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Abstract Summary To obtain different edaphic algae, different texture and color soil samples were collected from Egypt. Then, the physico-chemical characters of each sample were detected. The collected soil samples were enriched with synthetic nutrient media for algal propagation and identification. Algal diversity of the soil samples gave overall 37 algal taxa (25 genera) that belonging to four algal divisions. These were dominated with Cyanophycophyta (19 taxa, 11 genera) followed by Chlorophycophyta (11 taxa, 7 genera), while Bacillariophycophyta and Xanthophycophyta were represented only by 4 and 3 algal taxa respectively. Then, different isolation strategies and techniques were adopted to isolate some axenic soil algal taxa (Pleurochloris pyrenoidosa Pasch, Botrydiopsis eriensis Snow and Scenedesmus obliquus (Turpin) Kütz). In addition the mass growth of filamentous yellow green alga growing on soil and identified as Vaucheria geminata (Vaucher) De Candolle. The phytochemical compositions of four edaphic algae were evaluated included quantitative estimation of proteins, carbohydrates, phenols, flavonoids, pigments and lipids. The qualitative determination of amino acids, sugars, phenols, flavonoids and fatty acids components were carried out. Data showed measurable differences among the investigated algal taxa in their phytochemical composition. Quantitative estimation of total protein contents of the investigated four algal taxa revealed that, Pleurochloris pyrenoidosa recoded the maximum value for total proteins followed by both Scenedesmus obliquus and Botrydiopsis eriensis, while the lowest protein content was detected in Vaucheria geminata. Algal proteins have many nutritional values and could be used as supplement in a wide variety of food and feed products with favorable effect on both energy and health. Concerning amino acids analysis of the studied four algal taxa, results were in parallel to protein content. Maximum percentage of amino acids was detected also in Pleurochloris pyrenoidosa, while Vaucheria geminata showed the minimum value. Qualitative amino acids composition showed the presence of 17 different amino acids in all the investigated algae with different quantities including 10 essential and 7 non-essential amino acids. The highest value for the essential and the non-essential amino acids was for Pleurochloris pyrenoidosa and the lowest value for Vaucheria geminata. Leucine, lysine and valine were the most predominant essential amino acids among all algal taxa under study, while cystine recorded the minimum value in all of them. Meanwhile, glutamic acid, aspartic acid and arginine were the most dominant non-essential amino acids. Moreover, the ratio of essential over non-essential amino acids was ~1 among all algal taxa under study, where the highest value (1.07) was detected in Vaucheria geminata. Results of carbohydrate content of the studied algal taxa revealed that, Pleurochloris pyrenoidosa recoded the maximum value followed by both Scenedesmus obliquus and Botrydiopsis eriensis, while the lowest carbohydrate content was detected in Vaucheria geminata. Sugars composition of each alga identified the presence of 8 sugars in both Vaucheria geminata and Pleurochloris pyrenoidosa, While only 5 sugars components were detected in Botrydiopsis eriensis and 6 for Scenedesmus obliquus. Maximum values for arabinose, glucose and galactose were for Pleurochloris pyrenoidosa while fructose and sucrose recorded the higher values in Vaucheria geminata. On the other hand, Botrydiopsis eriensis sugars were characterized by mannose while Scenedesmus obliquus characterized with xylose and rhamnose. Moreover, the pigment composition (chlorophyll a and total carotenoids) of the four studied algal taxa showed that, Botrydiopsis eriensis recorded the highest content of both chlorophyll a and total carotenoids. Although, Scenedesmus obliquus recorded higher value of chlorophyll a and lower content of total carotenoids was noticed. On the other hand, moderate concentration of chlorophyll a and total carotenoids was detected in Pleurochloris pyrenoidosa and Vaucheria geminata. Data revealed that, both total phenols and flavonoids content showed similar pattern. Maximum content of total phenols and total flavonoids were detected in Botrydiopsis eriensis and Scenedesmus obliquus. Meanwhile, Pleurochloris pyrenoidosa showed moderate content of both total phenols and flavonoids. On the other hand, lower content of phenols and flavonoids were recorded in Vaucheria geminata. Additionally, the phenols and flavonoids fractions were identified. chromatograms of the investigated algae identified 7 types of phenolic compounds with nearable values in both Vaucheria geminata and Pleurochloris pyrenoidosa, while (5 and 6 phenols) were detected in Botrydiopsis eriensis and Scenedesmus obliquus, respectively. According to the quantitative analysis of phenols, higher ratios of gallic, resorcinol, chlorogenic and syringic were identified in Pleurochloris pyrenoidosa among all algae. On the other hand, caffeic was the dominant phenol in Botrydiopsis eriensis while coumaric and freulic characterized in Vaucheria geminata. Similarly, flavonoids exhibited narrow range among all algae under investigation. Seven types of flavonoids were detected from the