Influence of photoperiods on the growth rate and biomass productivity of green microalgae

Abstract

The effect of different photoperiods: 24 h illumination and a 12:12-h light/dark (12L:12D) cycle on the growth rate and biomass productivity was studied in five algal species: Neochloris conjuncta, Neochloris terrestris, Neochloris texensis, Botryococcus braunii and Scenedesmus obliquus. The green microalgae examined differ in the reproduction mode. Continuous illumination stimulated the growth of B. braunii and S. obliquus more effectively than the growth of the microalgal species from the genus Neochloris. However, under shorter duration of light of the same intensity (12L:12D cycle), the growth of all the three species of Neochloris was stimulated. Under continuous illumination, the specific growth rate in the first phase of B. braunii and S. obliquus cultures was higher than the growth rate of Neochloris, whereas under the 12L:12D cycle, the specific growth rate of all the three Neochloris species was generally higher than that in B. braunii and S. obliquus. As a result, the light regime influenced algal biomass productivity differently. The maximum biomass productivity was obtained in B. braunii and S. obliquus cultures carried out at continuous illumination. All the Neochloris species produced biomass more efficiently at the 12L:12D cycle, which was two–threefold higher than that of B. braunii and S. obliquus. The unicellular species of the green microalgae from the genus Neochloris, examined for the first time in this study, are promising prospective objects for algal biotechnology.

Characterization of fatty acids and hydrocarbons of chlorophycean microalgae towards their use as biofuel source

“…For example, Botryococcus sp. has been reported to accumulate high lipid/hydrocarbon content (>25% mass fraction) but with low growth rate and biomass productivity (34 mg L À1 day À1 ) [11,29] Therefore, strains with optimal biomass productivity and lipid content would be more favorable for biodiesel b i o m a s s a n d b i o e n e r g y 7 7 ( 2 0 1 5 ) 7 5 e9 1 b i o m a s s a n d b i o e n e r g y 7 7 ( 2 0 1 5 ) 7 5 e9 1 applications. A balanced parameter accounting for both biomass productivity and lipid content such as volumetric lipid productivity (mg L -1 day À1 ) could be applied for selection of such strains [16].…”

“…These hydrocarbons have odd carbon number (C23eC33) alkadiene/trienes, triterpenes (botryococcenes, C30eC37) and methylated squalenes (C31eC34) with potential fuel applications [9]. However, slow growth rate of B. braunii with an average doubling time of 36.5 h and low biomass productivity (34 mg L À1 day À1 ) have been the major limiting factors for its industrial exploitation [10,11].…”

Effect of Salinity, pH, Light Intensity on Growth and Lipid Production of Microalgae for Bioenergy Application

“…Haiying et al (2011) have reported similar result for the microalgal species Chlorella minutissima and other algal species also supports our results viz. S. dimorphus and S. quadricauda , P. lutheri (Shah et al, 2013) and S. obliquus and B. braunii (Krzemińska et al, 2014).…”

Algae-Based Bioremediation

“…Therefore the WWT ponds must have relatively larger populations of microalgae that accumulate lipids such as green algae or diatoms (Griffiths and Harrison, 2009;Ravishankar et al, 2012). Hence, the necessity of supplementation of nutrients for slow-growing organisms affects the economics of biofuel processes (Krzeminska et al, 2014). Botryococcus braunii accumulates a rare group of hydrocarbons that are not observed in other species.…”