstract

A review of the role of sugars in anhydrobiosis is presented.

Introduction

Ever since Leeuwenhoek first described the recovery of live ‘animalcules’ from dried sediment from his rooftop gutter in 1702 (Keilin, 1959), scientists and laymen alike have been fascinated by the ability of many organisms to dry out completely and then resume activity and metabolism upon rehydration (a phenomenon known as ‘anhydrobiosis’). A list of anhydrobiotic organisms includes the encysted gastrulae of the brine shrimp, Artemia salina, several nematodes, various ‘resurrection’ plants (Selaginella lepidophylla, Myrothamnus flabellifolia, Craterostigma planitagineum), tardigrades, rotifers (Leeuwenhoek's animalcules), lichen, some ferns, and many seeds, yeasts and bacteria. A common theme for all these organisms is that they contain large amounts of the disaccharides, trehalose or sucrose, in the dry state. In general, sucrose appears to be favored by seeds and higher plants, while lower plants and small animals and microorganisms utilize trehalose.

In the early 1970s, this laboratory began a series of studies of metabolism and survival of drying using the nematode, Aphelenchus avenae. This nematode is small and can be cultured in large quantities, so that considerable survival and metabolic data could be gathered. An important finding of these early studies was that the survival of drying by A. avenae is strongly correlated with the production of large amounts of trehalose; as much as 20% of the dry weight of the nematode (Madin and Crowe, 1975). Trehalose is also present in high quantities in yeast (Payen, 1949) and in Selaginella (Harding, 1923). This finding prompted us to undertake model studies, beginning in the late 1970s, to determine if and how trehalose could effect survival.

Section snippets

Results from model studies

Our first model was isolated sarcoplasmic reticulum and T-system membranes (SR) from the large abdominal flexor muscle of the lobster Homarus americanus. These membranes can be isolated in large amounts and exhibit a well-defined structure, calcium transport and ATPase activity that are easily quantified. The structure, ATPase activity and calcium transport activity of freeze-dried and rehydrated membranes were very similar to the fresh native membranes at trehalose contents similar to those

How does trehalose exert its protective effect?

Early in the model studies, evidence from infrared spectroscopy suggested an effect of trehalose on the phosphate asymmetric stretch of phospholipids (Crowe et al., 1984a, Crowe et al., 1984b). The phosphate group of dry phospholipids has a high wavenumber (∼1250 cm−1), while hydrated phospholipids have a lower wavenumber (∼1225 cm−1) due to the formation of hydrogen bonds between the phosphate and water hydroxyls. Dry SR had a phosphate asymmetric stretch at 1240 cm−1, hydrated SR at 1230 cm−1

What other effects might trehalose have?

Trehalose, like other sugars, is a good glass former. Glasses are amorphous solids of high viscosity, in which mobility of the components is highly restricted. In the glassy state, deleterious interactions between components in the glass can occur, such as free radical formation (Heckly, 1978) and lipid peroxidation (Mouradian et al., 1984, Mouradian et al., 1985) (for review, see Sun and Leopold, 1997). The glass transition temperature (Tg) is the temperature above which the high viscosity

How does the sugar/lipid interaction affect the glass transition?

Differential scanning calorimetry is the usual method of determining the glass transition temperature of substances. If the amount of glass present is small, the glass transition can be difficult to detect by DSC. Recently, a more sensitive method has been developed using FTIR (Wolkers et al., 1998b). It is based on the fact that the frequency of the OH stretching bands (νOH) in the region between 3600 and 3000 cm−1 is directly related to the force constant of the of the OH bond. For a single

Conclusions

Numerous studies over the last two decades have shown that two common sugars, sucrose and trehalose, found in anhydrobiotic organisms, have the ability to stabilize biological membranes, liposomes and proteins in the dry state. Direct interaction of sucrose and trehalose with lipids, membranes and proteins has been demonstrated. These direct interactions lower the phase transition temperature of membranes, thereby preventing leakage due to phase transitions during rehydration. Direct

References (40)

Cited by (281)

  • The melting of glucose

    2022, International Journal of Pharmaceutics
View all citing articles on Scopus

This paper was originally presented at a symposium on extremophiles held within the ESCPB 21st International Congress, Liège, Belgium, 24–28 July 2000.

View full text