Comprehending the influence of critical cultivation parameters on the oleaginous behaviour of potent rotten fruit yeast isolates

Abstract

Oleaginous yeasts were isolated from five different rotten fruits and their oleaginous behaviour was characterized with varying carbon source and concentration (C/N) to identify their possible future applicabilities. Sixteen yeasts were isolated, those accumulating around 20% of their cell dry weights as lipids were screened and identified as Candida tropicalis and Pichia kudriavzevii. Among glucose, maltose and sucrose, glucose was found favourable carbon source in terms of biomass yield and lipid content. Carbon concentration corresponding to C/N ratio 100/2 (C. tropicalis) and 120/2 (P. kudriavzevii) exhibited highest lipid contents-81·2 and 75·7%-and lipid yields-1·1 and 3gl-1 , respectively. Lipids contained 16-28 types of triacylglycerols, and major fatty acids detected were caprylic, caparate, lauric, stearic palmitic, oleic, linoleic, aracidic and erucic acid with caprylic acid as predominant one. Fatty acid profile also witnessed variations with changing C/N. Noteworthy lipid contents were achieved in the two isolates higher than any existing reports on them. Pichia kudriavzevii exhibited reasonable overall lipid yield extending the opportunity of improvement upon changing the cultivation conditions. The lipids contained a range of fatty acids with a predominance of caprylic acid having unequivocal biotechnological importance. Two potent oleaginous yeast isolates were studied, and this is the only successive report describing oleaginous behaviour of P. kudriavzevii. The cultivation parameters such as C source, concentration and C/N ratio which critically influence the oleaginous behaviour, lipid content, yield and composition have been accessed so as to provide comprehensive understanding on single cell oil production from these isolates. Study progressively contributes to current and upcoming researches in microbial oils and the characteristic fatty acid, and TAG profile provides important leads for their putative applicabilities.