Mixotrophic and photoautotrophic cultivation of 14 microalgae isolates from Saskatchewan, Canada: potential applications for wastewater remediation for biofuel production

Abstract

suitable for microalgal biofuel production due to unfavorable climate and solar insolation levels. However, these conditions can potentially be mitigated by coupling microalgal cultivation to industrial processes such as wastewater treatment. In this study, we have examined the biomass and lipid productivity characteristics of 14 microalgae isolates (Chlorophyta) from the Canadian province of Saskatchewan. Under both photoautotrophic and mixotrophic cultivation, a distinct linear trend was observed between biomass and lipid productivities in the 14 SK isolates. The most productive strain under cultivation in TAP media was Scenedesmus sp.-AMDD which displayed rates of biomass and fatty acid productivities of 80 and 30.7 mg L −1 day −1 , respectively. The most productive strain in B3NV media was Chlamydomonas debaryana-AMLs1b which displayed rates of biomass and fatty acid productivities of 51.7 and 5.9 mg L −1 day −1 , respectively. In 11 of the isolates tested, secondary municipal wastewater (MCWW) supported rates of biomass productivity between 21 and 33 mg L −1 day −1 with Scenedesmus sp.-AMDD being the most productive. Three strains, Chlamydomonas debaryana-AMB1, Chlorella sorokiniana-RBD8 and Micractinium sp.-RB1b, showed large increases in biomass productivity when cultivated mixotrophically in MCWW supplemented with glycerol. High relative oleic acid content was detected in 10 of the 14 isolates when grown mixotrophically in media supplemented with acetate. There was no detectable effect on the fatty acid profiles in cells cultivated mixotrophically in glycerol-supplemented MCWW. These data indicate that biomass and lipid productivities are boosted by mixotrophic cultivation. Exploiting this response in municipal wastewater is a promising strategy for the production of environmentally sustainable biofuels.

Biochemical characterization of microalgal biomass from freshwater species isolated in Alberta, Canada for animal feed applications

“…The isolates were identified by DNA sequence analysis of 18S, ITS1 and ITS2 regions (Eurofins Genomics, Huntsville, AL, USA) [19]. Species included Chlorella vulgaris, Nannochloris bacillaris, Tetracystis sp.…”

Ruminal in vitro gas production, dry matter digestibility, methane abatement potential, and fatty acid biohydrogenation of six species of microalgae

“…The six microalgae species used in this study were previously identified as promising candidates for carbon sequestration and biomass production in Northern climates (Bjornsson et al 2012;McGinn et al 2012;Park et al 2012;Bhatti et al 2014;Tibbetts et al 2014Tibbetts et al , 2015a. As such, they were mass cultivated in illuminated 1000-L enclosed photobioreactors to produce sufficient biomass for evaluation.…”

Prediction of phycoremediation of As(III) and As(V) from synthetic wastewater by Chlorella pyrenoidosa using artificial neural network

“…Microalgae and culture medium C. pyrenoidosa was collected from Department of Biotechnology, IIT Roorkee and grown in BG11 culture medium (without adding carbon source) (Park et al 2011;Yadavalli and Heggers 2013).The composition of BG11 media are given in Tables 1 and 2 as follows:…”