Physiological and enzymatic characterization of a novel pullulan-degrading thermophilic Bacillus strain 3183

Abstract

A new thermophilic Bacillus strain 3183 (ATCC 49341) was isolated from hot-spring sediments. The organism grew on pullulan as a carbon source and showed optimum pH and temperature at pH 5.5 and 62 ° C, respectively, for growth. The strain reduced nitrate to nitrite both aerobically and anaerobically. It produced extracellular thermostable pullulanase and saccharidase activities which degraded pullulan and starch into maltotriose, maltose, and glucose. Medium growth conditions for pullulanase production were optimized. The optimum pH and temperature for pullulanase activity were at pH 6.0 and 75 ° C, respectively. The enzyme was stable at pH 5.5-7.0 and temperature up to 70 ° C in the absence of substrate. The K,, for pullulan at pH 6.0 and 75°C was 0.4 mg/ml. The pullulanase activity was stimulated and stabilized by Ca 2+. It was inhibited by ethylenediaminetetraacetate (EDTA), betaand gamma-cyclodextrins but not by alpha-cyclodextrin and reagents that inhibit essential enzyme SHgroups.

Archaeal and bacterial thermostable amylopullulanases: characteristic features and biotechnological applications

“…Batch fermentation in the laboratory fermenter led to two-fold increase in amylopullulanase production by G. thermoleovorans NP33 as compared to that attained in shake flasks [34]. The strain has been [49], Geobacillus stearothermophilus TS-23 [50], Thermoanaerobacterium saccharolyticum [4], Pyrococcus furiosus DSM 3638 [40,42], Thermococcus litoralis DSM 5473 [42], Lctobacillus plantarum [27] and Bacillus sp. [13] have been experimentally characterized.…”

Amylolytic Yeasts: Producers of α-amylase and Pullulanase

“…Clostridium thermosulfurogenes [96][97], C. thermohydrosulfuricum Z 21-109 [98], Thermoanaerobacterium thermosaccharolyticum [99] and Thermococcus profundus [100]. Aerobic and thermophilic bacteria, such as species of Bacillus and Geobacillus, are identified as producing amylopullulanase: Bacillus species 3183 [101], Bacillus circulans F-2 [102], Bacillus sp. TS-23 [60], Bacillus sp.…”