Evaluation of microalgae growth in North Argentine: Response to temperature variations

MANRIQUE, SILVINA M; GONZÁLEZ LEIVA, NANCY; DÍAZ, DÉBORA; FRANCO, JUDITH

Londres

Conferencia; 2nd Euro Global Summit and Expo on BIOMASS AND BIOENERGY; 2017

Dalhousie University Canada

We assumed that it would be possible to offset sewage water treatment costs by utilizing microalgae in tertiary processes of sewage treatment in the north of Argentina - one of the seven regions with higher levels of solar radiation in the world. Because the temperature strongly influences the cellular chemical composition, uptake of nutrients, CO2 and the growth rates for every species of algae, we first wanted to explore the effect of temperature on the growth of Scenedesmus quadricauda. We reported the results of autumn growth (measured with Neubauer chamber) for two temperature conditions in a standard culture medium (modified Detmer) with 1820 lux, photoperiod 12:12: i) controlled temperature (18ºC) and ii) room temperature, recorded with 2 parallel measuring sensors. The mean temperature was 13.6 ± 3.1ºC (minimum/maximum were 7.6ºC and 23.4ºC). Assays were performed in all cases in triplicate, inoculating 2.5x105 cells/ml in 250 ml of sterile culture medium. Growth cycles were 20 days. Four cycles were repeated with daily shaking. Growth has accelerated in the second trial: the maximum specific growth rate (μ) of the exponential phase was 0.33 d-1 versus 0.19 d-1 of the first trial, which could indicate that Scenedesmus responds better against a thermal stress or incidence of higher temperatures. However, we compared statistically the meteorological records for the same date and time (average exterior: 11.12 ± 5.1ºC; rank: 1.25ºC - 29.45ºC), and significant differences were observed between temperature series room/exterior (H = 666.28; p