North by Southwest: Screening the Naturally Isolated Microalgal Strains from Different Habitats of Iran for Various Pharmaceutical and Biotechnology Applications.

Background and Aims: Microalgae are known as a promising source for food, pharmaceutical, and biofuel production while providing environmental advantages. The present study evaluates some newly isolated microalgal strains from north and southwest of Iran as a potential source for high-value products. Methods: Primitive screening was carried out regarding growth parameters. The molecular and morphological identifications of the selected strains were performed using 18S rRNA gene sequencing. After phylogenic and evolutionary studies, the selected microalgal strains were characterized in terms of protein and pigment content, in addition to the fatty acid profile content. Besides, the CO2 fixation rate was determined to assess capability for various environmental applications. Results: All of the selected strains were predominantly belonging to Scenedesmus sp. and Desmodesmus sp. The isolated Scenedesmus sp. VN 009 possessed the highest productivity content and CO2 fixation rate of 0.054 g·L-1d-1 and 0.1 g·L-1d-1, respectively. Moreover, data from GC/MS analysis demonstrated the high robustness of this strain to produce several valuable fatty acids including α-linolenic acid and linoleic acid in 45% and 20% of total fatty acids. Conclusions: The identified strains have a great but different potential for SCP, ß-carotene, and ω-3 production, as well as CO2 fixation for environmental purposes. In this study, considering the wide range of microalgal strains in different habitats of Iran, the potential applications of native microalgae for various pharmaceutical, food, and biotechnology purposes were investigated.

Bioinformatics Analysis and Identification of Phytoene Synthase Gene in Microalgae.

BACKGROUND: Carotenoids are known as lipophilic secondary metabolites with important biological activities, which are mostly used in the food and pharmaceutical industry. They contribute to the colours of many fruits and flowers. Studies on the biosynthetic pathways of isoprenoids and carotenoids are still scarce, especially in microalgae and are limited to specic groups. Dunaliella spp. in Chlorophyta taxon of algae, the 2-C-methyl-D-erythritol 4-phosphate/ 1-deoxy-D-xylulose 5-phosphate (DOXP/MEP) is the synthesis pathway of sterols and carotenoids. OBJECTIVES: In this study, we used 12 Psy gene sequences in Dunaliella sp., also Scenedesmus acutus and Diospyros kaki to investigate a genome-wide search. The results are useful for better identification of carotenoids metabolisms, and increasing the production rate of beta-carotene in pharmaceutical, food and industrial processes. METHODS: Phytoene synthase (Psy) from Dunaliella spp. was selected as the rst regulatory point in the carotenoids pathway that catalysis the formation of geranylgeranyl pyrophosphate in isoprenoid biosynthesis. Structural, evolutionary and physics-chemical characteristics were investigated, using various bioinformatics tools and computer techniques. Moreover, some recently published patents were also regarded. RESULTS: The maximum length of the conserved motif was 5167 bp for Dunaliella. sp. (DQ463306.1) and the smallest length of the conserved motif was 416 bp belonging to D. salina (JQ762451.1). The average molecular weight of species was 41820.53 Da. The theoretical pI of species varied from 4.87 to 9.65, indicating vernation in the acidic nature. Two strains of D. bardawil (U91900.1 and EU328287.1) showed just a long-distance relationship with all other Dunaliella strains. Whilst, D. parva displayed the furthest vicinity with all the studied strains. CONCLUSION: Our study highlighted the Psy regulatory mechanism, as a key factor in the carotenoids pathway, to facilitate genetic and metabolic engineering studies. The obtained tree-dimensional arrangement of the amino acids revealed the regional structures and folding of the diverse segments of helices, sheets and turns. This information is a key point to unveil the protein's operation mechanism. Besides, we confirmed the suitability of bioinformatic approaches for analysing the gene structures and identifying the new Psy genes in unstudied microalgal strains.

Treating Urban Wastewater: Nutrient Removal by Using Immobilized Green Algae in Batch Cultures.

Essential roles of microalgae during the tertiary treatment of municipal wastewater have been proven. In order to avoid wash out of the biomass and also modify the quality of the treated wastewater; some techniques such as cell immobilization have been developed. To do so, in this study four samples from two species of microalgae (Chlorella vulgaris and Chlamydomonas sp.) were determined and confirmed by taxonomic identification. The samples were immobilized in calcium alginate beads. Within 10 days the amounts of nitrate (No3(-)-N) and orthophosphate (Po4(3-)-P) were measured to calculate the removal efficacy for each individual sample. Based on the standard methods, the amount of nitrate and orthophosphate were determined every 3 days within 10 days. The results indicate that immobilized microalgae are able to remove the nutrients and reduce the amount of nitrate and orthophosphate, significantly. Furthermore, the C. vulgaris (YG02) was the best species in this experience with 72% and 99% of reduction in the amount of nitrate and orthophosphate, respectively.