Process Optimisation of Amylase Produced by Lactic Acid Bacteria Isolated from Indigenous Foods and Dumpsites

Abstract

Amylase is an essential industrial enzyme widely applied in sectors such as textiles, food processing, detergents, and biofuel production. Because of the high demand for efficient and affordable amylases with broad industrial applicability, the search for the enzyme from safe isolates is continuous. This study aimed to optimise amylase production by lactic acid bacteria isolated from fermented cassava mash, ogi, and dump sites. Isolated bacteria from the stated samples were characterized morphologically and biochemically, and their ability to produce amylase was qualitatively assessed. Four isolates showing positive amylase activity were molecularly characterized and identified as Lactobacillus brevis FJ476121.1, Pediococcus acidilactici CP096031.1, Pediococcus pentasaceus AB362605.1, and Pediococcus acidilactici CP053421.1. Effects of nutritional and environmental factors on amylase production were examined, and the influences of Na+, Ca2+, Mg2+, Zn2+ and Cu2+ on enzyme activity were investigated. Enzyme production was optimized, partially purified and characterized. A 1% ammonium nitrate yielded the highest amylase values for isolates CP096031.1, CP053421.1 and FJ476121.1 with 1.8, 0.8 and 0.73 mg/mL respedtively whereas Pediococcus pentasaceus produced its highest level (0.62 mg/mL) with KNO3. Maltose supported maximum amylase production by Lactobacillus brevis (0.86 mg/mL). pH 6 and 7 significantly improved amylase yield, while 350C supported optimum production for most isolates except Lactobacillus brevis, which peaked at 450C (1.15 mg/mL). Cu2+ significantly enhanced amylase synthesis (0.86 mg/mL) Pediococcus pentasaceus, while Mg2+ and Zn2+ improved enzyme activity. Purified amylase exhibited optimal activity with. 2 % starch. The results demonstrate the potential of these isolates as promising sources of industrially relevant amylases.