Penelitian pengaruh berbagai konsentrasi HCO3 - terhadap produksi lemak Nannochloropsis sp. telah dilakukan. Tujuan dari penelitian adalah mendapatkan konsentrasi HCO3 - yang dapat meningkatkan biomassa dan lemak Nannochloropsis sp. Penelitian dilakukan selama 14 hari. Perlakuan yang diberikan terhadap medium berupa kontrol dan penambahan HCO3 - sebesar 25, 50, 100, dan 200 ppm. Hasil penelitian menunjukkan bahwa rerata biomassa tertinggi didapat dari penambahan HCO3 - 200 ppm, yaitu 3,848 gram per liter dengan kadar dan produktivitas lemak sebesar 16,135% berat kering dan 4,39746 g/l/hari. Sementara itu, rerata biomassa terendah didapat dari penambahan HCO3 - 25 ppm, yaitu 1,8689 gram per liter dengan kadar dan produktivitas lemak sebesar 20,238% berat kering dan 2,66532 g/l/hari. Tidak terdapat perbedaan kadar lemak pada kontrol, perlakuan dengan penambahan HCO3 - 25, 50, dan 100 ppm. Dengan demikian, peningkatan kadar lemak Nannochloropsis sp. dapat dilakukan dengan menambahkan HCO3 - dengan konsentrasi tidak lebih dari 100 ppm.

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Research the effect of various concentrations of HCO3 - on lipid productions of Nannochloropsis sp. has been done. The purpose of this research is to obtain the concentration of bicarbonate which able to increase the biomass and lipid productions of Nannochloropsis sp. This research was conducted for 14 days. The treatments have been given to the medium are the control and with the addition of HCO3 - at 25, 50, 100, and 200 ppm.

The results showed that the mean of the highest biomass obtained from the addition of HCO3 - 200 ppm, that is equal to 3,848 grams per litre with lipid content and productivity of 16,135% dry weight and 4,39746 g/l/day. Meanwhile, the lowest biomass was obtained from the addition of HCO3 - 25 ppm, that is equal to 1,8689 grams per litre with lipid content and productivity of 20,238% dry weight and 2,66532 g/l/day.

There were no differences in lipid content on control, treatment with the addition of HCO3 - 25, 50, and 100 ppm. Hence, the increase of lipid content on Nannochloropsis sp. can be done by adding HCO3 - without over than 100 ppm.