title: Increasing the Triacylglycerol Content in Dunaliella tertiolecta through Isolation of Starch-Deficient Mutants.
abstract: The production cost of biodiesel from microalgae is still not competitive, compared with that of petroleum fuels. The genetic improvement of microalgal strains to increase triacylglycerol (TAG) accumulation is one way to reduce production costs. One of the most promising approaches is the isolation of starch-deficient mutants, which have been reported to successfully increase TAG yields. To date, such a stable mutant is not available in an oleaginous marine microalga, despite several advantages of using marine species for biodiesel production. Algae in the genus Dunaliella are known to tolerate high salt concentration and other environmental stresses. In addition, the cultivation processes for large-scale outdoor commercialization have been well established for this genus. In this study, Dunaliella tertiolecta was used to screen for starch-deficient mutants, using an iodine vapor-staining method. Four out of 20,016 UV-mutagenized strains showed a substantial reduction of starch content. A significantly higher TAG content, up to 3-fold of the wild-type level, was observed in three of the mutants upon induction by nitrogen depletion. The carotenoid production and growth characteristics of these mutants, under both normal and oxidative stress conditions, were not compromised, suggesting that these processes are not necessarily affected by starch deficiency. The results from this work open up new possibilities for exploring Dunaliella for biodiesel production.
authors: Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.|Center of Advanced Studies for Tropical Natural Resources, Kasetsart University, Bangkok 10900, Thailand.
authors: Anchalee
authors: A
authors: Sirikhachornkit
authors: Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.|Center of Advanced Studies for Tropical Natural Resources, Kasetsart University, Bangkok 10900, Thailand.
authors: Supachai
authors: S
authors: Vuttipongchaikij
authors: Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.|Center of Advanced Studies for Tropical Natural Resources, Kasetsart University, Bangkok 10900, Thailand.
authors: Anongpat
authors: A
authors: Suttangkakul
authors: Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.
authors: Kittisak
authors: K
authors: Yokthongwattana
authors: Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand.|Center of Advanced Studies for Tropical Natural Resources, Kasetsart University, Bangkok 10900, Thailand.
authors: Piyada
authors: P
authors: Juntawong
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.|Center of Excellence on Environmental Health and Toxicology (EHT), CHE, Ministry of Education, Bangkok, 10400, Thailand.
authors: Prayad
authors: P
authors: Pokethitiyook
authors: PTT Research and Technology Institute, PTT Public Company Limited, Ayudhaya 13170, Thailand.
authors: Kunn
authors: K
authors: Kangvansaichol
authors: Department of Biology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand.|Center of Excellence on Environmental Health and Toxicology (EHT), CHE, Ministry of Education, Bangkok, 10400, Thailand.
authors: Metha
authors: M
authors: Meetam
mesh_terms: D056804:Biofuels; D018533:Biomass; D002338:Carotenoids / Q000096:biosynthesis; D000460:Chlorophyta / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects; D005227:Fatty Acids / Q000378:metabolism; D016296:Mutagenesis; D009154:Mutation; D009584:Nitrogen / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology; D010788:Photosynthesis; D012623:Seawater / Q000382:microbiology; D013213:Starch / Q000172:deficiency* / Q000235:genetics* / Q000378:metabolism; D014280:Triglycerides / Q000096:biosynthesis*; D014466:Ultraviolet Rays
chemical_list: D056804:Biofuels; D005227:Fatty Acids; D014280:Triglycerides; D002338:Carotenoids; D013213:Starch; D009584:Nitrogen
keywords: Dunaliella; biodiesel; microalgae; mutant; starch; triacylglycerol