Optimization of culture conditions of the thraustochytrid Aurantiochytrium sp. strain 18W-13a for squalene production

Nakazawa, Atsushi; Matsuura, Hiroshi; Kose, Ryoji; Kato, Syou; Honda, Daiske; Inouye, Isao; Kaya, Kunimitsu; Watanabe, Makoto M.

doi:10.1016/j.biortech.2011.09.127

Cited by 84 publications

(50 citation statements)

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“…Specific physicochemical and antioxidant properties of squalene imply also its applications in food industry, pharmacology, and cosmetics (for review, see Spanova & Daum, 2011). Another promising approach in the search for new squalene resources is the use of microorganisms as squalene producers on industrial scale (Ghimire et al, 2009;Nakazawa et al, 2012). Shark liver as the traditional source of squalene is currently being substituted by plant sources such as olive or amaranth oil (He & Corke, 2003;Garc ıa-González et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

“…Shark liver as the traditional source of squalene is currently being substituted by plant sources such as olive or amaranth oil (He & Corke, 2003;Garc ıa-González et al, 2008). Another promising approach in the search for new squalene resources is the use of microorganisms as squalene producers on industrial scale (Ghimire et al, 2009;Nakazawa et al, 2012). Among these, yeasts represent an interesting alternative due to easy genetic and physiological manipulation of squalene content.…”

Section: Introductionmentioning

confidence: 99%

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Squalene epoxidase as a target for manipulation of squalene levels in the yeastSaccharomyces cerevisiae

et al. 2013

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Squalene is a valuable natural substance with several biotechnological applications. In the yeast Saccharomyces cerevisiae, it is produced in the isoprenoid pathway as the first precursor dedicated to ergosterol biosynthesis. The aim of this study was to explore the potential of squalene epoxidase encoded by the ERG1 gene as the target for manipulating squalene levels in yeast. Highest squalene levels (over 1000 μg squalene per 10(9) cells) were induced by specific point mutations in ERG1 gene that reduced activity of squalene epoxidase and caused hypersensitivity to terbinafine. This accumulation of squalene in erg1 mutants did not significantly disturb their growth. Treatment with squalene epoxidase inhibitor terbinafine revealed a limit in squalene accumulation at 700 μg squalene per 10(9) cells which was associated with pronounced growth defects. Inhibition of squalene epoxidase activity by anaerobiosis or heme deficiency resulted in relatively low squalene levels. These levels were significantly increased by ergosterol depletion in anaerobic cells which indicated feedback inhibition of squalene production by ergosterol. Accumulation of squalene in erg1 mutants and terbinafine-treated cells were associated with increased cellular content and aggregation of lipid droplets. Our results prove that targeted genetic manipulation of the ERG1 gene is a promising tool for increasing squalene production in yeast.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Squalene epoxidase as a target for manipulation of squalene levels in the yeastSaccharomyces cerevisiae

et al. 2013

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“…Such high proportions of squalene in alkenes detected in extractable fractions either from raw coals or from converted coals were seldom reported. As one of the value-added chemicals, squalene has many important applications in cosmetic, pharmaceutical, and medical industries (Nakazawa et al, 2012).…”

Section: Resultsmentioning

confidence: 99%

The Compositional Features of Thermally Soluble Fractions from Two Chinese Coals in Cyclohexane

Wang

Wei

Yue

et al. 2013

Energy Sources, Part A: Recovery, Utilization, and Environmenta

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Shengli lignite (SL) and Shenmu-Fugu subbituminous coal (SFSBC) were subjected to thermal dissolution in cyclohexane at 300 ı C for 1 h under hydrogen. The reaction mixtures were extracted with petroleum ether (PE) and the PE-extractable fractions (PEEFs) were analyzed with a gas chromatography/mass spectrometer. The results show that the PEEFs from thermally dissolved SL (TDSL) and thermally dissolved SFSBC (TDSFSBC) mainly consist of alkanes, alkenes, arenes, and oxygencontaining organic compounds (OCOCs); the yields of alkanes and alkenes in the PEEF from TDS-FSBC are appreciably higher than those from TDSL, while the yields of arenes and oxygen-containing organic compounds in the petroleum ether-extractable fraction from thermally dissolved Shenmu-Fugu subbituminous coal are significantly lower than those from thermally dissolved Shengli lignite; arenols are dominant OCOCs in the PEEF from TDSL, while main OCOCs in the PEEFs from TDSFSBC are arenols and esters.

