SUMMARY
In this study fifteen physico-chemical parameters with heavy metals were evaluated monthly from the Greater Zab River within Erbil province in twelve sites over a period of 10 months, also A study of non-diatom algal species composition was carried out from April 2021 to January 2022. Among them site 4,5,6,7 and 9 are the first for algal study in this area.
In the present study the result of physical and chemical parameters has been recorded: The air temperature fluctuations between 4.1 °C and 44.3 ºC. at Ble-Barzan river and Gwer pond. Water temperature was ranged between 12.0 ºC and 27.3 ºC at Bekhma river and Gwer pond. The pH, electrical conductivity and total dissolved solids were ranged from 7.30 to 8.22, 300 to 850 μS.cm-1 and 192 to 544 mg. l-1 respectively. In other hand, results of total hardness, calcium, magnesium ion was ranged from 128 to 359mg CaCO3. l-1, 15 to 81 mg. l-1 and 7.44 to 26.91 mg. l-1 respectively. However, total acidity and total alkalinity and chloride were ranged from 2.9 to 31.7 mg CaCO3. l-1 and 124 to 293 mg CaCO3. l-1 and 2 to 74 mg. l-1 respectively.
In respect to nutrients the concentration of each nitrate, nitrite, reactive phosphate and sulfate were ranged from 4.01 to 22.65 mg. l-1, 0.007 to 0.162 mg. l-1, 0.34 to 3.97 mg. l-1, and 110.3 to 270.2 mg. l-1 respectively. The value of chlorophyll-a was ranged between 0.001 and 21.613 mg. l-1. According to Canadian Council of Ministers of the Environment Water Quality Index (CCME WQI) status for all sites located under the category of “Fair” (65-79) except for site 12 was located under the category of “Marginal” (45-64) water quality for drinling pourpose. The decreasing trend of heavy metals were observed in the water as Fe > Cr > Zn > Mn > Pb > Ni > Co > Cu > Cd. According to single factor pollution index Ni, Cd, Cu, Zn and Mn were equal or less than 1 in all sites were considered no pollution. In addition, nearly half of sites for Co, Cr, Pb and two sites of Fe were recorded more than 1 which considered Slightly pollution. Moreover, half sites of Fe, one site of Co and two sites of Cr were more than 2 which are located of lightly pollution. According to result five site of Fe and two site of Cr were more than 3 which considered as moderately polluted. On basis of Nemerow Pollution Index, the comprehensive pollution index of Greater zab river was between 0.856 and 2.725 in the present study which means heavily polluted to moderately polluted water.
In term of phycological study a total of 116 taxa of algal flora were identified in 42 genera, 18 orders, 5 classes and 4 divisions, among the total identified algal species 13 of them were new records to Kurdistan region of Iraq and Iraqi algal flora. The greater part of identified algal species was 97 species with 83.621 % belong to Chlorophyta, followed by Cyanophyta 10 specie with 8.621%, Euglenophyta 8 species with 6.897%, and 1 species of Charophyta with 0.862%. In this study the dominancy of Chlorophyta over Cyanophyta was observed. According to Shannon Wiener Diversity Indices, the result of species diversity was ranged between 1.098 and 2.509 bits/ind.
In this study, antimicrobial activity of three species of algae Scenedesmus quadricauda 1, Scenedesmus quadricauda 2 and Dunaliella primolecta was tested against two pathogenic Gram positive and Gram negative bacteria Staphylococcus aureus (ATCC:25923), Escherichia coli (ATCC:35218) and fungi Candida albicans (ATCC:10231) by diffusion technique well. There were utilized eleven distinct concentrations of algal extract, including (2, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 mg/ml). For testing, the extracts’ minimum inhibitory concentrations (MIC) against particular bacteria and fungus at varied concentrations were calculated. In this study, Scenedesmus quadricauda 1 purified, antimicrobial compound was considered more effective against Staphylococcus aureus, Escherichia coli and fungi Candida albicans. But the highest activity of algal extracts by ethanol is more than methanol and ethyl acetate against pathogenic bacteria and causing prevent or kill growth them. Scenedesmus quadricauda 1 was more effective one against bacteria with antibacterial action starting at concentration 5 mg/ml for Candida albicans, 10 mg/ml for Staphylococcus aureus and 15 mg/ml for Escherichia coli.
The findings of the present investigation demonstrated that the three extracted algal methanol extracts had the maximum antifungal activity against the chosen humans infectious Candida albicans. The minimum inhibitory concentration of Scenedesmus quadricauda 1, Scenedesmus quadricauda 2 and Dunaliella primolecta extracts by methanol against fungi Candida albicans were 5 mg/ml, 20 mg/ml and 15 mg/ml respectively.
In the current investigation, several chemical components related to human health were found in the extract of three algae taxa. During Gas Chromatography–Mass Spectrometry (GC-MS) screening of solvent extract of Scenedesmus quadricauda 1, it was noticed that ethanol, methanol and ethyl acetate extract showed twenty, fifteen and thirteen compounds respectively and for Scenedesmus quadricauda 2 showed twenty five, twenty three and seventeen compounds through extract by ethanol, methanol and ethyl acetate respectively, finally extraction of Dunaliella primolecta by ethanol, methanol and ethyl acetate were including thirty one, eighteen and twenty compounds extract respectively.