Modelling and application of Box-Behnken Design and response surface methodology for optimization the biodegradation of crystal violet by an oleaginous yeast Rhodotorula toruloides

Rhodotorula toruloides is an oleaginous yeast which has been used in biotechnology for the production of single cell, fatty acids and carotenoids.In this proposal, polluted soil with used engine oil (UEO) was collected from various automobile service in Jeddah, KSA. Then, pigmented yeast was isolated on Sabouraud agar plates supplemented with 1% UEO. Selected strain was tested for its ability to remove crystal violet from mineral solution (MS). Dye degrading yeast was characterised at molecular level. In order to identify enzymes involved in dye biotransformation, DNA was extracted and whole genome sequencing was performed. Modelling and application of Box-Behnken Design followed by RSM was applied to optimize and determine the appropriate biotic and abiotic factors (Inoculum size, peptone concentration, temperature and agitation) related to biodegradation of crystal violet by the selected pigmented yeast Rhodotorula toruloides. From this study, the characterized active yeast was selected and the best growth conditions were proposed for further use in textile and leather wastewater treatment.