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Optimization of growth conditions and fatty acid analysis for three freshwater diatom isolates
Author(s) -
Li Xiaoli,
Marella Thomas Kiran,
Tao Ling,
Li Rong,
Tiwari Archana,
Li Gu
Publication year - 2017
Publication title -
phycological research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.438
H-Index - 44
eISSN - 1440-1835
pISSN - 1322-0829
DOI - 10.1111/pre.12174
Subject(s) - navicula , biology , diatom , algae , nutrient , phosphate , botany , food science , zoology , ecology , biochemistry
SUMMARY Diatoms are a group of highly abundant and diverse aquatic algae species. They contain high lipid content along with many bioactive compounds that can be exploited for biotechnological applications. Despite these attractive attributes, diatoms are underrepresented in production projects due to difficulties in their cultivation. To optimize the growth of three freshwater diatom isolates, Cyclotella sp., Synedra sp. and Navicula sp., an orthogonal assay on N , P , S i and F e, as well as temperature and p H , was designed using traditional single‐factor tests. We also studied the effect of using nanosilica as an alternate S i source on growth and found that the diatom isolates studied achieved their highest growth rates under different combinations of nutrient and environmental conditions. Silica had the greatest influence on growth, followed by phosphate and iron. The optimized growth conditions for Synedra sp. were N : 30 mg L −1 , P : 3 mg L −1 , S i: 14.8 mg L −1 , F e: 0.448 mg L −1 , temperature 25°C and p H 8. For Navicula sp.: N : 20 mg L −1 , P : 2.5 mg L −1 , S i: 19.7 mg L −1 , F e: 0.112 mg L −1 , temperature 30°C and p H 7.5–8. For Cyclotella sp.: N : 20 mg L −1 , P : 2.5 mg L −1 , S i: 19.7 mg L −1 , F e: 0.448 mg L −1 , temperature 30°C and p H 7.5–8. Nano silica negatively affected growth in Navicula sp. and Cyclotella sp., but no such effect was observed in Synedra sp. Fatty acid profiling showed C 16:0, C 16:1( n − 7), C 18:0 and C 20:5( n − 3) as major fatty acids, with no significant differences in fatty acid methyl ester profiles between traditional and modified media. This work gives us a new insight into the growth requirements of freshwater diatom species, which are less studied than marine species.