BIOETHANOL PRODUCTION FROM HYDROLYSATE DERIVED BY ULTRASONIC PRETREATED DEFATTED BIOMASS OF MUNICIPAL WASTEWATER GROWN MUTANT TETRADESMUS DIMORPHUS EMS2

Microalgae biomass is considered an emerging source for future generation feedstock for both biodiesel and bioethanol production due to the accumulation of high amounts of lipids and carbohydrates respectively. In this present investigation, 70% ultrasonic pre-treated municipal wastewater (MWW) grown defatted mutant green microalga, Tetradesmus dimorphus EMS2 biomass was ultrasonic pretreated for hydrolysate preparation and its essential process parameters were statistically optimized using CCD-RSM. The prepared hydrolysate used as a cheap culture medium for bioethanol production by fermentation using Saccharomyces cerevisiae NITTS1. The maximum bioethanol yield of 51.45±0.12 gL-1 was obtained from the hydrolysate prepared from 55 g L-1 defatted biomass pretreated at 0.35 WL-1 ultrasonic density for 20 min than un-pretreated defatted biomass. The hydrolysate prepared from 55 gL-1 defatted biomass primarily contained simple sugars such as glucose (78.17±0.13 % w/w) and xylose (16.02±0.21 % w/w). Further, in this study, the essential physical parameters were optimized by the classical method and found that the maximum bioethanol of 54.36±0.11 g L-1 was produced at optimum fermentation conditions of 30 ℃, pH 4 and 150 rpm. This finding suggests that ultrasonic pretreated MWW grown defatted mutant T. dimorphus EMS2 biomass could be used as an ecofriendly-sustainable feedstock for bioethanol production after ultrasonic pretreatment.