In this paper, the syntheses of kojic acid esters via chemical and enzymatic methods are
reviewed. The advantages and disadvantages of chemical process in term of process, safety and
efficiency are discussed. In enzymatic process, the significant process parameters related to the
synthesis of kojic acid esters such as the lipases, solvent, temperature and water content are
highlighted. Possible enzymatic synthesis using solvent and solvent-free system taking into
consideration of the difference in these systems involving cost, lipase reusability and efficiency
is comparatively reviewed. The possible approach for large scale production using various
enzyme reactor designs is also discussed and re-evaluated.
Biosurfactants are surface active compounds and amphiphatic in nature which consist of
hydrophilic head and hydrophobic tail accumulating at the interphase of two immiscible liquid
with different polarity. A study was conducted to investigate the effectiveness of sunflower oil in
the production of rhamnolipids (RLs) by locally isolated Pseudomonas aeruginosa in shake flask
fermentation. In this process, four different fermentation treatments were done for seven days at
30°C and 180 rpm. Sampling was carried out in time intervals of 24 h followed by monitoring of
cell growth and biosurfactants production. Colorimetric Orcinol analysis was used for
determination of RLs concentrations (g/L). The RLs were studied for emulsification activity
using emulsification index (E24%) methods. In addition, oil displacement activity and thermal
stability were also studied (4-120°C). All treatments allow the growth of P. aeruginosa and the
utilization of sunflower oil as carbon source and glucose as growth initiator were observed to be
the best strategy for maximum RLs production. The maximum RLs production was achieved
after 120 h with 3.18 g/L of RLs. Diesel shows the highest emulsification activity among the
substrate tested ranging from 55.56% - 60.00%. The oil displacement activity was corresponding
to RLs concentration with stability up to 120°C (for 60 min). Therefore, from this research a
good potential of RLs that may provide good application for industry were produced.