Influence of culture temperature on the growth, biochemical composition and fatty acid profiles of six Antarctic microalgae

Abstract

The growth, biochemical composition and fatty acid profiles of six Antarctic microalgae cultured at different temperatures, ranging from 4, 6, 9, 14, 20 to 30 • C, were compared. The algae were isolated from seawater, freshwater, soil and snow samples collected during our recent expeditions to Casey, Antarctica, and are currently deposited in the University of Malaya Algae Culture Collection (UMACC). The algae chosen for the study were Chlamydomonas UMACC 229, Chlorella UMACC 234, Chlorella UMACC 237, Klebsormidium UMACC 227, Navicula UMACC 231 and Stichococcus UMACC 238. All the isolates could grow at temperatures up to 20 • C; three isolates, namely Navicula UMACC 231 and the two Chlorella isolates (UMACC 234 and UMACC 237) grew even at 30 • C. Both Chlorella UMACC 234 and Stichococcus UMACC 238 had broad optimal temperatures for growth, ranging from 6 to 20 • C (µ = 0.19 -0.22 day -1 ) and 4 to 14 • C (µ = 0.13 -0.16 day -1 ), respectively. In contrast, optimal growth temperatures for Navicula UMACC 231 and Chlamydomonas UMACC 229 were 4 • C (µ = 0.34 day -1 ) and 6-9 • C (µ = 0.39 -0.40 day -1 ), respectively. The protein content of the Antarctic algae was markedly affected by culture temperature. All except Navicula UMACC 231 and Stichococcus UMACC 238 contained higher amount of proteins when grown at low temperatures (6-9 • C). The percentage of PUFA, especially 20:5 in Navicula UMACC 231 decreased with increasing culture temperature. However, the percentages of unsaturated fatty acids did not show consistent trend with culture temperature for the other algae studied.

Temperature-dependent growth rate and photosynthetic performance of Antarctic symbiotic alga Trebouxia sp. cultivated in a bioreactor

“…Faster growth found for Trebouxia sp. cultivated at 10°C is well comparable to the results of Teoh et al (2004) who investigated growth of several Antarctic microalgae in response to temperature. The authors reported the highest specific growth rates for temperature ranging from 6°C to 14°C.…”

Scenedesmus sp. NJ-1 isolated from Antarctica: a suitable renewable lipid source for biodiesel production

“…This strain was isolated from an extremely low-temperature environment, so it was able to adapt to the conditions with low temperatures. It can also grow at the temperatures over 25°C, which is consistent with the fact that many species of microalgae isolated from the polar habitats were able to grow at the temperatures exceeding 20°C (Teoh et al 2004). However, in previous studies, very few Antarctic strains have been found to be able to grow at the temperatures exceeding 30°C (Chen et al 2012).…”

Effects of UV radiation on five marine microphytobenthic Wadden sea diatoms, isolated from the Solthörn tidal flat (Lower Saxony, southern North Sea) – Part II: changes in carbohydrate, amino acid and fatty acid composition

“…Interestingly, in two of the species we studied (C. peltoides and D. littoralis) PAR+UVA+UVB induced an increase in the unsaturated fatty acids, whereas the other three taxa showed significant levels of saturated ones (P < 0.05). Here, the increased production of SFA at the expense of PUFAs could be an important strategy, as SFAs can serve as an important energy source for adaptation to UV-B stress (Teoh et al, 2005).…”