Chlorella vulgaris mixotrophic growth enhanced biomass productivity and reduced toxicity from agro-industrial by-products

• Published in: Chemosphere (Oxford) 2018-08, Vol.204, p.344-350
• Main Authors: Melo, Rebeca Gonçalves de, Andrade, Alexsandra Frazão de, Bezerra, Raquel Pedrosa, Correia, Dominick Spindola, Souza, Vanessa Cristina de, Brasileiro-Vidal, Ana Christina, Viana Marques, Daniela de Araújo, Porto, Ana Lúcia Figueiredo
• Format: Article
• Language: English
• Subjects: Allium cepa; biomass production; Cheese whey; chemical oxygen demand; Chlorella vulgaris; Corn steep liquor; culture media; genotoxicity; microalgae; nutrients; protein content; remediation; seeds; specific growth rate; Toxicity; Vinasse; wastewater
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2018.04.039

Algal wastewater remediation has become attractive for a couple of years now, however the effectiveness of genetic toxicity reducing of some by-products through microalgae are still not well reported. This study aimed to evaluate the growth, nutrients and toxicity removal of Chlorella vulgaris cultivated under autotrophic and mixotrophic conditions in three agro-industrial by-products. Mixotrophic culture using corn steep liquor showed higher cell concentration, specific growth rate, maximum cell productivity and biomass protein content when compared to cheese whey and vinasse. Nutrient removal results showed that C. vulgaris was able to completely remove corn steep liquor nutrients, while in cheese whey and vinasse culture this removal was not as efficient, observing remaining COD. This work evaluated for the first time the corn steep liquor and cheese whey genetic toxicity through Allium cepa seeds assay. These results demonstrate that corn steep liquor toxicity was totally eliminated by C. vulgaris cultivation, and cheese whey and vinasse toxicity were minimized. This study proves that the mixotrophic cultivation of C. vulgaris can increase cellular productivity, as well as it is a suitable and economic alternative to remove the toxicity from agroindustrial by-products. [Display omitted] •Toxicity of corn steep liquor and cheese whey was reported for the first time.•Corn steep liquor toxic power was totally eliminated after microalgae treatment.•Total phosphorus was completely removed in all treated groups.•C. vulgaris is a great alternative for agroindustrial by-products biotreatment.