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In the present investigation, formulate the new ecofriendly, low-cost commercial fertilizer for pilot-scale cultivation of a green microalgae, Tetradesmus obliquus RDS01, using bubble column photo bioreactor. Initially, we optimized the four different fertilizers, viz., urea—500 mg L−1, di-ammonium phosphate (DAP)—350 mg L−1, potassium—280 mg L−1, and sodium bicarbonate—165 mgL−1 using response surface methodology (RSM). The Tetradesmus obliquus RDS01 microalga was produced 350.25 mg g−1 of lipid, 240.35 mg g−1 of carbohydrate, 17.50 g L−1 of biomass, 98.52% of CO2 utilization efficiency, 325 U mL−1 of acetyl CoA carboxylase enzyme, 5.73 mL g−1 of biodiesel, and 4.25 mL g−1 of bioethanol obtained in pilot-scale cultivation in optimized commercial fertilizer medium. The Acetyl CoA carboxylase enzyme protein molecular weight was observed at 64KDa on 15% SDS-PAGE. The 3D structure homology modeling of Acetyl CoA carboxylase enzyme protein structure was predicted and protein encodes with 498 amino acid residues. The Acetyl CoA carboxylase specific genes (aCCD) were 1230 bp isolated. The Tetradesmus obliquus RDS01 microalga–produced biodiesel was subjected to gas chromatograph mass spectrometer (GCMS) analysis and identified the 50 biodiesel compounds. The major biodiesel compounds, viz., Cis-8-methylicosanoate methyl ester (28.36%). Eicosanoic acid, methyl ester (12.36%), hexadecanoic acid methyl ester (13.15%), 14-heptadecatrienoic acid methyl ester (3.25%), tridecanoic acid methyl ester (10.96%), tetradecanoate methyl ester (11.35%), pentadecanoic acid methyl ester (12.57%). The presences of functional groups were identified from the biodiesel such as amides, alcohols, carboxylic acids, alkenes, alkenyl, carbonyl, and ketones groups using FTIR. The bioethanol was confirmed in the peak range 3.52 min by HPLC. [ABSTRACT FROM AUTHOR]

The present study explored the process of bioremediation, sequestration of carbon dioxide, and biofuel production using multifarious potent freshwater microalgae Tetradesmus obliquus TS03. The heavy metals were reduced, viz., 8.34 mg of cadmium (95.13%), 4.56 mg of chromium (97.28%), 1.34 mg of copper (98.67%), 1.24 mg of cobalt (98.19%), 1.93 mg of lead (96.72%), 2.31 mg of nickel (97.14%), and 2.23 mgL−1 of zinc (96.59%) using photobioreactor microalgal treatment method. The heavy metal biosorption capacity rate (qmax) was 98.90% determined by the Langmuir and Freundlich isotherm kinetics model at 10 days of effluent treatment using Tetradesmus obliquus TS03. The microalgae T. obliquus TS03 utilized 98.34% of carbon dioxide (CO2) enhanced by acetyl CoA carboxylase and RuBisCO enzymes. The biodiesel was extracted from microalga and identified 32 fatty acid methyl ester major compounds viz., tetradecanoate methyl ester, hexadecanoic acid methyl ester, tridecanoic acid methyl ester, heptadecatrienoic acid methyl ester, octadecanoic acid methyl ester, eicosanoic acid methyl ester, pentadecanoic acid methyl ester, and cis-methylicosanoate using gas mass chromatography (GCMS). The biodiesel functional groups were identified, viz., amides, phenols, alcohols, alkynes, carboxylic acids, carbonyls, and ketones groups using Fourier transformation infrared (FTIR). The bioethanol was identified using high-performance liquid chromatography (HPLC) and determined the peak presented at RT of 4.35 min (75,693.1046 µV s−1). [ABSTRACT FROM AUTHOR]

Back ground: Rising level of carbon dioxide, increasing demands and value of fuel, generation of waste are the key issues of the modern society. Biodiesel is an alternate to standard fossil fuel. Currently, it's primarily made from vegetable oils associated consequently it's an adverse impact on food security. Lipids from oleaginous microorganisms (e.g. microalgae, bacteria, fungi and yeasts) may well be an alternate feedstock for biodiesel production and therefore the growth and lipid accumulation of Rhodococcus opacus was studied under different environmental conditions. Results: The current aim of the study is to utilized Box Behnken Design (BBD) of the response surface methodology, for identifying optimum levels of particular variables. BBD design was performed on oleaginous bacterium, Rhodococcus opacus considering pH, temperature and incubation period as independent variables. Lipid and biomass contents were analyzed as response variables. A second order polynomial model produced a satisfactory results of the experimental data with regard to biomass yield and lipid content % (R2 = 98, 04, 96.96 (P = 0.01). Optimum results of the experiments were 3.82 gL-1 biomass and lipid content 33.55% at optimized conditions pH-7, temperature-300C and incubation time - 72 hrs. Results of predicted and actual response were differing with 2 to 3 % and desirability of model 98%. [ABSTRACT FROM AUTHOR]