Journal of Phycological Research
Volume:2 Issue: 1, Mar 2018

This study investigated the effects of monocultures of three dominant cyanobacterial species Nostoc spongiaeforme C. Agardh ex Bornet & Flahault, Anabaena vaginicola F.E. Fritsch & Rich and oscillatoria limosa C. Agardh ex Gomont on a brackish water phytoplankton community in Miankaleh international wetland and peninsula, north of Iran. We compared the chlorophyll a concentration and cell numbers after treatment. As a result, among three cyanobacterial species, N. spongiaeforme had most allelopathic effects on phytoplankton community whereas O. limosa and A. vaginicola showed no noticeable effects. The effects of N. spongiaeforme on phytoplankton community could be divided into two types: Strong negative effects and positive effects.

Almost 309 species and infraspecific taxa of macroalgae including 78 Chlorophyta (within 15 families), 70 Ochrophyta (Phaeophyceae; within 7 families) are and 161 Rhodophyta (within 30 families) listed in coastal line of the Persian Gulf and iranian water of Oman Sea. Among them, Sargassum ilicifolium, a dominant brown seaweed, which was used as a part of aquatic animal feed in order to investigate its effect on physico chemical formulated feed. Two isocaloric diets (336 kcal metabolizable energy /100g diet) containing 33% crude protein, with and without inclusion of brown seaweed S. ilicifilium (0 and 15, replaced on protein resources of shrimp diet) were used. Seaweed supplement in formulated feed not only improved the humidity absorbance (110.20%±5.00%) and stability of pellet feed in seawater (98.11±3.23%) compared to the control but also acted as the best binder and increased the periods of leaching pellet (5.20±0.50) when they were dropped in seawater. It can be replaced instead of vitamin and mineral premixes when the feed is enriched by vitamin pyridoxine (6.4 mg.100-1 seaweed DW) and minerals cobalt (0.06 mg.100-1 seaweed DW) and zinc (1.1 mg.100-1 seaweed DW).

The Cyanobacteria Spirulina is an attractive target for its pigments, proteins, vitamins and other high-value cell components. Also, it can be easily and cheaply harvested by filtration from the cultivation medium. In this study a simple protocol was developed for Spirulina production by using different types of nitrogen in ammonium (Urea and (NH4)2SO4) and nitrate (KNO3, NaNO3) forms in combination with NPK fertilizer. Results demonstrated high amount of nitrogen in both forms inhibited Spirulina growth. Ammonium showed a stronger inhibitory role than nitrate in biomass production while increased phycocyanin content. Best phycocyanin content occurred in high ammonium or low nitrate concentration. In media based on 1% Urmia lake salt and 1g/L NPK, a combination of low concentration (0.1 -0.5g/L) of Urea and (NH4)2SO4 obtained best results in biomass production. 1.2g/L biomass during 14 days without any carbon source can be compared with Zarrouk/2 medium. This composition can be used economically for Spirulina production since little amount of cheap material make the possibility of Spirulina production.

As the simplest photosynthetic organisms, cyanobacteria are the interface between bacteria and plants in terms of evolutionary process. The positive effect of these photosynthetic microorganisms on plant growth is one of the important roles in biotechnology. Their production of various secondary metabolites is another known application of these microalgae in agricultural biotechnology. In this study, the effect of two species of heterocystous cyanobacteria, isolated from paddy fields of Golestan Province in Iran, on the growth of peppermint (Mentha piperita L.) was evaluated. A significant difference was observed between treated plants and control in terms of growth parameters. In addition, as one of the factors influencing the vegetative parameters of plants, the qualitative identification of phytohormones in cyanobacterial biomass was investigated by biochemical methods and High Performance Liquid Chromatography technique. The results indicated the presence of plant growth hormones such as indole acetic acid and indole butyric acid in extracts of studied cyanobacteria.

The purpose of this study is to develop a biofertilizer based on filamentous nitrogen- fixing cyanobacteria selected from rice fields and to generate a technological package compatible with its use for the rice crop in Iran. Cyanobacteria was isolated and purified from rice fields in Kalate Naderi. In this research we studied the effect of salinity (NaCl, 0, 1, 2 and 4%) and pH (5, 7, 9 and 11) on growth and chlorophyll-a contents in six species of Anabaena. Results showed that Anabaena sphaerica Bornet & Flanault possessed the best adaptation to pH changes. It could be more active in 5-11 pH values. A. vaginicola F.E. Fritsh & Rich and A. variabilis Kutzing ex Bornet & Flanault were remarkable for salinity tolerance. They adapted to salinity stress up to 2% salt concentration in the medium. Our results indicated that the growth of all strains decrease by 4% salt concentration and pH 11. Indeed, Anabaena is a cyanobacterium with nitrogen fixation ability and high potency of adaptation to environmental stress. So, it can be a useful candidate for biofertilizer in agriculture, particularly in rice fields.

Chara is a morphologically variable genus. Molecular analysis (ISSR) of genetic diversity and population structure was performed an Chara species. Population groups identified based on geographical provinces showed a significant genetic difference, but Mantel test did not show isolation by distance in the studied species. Bayesian analysis of population structure grouped Chara species in 2 distinct genetic groups differing in allelic composition and frequency. STRUCTURE analysis revealed genetic admixture among species which was supported by reticulation analysis. Coalescence analysis showed the occurrence of gene duplication and extinction as possible evolutionary changes along with polyploidy as the main forces of speciation in the genus Chara.