Addition of chemicals for increasing solubility of ERG12 and production of mevalonate phosphate (MVAP). The use of high concentration of sorbitol was also found to increase solubility of ERG12, a critical enzyme in the mevalonate pathway (the other isoprenoid precursor production pathway), and production of MVAP (product of ERG12). A: Metabolites and enzymes related to the mevalonate (MVA) pathway; MVA: Mevalonate, MVAP: Mevalonate phosphate, MVAPP: Mevalonate diphosphate, IPP: Isopentenyl diphosphate, DMAPP: Dimethylallyl diphosphate; ERG12: mevalonate kinase, ERG8: mevalonate phosphate kinase, ERG19: mevalonate diphosphate decarboxylase; B: Effects of sorbitol addition on solubility of ERG12, S: soluble fraction, IS: insoluble fraction; C: Effects of sorbitol addition on production of MVAP; Since ERG8 and ERG19 were not present in E. coli and also not recombinantly expressed, MVAP accumulated in ERG12 expressing E. coli , directly indicating activity of ERG12. Presented data were average of triplicates and standard errors were drawn on the plot. Student’s t-test was used to calculate the p values in the statistical analysis.