The extremophilic unicellular red microalga Galdieria sulphuraria (Cyanidiophyceae) is able to grow autotrophically, or mixo- and heterotrophically with 1% glycerol as a carbon source. The alga divides by multiple fission into more than two cells within one cell cycle. The optimal conditions of light, temperature and pH (500 µmol photons m-2 s-1, 40 °C, and pH 3; respectively) for the strain Galdieria sulphuraria (Galdieri) Merola 002 were determined as a basis for synchronization experiments. For synchronization, the specific light/dark cycle, 16/8 h was identified as the precondition for investigating the cell cycle. The alga was successfully synchronized and the cell cycle was evaluated. G. sulphuraria attained two commitment points with midpoints at 10 and 13 h of the cell cycle, leading to two nuclear divisions, followed subsequently by division into four daughter cells. The daughter cells stayed in the mother cell wall until the beginning of the next light phase, when they were released. Accumulation of glycogen throughout the cell cycle was also described. The findings presented here bring a new contribution to our general understanding of the cell cycle in cyanidialean red algae, and specifically of the biotechnologically important species G. sulphuraria.

• Klíčová slova
• Galdieria, cell cycle, cell division, growth, light intensity, red algae, synchronization, temperature, trophic regimes,
• MeSH
• buněčný cyklus fyziologie   MeSH
• heterotrofní procesy fyziologie   MeSH
• kultivované buňky MeSH
• mikrořasy cytologie   růst a vývoj   MeSH
• Rhodophyta cytologie   růst a vývoj   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Sphingolipids are significant component of plant-cell plasma membranes, as well as algal membranes, and mediate various biological processes. One of these processes is the change in lipid content during the cell cycle. This change is key to understanding cell viability and proliferation. There are relatively few papers describing highly glycosylated glycosyl inositol phosphorylceramide (GIPC) due to problems associated with the extractability of GIPCs and their analysis, especially in algae. After alkaline hydrolysis of total lipids from the red alga Galdieria sulphuraria, GIPCs were measured by high-resolution tandem mass spectrometry and fragmentation of precursor ions in an Orbitrap mass spectrometer in order to elucidate the structures of molecular species. Fragmentation experiments such as tandem mass spectrometry in the negative ion mode were performed to determine both the ceramide group and polar head structures. Measurement of mass spectra in the negative regime was possible because the phosphate group stabilizes negative molecular ions [M-H]-. ANALYSIS: of GIPCs at various stages of the cell cycle provided information on their abundance. It was found that, depending on the phases of the cell cycle, in particular during division, the uptake of all three components of GIPC, i.e., long-chain amino alcohols, fatty acids, and polar heads, changes. Structural modifications of the polar headgroup significantly increased the number of molecular species. Analysis demonstrated a convex characteristic for molecular species with only one saccharide (hexose or hexuronic acid) as the polar head. For two carbohydrates, the course of Hex-HexA was linear, while for HexA-HexA it was concave. The same was true for GIPC with three and four monosaccharides.

• Klíčová slova
• Cell cycle, Galdieria sulphuraria, Galdieriaceae, Glycosyl inositol phosphoceramides, Liquid chromatography-electrospray mass spectrometry, Red alga,
• MeSH
• buněčný cyklus MeSH
• inositol * MeSH
• Rhodophyta * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• inositol * MeSH

In recent decades, a shift has been seen in the use of light-emitting diodes over incandescent lights and compact fluorescent lamps (CFL), which eventually led to an increase in wastes of electrical equipment (WEE), especially fluorescent lamps (FLs) and CFL light bulbs. These widely used CFL lights, and their wastes are good sources of rare earth elements (REEs), which are desirable in almost every modern technology. Increased demand for REEs and their irregular supply have exerted pressure on us to seek alternative sources that may fulfill this demand in an eco-friendly manner. Bio-removal of wastes containing REEs, and their recycling may be a solution to this problem and could balance environmental and economic benefits. To address this problem, the current study focuses on the use of the extremophilic red alga, Galdieria sulphuraria, for bioaccumulation/removal of REEs from hazardous industrial wastes of CFL bulbs and the physiological response of a synchronized culture of G. sulphuraria. A CFL acid extract significantly affected growth, photosynthetic pigments, quantum yield, and cell cycle progression of this alga. A synchronous culture was able to efficiently accumulate REEs from a CFL acid extract and efficiency was increased by including two phytohormones, i.e., 6-Benzylaminopurine (BAP - Cytokinin family) and 1-Naphthaleneacetic acid (NAA - Auxin family).

• Klíčová slova
• Galdieria sulphuraria, Rhodophyta, bio-removal, compact fluorescent lamp, extremophile, industrial wastes, plant hormones,
• Publikační typ
• časopisecké články MeSH

This is a protocol for quantitative determination of storage and total carbohydrates in algae and cyanobacteria. The protocol is simple, fast and sensitive and it requires only few standard chemicals. Great advantage of this protocol is that both storage and total saccharides can be determined in the cellular pellets that were already used for chlorophyll and carotenoids quantification. Since it is recommended to perform the pigments measurement in triplicates, each pigment analysis can generate samples for both total saccharide and glycogen/starch content quantification. The protocol was applied for quantification of both storage and total carbohydrates in cyanobacteria Synechocystis sp. PCC 6803, Cyanothece sp. ATCC 51142 and Cyanobacterium sp. IPPAS B-1200. It was also applied for estimation of storage polysaccharides in Galdieria (IPPAS P-500, IPPAS P-507, IPPAS P-508, IPPAS P-513), Cyanidium caldarium IPPAS P-510, in green algae Chlorella sp. IPPAS C-1 and C-1210, Parachlorella kessleri IPPAS C-9, Nannochloris sp. C-1509, Coelastrella sp. IPPAS H-626, Haematococcus sp. IPPAS H-629 and H-239, and in Eustigmatos sp. IPPAS H-242 and IPPAS C-70.

• Klíčová slova
• Carbohydrates, Chlorella, Colorimetry, Haematococcus, Polysaccharides, Spectrophotometry, Sugars, Synechocystis,
• Publikační typ
• časopisecké články MeSH