Cryopreservation, Reactivation, and Propagation of Candida tropicalis (Castellani) Berkhout 750™ for Biotechnological Applications.

Candida tropicalis is a nonconventional yeast with biotechnological applications based on its capacity to produce sweeteners, biofuels, enzymes, and polysaccharides from the assimilation of different carbon sources. The biotechnological advantages are dependent on its metabolism, which can be preserved avoiding genotypic or phenotypic changes through cryopreservation. Hence, the protocols needed to carry out the cryopreservation of C. tropicalis (Castellani) Berkhout 750™ obtained from the KWIK-STIK™ are described. KWIK-STIK™ provides lyophilized microorganisms useful as control strains at the laboratory level; however, these strains, once reactivated, are genetically unstable, and a series of passages compromise their metabolism. In this sense, cryopreservation favors the obtaining of pure cultures stable for prolonged periods and with the ease of obtaining large quantities of biomass from small inoculum. These advantages can be used for various purposes, either for the generation of bioactive compounds or as starters for the reproduction of new metabolically stable batches.