Production of Amylase by Arthrobacter kerguelensis VL-RK_09 Isolated from Mango Orchards

Abstract

Objectives: To optimize the cultural parameters for improved production of amylase by Arthrobacter kerguelensis VL-RK_09 isolated from Mango orchards of Vissannapet, Krishna District, A.P., India. Methods: The strain A. kerguelensis was screened initially for amylase production on Inorganic salts starch agar medium (ISP-4). The enzyme assay was performed as per the procedure described by Bernfield (1955). One amylase unit equals to that amount of enzyme needed to release 1 mg of reducing sugar (maltose as standard) for 15 min at 37°C. Attempts were also made to optimize cultural parameters such as pH, temperature, carbon and nitrogen sources affecting the production of amylase by the strain. Results: Maximal yields of amylase were recorded after 4 days of incubation in Inorganic salts starch medium with initial pH 7.0 and temperature 35°C. ISP-4 broth amended with sorghum flour (2%) and yeast extract (0.5%) with initial pH 7.0 inoculated with Arthrobacter kerguelensis VL-RK_09 and incubated at 30°C for 96 h resulted in improved production of amylase from initial 4.0 U to 10.4 U/mL. Conclusion: This is the first report on the production and optimization of amylase by A. kerguelensis and further studies on purification and characterization of the enzyme are in progress.