Spirulina Species Research Articles

English

Using a modification of the Bangladesh 3 medium, dose response analysis was carried out to evaluate the effect of certain parameters on biomass production and protein biosynthesis in a Spirulina sp. isolated from an oil-polluted flame pit. A set of conditions described as optimized was compared with another set of conditions described as normal. The optimized parameters include pH 9.0, temperature 30oC, 0.30 mg/L SO4-2, 0.008 mg/L P043-, 2.0 g/L HC03-, 25 mg/L N032-, 1.0% Cl- and light intensity 15 µEm-2s-1. Agitation was achieved through aeration using an aquarium pump to supply air at ca 150 bubbles min-1. Biomass and protein produced were significantly (P = 0.05) higher in the optimized than in the normal condition; that is, biomass and protein produced in optimized condition were 22.7 and 25.8%, respectively, higher than those produced in normal growth condition. The total amino acid concentration in optimized condition was 58.7% higher than in normal conditions. These results show that cultivating the Spirulina species at these optimized environmental conditions could significantly improve biomass yield and protein synthesis in the organism.   Key words: Optimal parameters, optimized condition, normal condition, biomass, protein biosynthesis, environmental factors, Spirulina.

Mode of Biosorption of Chromium(III) by Spirulina Species Cells from Aqueous Solutions

The ability of commercial Spirulina species to remove chromium(III) [Cr(III)] from an aqueous environment was studied under photoautotrophic conditions. Biomass displayed high adsorptive capacity, with recorded sorption rates up to 99% at a concentration range of 0.02 to 0.18 mg chromium ions/mL of medium. Using isolated cell wall preparations, it was shown that Cr(III) is mainly sorbed onto the surface of cell walls and that the sorption capacity of the walls is enormously high. Living cells of cyanobacteria show the tendency to form multilayer sorption systems, as indicated electron microscopy.

Spirulina Species as a Source of Carotenoids and a-Tocopherol and its Anticarcinoma Factors

In the present study blue-green alga Spirulina platensis and Spirulina maxima were grown in batch culture at different nitrogen and NaCl concentrations, respectively. Both species were found to respond to nitrogen deficiency and high NaCl level by accumulation of large amounts of commercially important chemicals such as carotenoids and tocopherols. The higher carotenoids and a-tocopherol contents was obtained when Spirulina sp grown at low nitrogen level (51 ppm N), with values ranged from 19.82 to 24.1 mg g-1and from 533.2 to 978.5 ?g Kg-1 (dry weight, d.w.), respectively. Whilst, these values in cells grown in free nitrogen medium were ranged from 30.15 to 31.13 mg g-1and from 960.4 to 1325.7 ?g Kg-1 (d.w), respectively. The high performance liquid chromatography (HPLC) elution patter of total caroteniods extracted from S. platensis and S maxima culture contained a-carotene (49.6 to 319.5 ?g g-1lutein (0.06 to17.21 ?g g-1, astaxanthin (6.61 to 160.27 ?g g-1,zeaxanthin (1.25 to 18.55 ?g g-1) and cryptoxanthin (1.41 to 20.13 ?g g-1). S. maxima accumulated a large amount of cryptoxanthin and zeaxanthin than that found in S. platensis. The effect of Spirulina species extracts containing various carotenoid compounds and tocopherols on the viability of Ehrlich ascites carcinoma cells (EACC) were evaluated. All algae extracts at different concentration of 200 and 400 ppm significant reduced the cell viability ranged from 89.11 to 5.25%. These extracts did not induce any significant changes in DNA fragmentation of treated EACC compared with untreated cells. But lactate dehydrogenase (LDH) and glutathione-S- transferase (GST) enzyme activities and glutathione level in treated EACC were significantly higher than that in untreated cells. These finding suggest that algae extracts may be reduce cell viability by other mechanism such as membrane lyases instead of apoptosis. Thus, Spirulina extract rich in carotenoids and tocopherols could be used as chemopreventive agents since they are relative non-toxic.

Occurrence of poly-beta-hydroxybutyrate in Spirulina species

Several strains of photoautotrophically grown Spirulina spp. contained poly-beta-hydroxybutyrate (PHB) at concentrations never exceeding a few milligrams per gram of dry weight. Under mixotrophic growth conditions in the presence of acetate, PHB reached values greater than 2.5% of dry weight. With pyruvate, no significant effect on PHB accumulation was obtained.

Lack of relationship between gliding cyanobacteria and filamentous gliding heterotrophic eubacteria: comparison of 16S rRNA catalogues of Spirulina, Saprospira, Vitreoscilla, Leucothrix, and Herpetosiphon

Spirulina platensis and Spirulina maxima were characterized by 16S ribosomal RNA oligonucleotide cataloguing. Both species are highly related. They fall into the main group of the cyanobacteria, showing a remote relationship to Nostoc, Fischerella, Aphanocapsa, and also to Prochloron. Low similarity coefficients were found between the Spirulina species and certain organotrophic and sulfide oxidizing bacteria, viz. Saprospira grandis, Vitreoscilla stercoraria, Leucothrix mucor, Herpetosiphon aurantiacus, and Beggiatoa leptomitiformis, respectively. This result does not support the classical hypothesis that certain filamentous gliding bacteria are apochlorotic cyanobacteria.

Peuplements benthiques à Cyanophycées des marais salants de Salin-de-Giraud (Sud de la France)

In Salin-de-Giraud solar salt work pools, Cyanophyceae are dominant in benthic populations. Two main types of communities can be recognized : 1) Laminated mats in weak salinity areas (<150 g/1) with Microcoleus chthonoplastes frequently exclusive (but which may be covered by a Lyngbya aestuarii layer), being the result of superposition in time of two competitive phenomena : Cyanophycean growth and sedimentary contribution either of detrital or chemical origin. As the gypsum precipitation occurs, Microcoleus mats disappear. 2) Communities associated with gypsum and halite crusts. In gypsum pools, they may be composed of several layers : a) a lower purple layer of ph.otosynthetic bacteria ; b) a mid dark-green layer of filamentous Cyanophyceae (Phormidium and Spirulina species) mixed with some coccoids (Aphanothece div. sp. essentially) ; c) an upper orange-colored layer of coccoids (with an Aphanothece sp. as major component) may grow during summer, but disappears during winter when pools are emptied, which is the rule in Salin-de-Giraud. The basal level of halite crust is colonized by a filamentous form Phormidium sp. For these communities, stratification of species is associated to physiological properties of organisms, and sedimentary deposits only act as a support in such pools.

On the morphology and ultrastructure of the cell wall of Spirulina platensis

The cell wall of the blue-green alga Spirulina platensis was studied with the electron microscope using ultra-thin sectioning, shadowing, carbon-replication or freeze-etching techniques for specimen preparation. The cell wall could be resolved into four layers, L-I through L-IV. The L-I and L-III layers contain fibrillar material. The septum is a three-layered wall: an L-II layer sandwiched between L-I layers. The shape in vitro of isolated septa might be an artifact due to the preparation technique used. Certain structural properties of the septum seem to allow tangential stretching; they might be reflected in the flexible gliding mobility of Spirulina species. The outer, L-IV layer contains material longitudinally arranged along the trichome axis.