Isolation, Production Optimization, and Purification of a Debittering Enzyme from Bacillus megaterium AULS 1

Abstract

Bitterness in citrus juice is a common quality issue in the fruit-based beverage industry. Naringin, the dominant flavonoid responsible for bitterness in citrus fruit juice, can be mitigated by the enzyme naringinase. This study focuses on the isolation of novel naringinase-producing bacterium from mandarin orange peel, followed by the production and partial purification of naringinase. The bacterial strain exhibiting the highest enzyme production potential was identified as Bacillus megaterium AULS 1. The effects of carbon source (naringin) concentration, inducer (naringenin), pH, and temperature on naringinase production were investigated. Optimized conditions yielded a maximum naringinase production of 386.43 U mL–1. The produced enzyme was partially purified using ammonium sulfate precipitation and dialysis. The effects of pH, temperature, and metal ion concentration on the activity of the partially purified enzyme were evaluated, resulting in a highest activity of naringinase of 539.25 U mL–1 under optimized conditions. The debittering activity of the partially purified enzyme was 45.78 %. These findings demonstrate that Bacillus megaterium AULS 1 has the potential for naringinase production, and can be utilized for debittering citrus juices.

Keywords

• naringinase
• debittering
• bacillus megaterium
• naringin
• citrus juice