Bioremediation of Parboiled Rice Effluent Supplemented with Biodiesel-Derived Glycerol Using Pichia pastoris X-33

Abstract

This paper describes the use of Pichia pastoris X-33 as a bioremediator to reduce the chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), and phosphorus (P-PO ₄ ³⁻), after culture in parboiled rice effluent supplemented with p.a. glycerol or a glycerol by-product of the biodiesel industry. The greatest reduction in the COD (55%), TKN (45%), and P-PO ₄ ³⁻ (52%) of the effluent was observed in cultures of P. pastoris X-33 supplemented with 15 g  ·L ⁻¹ of biodiesel-derived glycerol. Furthermore, the overall biomass yield was 2.1 g  ·L ⁻¹. These data suggest that biodiesel-derived glycerol is an efficient carbon source for the bioremediation of parboiled rice effluent and biomass production.