• cold-active enzyme;
  • Mrakia frigida;
  • pectate lyase;
  • pectinase;
  • psychrophilic yeast


Aims:  This study was conducted to determine optimal conditions for pectate lyase (PL) production by two psychrophilic yeast strains and to compare the properties of the cold-active enzymes using mesophilic PL as reference enzyme.

Methods and Results:  Two psychrophilic yeasts isolated from remote geographical locations (European Alps, north Siberia) produced extracellular cold-active PL. Both strains were identified as Mrakia frigida by analysis of ITS and large subunit (LSU) rRNA sequences. Maximum enzyme production occurred at a cultivation temperature of 1 or 5°C. The apparent optimum for enzyme activity was observed at 30°C and pH 8·5–9. The enzymes were thermolabile, but were resistant to repeated freezing and thawing.

Conclusion:  We describe for the first time alkaline PL-producing representatives of the yeast species M. frigida. The two strains produce cold-active PL with similar properties, but have a different enzyme production pattern.

Significance and Impact of the Study:  The enzymes described in this study could be useful for a wide range of applications, such as low-temperature pretreatment of wastewater containing pectic substances.