chromatograms of both Vaucheria geminata and Pleurochloris pyrenoidosa while only five flavonoids for each Botrydiopsis eriensis and Scenedesmus obliquus were recorded. Kaempferol, rutin and quercitrin were characterized with higher ratios in Pleurochloris pyrenoidosa while similar values of hesperetin and apigenin were present in Botrydiopsis eriensis and Pleurochloris pyrenoidosa. Regarding Scenedesmus obliquus, maximum values of catechin and quercetin were present. Total antioxidant activity was estimated by Phosphomolybdenum assay and data revealed higher activity occupied by both Scenedesmus obliquus and Botrydiopsis eriensis followed by Pleurochloris pyrenoidosa while lower activity was for Vaucheria geminata. Also, antioxidant activity measured by the % inhibition of DPPH radical recorded maximum antioxidant activity of Scenedesmus obliquus, Pleurochloris pyrenoidosa and Botrydiopsis eriensis and moderate activity for Vaucheria geminata were detected. The total lipids contents of the investigated algae were evaluated, and data revealed maximum value for Botrydiopsis eriensis and Pleurochloris pyrenoidosa followed by Scenedesmus obliquus and minimum value for Vaucheria geminata. chromatographic analysis showed about 21 different fatty acids ranged from C14 to C23. About half of them are belonging to C16/C18 saturated or unsaturated fatty acids. Fatty acids of the studied algae were composed mainly of 6 saturated and 15 unsaturated fatty acids including 8 monounsaturated and 7 polyunsaturated fatty acids. Remarkable difference in algal fatty acids profiles were observed throughout this study. In Vaucheria geminata 13 fatty acids representing about 82.12 % of the total constituents were identified, only 2 of them belonging to SFAs while 11 from USFAs. In similar, Pleurochloris pyrenoidosa contained 10 FA about 84.53 % of the total constituents, of them 5 SFAs and 5 UFAs was characterized. It was noted that, only two fatty acids were detected in Botrydiopsis eriensis representing large proportion (98.36 %) of the total constituents composed mainly of PUFA (ω-3 α-Linolenic acid) and low portion of palmitic acid. Also, Scenedesmus obliquus showed only 3 fatty acids (87.51 %) with high ratio of MUFAs to SFAs composed mainly of ω-9 oleic acid followed by palmitic acid. It was noticeable in all tested algae that, the percentage of the unsaturated to saturated fatty acids. This investigation indicated that, not only green-algae having different and important application in human life, but also members of Xanthophycophyta will play an important applied roles in the future of animal feeds, human foods, drugs industry, as well as hydrocarbon and biofuels or biodiesel production. Summary To obtain different edaphic algae, different texture and color soil samples were collected from Egypt. Then, the physico-chemical characters of each sample were detected. The collected soil samples were enriched with synthetic nutrient media for algal propagation and identification. Algal diversity of the soil samples gave overall 37 algal taxa (25 genera) that belonging to four algal divisions. These were dominated with Cyanophycophyta (19 taxa, 11 genera) followed by Chlorophycophyta (11 taxa, 7 genera), while Bacillariophycophyta and Xanthophycophyta were represented only by 4 and 3 algal taxa respectively. Then, different isolation strategies and techniques were adopted to isolate some axenic soil algal taxa (Pleurochloris pyrenoidosa Pasch, Botrydiopsis eriensis Snow and Scenedesmus obliquus (Turpin) Kütz). In addition the mass growth of filamentous yellow green alga growing on soil and identified as Vaucheria geminata (Vaucher) De Candolle. The phytochemical compositions of four edaphic algae were evaluated included quantitative estimation of proteins, carbohydrates, phenols, flavonoids, pigments and lipids. The qualitative determination of amino acids, sugars, phenols, flavonoids and fatty acids components were carried out. Data showed measurable differences among the investigated algal taxa in their phytochemical composition. Quantitative estimation of total protein contents of the investigated four algal taxa revealed that, Pleurochloris pyrenoidosa recoded the maximum value for total proteins followed by both Scenedesmus obliquus and Botrydiopsis eriensis, while the lowest protein content was detected in Vaucheria geminata. Algal proteins have many nutritional values and could be used as supplement in a wide variety of food and feed products with favorable effect on both energy and health. Concerning amino acids analysis of the studied four algal taxa, results were in parallel to protein content. Maximum percentage of amino acids was detected also in Pleurochloris pyrenoidosa, while Vaucheria geminata showed the minimum value. Qualitative amino acids composition showed the presence of 17 different amino acids in all the investigated algae with different quantities including 10 essential and 7 non-essential amino acids. The highest value for the essential and the non-essential amino acids was for Pleurochloris pyrenoidosa and the lowest value for Vaucheria geminata. Leucine, lysine and valine were the most predominant essential amino acids among all algal taxa under study, while cystine recorded the minimum value in all of them. Meanwhile, glutamic acid, aspartic acid and arginine were the most