A microalgal biorefinery approach for bioactive molecules, biofuel, and biofertilizer using a novel carbon dioxide-tolerant strain Tetradesmus obliquus CT02

Autor: Gargi Goswami, Ratan Kumar, Ankan Sinha, Debasish Das
Rok vydání: 2021
Předmět:
Zdroj: Biomass Conversion and Biorefinery.
ISSN: 2190-6823
2190-6815
DOI: 10.1007/s13399-021-02098-1
Popis: A microalgal biorefinery approach has been established through bioprospecting of an indigenous CO2-tolerant freshwater isolate Tetradesmus obliquus CT02 biomass in two sequential steps, resulting in alternate product cascades of bioactive molecules and biodiesel or biofertilizer. In the first step, crude microalgal extracts in five different solvents were screened for their antioxidant and anticancer activities. While acetone extract showed the highest antioxidant activity with an IC50 value of 137 µg mL−1, ethyl acetate extract exhibited maximum anticancer activity with an IC50 value of 306.67 µg mL−1. This antioxidant and anticancer activity may be attributed to the coordinated action of multiple bioactive molecules as detected by HR-LCMS analysis. In the next step, post extracted residual biomass of CT02 was evaluated as feedstock for biodiesel production. The lipid content was found to be 35.7–39.1% w/w, and further to that, FAME yield of 33.1–36.7% w/w was obtained via direct transesterification of both the acetone and ethyl acetate extracted biomass. Analysis of FAME composition revealed an abundance of palmitic acid (C16:0), stearic acid (C18:0), and elaidic acid (C18:1n9t) as the major constituents, making it suitable for use as biodiesel. The post extracted residual biomass was also evaluated for its application as biofertilizer through induced germination of Solanum lycopersicum seeds. The highest final germination percentage and germination index was estimated to be in the range of 75–80% and 117.5–118.5, respectively, comparable to that of commercial grade NPK (20:20:13).
Databáze: OpenAIRE