Мicroscopic investigations (LM, TEM and SEM) and identification ofChlorellaisolate R-06/2 from extreme habitat in Bulgaria with a strong biological activity and resistance to environmental stress factors

Hormesis effects of phosphorus on the viability of Chlorella regularis cells under nitrogen limitation

“…The ultrastructure of the cell was observed with a transmission electron microscope (TEM) equipped with an energy dispersive X-ray spectrometer (EDX) (JEM 1200EX, JEOL, Japan). Prior to SEM and TEM observation, the cells were pretreated by a series of multiple fixative and dehydrated procedures [32, 33]. Before TEM–EDX analysis, the dehydrated cells should be embedded in epoxy resin (Epon812, Shell Chemical, USA) for cutting (Microtome, Leica UCT, Germany) and ultrathin sections were further stained with uranyl acetate [34].…”

Chroococcidiorella tianjinensis, gen. et sp. nov. (Trebouxiophyceae, Chlorophyta), a green alga arises from the cyanobacterium TDX16

“…Their common features include (1) chloroplasts are embedded with starch granules and a pyrenoid that is surrounded by two starch plates and bisected by two pairs of thylakoids in TDX16-DE ( Fig. 2) and C. vulgaris [33][34][35] and (2) reproduction is achieved by autosporulation, generating two, three and four autospores in TDX16-DE ( Fig. 1, Fig.…”

<i>Chroococcidiorella tianjinensis</i> gen. et sp. nov. (Trebouxiophyceae, Chlorophyta), a Green Alga Arises from the Cyanobacterium TDX16

“…The presence of typical chlorophyte pigments of Chl a, Chl b and lutein in TDX16-DE ( Figure 4) Figure 2) and C. vulgaris [33] [34] [35] and 2) reproduction is achieved by autosporulation, generating two, three and four autospores in TDX16-DE ( Figure 1, Figure 3) and C. vulgaris [33] [36]. By contrast, their different characters encompass 1) TDX16-DE (2.0-3.6 µm) (Figure 1, Figure 2) is only about half the size of C. vulgaris (5.0-7.0 µm) [35] [36]; 2) TDX16-DE's chloroplast is "e"-shaped ( Figure 2), while the chloroplast of C. vulgaris is cup-shaped and sometimes has two (Figure 2), while C. vulgaris possesses both of the two organelles [34] [37] [38] [39]; 4) TDX16-DE's nucleus is enclosed by two sets of envelopes ( Figure 2), while the nucleus of C. vulgaris has one envelope [38]; 5) TDX16-DE has a double-membraned cytoplasmic envelope (Figure 2), while C. vulgaris has a single-membraned cytoplasmic membrane [36]; and 6) daughter cell nuclei form de novo in TDX16-DE ( Figure 3), but develop by division of the existing one in C. vulgaris [36] [37].…”