Invertase and �−glucosidase production by the endemic Antarctic marine yeast Leucosporidium antarcticum

• Main Authors: Marianna Turkiewicz, Marzena Pazgier, Stuart P. Donachie, Halina Kalinowska
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Key words; Antarctica; invertase; �−glucosidase; psychrophile yeast; Leucosporidium; Antarctic; Sion; Antarc*; Leucosporidium antarcticum
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.424.381; http://www.polar.pan.pl/ppr26/ppr26-125.pdf

Abstract: The marine psychrophilic and endemic Antarctic yeast Leucosporidium antarc− ticum strain 171 synthesizes intracellular �−fructofuranosidase, and intra − and extracellular �−glucosidases. Each enzyme is maximally produced at 5�C, while the strain’s optimum growth temperature is 15�C. Invertase biosynthesis appeared regulated by catabolic repres− sion, and induced by sucrose; the enzyme was extremely unstable ex vivo, and only EDTA, Mn 2+, and BSA stabilized it for up to 12 h after yeast cell lysis. Thermal stability of the invertase was also low (30 min at temperatures up to 12�C). The optimum temperature for invertase activity was 30�C, and optimum pH was 4.55 to 4.75. The extracellular �−gluco− sidase was maximally active at 35�C and pH 6.70–7.50, and stable for 30 min up to 20�C.