dominant non-essential amino acids. Moreover, the ratio of essential over non-essential amino acids was ~1 among all algal taxa under study, where the highest value (1.07) was detected in Vaucheria geminata. Results of carbohydrate content of the studied algal taxa revealed that, Pleurochloris pyrenoidosa recoded the maximum value followed by both Scenedesmus obliquus and Botrydiopsis eriensis, while the lowest carbohydrate content was detected in Vaucheria geminata. Sugars composition of each alga identified the presence of 8 sugars in both Vaucheria geminata and Pleurochloris pyrenoidosa, While only 5 sugars components were detected in Botrydiopsis eriensis and 6 for Scenedesmus obliquus. Maximum values for arabinose, glucose and galactose were for Pleurochloris pyrenoidosa while fructose and sucrose recorded the higher values in Vaucheria geminata. On the other hand, Botrydiopsis eriensis sugars were characterized by mannose while Scenedesmus obliquus characterized with xylose and rhamnose. Moreover, the pigment composition (chlorophyll a and total carotenoids) of the four studied algal taxa showed that, Botrydiopsis eriensis recorded the highest content of both chlorophyll a and total carotenoids. Although, Scenedesmus obliquus recorded higher value of chlorophyll a and lower content of total carotenoids was noticed. On the other hand, moderate concentration of chlorophyll a and total carotenoids was detected in Pleurochloris pyrenoidosa and Vaucheria geminata. Data revealed that, both total phenols and flavonoids content showed similar pattern. Maximum content of total phenols and total flavonoids were detected in Botrydiopsis eriensis and Scenedesmus obliquus. Meanwhile, Pleurochloris pyrenoidosa showed moderate content of both total phenols and flavonoids. On the other hand, lower content of phenols and flavonoids were recorded in Vaucheria geminata. Additionally, the phenols and flavonoids fractions were identified. chromatograms of the investigated algae identified 7 types of phenolic compounds with nearable values in both Vaucheria geminata and Pleurochloris pyrenoidosa, while (5 and 6 phenols) were detected in Botrydiopsis eriensis and Scenedesmus obliquus, respectively. According to the quantitative analysis of phenols, higher ratios of gallic, resorcinol, chlorogenic and syringic were identified in Pleurochloris pyrenoidosa among all algae. On the other hand, caffeic was the dominant phenol in Botrydiopsis eriensis while coumaric and freulic characterized in Vaucheria geminata. Similarly, flavonoids exhibited narrow range among all algae under investigation. Seven types of flavonoids were detected from the chromatograms of both Vaucheria geminata and Pleurochloris pyrenoidosa while only five flavonoids for each Botrydiopsis eriensis and Scenedesmus obliquus were recorded. Kaempferol, rutin and quercitrin were characterized with higher ratios in Pleurochloris pyrenoidosa while similar values of hesperetin and apigenin were present in Botrydiopsis eriensis and Pleurochloris pyrenoidosa. Regarding Scenedesmus obliquus, maximum values of catechin and quercetin were present. Total antioxidant activity was estimated by Phosphomolybdenum assay and data revealed higher activity occupied by both Scenedesmus obliquus and Botrydiopsis eriensis followed by Pleurochloris pyrenoidosa while lower activity was for Vaucheria geminata. Also, antioxidant activity measured by the % inhibition of DPPH radical recorded maximum antioxidant activity of Scenedesmus obliquus, Pleurochloris pyrenoidosa and Botrydiopsis eriensis and moderate activity for Vaucheria geminata were detected. The total lipids contents of the investigated algae were evaluated, and data revealed maximum value for Botrydiopsis eriensis and Pleurochloris pyrenoidosa followed by Scenedesmus obliquus and minimum value for Vaucheria geminata. chromatographic analysis showed about 21 different fatty acids ranged from C14 to C23. About half of them are belonging to C16/C18 saturated or unsaturated fatty acids. Fatty acids of the studied algae were composed mainly of 6 saturated and 15 unsaturated fatty acids including 8 monounsaturated and 7 polyunsaturated fatty acids. Remarkable difference in algal fatty acids profiles were observed throughout this study. In Vaucheria geminata 13 fatty acids representing about 82.12 % of the total constituents were identified, only 2 of them belonging to SFAs while 11 from USFAs. In similar, Pleurochloris pyrenoidosa contained 10 FA about 84.53 % of the total constituents, of them 5 SFAs and 5 UFAs was characterized. It was noted that, only two fatty acids were detected in Botrydiopsis eriensis representing large proportion (98.36 %) of the total constituents composed mainly of PUFA (ω-3 α-Linolenic acid) and low portion of palmitic acid. Also, Scenedesmus obliquus showed only 3 fatty acids (87.51 %) with high ratio of MUFAs to SFAs composed mainly of ω-9 oleic acid followed by palmitic acid. It was noticeable in all tested algae that, the percentage of the unsaturated to saturated fatty acids. This investigation indicated that, not only green-algae having different and important application in human life, but also members of Xanthophycophyta will play an important applied roles in the future of animal feeds, human foods, drugs industry, as well as hydrocarbon and biofuels or biodiesel production. |