Understanding PHB Production profile in Bacillus thuringiensis IAM12077 and development of strategies for R-3 Hydroxybutyrate production

摘要

Bacillus thuringiensis IAM12077 is a PHB producer with maximum accumulation of 0.5g/L after 48 h growth in glucose rich media with nitrogen deficiency. An attempt to understand the in-vivo PHB depolymerase of the system was made by altering resting cell conditions. Cells of 48h grown culture was harvested and resuspended in nutrient limiting conditions to trigger in-vivo depolymerisation. Highest depolymerisation of PHB yielding 0.56g/L 3HB was noticed under pH9, 60μM MgCl 2 and 8h incubation. An understanding of the in-vivo depolymerase system helps in formulating conditions to increase either PHB accumulation or in-vivo degradation to release enantiomerically pure 3 hydroxubutyrate (3HB).