B. Mazalska's research while affiliated with Medical University of Bialystok and other places

In our study we analyzed the species composition of fungi and heterotrophic straminipiles in four ponds of a fish farm in Popielewo and in four ponds in Poryta Jabloń situated in the vicinity of Knyszyn, Poland. Samples of water were collected during the spring and autumn of 2009. Fourty-two species (11 fungi and 31 heterotrophic straminipiles) were recovered. We found some potential pathogens of economically valuable fish and fish spawn, such as Achlya americana, Ac. polyandra, Saprolegnia ferax, and S. parasitica. In addition, we found some common human pathogens such as Aspergillus niger, and Candida tropicalis. Some saprotrophs such as Rhizophlyctis rosea, Nowakowskiella elegans, Olpidiopsis saprolegniae, Pythium debaryanum, Py. gracile, Py. hemmianum, and Py. inflatum appeared to be relatively common. Most species of fungi and straminipiles were Recovered from ponds in Poryta Jabloń (34), while the smallest number was found in Popielewo ponds (25). The physico-chemical analysis of water showed that ponds in Poryta Jabloń were the least polluted with organic matter, whereas biogenic compounds were most abundant in Popielewo.

Studies of fungi and fungus- like organisms in the northeastern Poland have mainly concentrated on running waters in the vicinity of Białystok, including the Horodnianka River. The main objective was to investigate biodiversity of fungi and fungus-like organisms which take part in decomposition of organic matter commonly found in inland waters. To obtain a complete picture of species composition of fungi and fungus-like organisms in running waters we decided to explore representative sites of the Horodnianka River such as Olmonty, Hryniewicze and Horodniany with close localization of landfill. Fungal species were isolated using baiting technique. Baits of onion skin (Alium cepa), hemp-seeds (Cannabis sativa), impregnated cellophane and snake skin (Natrix natrix) were applied to isolate fungi from water of the Horodnianka River. The fungal community consists of 26 species, 10 species of fungi belonging to class Chytridiomycetes (3), anamorphic fungi (6), and Zygomycetes (1). 16 species belong to fungus-like organisms from class Oomycetes. Most of the recognized species have already been found in other running waters. From all the examined habitats the fungi belonging to 26 species of 18 genera Achlya, Alternaria, Aphanomyces, Aspergillus, Catenophlyctis, Dictyuchus, Fusarium, Karlingia, Lagenidium, Leptomitus, Olpidiopsis, Penicillium, Phlyctochytrium, Pythium, Saprolegnia, Scoliognia, Thraustotheca and Zoophagus were obtained. Certain fungal species like Aphanomyces laevis, Fusarium aqueductum, F. moniliforme, F. oxysporum, Leptomitus lacteus, Saprolegnia feax and S. parasitica were found at all the study sites. Among fungi potentially pathogenic and allergogenic for humans the genera Alternaria, Aspergillus, Fusarium, Lagenidium and Penicillium have already been described. However, the species Lagenidium giganteum and Achlya androgyna are new in the fungal biota of Poland. The greatest number of fungal species occurred in Olmonty (24), the smallest in Horodniany (13). Presence of fungi such as Leptomitus lacteus, Fusarium aqueductum in the water of the Horodnianka River offers the possibility of using them as indicators of water quality.

We investigated the growth of straminipilous organisms on the skin, muscles and liver of herbivorous pirapitinga (Piaractus brachypomus) and carnivorous piranha (Pygocentrus nattereri) in water of three different eutrophication levels. Sixteen straminipilous organism species were found growing on the investigated body parts of both species of fish used as baits. The higher number of species was found on the baits of carnivorous species (15) when compared with the ones from the herbivorous pirapitinga (10 species). The highest number of straminipilous organisms species developed on the skin of both species of fish. The highest number of species of straminipilous organisms was observed growing in the water of the BiaBa river (middle eutrophication), while the lowest number occurred in the baits of vessels with water from the Dojlidy pond (low eutrophication).

The diversity of fungi and fungus-like organisms on fruits of 251 plant taxa from three water reservoirs in Poland was investigated. A total of 348 taxa, including 142 fungal species, 203 straminipilous organisms and three plasmodiophorids were recorded. The largest number of fungal species and straminipilous organisms occurred on fruits of Rhamnus alaternus (35 species), Crataegus azarolus (34), Arum maculatum (28), Morus alba (26) and Mahonia japonica (24). The most common species were Saprolegnia ferax (on fruits of 116 species), Rhipidium interruptum (72), R. americanum (70), Aphanomyces irregularis (66), Pythium rostratum (57), Saprolegnia glomerata (57) and Aphanomyces laevis (56). The greatest numbers of species was recorded from running waters at Cypisek Spring (246) and the smallest (209) from stagnant waters at Komosa Lake, i.e. 56 and 42 exclusive for each of the water bodies, respectively. Aphanomyces polysporus, Gracea waterhouseae, Pythium horinouchiense, Pythium pachycaule and Saprolegnia multispora are first noted for Polish waters.

