PRODUKSI LIPID DARI MIKROALGA SCENEDESMUS SP. YANG DIKULTIVASI SECARA FOTOHETEROTROF DENGAN PENAMBAHAN MONOSAKARIDA DAN DISAKARIDA

• Main Author: Adrian, Marcel
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/76642
• Institution: Institut Teknologi Bandung

Polyunsaturated Fatty Acids (PUFA) are essential fatty acids that hold significance in the nutraceutical, cosmeceutical and pharmaceutical fields. PUFA can be produced by microorganisms, especially microalgae, as lipids. This study employs the microalgae Scenedesmus sp., which is known to yield lipids ranging from 13% to 40% (w/w) dry weight. Cultivation was performed using two methods, photoautotrophic and photoheterotrophic to compare the effects of both cultivation methods on the growth and lipid accumulation of Scenedesmus sp. In photoheterotrophic cultivation, 3 g.L-1 sugars were used, namely monosaccharides (glucose and fructose) and disaccharides (sucrose). The objective of this research was to compare effect of different sugars on growth and lipid accumulation. NPK fertilizer 1 g.L-1 was used as the cultivation medium. The cultivation was carried out for 216 hours in a working volume of 800 mL, under conditions of 25°C, initial pH of 7.5 – 8, inoculum concentration of 106 cells.mL-1 with a volume of 10% (v/v). This study also compared the growth kinetics of Scenedesmus sp. in the photoautotrophic and photoheterotrophic cultivation with the three sugars. The logistic equation was used to construct the growth model of Scenedesmus sp. The results showed that photoheterotrophic cultivation enhance biomass accumulation by increasing the specific growth rate from 0.06 ± 0.001 h-1 to 0.08 ± 0.005 h-1. Photoheterotrophic cultivation also increased lipid concentrations from 0.10 ± 0.019 g.L-1 to 0.22 ± 0.066 g.L-1. Among of three sugars, glucose was found to be the best sugar, followed by sucrose and fructose. The specific growth rates of glucose, fructose, and sucrose variations were 0.08 ± 0.005 h-1, 0.06 ± 0.003 h-1, and 0.06 ± 0.001 h-1, while the corresponding lipid concentrations were 0.22 ± 0.066 g.L-1, 0.13 ± 0.030 g.L-1, and 0.17 ± 0.006 g.L-1, respectively. Photoautotrophic cultivation had the highest YX/S-ammonia and YP/S-ammonia values of 8.57 g g-1 and 3.11 g g-1, respectively. As for the sugar substrate, sucrose had the highest YX/S-sugar and YP/S-sugar values, with respective values of 0.30 ± 0.113 g g-1 and 0.09 ± 0.025 g g-1. The highest lipid productivity was achieved by the glucose variation, with a value of 1.00 ± 0.308 mg.L-1 hour-1. The logistic equation succesfully model the growth of photoautotrophic and photoheterotrophic of sugar and sucrose variations.