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Bacteria from Patagonian Merino wool were isolated to assess their wool-keratinolytic activity and potential for felt-resist treatments. Strains from Bacillus, Exiguobacterium, Deinococcus, and Micrococcus produced wool-degrading enzymes. Bacillus sp. G51 showed the highest wool-keratinolytic activity. LC-MS/MS analysis revealed that G51 secreted two serine proteases belonging to the peptidase family S8 (MEROPS) and a metalloprotease associated with Bacillolysin, along with other enzymes (γ-glutamyltranspeptidase and dihydrolipoyl dehydrogenases) that could be involved in reduction of keratin disulfide bonds. Optimum pH and temperature of G51 proteolytic activity were 9 and 60 °C, respectively. More than 80% of activity was retained in HO, Triton X-100, Tween 20, Lipocol OXO650, Teridol B, and β-mercaptoethanol. Treatment of wool top with G51 enzyme extract caused a decrease in wool felting tendency without significant weight loss (<1.5%). Sparse work has so far been performed to investigate suitable keratinases for the organic wool sector. This eco-friendly treatment based on a new enzyme combination produced by a wild bacterium has potential for meeting the demands of organic wool processing which bans the use of hazardous chemicals and genetic engineering.

In addition to their ecological importance in the acquisition of nitrogenrich organic compounds, extracellular proteases also have interesting biotechnological applications. Particularly, alkaline proteases represent one of the most important groups of commercial enzymes. First, we introduce the classifi cation and catalytic mechanisms of proteases. Then, this chapter reviews the advances in the bioprospection of alkaline proteases produced by bacteria adapted to selective conditions from different environments of Patagonia (Argentina). Among them, the arid soils of the Patagonian Monte are propitious for the development of alkaliphilic microorganisms. Thus, we focus on the description of the species Bacillus patagoniensis and the biochemical and catalytic properties of its alkaline protease. Then, we discuss investigations about alkaline protease-producing bacteria from the southern Patagonian coast, the prevalence of psychrophilic and psychrotolerant strains, and the response of their extracellular proteases to temperature.

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