The authors investigated the influence of periphyton that abundantly overgrow stalks of reeds (reed-periphyton) submerged in water [Phragmites australis (Cav.) Trin. ex Stewdel], especially the old ones, on the occurrence of mycoflora species in different trophic seasons in the water of 4 trophically different water bodies. The seeds and snake exuviae were used as bait. In the spring, diatoms were the predominant group of algae forming the periphyton on old reed stalks, green algae predominated in the summer, and cyanobacteria in the autumn. During the seasons studied, in the water from Lake Blizno equal numbers of mycoflora species were noted inside the control containers and in those with reedperiphyton. In water from the other 3 water bodies completely different results were obtained. In the spring and autumn, a smaller number of mycoflora species grew inside the containers with reed-periphyton. However, during the summer the number of mycoflora species was higher in the Biała river water (control) as compared to the containers with reedperiphyton; in the other 2 water bodies the findings were the opposite. As known, all algae, including the periphyton constituents, excrete many different organic substances into the environment. Some of them are a medium for various hydrobionts, while others inhibit the growth of aquatic organisms including mycoflora species.

Our study involved the quantitative analysis of species composition of fungi and straminipilous organisms in four ponds situated in Biatystok, Poland. The observations performed in April and November 2006 with respect to hydrochemical conditions revealed the occurrence of 48 species, including 9 fungi and 39 straminipilous organisms. Among species of fungi and straminipilous organisms, we found such pathogens of crustaceans and fish as Achlya dubia, Ac. oblongata, Ac. polyandra, Aphanomyces bosminae, Ap. laevis, Dictychus monosporus, Pythium jirovecii, Py. undulatum, Saprolegnia ferax, S. parasitica, S. pseudocrustosa and Thraustotheca clavata. The human pathogens Aspergillus niger, Candida tropicalis and Catenophlyctis variabilis as well as plant pathogens Pythium butleri and Py. debaryanum were also found. Such phytosapro- phytes as Achlya klebsiana, Karlingia rosea, Nowakowskiella elegans, N. macrospora, Pythium akanense, Py. aquatile, Py. elongatum, Py. injlatum and Py. intermedium were relatively common. Most species of fungi and straminipilous organisms were found to grow in Dojlidy Pond (27), the fewest in Akcent Pond (14). The hydrochemical analysis of water showed that Dojlidy was the least burdened with organic matter, whereas Akcent was the most abundant in biogenic compounds.

The authors described and illustrated 8 rare aquatic fungus-like organisms of the order Leptomitales (Chromista), which were isolated from the water of nine water bodies of different trophy of north-eastern Poland: Apodachlya punctata, Apodachlyella completa, Araiospora spinosa, Mindeniella spinospora, Nellymyces megaceros, Rhipidium europaeum, Sapromyces androgynus, and Sapromyces elongatus.

The authors investigated the dead fragments of 22 species of submerged plants in the water from three limnological and trophical different water bodies (spring, river and pond). A total of 184 species of aquatic fungi, including 119 zoosporic and 65 conidial species were found on the fragments investigated plants. The most common fungus species were Aphanomyces laevis, Saprolegnia litoralis, Pythium rostratum (zoosporic fungi) and Acrodictys elaeidicola, Anguillospora longissima, Angulospora aquatica, Lemonniera aquatica, Mirandina corticola, Tetracladium marchalianum, Tetracladium maxiliformis, Trinacrium subtile (conidial fungi).Most fungus species were observed on the specimens of Elodea canadensis (33 fungus species), Hippuris vulgaris f. submersa (33), Myriophyllum spicatum (34) and Potamogeton crispus (33), fewest on Ceratophyllum demersum (24), Fontinalis dalicarlica and Potamogeton nitens (each 25).The most fungi were growing in the water from River Supraśl (107), the fewest in the water from Pond Dojlidy (99). Some aquatic fungus species were observed in the water of only one of the three water bodies – in Pond Dojlidy (30), in Spring Jaroszówka (32) and in the River Supraśl (39) species. Seventy-five species growing only on fragments of single submerged plants. A number of zoosporic and conidial species (22 and four, respectively) appeared new to Polish waters. Out of these 119 zoosporic species, some are known as parasites or necrotrophs of fish.

The authors investigated the influence of 9 species of aquatic plants (Ceratophyllum demersum, Elodea canadensis, Hydrocharis morsus-ranae, Lemna minor, Nuphar luteum, Potamogeton natans, Sagittaria sagittifolia, Sparganium ramosum, Stratiotes aloides) on the occurrence of aquatic zoosporic fungus spe- cies in the water of three water bodies of different trophy. The fewest fungi were noted in the containers with Potamogeton natans (9), Elodea canadensis (15) and Hydrocharis morsus-ranae (16), the most in containers with Sparganium ramosum (23), Lemna minor (24) and Nuphar luteum (25). More fungi were found to grow in the containers with 7 plants than in the controls (the mean ratio of Co/Pl ranged from 1.7/3.7 to 6.7/8.7). However, for Potamogeton natans and Sparganium ramosum, control samples con- tained more fungus species. The mean ratio for the samples with Potamogeton natans was 5.7/2.7 and with Sparganium ramosum - 6.3/5.4.