| Congresso Brasileiro de Microbiologia 2023 | Resumo: 1243-1 | ||||
Resumo:In extremely cold environments, microorganisms are subject to temperature variation and water may freeze. There are some microorganisms that have adapted to the cold and can tolerate a lack of liquid water. These features include efficient metabolism at low temperature, fluidity of the plasmatic membrane and production of cryoprotective substances such as antifreeze proteins – AFP. Antifreeze proteins can be produced by microorganisms depending on the extreme environment condition itself. The main function of antifreeze protein is to prevent freezing in very cold temperatures. The aim of this review was describe the state of the art of antifreeze proteins produced by microorganisms. A total of 172 antifreeze protein studies were found, which include culture-dependent and independent studies. The examined microorganisms are distributed in the groups of Algae, Fungi, Bacteria and Archaea. Among the these, the most commonly described as AFP-producer was the Bacteria of the phylum Proteobacteria, followed by Fungi of the phylum Basidiomycota. Within the algae group, classes Bacillariophyceae and Chlorophyceae were the most frequently described as AFP-producers. Only one archaea (phylum Euryarchaeota) was found as producer of antifreeze proteins. In addition, 15 proteins have been described for the algae group, 22 proteins for the bacteria group, and 8 proteins for the fungus group. Among the studies gathered in this review, 29 protein extracts were tested and showed Recrystallization Inhibition activity (IR). In addition to IR activity, Thermal Hysteresis (TH) activity was also tested, with a total of 24 protein extracts exhibiting antifreeze activity. This strategy is fundamental for the successful survival of these microorganisms exposed to temperature variation and that can be used for biotechnological purposes in the cryopreservation of products. Despite the relatively great diversity of AFP-producing microorganisms, knowledge of the function, regulatory factors, binding spin, and activity of these proteins in nature is still poorly studied. Since antifreeze proteins prevent ice formation, they have several applications in biotechnology. As a concluding remark, cold-adapted microorganisms present a broad range of antifreeze proteins with different properties, but further studies are needed to better explore the complete potential of microbial AFPs in biotechnological applications. Palavras-chave: Biotechnology, extremophiles, microbiology, cryoprotective substances, cold temperature Agência de fomento:Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina - FAPESC | |||||