Production of microbial carotenoid using innate inherent of the food industry wastewater

Abstract

Yeast is considered as the leading participant in natural pigment production, which has a wide application in the industries relevant to food, medicine and health. This study is aimed to focus on producing carotenoids from food industry waste. The food industry waste's innate microbe (Rhodotorula mucilaginosa) is used for the bioremediation of the same waste, and it was also used as the precursor for carotenoid production. The nutritional supplement (different carbon sources) and their effect on carotenoid production were also studied in this research, revealing glucose could be a good carbon source for carotenoid production. The solvent effect on carotenoid separation was studied, which revealed that methanol, combined with ultrasonication, is the best solvent system for carotenoid extraction from Rhodotorula mucilaginosa. The batch study of this conjoint bioremediation and carotenoid production process was studied for its persuading parameters (pH, temperature, light, time and agitation) effects. The maximum carotenoid production (810 µg/g) was achieved at 72 hr with the pH 6 and 27 °C in light irradiation (White light), agitation (200 rpm) and with ethanol + ultrasonication recovery system in carotenoid extraction. HPLC, FTIR and UV analysis were performed to confirm the presence of β-carotene. The analytical studies revealed that the extracted pigment contains 32.5 % of β-carotene, 54 % of torulene and 13.5 % of torularhodin, respectively. The characteristic property of the treated water was analyzed and compared with the raw wastewater, which was also found to be within the limit for discharge and reusability. These results prove that the innate yeast of food industry wastewater could be a potential candidate for wastewater remediation and carotenoid production.