title: Consecutive hydrolysis of creatinine using creatininase and creatinase encapsulated in Saccharomyces cerevisiae spores.
abstract: OBJECTIVE
  To achieve consecutive conversion from creatinine to urea and sarcosine using creatininase and creatinase encapsulated in spores of Saccharomyces cerevisiae.
  
  
  RESULTS
  Creatininase encapsulated into the spore wall was produced and its specific activity was 3.4 ± 0.4 U/mg. By deletion of OSW2 gene, which causes a mild spore wall defect, the activity was increased to 10.9 ± 0.5 U/mg. Compared with soluble enzymes, spore-encapsulated creatininase was tolerant to environmental stresses; creatininase encapsulated in osw2∆ spores retained more than 90 % of the activity after treatment by SDS or proteinase K. Creatinase capsules could also be produced through spore encapsulation. The mixture of spores containing either creatininase or creatinase could mediate a two-step reaction to produce urea from creatinine; 5 mg spores produced 19 µmol urea in 10 min. Spores co-expressing creatininase and creatinase could also mediate the reactions more efficiently than the mixture of spores individually expressing each enzyme; the yield in 10 min was 38 µmol.
  
  
  CONCLUSIONS
  Yeast spores can hold creatininase and creatinase simultaneously and catalyze the consecutive reactions.
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Kong
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Zijie
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
authors.forename: Huijie
authors.initials: H
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. xdgao@jiangnan.edu.cn.
authors.forename: Xiao-Dong
authors.initials: XD
authors.lastname: Gao
authors.affiliation: Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. hideki@jiangnan.edu.cn.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakanishi
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D003404:Creatinine / Q000378:metabolism*; D006868:Hydrolysis; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D013172:Spores, Fungal / Q000201:enzymology*; D014512:Ureohydrolases / Q000378:metabolism*
chemical_list: D003404:Creatinine; D000581:Amidohydrolases; C019946:creatininase; D014512:Ureohydrolases; C019944:creatinase
keywords: Creatinase; Creatininase; Encapsulated enzymes; Saccharomyces cerevisiae; Spores