Fluorescence lifetime imaging of red yeast Cystofilobasidium capitatum during growth

Abstract

Red yeast Cystofilobasidium capitatum autofluorescence was studied by means of confocal laser scanning microscopy (CLSM) to reveal distribution of carotenoids inside the cells. Yeasts were cultivated in 2L fermentor on glucose medium at permanent light exposure and aeration. Samples were collected at different times for CLSM, gravimetric determination of biomass and HPLC determination of pigments. To compare FLIM (Fluorescence Lifetime Imaging Microscopy) images and coupled data (obtained by CLSM) with model systems, FLIM analysis was performed on micelles of SDS:ergosterol and SDS:coenzyme Q with different content of ergosterol and coenzyme Q, respectively, and with constant addition of beta-carotene. Liposomes lecithin:ergosterol:beta-carotene were investigated too. Two different intracellular forms of carotenoids were observed during most of cultivations, with third form appeared at the beginning of stationary phase. Observed behavior is probably due to formation of some kind of carotenoid protective system in membranes of different compartments of yeast cell, especially cytoplasmic membrane.

Revealing the Potential of Lipid and β-Glucans Coproduction in Basidiomycetes Yeast

“…It has been previously shown that the C/N ratio is the key feature significantly affecting the accumulation of carbon-based intracellular metabolites (carbohydrates, lipids, pigments, etc.) [ 3 , 56 , 57 , 58 ]. Although there are many reports published on how C/N ratio influenced accumulation of lipids or carotenoids in Basidiomycetes yeast [ 3 , 7 ], the effect on β-glucan biosynthesis has not yet been investigated.…”

Label-Free Optical Metabolic Imaging in Cells and Tissues

“…β-carotene and lutein have been shown to exhibit weak fluorescence with a peak near 520 nm when dissolved in hexane, while carotenoid-associated fluorescence in brain tissues had broad features with a maximum near 540 nm ( 70 ). Carotenoids with three distinct lifetimes of 0.03, 0.3, and 3.5 ns have been identified in yeast, where fluorescence lifetime was used to assess the abundance of different carotenoids on the basis of growth medium and phase ( 71 ). Mean autofluorescence of carotenoids such as lutein and zeaxanthin is in the range of 30–80 ps.…”