Screening for and identification of starch-, amylopectin-, and pullulan-degrading activities in bifidobacterial strains.
Forty-two bifidobacterial strains were screened for alpha-amylase and/or pullulanase activity by investigating their capacities to utilize starch, amylopectin, or pullulan. Of the 42 bifidobacterial strains tested, 19 were capable of degrading potato starch. Of these 19 strains, 11 were able to degrade starch and amylopectin, as well as pullulan. These 11 strains, which were shown to produce extracellular starch-degrading activities, included 5 strains of Bifidobacterium breve, 1 B. dentium strain, 1 B. infantis strain, 3 strains of B. pseudolongum, and 1 strain of B. thermophilum. Quantitative and qualitative enzyme activities were determined by measuring the concentrations of released reducing sugars and by high-performance thin-layer chromatography, respectively. These analyses confirmed both the inducible nature and the extracellular nature of the starch- and pullulan-degrading enzyme activities and showed that the five B. breve strains produced an activity that is consistent with type II pullulanase (amylopullulanase) activity, while the remaining six strains produced an activity with properties that resemble those of type III pullulan hydrolase.
Ryan
Sinéad M
SM
Alimentary Pharmabiotic Centre, Bioscience Institute, National University of Ireland, Cork, Western Road, Cork, Ireland.
Fitzgerald
Gerald F
GF
van Sinderen
Douwe
D
D000595:Amino Acid Sequence; D000687:Amylopectin / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001644:Bifidobacterium / Q000145:classification / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D003470:Culture Media; D005936:Glucans / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D017422:Sequence Analysis, DNA; D013213:Starch / Q000378:metabolism*; D000516:alpha-Amylases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D003470:Culture Media; D005936:Glucans; C009109:pullulan; D013213:Starch; D000687:Amylopectin; D006026:Glycoside Hydrolases; D000516:alpha-Amylases; C082507:amylopullulanase; C100181:pullulanase