The isolation and characterization of Pseudozyma sp. JCC 207, a novel producer of squalene

Abstract

In examining the production of valuable compounds by marine microorganisms, we isolated a novel yeast strain that produces a large amount of squalene and several polyunsaturated fatty acids. Molecular and phylogenetic analyses of the ribosomal DNA suggest that the isolate belongs to the genus Pseudozyma, which comprises ustilaginomycetous anamorphic yeasts. The nucleotide sequence of an internally transcribed spacer region from isolate Pseudozyma sp. JCC207 showed 98% similarity with those of Pseudozyma rugulosa and Pseudozyma aphidis, which are close relatives of the isolate. In considering use of Pseudozyma sp. JCC207 for squalene production, the efficiency of squalene production was investigated under different conditions. Glucose was the best carbon source for the production of squalene. In the presence of yeast extract, squalene production was activated and an optimum ratio of glucose to yeast extract was 4.5. For the optimal squalene production, the concentration of glucose was 40 g l(-1) and the best nitrogen source was sodium nitrogen. Pseudozyma sp. JCC207 was shown to produce up to 5.20 g/L of biomass and 340.52 mg/L of squalene. In an optimal condition, the content and yield of squalene produced by Pseudozyma sp. JCC207 were much greater than those obtained from microorganisms previously reported as squalene producers. We identified, classified, and characterized Pseudozyma sp. JCC207 as a novel squalene producer. The squalene production rate of Pseudozyma sp. JCC207 makes it an ideal candidate for the commercialization of microbial squalene.

Molecular identification of Pseudozyma aphidis (Henninger & Windisch) Boekhout: first record from a Brazilian mangrove swamp

“…Our isolates of P. aphidis are well supported and clustered together with other isolates of the same species (90% of bootstrap support with high values of posterior probability (0.98), as shown in figure 2. This species has a close phylogenetic affinity with P. rugulosa (80% of bootstrap support and 0.98 of posterior probability), as previously demonstrated (Chang et al 2008).…”

“…They are also reported as a potential source of squalene (Chang et al 2008), lipase (Dimitrijevic et al 2011) and biosurfactant mannosylerythritol lipids (Morita et al 2007, Fan et al 2014, Lorenz et al 2014, Gunther et al 2015.…”

Overproduction of squalene synergistically downregulates ethanol production in Saccharomyces cerevisiae

“…Plants and microbes have also been used for overproduction of squalene, but none are viable for industrial scale production of squalene because these methods are limited in yielding sufficient quantities. Indeed, the approximate amount of squalene produced by plants, yeasts and thraustochytrids ranged from 1 to 61 mg/g dry cell weight (DCW) ( Han-Ping H, 2002), <0.43-0.70 mg/g DCW (Chang MH, 2008;Mantzouridou F, 2009) and 0.1-0.38 mg/g DCW (Chen G, 2010;Fan KW, 2010;Li Q, 2009), respectively.…”

Engineering of the terpenoid pathway in Saccharomyces cerevisiae co-overproduces squalene and the non-terpenoid compound oleic acid

“…Researchers have thoroughly screened plant and microbial sources for the potential capacity to produce high levels of squalene, but because of their limited squalene production capacity, none of them have been suitable for large-scale production. For example, the production of squalene in plants, yeasts and thraustochytrids was estimated to be only 1-61 mg g -1 dry cell weight (DCW) (He HP, 2002), <0.43-0.70 mg g -1 DCW (Chang MH, 2008;Mantzouridou F, 2009) and 0.1-0.38 mg g -1 DCW (Chen G, 2010;Fan KW, 2010;Li Q, 2009), respectively.…”