اختبار القدرة التكيفية لعزلات محلية من الطحالب الخضر المزرقة على تحمل بعض المعادن الثقيلة و ملاحظة تأثيرها على المكونات الخلوية

الملخص EN

In this study, pure isolates of blue green algae (Oscillatoria limnitica , Nostoc muscorum and Anabaena helicoidea) were obtained from alocal environment in Nineveh province (AL-Shlalat and AL-Hamdania regions).

The effect of different concentrations of heavy metals on growth and number of cellular constituents were studied for the locally isolated blue green algae.

The results showed that the best growth was achieved when not adding heavy metals to the medium and reduction of growth and cellular constituents were noticed with continuous addition of each heavy metal to the medium although the isolates were able to grow and survive under relatively high concentrations of heavy metals.

The daily growth rate reached (0.122, 0.330, 0.510)as an optical density and biomass (223, 300, 900mg / l), chlorophyll content (22.32, 60, 60.15 mg / l), protein content(79, 152, 71mg / l), carbohydrate content (101, 72, 330mg/l) and final pH reached (7.7, 7.80, 7.90) for O.

limnitica, N.

muscorum and A.

helicoidea isolates respectively after fifteen days of incubation when iron was used at concentration (2.37 %) in the form of iron chloride, and it was noticed that the growth of N.

muscorum was more stimulated when iron was used at concentration (0.71%) while growth of O.

limnitica isolate was stimulated at concentration (0.23 %) related to control treatment.

It was found that the growth reached to( 0.990,0.870,0.350) as an optical density, biomass (910, 905, 700 mg / l), chlorophyll content (21.15, 42.09, 31.56 mg/l), protein content (73, 70, 70 mg / l), carbohydrate content (133, 132, 160 mg / l) and final pH reached (8.20, 7.90, 7.80) for O.

limnitica , N.

muscorum and A.

helicoidea respectively.

When copper was used at concentration (3.72 %) in the form of copper chloride it was found that the growth of (O.

limnitica and N.muscorum) were more adapted when copper was added to the medium at concentration (0.74 %) compared with control treatment.

Also noticed that the growth rate reached to (0.101, 0.71, 0.330) as an optical density, weight of biomass (260, 400, 270mg/l), chlorophyll content (10, 10.12, 42.32 mg / l) protein content (67, 46, 47mg / l) carbohydrate content (71, 210, 130mg/l) and final pH (7.30, 7.7, 7.80) for O.

limnitica , N.

muscorum and A.

helicoidea cultures respectively at (2.46 %) in the form of nickel chloride.Also it was noticed that the reduction of growth and cellular constituents of the studied algae when nicke and cobalt used at concentration (6.12,4.5 %) respectively as compared with control treatment.