Mass balance and kinetics of biodegradation of endocrine disrupting phthalates by Cellulosimicrobium funkei in a continuous stirred tank reactor system

This study investigated the potential of Cellulosimicrobium funkei for degrading dimethyl phthalate (DMP) and diethyl phthalate (DEP). Effect of different initial concentrations of phthalates on their biodegradation and growth of C. funkei was examined using shake flasks and a continuous stirred tank reactor (CSTR). Complete degradation of both DMP and DEP was achieved in CSTR, even up to 3000 and 2000 mg/L initial concentrations, respectively. Simultaneous degradation of the phthalates in mixture, i.e. more than 80% and 55% biodegradation efficiency were achieved at 1000 and 2000 mg/L initial concentrations of DMP and DEP, respectively, using the CSTR. Mass balance analysis of the degradation results suggested proficient degradation of DMP and DEP with biomass yield values of 0.64 and 0.712, respectively. The high values of inhibition constant Ki estimated using the Tessier and Edward substrate inhibition models indicated very good tolerance of C. funkei toward biodegradation of DMP and DEP.

Automated summary

This study investigated the potential of Cellulosimicrobium funkei for degrading dimethyl phthalate (DMP) and diethyl phthalate (DEP). The results showed that in a continuous stirred tank reactor (CSTR), complete degradation of both DMP and DEP was achieved even at high initial concentrations, indicating good tolerance of C. funkei towards biodegradation.