TY - JOUR
T1 - β-Glucosidase in Candida albicans and its application in yeast identification
AU - Polacheck, I.
AU - Melamed, M.
AU - Bercovier, H.
AU - Salkin, I. F.
PY - 1987
Y1 - 1987
N2 - In this report we attempt to explain the discrepancy between β-glucosidase (EC 3.2.1.21) activity in Candida albicans as measured by commercial kits and that found in an experimental assay. β-Glucosidase activity in American and Israeli isolates of C. albicans was evaluated with the API ZYM and YeastIdent systems (Analytab Products) and with experimental biochemical assays. Activity was found with whole cells and cell extracts of isolates from both sources. The greatest β-glucosidase activity was found at pH 5.0 and with p-nitrophenyl-β-glucopyranoside (PNP-BDG) as the substrate. In assays with β-naphthyl-β-D-glucopyranoside and 6-bromo-2-naphthyl-β-D-glucopyranoside (6-Br-2-naphthyl-BDG), no enzyme activity was detected in whole cells and only limited activity was found in cell extracts of isolates from both sources. In studies with PNP-BDG at pH 5.0 and 7.5, 29 to 38% less activity was found at both pHs with American whole cells, and minor activity (20%) was found at pH 7.5 with isolates from both sources. Because assays with PNP-BDG in cell extracts of isolates from both sources showed no significant differences in activity, the more limited β-glucosidase activity in American whole cells was most likely due to less efficient transport. Because the API ZYM system uses 6-Br-2-naphthyl-BDG as the substrate and because the substrate is buffered at pH 7.5 in the API YeastIdent kit, both systems appear to be of limited value for the detection of β-glucosidase activity in C. albicans.
AB - In this report we attempt to explain the discrepancy between β-glucosidase (EC 3.2.1.21) activity in Candida albicans as measured by commercial kits and that found in an experimental assay. β-Glucosidase activity in American and Israeli isolates of C. albicans was evaluated with the API ZYM and YeastIdent systems (Analytab Products) and with experimental biochemical assays. Activity was found with whole cells and cell extracts of isolates from both sources. The greatest β-glucosidase activity was found at pH 5.0 and with p-nitrophenyl-β-glucopyranoside (PNP-BDG) as the substrate. In assays with β-naphthyl-β-D-glucopyranoside and 6-bromo-2-naphthyl-β-D-glucopyranoside (6-Br-2-naphthyl-BDG), no enzyme activity was detected in whole cells and only limited activity was found in cell extracts of isolates from both sources. In studies with PNP-BDG at pH 5.0 and 7.5, 29 to 38% less activity was found at both pHs with American whole cells, and minor activity (20%) was found at pH 7.5 with isolates from both sources. Because assays with PNP-BDG in cell extracts of isolates from both sources showed no significant differences in activity, the more limited β-glucosidase activity in American whole cells was most likely due to less efficient transport. Because the API ZYM system uses 6-Br-2-naphthyl-BDG as the substrate and because the substrate is buffered at pH 7.5 in the API YeastIdent kit, both systems appear to be of limited value for the detection of β-glucosidase activity in C. albicans.
UR - http://www.scopus.com/inward/record.url?scp=0023111368&partnerID=8YFLogxK
U2 - 10.1128/jcm.25.5.907-910.1987
DO - 10.1128/jcm.25.5.907-910.1987
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 3108312
AN - SCOPUS:0023111368
SN - 0095-1137
VL - 25
SP - 907
EP - 910
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
IS - 5
ER -