Viorica Corbu
Tatiana Vassu
İoana Bala
Stefana Petrut
Ortansa Csutak
Abstract
Yeasts are an important group of microorganisms with a wide range of biotechnological applications, able to synthetize various enzymes (lipases, proteases) and chemical compounds (pigments, flavor precursors). Many yeast strains are used for biocontrol in agriculture or for biomedical applications due to their ability to inhibit the growth of pathogenic microorganisms isolated from crops or nosocomial infections. Candida vanderwaltii is one of the yeast species isolated from natural environment with multiple, yet unexplored, applications. The present work deals with the identification and characterization of the new yeast strain CMGB-ST1 isolated from peony (Paeonia lactiflora) petals from Bucharest Botanical Garden (Romania).
The conventional tests (classic, BIOLOG system) and PCR-RFLP analyses of the ITS1-5,8S-ITS2 region showed that CMGB-ST1 belongs to Candida vanderwaltii species. Further tests were performed for determination of lipase production on optimized media with trybutirin as sole carbon source supplemented with Tween 80. The strain C. vanderwaltii CMGB-ST1 showed good lipolytic activity forming clear halos after only three days of incubation. The mechanism of trybutyrin assimilation was studied using two different liquid media containing trybutirin and inorganic nitrogen source and trybutirin-glucose as carbon source and organic nitrogen source. The results showed that lipase synthesis during the first three days of monitoring is mainly influenced by the carbon source because adding glucose increases the growth rate of the yeast cells. C. vanderwaltii CMGB-ST1 had also high antimicrobial activity against pathogenic and industrial Candida strains in presence of low pH values. In conclusion, the newly characterized strain C. vanderwaltii CMGB-G1 isolated from peony petals proved important potential for biotechnological and biomedical applications.