Effects of feeding and induction strategy on the production of BmR1 antigen in recombinant E. coli.

AIM: To investigate the effects of feeding and induction strategies on the production of BmR1 recombinant antigen.

METHODS AND

RESULTS

Fed-batch fermentation was studied with respect to the specific growth rate and mode of induction to assess the growth potential of the bacteria in a bioreactor and to produce high yield of BmR1 recombinant antigen. Cells were grown at a controlled specific growth rate (mu(set)) during pre-induction, followed by constant feeding postinduction. The highest biomass (24.3 g l(-1)) was obtained during fed-batch process operated at mu(set) of 0.15 h(-1), whereby lower mu(set) (0.075 h(-1)) gave the highest protein production (9.82 mg l(-1)). The yield of BmR1 was increased by 1.2-fold upon induction with 1 mmol l(-1) IPTG (isopropyl-beta-d-thiogalactoside) compared to using 5 mmol l(-1) and showed a further 3.5-fold increase when the culture was induced twice at the late log phase.

CONCLUSIONS

Combination of feeding at a lower mu(set) and twice induction with 1 mmol l(-1) IPTG yielded the best result of all variables tested, promising an improved method for BmR1 production.

SIGNIFICANCE AND IMPACT OF THE STUDY: This method can be used to increase the production scale of the BmR1 recombinant antigen to meet the increasing demand for Brugia Rapid(), a commercial diagnostic test for detection of brugian filariasis.