Optimization of Amylase Production from <i>Lactobacillus plantarum</i> CS by Submerged Fermentation Using Agro Wastes Substrates

Abstract

Amylases are known to be of great importance worldwide. Most of their production using refined carbon and nitrogen substrates are expensive, resulting in the production of expensive goods which are not easily affordable by end users in our country Nigeria. This necessitates the call for the use of cost-effective substrates under optimized condition for maximum amylase yield. Hence, the present study was focused on the optimization of amylase production from <i>Lactobacillus plantarum</i> CS using agro wastes from local substrates. The parameters assayed were carbon and nitrogen substrates from agro wastes, fermentation period (24-168h), pH (3.5-11) and temperature (30°C-70°C). Others included solvents for preparation of fermentation medium and metal ions of Mg²⁺, Mn²⁺, K⁺, Na⁺, Hg²⁺, Fe²⁺, Cu²⁺ and Pb²⁺ as supplements. The amylase produced via shake-flask fermentation was assayed using Dinitro salicylic acid method. The result revealed 3% sweet potato and 1% bambara nut wastes as the best carbon and nitrogen components of the required fermentation medium of pH 6.5. The optimal amylase produced (38.6U/ml) was achieved within 48h at 35°C with 1% inoculum and Mn²⁺/ Mg²⁺ as a co-factor. Relatively, Cu²⁺, Pb²⁺ and Hg²⁺ reduced the amylase yield to < 68.13% as against Mn²⁺ and Mg²⁺ which enhanced the production to 121.66% and 101.09% respectively. Natural rain water used as solvent for the preparation of fermentation medium significantly enhanced amylase production (24.65 U/ml) in relation to other test waters at P>0.05. Comparatively, there was a significant increase in amylase produced under optimized condition than not. Conclusively, the obtained results which revealed high amylase yield with available and cost effective agro-wastes is promising for industrial application in Nigeria.