Statistical optimization of thermostable alpha amylase production by Laceyella sacchari THS-B4 and its application in cereal porridge thinning

Abstract

The high industrial demand for α-amylase necessitates the availability of thermostable forms of the enzyme in enhanced yields, which can be achieved by optimising production using statistical approaches. This study reports the optimization and characterization of a potent α-amylase from the thermophilic actinobacterium Laceyella sacchari strain THS-B4, isolated from the Tuva thermal spring, Gujarat. Medium components were screened using a Plackett–Burman Design, which identified starch, pH, and NaCl as the most critical factors. Subsequent optimization using Central Composite Design (RSM) resulted in a 3.8-fold increase in enzyme production. The purified 62 kDa enzyme exhibited maximum activity at 80 °C and pH 7.0, with ~ 99% residual stability in SDS. Kinetic constants Km and Vmax were 0.753 mg mL⁻¹ and 1.603 µmol min⁻¹ mL⁻¹, respectively. Application trials with wheat porridge demonstrated a ~ 90% reduction in viscosity, thereby increasing the energy density of weaning formulations. These findings highlight L. sacchari THS-B4 as a promising candidate for both industrial bioprocesses and nutritional applications. Laceyella sacchari THS-B4 was isolated from the Tuva thermal spring. α-Amylase production was enhanced 3.8-fold using PBD and RSM optimisation. The purified 62 kDa enzyme showed high thermostability and broad pH tolerance. The enzyme reduced cereal porridge viscosity by ~ 90%, enabling energy-dense weaning foods. To the best of our knowledge, this is the first report of Laceyella α-amylase application in cereal porridge thinning.