TY - JOUR
T1 - Evaluation of co-culturing a diatom and a coccolithophore using different silicate concentrations
AU - Dogdu Okcu, Gamze
AU - Eustance, Everett
AU - Lai, Yen Jung Sean
AU - Rittmann, Bruce E.
N1 - Funding Information:
The first author would like to thank The Scientific and Technological Research Council of Turkey (TUBITAK) Science Fellowships and Grant Programmes Department for the Post-Doctoral Research given to Gamze Dogdu Okcu within “2219-Post-Doctoral Post-Fellowship Scholarship Program”.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/5/15
Y1 - 2021/5/15
N2 - Globally, the demand for sustainable energy production and high-value biological compounds have become intertwined in an attempt to improve the feasibility of sustainable algal cultivation. Marine microalgae, especially diatoms and coccolithophores, represent viable cultures that can produce biofuels and high-value compounds. Growing them in co-culture offers the potential to produce lipids and pigments, while also generating CaCO3 for C sequestration. The main objective of this work was to investigate competition or co-existence of the diatom Chaetoceros gracilis and the coccolithophore Pleurochrysis Carterae. The focus was on the effects of silicate and co-culturing on the growth rate, productivity, pigment production, and ash production for C. gracilis and P. carterae in laboratory conditions. The results showed that, in monoculture, 2-mM Si enhanced the specific growth rate of C. gracilis, but did not affect P. carterae. Regardless of silicate concentration, C. gracilis was more productive than P. carterae. In co-culture, P. carterae had a slower growth rate, indicating an inhibitory effect of C. gracilis on P. carterae. Neither silicate concentration nor co-culturing had an impact on the contents of pigments fucoxanthin, chlorophyll-a, and chlorophyll-c, which means that pigment productivity was proportional to biomass productivity. Finally, the ash content increased in all cultures with the lower silicate concentration (0.2 mM) in the medium. With one exception, the ash content was dominated by SiO2 regardless of silicate amount, and CaCO3 was a major part of the ash only when P. carterae was grown separately with the higher silicate level. These results highlight that co-culturing did not provide an advantage for improving biomass, pigments, or CaCO3 productivity.
AB - Globally, the demand for sustainable energy production and high-value biological compounds have become intertwined in an attempt to improve the feasibility of sustainable algal cultivation. Marine microalgae, especially diatoms and coccolithophores, represent viable cultures that can produce biofuels and high-value compounds. Growing them in co-culture offers the potential to produce lipids and pigments, while also generating CaCO3 for C sequestration. The main objective of this work was to investigate competition or co-existence of the diatom Chaetoceros gracilis and the coccolithophore Pleurochrysis Carterae. The focus was on the effects of silicate and co-culturing on the growth rate, productivity, pigment production, and ash production for C. gracilis and P. carterae in laboratory conditions. The results showed that, in monoculture, 2-mM Si enhanced the specific growth rate of C. gracilis, but did not affect P. carterae. Regardless of silicate concentration, C. gracilis was more productive than P. carterae. In co-culture, P. carterae had a slower growth rate, indicating an inhibitory effect of C. gracilis on P. carterae. Neither silicate concentration nor co-culturing had an impact on the contents of pigments fucoxanthin, chlorophyll-a, and chlorophyll-c, which means that pigment productivity was proportional to biomass productivity. Finally, the ash content increased in all cultures with the lower silicate concentration (0.2 mM) in the medium. With one exception, the ash content was dominated by SiO2 regardless of silicate amount, and CaCO3 was a major part of the ash only when P. carterae was grown separately with the higher silicate level. These results highlight that co-culturing did not provide an advantage for improving biomass, pigments, or CaCO3 productivity.
KW - Calcium carbonate
KW - Chaetoceros gracilis
KW - Co-culture
KW - Pleurochrysis carterae
KW - Silicate
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U2 - 10.1016/j.scitotenv.2021.145217
DO - 10.1016/j.scitotenv.2021.145217
M3 - Article
C2 - 33493907
AN - SCOPUS:85099652001
SN - 0048-9697
VL - 769
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 145217
ER -