title: Characterization of thermostable β-amylase isozymes from Lactobacillus fermentum.
abstract: A strain of Lactobacillus fermentum producing two isozymes of a 20kDa β-amylase was isolated from the faecal sample of a newborn. The starin was identified by sequencing its 16S rRNA gene. The two β-amylase isozymes were resolved and visualized by two dimensional protein gel electrophoresis (2-D gel electrophoresis). Some of the physical and biochemical properties of the enzymes were characterized. The β-amylase displayed two optimum pH s, 5.0 and 10.0 and two optimum temperatures, 45°C and 37°C, respectively. The isozymes hydrolyzed different substrates: glycogen at pH 5.0, and corn starch at pH 10.0. The activity did not require Ca2+, though the activity at pH 10.0 was enhanced in the presence of 5.0mM and 10.0mM CaCl2,110% and 130%, respectively.
authors: Inönü University, Faculty of Science, Department of Molecular Biology and Genetic, Malatya, Turkey.
authors: Samet
authors: S
authors: Kocabay
authors: Cumhuriyet University, Faculty of Science, Department of Molecular Biology and Genetic, Sivas, Turkey.
authors: Serap
authors: S
authors: Çetinkaya
authors: Cumhuriyet University, Faculty of Science, Department of Molecular Biology and Genetic, Sivas, Turkey. Electronic address: bakkaya@cumhuriyet.edu.tr.
authors: Birnur
authors: B
authors: Akkaya
authors: Cumhuriyet University, Faculty of Science, Department of Molecular Biology and Genetic, Sivas, Turkey.
authors: Ali Fazil
authors: AF
authors: Yenidünya
mesh_terms: D004795:Enzyme Stability; D006003:Glycogen / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007527:Isoenzymes / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D052197:Limosilactobacillus fermentum / Q000201:enzymology*; D008670:Metals / Q000494:pharmacology; D011489:Protein Denaturation / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013213:Starch / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D001614:beta-Amylase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D008670:Metals; D012965:Sodium Chloride; D013213:Starch; D006003:Glycogen; D001614:beta-Amylase
keywords: Beta-amylase; Isozyme; Lactobacillus fermentum; Purification; Two dimentional protein electrophoresis