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Metal resistance of soil algae [Chlorophyta] occurring in post-flotation Zn-Pb and Cu-tailing ponds

100%

Kalinowska R., Pawlik-Skowronska B.

Polish Journal of Ecology

2008

tom 56

nr 3

415-430

Algae as pioneer organisms are important in extreme environments. We isolated several green algae (Chlorophyta) from Zn/Pband Cu-enriched ground samples of post-flotation tailing ponds, containing 17200–18400 mg Zn kg⁻¹, 3017–6566 mg Pb kg⁻¹ or 1420 mg Cu kg⁻¹. The algae with different morphologies belonged to following classes: Chlorophyceae and Trebouxiophyceae. Their Zn-, Pb- and Cu- resistance in comparison with soil green algae (Chlorophyceae) isolated from the unpolluted control soil was evaluated under laboratory conditions on the basis of 96h-EC₅₀ (effective metal concentration which causes 50% inhibition of algal growth after 96 h exposure). Among isolated algae Dictyococcus cf. varians Gerneck em. Starr from the Zn/Pb-tailing pond was highly resistant both to lead (EC₅₀ 48 μM) and zinc (EC₅₀ 126 μM), but sensitive to copper (EC₅₀ 2 μM). Stichococcus minor Nägeli and Chlamydomonas boldii Ettl from the Cu-tailing pond were resistant to copper (EC₅₀ 17.8 μM and 10 μM, respectively). Simultaneously, S. minor revealed co-resistance to Zn (EC₅₀ 251 μM), while C. boldii to Pb (EC₅₀ 38.9 μM). Geminella terricola J.B. Petersen (Chlorophyceae), isolated from the unpolluted control soil, revealed high sensitivity to the three metals (Zn-EC₅₀ 44.6 μM; Pb-EC₅₀ 10.2 μM and Cu-EC₅₀ 6.4 μM). Simultaneously, G. terricola accumulated intracellularly higher amounts of Zn (7.1 amol μm⁻³) and Cu (5.5 amol μm⁻³) than all the algae from the polluted ground samples (Zn: 1.2–6.4 amol μm⁻³ and Cu: 0.4–2.7 amol μm⁻³). It also accumulated high amounts of Pb (6.0 amol μm⁻³), but two-fold lower than D. cf. varians. Using cytochemical staining of metals dark pink Pb-rhodizonate complexes were detected in thick cell walls of the Pb/Zn-resistant D. cf. varians and in thick mucilage layers of the Cu/Pb-resistant C. boldii. However, in the Pb-sensitive S. minor Pb-complexes were detected inside deformed cells. Pink-orange Zn-dithizone complexes were mainly distributed inside the cells of the Zn-resistant D. cf. varians. The results obtained suggest that thick cell walls or envelopes may be partly responsible for the higher Pb-resistance of some studied algae. However, in the case of micro-nutrients like Zn or Cu other resistance mechanisms (biochemical / physiological) may be involved. It seems that algal species or ecotypes living in the grounds of metal post-flotation tailing ponds have been adapted to heavy metals present in their habitats and may be useful for remediation of such degraded environments.

Heavy metal accumulation, resistance and physiological status of some epigeic and epiphytic lichens inhabiting Zn and Pb polluted areas

100%

Pawlik-Skowronska B., Wojciak H., Skowronski T.

Polish Journal of Ecology

2008

tom 56

nr 2

195-207

Heavy metal accumulation, physiological status and resistance against Zn and Pb were compared in lichens occurring in metalpolluted (Silesian Upland, S. Poland) and unpolluted (forest complex, NE Poland) areas. Sandy soil near Zn/Pb ore mine had significantly lower (5–35-times) metal content than dolomite-containing ground of mine tailing dump in polluted area (S. Poland). Metal contents in native lichens sampled from those sites followed the same pattern. Total Zn, Pb, Cd and Cu contents in native lichens recorded in two sites of Zn/Pb mining area varied broadly and were considerably higher than in lichens from a control unpolluted site. Independently of the sampling site, epiphytic lichens of higher surface to biovolume ratio (i.e. Candelariella Mull. Arg., Lepraria Ach.) accumulated much more metals (6.05 – 9.57 mg g–1 DW) than lichens of a lower ratio (e.g. 0.25 mg g–1DW in Peltigera didactyla (With.) J.R.Laundon or 0.29 mg g–1 DW in some Cladonia Hill ex Browne). In general, the studied lichens accumulated metals in the following order: Zn>Pb>Cd≥Cu, that was in agreement with the metal content in soils. However, Cladonia furcata (Huds.) Schrad. From tailing dump contained 2-fold more Pb than Zn. Internal Zn and Pb contents (non-exchangeable fraction) in the studied lichens ranged broadly from 17 to 90% of the total metal content. Phaeophytinisation quotients (PhQ), total chlorophyll contents and chl a/b ratios in the native lichens from polluted sites ranged 0.84 – 1.44; 0.514 – 4.858 mg g–1 DW and 2.09 – 5.56, respectively. Experimental exposure of selected species (Hypogymnia physodes (L.) Nyl., Hypocenomyce scalaris (Ach.) Choisy, Lepraria elobata Tonsberg, L. incana (L.) Ach., sampled from the both polluted and unpolluted sites, to high doses of Zn2+ and Pb2+ (0.36 or 0.72 mmol g–1 DW) revealed higher resistance of lichens from the Zn/Pb-polluted sites than con-specific lichens from the unpolluted one. The resistance of epiphytic species from the polluted area to high doses of Zn2+ and Pb2+ increased as follows: H. physodes

Ograniczanie wyników

2 Polish Journal of Ecology

2 Pawlik-Skowronska B.

1 Kalinowska R.

1 Skowronski T.

1 Wojciak H.

2 2008

Wyniki wyszukiwania

Metal resistance of soil algae [Chlorophyta] occurring in post-flotation Zn-Pb and Cu-tailing ponds

Heavy metal accumulation, resistance and physiological status of some epigeic and epiphytic lichens inhabiting Zn and Pb polluted areas