Bioprocess exploration for thermostable α-amylase production of a deep-sea thermophile Geobacillus sp. in high temperature bioreactor

In this work, culture medium and conditions were firstly optimized to enhance production of thermostable α -amylase by statistical methodologies. The resulting extracellular production was increased by 5 times and reached 6.40 U/ml.

Then, a high-temperature batch culture of the thermophile in a 15 L house designed bioreactor was studied. The results showed that, a relatively high dissolved oxygen (600 rpm and 15 L/min) and culture temperature of 60°C facilitated both cell growth and α -amylase production. Thus, an efficient fermentation process was established with initial medium pH of 6.0, culture temperature of 60°C and keeping dissolved oxygen above 20%.