Lutein production from Scenedesmus obliquus cultivated in stirred-tank bioreactor /
Microalgae were known to have higher lutein content, easy to grow, and abundantly live in the wet environment. Optimization of lutein from microalgae, Scenedesmus obliquus is critical for commercialization of lutein. This research focused on lutein production from locally isolated S. obliquus which...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
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Kuala Lumpur :
Kulliyyah of Engineering, International Islamic University Malaysia,
2017
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| Subjects: | |
| Online Access: | http://studentrepo.iium.edu.my/handle/123456789/4961 |
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| Summary: | Microalgae were known to have higher lutein content, easy to grow, and abundantly live in the wet environment. Optimization of lutein from microalgae, Scenedesmus obliquus is critical for commercialization of lutein. This research focused on lutein production from locally isolated S. obliquus which was cultivated in 2.5 L stirred tank bioreactor. Five bioreactors parameters which were stirrer speed, air flow rate, light exposure period, starting inoculums size, and temperature were investigated for their effects towards lutein content as well as biomass of microalgae. Initial lutein amount detected was 41.4 mg/g with biomass density of 0.456 g/l at 25°C, 0.5 liter/minute of aeration flow rate, 100 rpm, and 12 hours light exposure. The effect of five bioreactor parameters was analyzed by using Main Effect Pareto Charts, followed by ANOVA analysis. Stirrer speed and starting inoculums size have been identified as noise and removed from further optimization. Face-Centred Central Composite Design (FCCCD) under Response Surface Method (RSM) was used as design tool to optimize temperature, lighting period and air flow rate. Based on the 20 runs of FCCCD, microalgae biomass density observed was between 0.285 g/l (min) to 0.717 g/l (max), while the lutein content was between 12.231 mg/g (min) to 91.099 mg/g (max). It was observed that the flow rate negatively affect the microalgae biomass density but less effect towards lutein content. Lowered aeration increased biomass but provide small increment on lutein content. The lighting period offer positive impact towards biomass, with U-shape response towards lutein content. Biomass increased with prolonged light exposure. Higher lutein content is only observed when daily light is either 24hr or 8hr. The temperature provides bell shape like response towards both biomass density and lutein content. Lutein and biomass was elevated when temperatures are between 27°C to 30°C. Based on this study, the lutein content was successfully increased to 80.18 mg/g with biomass density at 0.426 g/l. |
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| Physical Description: | xii, 89 leaves : illustrations ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 75-83). |