title: Enhanced Oil Production by the Tropical Marine Diatom Thalassiosira Sp. Cultivated in Outdoor Photobioreactors.
abstract: Microalgae-derived oils have potential as a biofuel feedstock. To produce microalgal oils at a large scale, large amounts of nutrients and energy are needed to grow the algae. In this study, we evaluated three types of agricultural fertilizer (AF)-based culture media (AF1, AF2, and AF3) based on a previously published enriched seawater (ES) medium to produce biomass and oils from Thalassiosira sp. Under laboratory conditions, the highest cell productivity of Thalassiosira sp. was obtained with the AF3 medium. Thalassiosira sp. cultured in the AF3 medium produced 10.4 ± 0.9 mg L-1day-1oils, which is significantly higher than the 5.8 ± 0.7 mg L-1day-1produced in the ES medium. The higher production was due to the presence of nitrate and trace elements, both of which played roles in enhancing biomass and oil content, respectively. During cell growth, resting spores appeared inside the cells and were a marker to harvest the cells. Because of the abundant availability of sunlight in the tropics during the year, the oil production of Thalassiosira sp. in the AF3 medium was scaled up using outdoor photobioreactors under different weather conditions (rainy and dry seasons). Thalassiosira sp. produced more unsaturated fatty acids during the rainy season and produced more saturated fatty acids during the dry season. This study also demonstrated that it was possible to culture Thalassiosira sp. under outdoor conditions using a low-cost agricultural fertilizer-based culture medium (AF3 medium) to produce biodiesel feedstock with an annual production of 8.1 ± 0.4 t ha-1during the dry season and of 23.9 ± 6.8 t ha-1during the rainy season.
authors.affiliation: Biochemistry Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia.
authors.forename: Pintaka
authors.initials: P
authors.lastname: Kusumaningtyas
authors.affiliation: Biochemistry Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia.
authors.forename: Santi
authors.initials: S
authors.lastname: Nurbaiti
authors.affiliation: Microbial Biotechnology Research Group, School of Life Sciences and Technology, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia.
authors.forename: Gede
authors.initials: G
authors.lastname: Suantika
authors.affiliation: Analytical Chemistry Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia.
authors.forename: Muhammad Bachri
authors.initials: MB
authors.lastname: Amran
authors.affiliation: Biochemistry Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, 40132, Indonesia. zeily@chem.itb.ac.id.
authors.forename: Zeily
authors.identifier: http://orcid.org/0000-0001-9284-2237
authors.initials: Z
authors.lastname: Nurachman
mesh_terms: D000383:Agriculture; D056804:Biofuels / Q000382:microbiology*; D046508:Culture Techniques; D017377:Diatoms / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D005308:Fertilizers; D042541:Intracellular Space / Q000378:metabolism; D008055:Lipids / Q000096:biosynthesis; D058433:Photobioreactors / Q000382:microbiology*; D014329:Tropical Climate
chemical_list: D056804:Biofuels; D005308:Fertilizers; D008055:Lipids
keywords: Agricultural fertilizer-based medium; Oil productivity; Outdoor cultivation; Thalassiosira sp.; Tropical marine diatom