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“…La temperatura a medida que se incremen ta así como los días de cultivo, produce un incremento de la biomasa, alcanzando su fase estacionaria al cuarto día de los ensa yos. Resultados similares es reportado por Arafiles et al (2011) al tercer día de cultivo a temperatura de 30°C; a pesar que estos microorganismos pueden tolerar una am plia gama de temperaturas (Nakazawa et al 2012;Taoka et al 2009;Fan, Vrijmoed and Jones 2002). La temperatura óptima para cultivo de este microrganismo está en el rango de 25 a 30°C (Bajpai, Bajpai andWard 1991, Yokochi et al 1998;Byung-Ki et al 2002, Leaño et al 2003Perveen et al 2006;Chochoey y Verduyn 2012).…”

Section: Discussionunclassified

Effect of culture conditions on the growth and docosahexaenoic acid production from Aurantiochytrium limacinum strain 85

Cayra

Sabas²,

Rosales³

et al. 2015

manglar

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Efecto de las condiciones de cultivo sobre el crecimiento y la producción de ácido docosahexaenoico por Aurantiochytrium limacinum cepa 85Effect of culture conditions on the growth and docosahexaenoic acid production from Aurantiochytrium limacinum strain 85. ResumenEl efecto de la velocidad de rotación, pH, temperatura y salinidad sobre el crecimiento y producción de ácido docosahexaenoico (DHA) en una cepa de traustoquitridio con 99% de similaridad a Aurantiochytrium limacinum fueron investigados con ensayos a tres niveles: 50, 100 y 150 rpm; 4, 7 y 9 pH; 20, 25 y 30°C; 10, 20 y 30 ppm, respectivamente. La biomasa se estimó por el peso seco de las células, y el DHA por cromatografía de gases expresados como AGT en porcentaje. Se encontró que la velocidad de rotación afecto más al crecimiento, en donde una excesiva agitación afecta el crecimiento y una deficiente agitación disminuye su tasa de crecimiento. Iguales resultados se obtuvieron en relación al pH, en donde a pH más alcalino (pH9) afecta el crecimiento más que a la producción de DHA. En cambio cuando se evaluó la temperatura, este parámetro afecto el crecimiento y la producción de DHA de manera inversa, observando que a temperaturas altas hay mayor crecimiento, pero a temperaturas bajas hay un mayor porcentaje de DHA, similares resultados se obtuvieron al evaluar diferentes niveles de la salinidad, en donde mejores crecimiento fueron a salinidades más altas, pero la producción de DHA fue ligeramente más alta a la salinidad más baja. Los resultados demuestran que el crecimiento en función de la biomasa y el porcentaje de DHA en relación los ácidos grasos totales, están estrechamente relacionados a las variaciones de los parámetros evaluados. AbstractThe effect of the rotation speed, pH, temperature and salinity on the growth and production of docosahexaenoic acid (DHA) in a thraustochytrids strain with 99% similarity to Aurantiochytrium limacinum were researched with tests at three levels: 50, 100 and150 rpm; 4, 7 and 9 pH; 20, 25 and 30°C; 10, 20 and 30 ppm, respectively. The biomass is estimated by dry weight of cells, and DHA by gas chromatography expressed as a percentage AGT. It was found that the speed of rotation affects growth, whereby excessive shaking affects the growth and inadequate shaking decreases its rate of growth. Similar results were obtained in relation to the pH, whereby the more alkaline the (pH9), the more it affects growth rather than DHA production. On the other hand, when temperature was assessed, this parameter inversely affected the growth and production of DHA, noting that the higher the temperatures the higher the growth, but the lower the temperatures the higher the DHA percentage. Similar results were obtained when assessing different levels of salinity, whereby better rates of growth were measured at higher degrees of salinity; however, DHA production was slightly higher at lowest salinity. The results show that the growth based on the biomass and the DHA percentage in relation to total fatty acids are closely related to ...

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Optimization of culture conditions of the thraustochytrid Aurantiochytrium sp. strain 18W-13a for squalene production

Cited by 84 publications

References 14 publications

Squalene epoxidase as a target for manipulation of squalene levels in the yeastSaccharomyces cerevisiae

Squalene epoxidase as a target for manipulation of squalene levels in the yeastSaccharomyces cerevisiae

The Compositional Features of Thermally Soluble Fractions from Two Chinese Coals in Cyclohexane

Effect of culture conditions on the growth and docosahexaenoic acid production from Aurantiochytrium limacinum strain 85

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