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Development of efficient wastewater treatment technologies along with circular economic approaches are the most imperative biotechnological attention presently. Thus, to add more value in this process, current study accessed a novel oleaginous yeast strain, R. glutinis ISO A1 for its biodegrading potential in sewage wastewater encompassing toxic formulations. To achieve improved performance light irradiance of various intensities (50 lux–150 lux) was applied during the cultivation period as an abiotic stress factor. All irradiances significantly stimulated nutrient removal efficiency of R. glutinis and improved growth rate but intracellular accumulation of carotenoids was found slightly inhibited. Boosted lipogenesis (lipid content ⁓40.66%) along with phenomenal reduction in COD (88.33 ± 1.88%), nitrate (73.2 ± 3.95%) and phosphate (85.1 ± 2.97%) was monitored with an optimum exposure condition at 100 lux. Cultures illuminated with light (50 lux–150 lux) also showed excellent tolerance for multiple heavy metals (Zn, Cd, Cr) and exhibited their complete removal. Further, analysis of fatty acid methyl esters (FAME) presented an increase in saturated fatty acids that reveal modulations in R. glutinis 's membrane fluidity against stress generated due to the light exposure. Besides, estimated biodiesel properties of obtained FAME complying European and American fuel standards. These findings shed new light on the factors affecting wastewater bioremediation and successfully established a photo-induced biological treatment system in an oleaginous yeast for the very first time with an addition to successive lipid enhancement. [ABSTRACT FROM AUTHOR]

Algae-based wastewater bioremediation offers a cost-effective method for sustainably treating wastewater while simultaneously addressing global water scarcity and pollution. This study highlights the benefits of treating primary-treated (PTW) and secondary-treated (STW) paper-pulp industrial wastewaters using the microalga Tetradesmus obliquus (Turpin) Kützing. A batch culture study revealed that 50 % secondary treated wastewater can increase the biomass yield 1.8 fold to 2.51 g L−1 in 15 days with a corresponding lipid yield of 390.2 mg L−1. Upscaling this work in 200 L open raceway ponds with 50 % STW as the growth medium showed areal biomass and lipid productivities of 26.80 and 3.90 g m−2 day−1, respectively, in 15 days at 20 cm culture depth. This translates to a projected high annual biomass productivity of approximately 85.0 tons hectare−1 year−1 based on datasets spanning two consecutive years. Bioremediation efficiencies of 80.0 %, 91.51 %, and 92.10 % were achieved for COD, TOC, and NH 4 + respectively. Biodiesel produced showed a large percentage of saturated and monounsaturated fatty acids (∼90 %) and its fuel properties complied with the global biodiesel standards. This study thus shows that using paper-pulp industrial wastewater for algal growth offers a sustainable solution for energy generation and wastewater treatment, with significant implications for environmental sustainability. [ABSTRACT FROM AUTHOR]

Algae-based wastewater bioremediation offers a cost-effective method for sustainably treating wastewater while simultaneously addressing global water scarcity and pollution. This study highlights the benefits of treating primary-treated (PTW) and secondary-treated (STW) paper-pulp industrial wastewaters using the microalga Tetradesmus obliquus (Turpin) Kützing. A batch culture study revealed that 50 % secondary treated wastewater can increase the biomass yield 1.8 fold to 2.51 g L−1 in 15 days with a corresponding lipid yield of 390.2 mg L−1. Upscaling this work in 200 L open raceway ponds with 50 % STW as the growth medium showed areal biomass and lipid productivities of 26.80 and 3.90 g m−2 day−1, respectively, in 15 days at 20 cm culture depth. This translates to a projected high annual biomass productivity of approximately 85.0 tons hectare−1 year−1 based on datasets spanning two consecutive years. Bioremediation efficiencies of 80.0 %, 91.51 %, and 92.10 % were achieved for COD, TOC, and NH 4 + respectively. Biodiesel produced showed a large percentage of saturated and monounsaturated fatty acids (∼90 %) and its fuel properties complied with the global biodiesel standards. This study thus shows that using paper-pulp industrial wastewater for algal growth offers a sustainable solution for energy generation and wastewater treatment, with significant implications for environmental sustainability. [ABSTRACT FROM AUTHOR]