Journal of Phycological Research
Volume:6 Issue: 2, Sep 2022

Haematococcus pluvialis can accumulate large amounts of astaxanthin under stress conditions. Azide as an effective respiratory inhibitor can induce oxidative stress. In this study, the effect of pre-treatment (7 days) and treatment (14 days) of different concentrations of azide (0, 25, 50, and 100 μM) was investigated on growth and biochemical parameters in green and red cells. Azide treatment and pre-treatment caused a decrease in all measured parameters except for the carotenoid in the green stage. Carotenoid content did not show any changes in azide treatment but pre-treatment with low concentration induced carotenoid accumulation in the green stage. The dry weight, protein, and carbohydrate amount did not change in red cells treated with azide, but carotenoid content decreased in these cells. Pre-treated with azide hurt the amount of protein and carbohydrates but increased the carotenoid content. Azide pre-treatment had better performance in increasing the carotenoid amount in red cells. These results showed that H. pluvialis has good potential for phytoremediation of azide and carotenoid accumulation.

Chaetomorpha and Rhizoclonium, two genera of the Cladophoraceae family, are rich in antioxidant, phenolic, and flavonoid compounds that have potential applications in the pharmaceutical, food, and cosmetic industries. This work examined thallus features in several populations of four Chaetomorpha species and one Rhizoclonium species. This study aimed to look into the morphological and anatomical characteristics of several populations of these taxa along the Persian Gulf and Oman Sea coasts. Good species identification in the studied species was indicated by the UPGMA dendrogram. According to a PCA-biplot of Chaetomorpha and Rhizoclonium based on equivalent morphological and anatomical parameters, the examined species can be distinguished by variables including cell wall thickness, diameter, thallus form, cell shape, and cell length. High agreement between the PCA biplot results and the heat map created using standardized morphological and anatomical features were observed. While CCA analysis of Chaetomorpha showed that the characteristic of cell wall thickness was affected by latitude, tallus form, and cell length were related to the longitude.

Lettuce (Lactuca sativa) represents a major horticultural crop in Iran and worldwide. Lettuce requires a high amount of water to grow well and is adversely affected by drought. Regarding the reports of the positive effect of seaweed extract on increasing the resistance of plants to abiotic stresses, the present study aimed to evaluate the effect of the seaweed Sargassum angustifolium extract on growth and yield indices of lettuce under drought stress. This study was conducted as a factorial experiment with three treatments of algae extracts concentrations and two treatments of drought stress, and non-stress treatment with three replications. To evaluate the effects of algae extract on lettuce under drought stress conditions, a combination of morphological and physiological characteristics including plant height and dry weight, photosynthetic pigment content, and antioxidant activities were measured. Results showed that treatment of seaweed extract significantly increased plant resistance to drought stress and improved morphological and physiological indices of lettuce (p< 0.05). The best results were obtained in the 1.5 g/l treatment of seaweed extract.

Nowadays, the increase in microplastic pollution has become a global problem. The food chain can be polluted by the presence of microplastics in macroalgae. To measure the presence and amount of microplastics in macroalgae and water, sampling was performed from the rocky shores of Bushehr province during the winter season of 2021 and summer season of 2022 from four stations of Jofreh, Rishehr, Bojikdan, and Halileh. The result indicates the presence of microplastics in the macroalgae and the water, which were separated using a stereomicroscope. The microplastics were analyzed by FTIR-ATR device to determine the type of microplastic. The dominant species of the sampling stations were macroalgae Sargassum sp.Although, according to the results, the microplastic pollution in macroalgae samples was higher in the summer than in winter, the microplastic pollution in the water was more in the winter season. The average abundance of microplastics was calculated as 173±96.96 and 116.75±63.36 microplastics/kg in the summer and winter seasons, respectively. Jofreh and Halileh stations, with a mean frequency of 225±50.48 and 23±5.69 microplastics/kg, were the most polluted and clean stations, respectively. The sphere form of the microplastic fragments was more frequent after the fiber type. The results of the FTIR-ATR analysis showed that the microplastic polymers in Sargassum sp. and water were polyamide (nylon)˃ polystyrene˃ polyvinyl chloride,  respectively. Since the main activities that pollute the beaches of Bushehr province are fishing, shipping, tourism, etc., and they are more in the summer. So it can be seen as evidence for the results of this study.

Cyanobacteria have the ability to nitrogen fixation, and the production of plant growth-stimulating substances, which increases plant growth and productivity as biological elicitors. Considering the medicinal value of Echinacea purpurea (L.) Monch, the effect of two species of heterocystous cyanobacteria, Nostoc punctiforme Hariot and, and Nostoc calcicola Brébisson ex Bornet & Flahault, on growth factors and phenolic content of this medicinal plant were evaluated. For this purpose, four pots were considered for each treatment and four others for the control plants. E. purpurea cultivated in a randomized complete block design in an experimental greenhouse condition. Then the treated plants were irrigated with 120 ml of 0.2% cyanobacterial suspensions at 20-day intervals. After 60 days, plants were collected and dried under shade and at room temperature. The total phenolic content of the aerial part and root of treated and control plants were evaluated using the Folin-Ciocaltiu method. The results showed that the total phenolic content of cyanobacterial-treated plants, especially plants treated with N. calcicola, significantly increased. This metabolite improvement was observed both in the aerial part and the root system of the N. calcicola treated plants. The results also showed that plant growth parameters such as root and stem length, as well as number of leaves in both treatments increased significantly compared to the control. As a result of this study, cyanobacteria can be improving the phenolic content and growth indices of the medicinal plant E. purpurea.

The increasing need for water resources and other factors in reducing these resources, along with the health and environmental problems of wastewater, make it clear that our linear water economy must evolve into a resilient circular water economy, where water is continuously reused, and contaminants become the feedstocks for other economically valuable processes. Biofilters utilize biological living things as catalysts to harvest valuable components which is a critical emerging technique.Cyanobacteria and microalgae's ability to be mixotrophs provides a competitive advantage against bacteria and fungi to be used in biofilters. Due to the reduction of environmental nutrients, heavy metals, pathogens, oxygen production for aerobic organisms, and carbon dioxide consumption, microalgae play a prominent role in purification processes.In this research, the appropriate species were chosen by examining different types of algal species and immobilization methods to produce biofilters. The performance of the optimally produced biofilter to reduce the pollution indicators of the industrial effluent was investigated.The results show the appropriate performance of the biofilter produced with AFC008 and AFC110 species to perfect removal of nitrate and phosphate and 76%  COD reduction and 79% reduction of BOD in less than a week (along with aeration pretreatment).

This study tries to review the algal assemblage of Urmia Lake in different environmental circumstances. There was an inconsistency about the phytoplankton of Urmia Lake in references. For example, Enteromorpha intestinalis macroscopic green alga was already reported from the lake and permanently vanished in the 1990s. On the other hand, various researchers have reported different algae from different sampling sites. These variations are related to limited and irregular samplings or increased salinity during recent years, which has eliminated some intolerant species. Dunaliella salt-tolerant green alga is responsible for more than 90% of primary production in hypersaline environments. This two-flagellate unicellular alga, in Urmia Lake, composed 92.1% and 99.6% of algal population density in high-stand and low-stand periods, respectively. In drought conditions, eight species of algae were observed in Urmia Lake. Chlorophyll as an indicator of primary production was lower in Urmia Lake than in its sister Great Salt Lake. So, it can be categorized as an oligotroph lake from this point of view. This study showed the significance of an algal herbarium on the national or regional scale to record and preserve algae species that may be vanished someday from the ecosystems.