Combined effect of temperature and light intensity on growth and extracellular polymeric substance production by the cyanobacterium Arthrospira platensis

Abstract

The effects of light intensity and temperature on Arthrospira platensis growth and production of extracellular polymeric substances (EPS) in batch culture were evaluated using a three-level, full-factorial design and response surface methodology. Three levels were tested for each parameter (temperature: 30, 35, 40°C; light intensity: 50, 115, 180 μmol photons m −2 s −1 ). Both growth and EPS production are influenced mainly by the temperature factor but the interaction term temperature*light intensity also had a significant effect. In addition, conditions optimising EPS production are different from those optimising growth. The highest growth rate (0.414±0.003 day −1 ) was found at the lowest temperature (30°C) and highest light intensity (180 μmol photons m −2 s −1 ) tested, no optima were detectable within the given test range. Obviously, optima for growth must be at a temperature lower than 30°C and a light intensity higher than 180 μmol photons m −2 s −1 . For EPS production, light intensity had a positive linear effect (optimum obviously higher than 180 μmol photons m −2 s −1 ), but for the temperature parameter a maximum effect was detectable at 35°C.

Extracellular Polymeric Substance (EPS) Production by <i>Nostoc minutum</i> under Different Laboratory Conditions

“…Several works are available that report the effects of light intensity both in diazotrophic and non-diazotrophic conditions. In general, the EPS production showed a positive linear effect with light intensity especially in the presence of combined nitrogen for different Nostoc species [5], Arthrospira platensis [6] and Cyanothece sp. CCY 0110 [7].…”

Biological activity of microalgae can be enhanced by manipulating the cultivation temperature and irradiance

“…The influence of temperature on growth and biochemical composition depends on the irradiance level and vice versa [63,[67][68][69]. For most algae, the combinations of high temperatures with high light intensities or low temperatures with high irradiance levels are unfavorable conditions at which negligible growth is observed.…”

“…In Scytonema, increasing irradiance levels gradually increases antibiotic production [87]. The increase of light intensity stimulates the secretion of polymeric substances from Arthrospira platensis [68] and improves its carotenoid content [88].…”

Effects of light intensity on components and topographical structures of extracellular polysaccharides from the cyanobacteria Nostoc sp.

“…Several recent studies on the influence of light intensity (Friedman et al, 1991;Moreno et al, 1998;Otero and Vincenzini, 2003;Trabelsi et al, 2009;Yu et al, 2010;Mota et al, 2013) and wavelengths (Ehling-Schulz et al, 1997;Chen et al, 2009) on EPS yield have been reported. Different light regimens (continuous light and light-dark cycles) do not significantly affect the monosaccharidic composition of EPS (Vincenzini et al, 1993;De Philippis and Vincenzini, 1998).…”

“…1). (Friedman et al, 1991;Moreno et al, 1998;Otero and Vincenzini, 2003;Trabelsi et al, 2009;Yu et al, 2010;Mota et al, 2013), suggesting that energy availability significantly affects the EPS biosynthesis of cyanobacteria. Higher light intensity results in higher EPS production, which may constitute mechanism of releasing the excess energy absorbed by the cells (Mota et al, 2013) and increasing CO2 fixation rate in the cells under high light intensity.…”