Isolation and Characterization of Two Squalene Epoxidase Genes from Botryococcus braunii, Race B

Uchida, Hidenobu; Sumimoto, Koremitsu; Ferriols, Victor Marco Emmanuel N.; Imou, Kenji; Saga, Kiyotaka; Furuhashi, Kenichi; Matsunaga, Shigeki; Okada, Shigeru

doi:10.1371/journal.pone.0122649

Cited by 17 publications

(8 citation statements)

References 40 publications

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“…In this study, squalene was found to be 2.42%. Squalene can also be used as biofuel feedstock through methylation that can also be converted to sterol membrane through epoxidation process (Uchida et al, 2015). The most common hydrocarbon found in B320 is pentacosane (8.61%) that is a saturated aliphatic hydrocarbon generally found in beeswax.…”

Section: Resultsmentioning

confidence: 99%

Effect of Electron-Beam Irradiation on the Growth Profile and Fatty Acid Composition of Botryococcus sp.

Yuniarsih¹,

Halimatul²,

Wulandari³

2018

J Bio Bio Edu

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Botryococcus sp. is an economically important microalgae as it contains carbohydrates, lipids, proteins, and a number of phytochemicals. The high concentrations of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) in this strain also a valuable source for production of biofuel. Mutagenic engineering using irradiation has been known to increase the content of these biomass. The aim of this study is to know the effect of electron-beam irradiation to the growth profile and fatty acid composition of Botryococcus sp. In this study, Botryococcus sp. adjusted an optical density 1.0 after being exposed to different doses of electron-beam irradiation (160 kGy, 240 kGy, and 320 kGy) and induced random mutagenesis for strain improvement was observed based on high energy (1.5 MeV and 2 mA). Several mutants obtained were designated as strain B160, B240, and B320, respectively. The profile growth was significantly different between control (0 kGy) and irradiated microalgae strain. The highest growth is found in B320 mutant. Fatty acid of Botryococcus sp. control produced 7 fatty acids, B160 produced 7 fatty acids, B240 produced 6 fatty acids, whereas B320 produced 9 fatty acids. B320 produced hydrocarbon and phtalic acid as well as fatty acids. Total SFAs and MUFAs of B240 was increased 1.6 times compared to the wild type. The results would give some implications to improve the quality of biodiesel from Botryococcus sp.

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Section: Resultsmentioning

confidence: 99%

Effect of Electron-Beam Irradiation on the Growth Profile and Fatty Acid Composition of Botryococcus sp.

Yuniarsih¹,

Halimatul²,

Wulandari³

2018

J Bio Bio Edu

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“…Squalene (27) is metabolized into squalene 2,3-epoxide (28) in higher plants (Uchida et al 2007b), which is subsequently converted into membrane sterols. While two squalene 2,3-epoxidase have been found in B. braunii (Uchida et al 2015), some squalene derivatives appear to be epoxidized at the 10,11 positions. Tetramethylsqualene 10,11-epoxide (34) (Delahais and Metzger 1997) might be covalently conjugated with carotenoids to form botryoxanthin (Okada et al 1996) or braunixanthin (Okada et al 1997), and these compounds might be excreted to the extracellular matrix (right panel in Fig.…”

Section: Biosyntheses Of Isoprenoids and Triterpenesmentioning

confidence: 94%

Algal Genes Encoding Enzymes for Photosynthesis and Hydrocarbon Biosynthesis as Candidates for Genetic Engineering

et al. 2018

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In order to increase the biomass of photosynthetic organisms, upregulation of net CO 2 fixation in daytime appears to be a promising approach. This can be attained by improving the turnover of chloroplast enzymes such as ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) or fructose bisphosphate phosphatase (FBPase). In a previous report, the genes for the large and small subunits of cyanobacterial Rubisco were coexpressed in tobacco with either with cyanobacterial chaperone for Rubisco or the carboxysomal CO 2 concentrating mechanism (CCM) gene. This resulted in the generation of faster carboxylation of Rubisco and a similar gene expression approach may be adopted into algal hosts in the future. Expression of the cyanobacterial FBPase gene with protein targeting to the chloroplast in Euglena gracilis was reported to increase the wax ester content effectively. Though stable transformation of the oil producing alga Botryococcus braunii race B, is yet to be achieved, genes for key regulatory enzymes in 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway, such as 1-deoxy-Dxylulose 5-phosphate synthase (DXS) or 4-hydroxy-3-methylbut-2-enyl diphosphate reductase (HDR), might be possible targets for genetic modification in this alga. Challenging problems in the transformation of the microalgae, including C. reinhardtii, or those of the macroalgae are discussed herein for the design of transformation aiming at higher yield of biofuel production.

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“…Three cyclic botryococcene C 33 molecules and a trimethylsqualene isomer were recently found [44]. Also, two squalene epoxidase (BbSQE-I and -II) enzymes converting squalene into membrane sterols were identified [45]. Data of the B. braunii race B nuclear genome will allow the search for possible regulatory routes of this singular metabolism [46].…”

Section: Lycopadiene Biosynthetic Pathway (A) Reduction Of Ggpp To Pmentioning

confidence: 99%

The Colonial Microalgae Botryococcus braunii as Biorefinery

Lozoya‐Gloria¹,

Cruz²,

Ozawa-Uyeda³

2020

Microalgae - From Physiology to Application

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The growing shortage of fossil fuels caused an increase in the demand for alternative and renewable fuels. Biofuels, like bioethanol and biodiesel, have received more attention as a sustainable replacement of fossil fuels. However, these have a poor oxidative stability, little energy content by volume, and many oxygenated compounds, which may cause corrosion and damage to the engines. Therefore, they are used as a mixture with standard fuels. Some species of microalgae are candidates to produce oils as triglycerides (TGA) to produce biodiesel by transesterification; however, the problem will remain. The colonial microalgae Botryococcus braunii produces and accumulates a high amount of long-chain nonoxygenated hydrocarbons, similar to those obtained from the fractionated distillation of crude petroleum. This is one of the few organisms reported to have a direct contribution in the formation of the oil reserves currently in use. Additionally, B. braunii produces pigments and long-chain carbohydrates that have interesting properties for various industries. There are still problems to be solved in order to consider it as economically viable and profitable, but important progress is being made. Therefore, this microalga is very attractive for the synthesis of hydrocarbons and other value-added compounds, making it an interesting biorefinery organism.

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Isolation and Characterization of Two Squalene Epoxidase Genes from Botryococcus braunii, Race B

Cited by 17 publications

References 40 publications

Effect of Electron-Beam Irradiation on the Growth Profile and Fatty Acid Composition of Botryococcus sp.

Effect of Electron-Beam Irradiation on the Growth Profile and Fatty Acid Composition of Botryococcus sp.

Algal Genes Encoding Enzymes for Photosynthesis and Hydrocarbon Biosynthesis as Candidates for Genetic Engineering

The Colonial Microalgae Botryococcus braunii as Biorefinery

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