Cold active proteins in Food and pharmaceutical industry:

The cold active xylanase from the Antarctic bacterium Pseudoalteromonas haloplanktis is a nice example of the successful biotechnological transfer from academic research to industry. Xylanases are glycoside hydrolases that degrade the polysaccharide beta-1, 4-xylan, thus breaking down hemicellulose, one of the major components of plant cell walls. Xylanases are also a key ingredient of industrial dough conditioners used to improve bread quality. Furthermore, baking trials have revealed that the psychrophilic xylanase was very effective in improving the dough properties and final bread quality with, for instance, a positive effect on loaf volume. This efficiency appears to be related to the high activity of the psychrophilic xylanase at cool temperatures required for dough resting and to its specific mode of xylan hydrolysis. Following careful production optimization of this peculiar xylanase, the product is now sold by Puratos (Belgium). This is apparently the psychrophilic enzyme produced at the highest amounts at present time.

Beta-galactosidase, or lactase, is also a glycoside hydrolase that specifically hydrolyzes the milk sugar lactose into galactose and glucose. It should be stressed that 75% of the world population suffers from lactose intolerance arising from deficient synthesis of intestinal lactase in adults and resulting in digestive disorders due to fermentation of lactose by enteric bacteria. In this context, a cold-active lactase from an Antarctic bacterium has been patented for its capacity to hydrolyze lactose during milk storage at low temperatures. It is worth mentioning that commercially available lactases require milk heating to become active. This heating step has, however, detrimental effects on milk quality as it alters the aspect, the taste and texture (Maillard reactions, activation of proteases, coagulation, and so on). Although the psychrophilic lactase is apparently not used for this specific application, it is expected that many industries will be produced soon in large quantities to hydrolyze lactose (a by-product of the dairy industry) in the process of the high value sweetener D-tagatose, a natural monosaccharide with low caloric value and glycaemic index.

Antarticine-NF3 is a glycoprotein with antifreeze properties produced by the bacterium Pseudoalteromonas Antarctica that has been patented by Spanish researchers (Parente Duena et al. 2006). It was found that Antarticine is effective for scar treatments and re-epithelialization of wounds. This glycoprotein is now included in some cosmetic regeneration creams (sometimes under the name Antarctilyne). It is also proposed in association with edelweiss extract: this is of course reminiscent of the peculiar resistance to harsh conditions of both the Antarctic bacterium and the Alp flower. The extracts of the Antarctic algae Durvillea Antarctica are included in cosmetics creams to improve skin vitality such as in the Extra Firming Day Cream, a top seller of Clarins (France) (Margesin and Feller, 2010). The successful business endeavor has been the introduction of AFPs into ice cream and yogurt products. AFPs allow the production of very creamy, dense, reduced fat ice cream with fewer additives. They control ice crystal growth brought on by thawing on the loading dock or kitchen table which drastically reduces texture quality.

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