Characterization of cold-active pectate lyases from psychrophilic Mrakia frigida.
OBJECTIVE
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.


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 degrees C. The apparent optimum for enzyme activity was observed at 30 degrees C and pH 8.5-9. The enzymes were thermolabile, but were resistant to repeated freezing and thawing.


CONCLUSIONS
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.


CONCLUSIONS
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.
Margesin
R
R
Institute of Microbiology, Leopold Franzens University, Innsbruck, Austria. rosa.margesin@uibk.ac.at
Fauster
V
V
Fonteyne
P-A
PA
D001487:Basidiomycota / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification; D003080:Cold Temperature; D004271:DNA, Fungal / Q000737:chemistry; D004275:DNA, Ribosomal / Q000737:chemistry; D021903:DNA, Ribosomal Spacer / Q000737:chemistry; D004795:Enzyme Stability; D020459:Genes, rRNA; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D011133:Polysaccharide-Lyases / Q000096:biosynthesis* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D013696:Temperature
D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D011133:Polysaccharide-Lyases; C023911:pectate lyase