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Methods of physical and chemical adsorption of heavy metals have disadvantages in some ways- such as high cost and ineffectiveness at low concentrations. In recent decades methods of biological uptake of heavy metals have been investigated. The biological adsorbents include bacteria, fungi and alga, among which algae have the highest efficiency of metal uptake. This study indicated that Alginic acid is most responsible for the uptake of metals, such as nickel (II) and cadmium (II). Fucus serratus, brown alga, used as a cost-effective adsorbent for the biological uptake of cadmium and nickel ions simultaneously in a batch reactor in this study. Surface structure of algae has also been investigated. Adsorption kinetics have been measured and the results have indicated that the equilibrium time is about 300 minutes. The adsorption isotherm was interpreted by means of the Langmuir equation. The maximum adsorption rate for cadmium (II) and nickel (II) turned out to be about 0.85 and 0.95 mmol/g, respectively.

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The effects of some pretreatments including blue-green and green algae and minerals on the induction of me-tabolic and biochemical process of germination were studied in Dracocephalum kotschyi Boiss. seeds. The seeds were pretreated with green algae Spirulina platensis, Chlorella vulgaris and Dunaliella bardawil or D. IR-1 (Isolated from Gave-Khooni-salt marsh) and modified Johnson nutrient medium. Dunaliella species belong to salt marshs and waters, hence their medium was prepared by means of 0.6 % NaCl. Spirulina's nutrient medium (NM) included 0.1% NaCl. The activities of α-amylase, ß-amylase, dehydrogenase, content of total sugar, reducing sugars and total protein (all we-re measured after priming) increased in comarsion with control. Treatment without NaCl and the treatment with 0.1 % NaCl caused the highest amount of the parameters mentioned. In the presence of salt (often at 0.6 % NaCl), algae could not improve and increase the parameters. In contrast, in the absence of salt, the positive effects of algae increased. Ge-rmination indices and length of shoots and roots which were measured after sowing the seeds into Petri-dishes, showed some positive effects regarding the pretreatments. Spirulina cells filteration with or without NM (including 0.1% NaCl) caused the highest activities in α-amylase and ß-amylase and the highest amount of total sugar and FGP. Chlorella filt-eration led to the increment of dehydrogenase activity and also the root's lenght. Dunaliella cells filteration in NM (without salt) increased α-amylase and ß-amylase activities and the reducing sugars.

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In this study, the effects of seaweed extract (Ascophyllum nodosum) on seed germination stimulation and growth indices in chickpea were studied. A factorial experiment was performed on the basis of a completely randomized design with 3 replications. Treatments consisted of seaweed extract at four levels (0, 1.5, 2.5 and 3.5%) and drought stress at four levels (0, -0.3, -0.6 and -0.9 MP). Drought stress was induced by PEG 6000. Results showed that drought stress at -0.6 and -0.9 MP reduced the germination traits significantly compared with the controls. Seaweed extract at 2.5 and 3.5% resulted in a significant increase in the germination percentage (+18%, +24%), germination rate (+15%, +20%), seedling length (+13.3%, +15.7%), radicle area (+10.4%, +12.8%), radicle diameter (+14.2%, +25%), plumule length (+14%, +16.6%) and plumule dry weight (+10.3%, +12.6%). Under non-stress and -0.3 MP, seaweed extract levels at 2.5 and 3.5% could significantly increase the germination vigor, seed vigor index, consumed endosperm, radicle length and radicle dry weight. The application of seaweed extract at 3.5% improved the germination vigor, seed vigor index and radicle dry weight under -0.6 MP conditions. It also improved the consumed endosperm, length and radicle dry weight in samples affected by -0.9 MP conditions. According to the results, the use of seaweed extract (Ascophyllum nodosum) in the seed germination of beans is recommended for the reduction of the negative effects of drought stress.
 

 

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Nowadays, brown macroalgae are considered to be a source of various nutritional and pharmaceutical compounds. In addition, fish roe is very susceptible to spoilage due to its high amount of protein and unsaturated fatty acids. In order to postpone the deterioration of roe-related products, salt and preservatives are utilized. Natural preservatives are recommended because of the adverse effects of chemical additives. Thus, different concentrations of pure alginate (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) were chose and then the 0.2% alginate was selected on the basis of the sensory evaluation of the results. Moreover, the treatments including control (salt-alginate-free), A₁ (containing 2.5% salt) A₂ (containing 0.2% alginate), A₃ (containing 2.5% salt and 0.2% alginate) were used to investigate their preservative effects on fish roe. The quality of rainbow trout roe was assessed within 0, 15, 30, 45 days at refrigerated storage. The treatment A₃ showed significant differences in microbial, chemical and sensory results compared with other treatments (p≤0.05). According to the results, salting 2.5% and alginate 0.2% method gave good flavor and increased shelf life to the roe.
 


 

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In the present study, two regulatory phytohormones, abscisic acid and auxin, were extracted from two different macroalgae, Sargassum muticum and Gracilaria corticata, for the first time. Sampling was performed each month with three replicates, from Bushehr Province shores located in the north region of Persian Gulf for six alternative months. The alteration of seaweeds biomass and the probable impacts of some environmental factors were measured. The extracted phytohormones were isolated employing HPLC method and identified by injection of standards. The highest amount of ABA phytohormone in the two species, occurred in November. Also, the highest amount of Auxin in Sargassum muticum was reported in May, while the highest amount of this hormone in Gracilaria corticata was observed in January. In January, the maximum mean biomass in Sargassum muticum was 679gr/m², while the minimum mean of 20.66gr/m² was observed in September. Moreover, the highest average biomass in Gracilaria corticata was 423/33gr/m² in March and the lowest mean of 158g/m² was reported in November. ANOVA and Chi-squared test results showed a significant difference in all samples. These phytohormones could be applied in preparing algae liquid fertilizer in future studies.