A New Bacillus licheniformis Alpha‐Amylase Capable of Low pH Liquefaction

Abstract

A new alpha‐amylase has been developed capable of catalyzing industrial scale liquefaction of starch at lower than conventional pH levels. Low pH liquefaction results in significant cost savings and less complex operations for a starch processor. Liquefaction studies in a pilot scale jet cooker demonstrated that, surprisingly, commercial starch slurries taken from different sources vary greatly as to ease of liquefaction at lower than conventional pH values. Apparently low levels of stabilizing or destabilizing factors exist in commercial starch slurries which affect the stability of alpha‐amylase during high temperature (103–107°C) liquefaction.

Statistical factorial designs for optimum production of thermostable α-amylase by the degradative bacterium Parageobacillus thermoglucosidasius Pharon1 isolated from Sinai, Egypt

“…Commercially, the interest has been focused on thermophilic amylase capable of functioning at a low pH range of 4.5–5.5 [ 35 ]. A similar result was obtained by Antrim et al [ 36 ] who reported a thermostable α-amylase with activity at pH 5.5. Uguru et al [ 37 ] isolated a strain of Thermoactinomyces thalpophilus which produced an extracellular amylase with optimum pH of 5.0.…”

The effect of process conditions on the ?-amylolytic hydrolysis of amylopectin potato starch: An experimental design approach

“…It may be surprising that the initial hydrolysis was not significantly influenced by pH or temperature. However, the reported maximum pH activity range for B. licheniformis ␣-amylase is quite broad and in the investigated range (pH 6-pH 7.2) about constant (Antrim et al, 1991;Anyangwa et al, 1993;Bajpai and Bajpai, 1989;Dobreva et al, 1994;Madsen et al, 1973;Morgan and Priest, 1981;Ramesh and Lonsane, 1990;Rosendal et al, 1979;Saito, 1973). This may explain why there was no significant influence of pH on the initial rate of hydrolysis.…”

“…In industrial applications, pH and temperature are controlled and calcium is often added to enhance enzyme stability. Knowledge of interactions between factors such as pH and calcium (Antrim et al, 1991) or pH and temperature (Henderson and Teague, 1988) is limited. Furthermore, the effect of stirring on the enzymatic conversion is not known.…”

Comparative production of glucose and high fructose syrup from cassava and sweet potato roots by direct conversion techniques

“…Although the percentage conversion to glucose was almost similar in the case of T1 and T2, the different working temperatures (90-100°C for liquezyme-X and 60°C for Dextrozyme GA) and pHs (6.5 for liquezyme-X and 4.0 for glucoamylase) required for T1 make the treatment economically disadvantageous. Further, Antrim et al (1991) observed that maltulose formation was higher when liquefaction was performed at pH above 6.0. Use of Stargen at pH 4.5 may also prevent maltulose formation, thereby increasing the glucose yield.…”