Soil Algae Research Articles

Wyniki badań glonów i sinic w różnych ekotypach gleb w Adżarii w Gruzji

The publication deals with the studies on the diversity of species composition of Algae and cyanobacteria in various layers of soils (yell, red, soilsod-podzolic, marsh, urban) of the Adjara. The aim of the study was to identify and determine the composition of Algae and cyanobacteria; Establishment of the scale of development and spread of algoflora; Assessment of the ecological state of the Algae and cyanobacteria in adverse and favorable conditions. The diversity of algae and cyanobacteria was studied in soil cultures using the method of fouling glasses. Each treatment included 5 ste-rile cover glasses for micropreparations; cultures were wetted with distilled water. The presence of algoflora was detected in various soil samples based on morphological characteristics, percentage frequency, growth rate, and colony forming units. The study has found 171 species and subspecies of soil Algae and cyanobacteria, belonging to the divisions of Ochrophyta (59 species), Chlorophyta (51 species), Xanthophyta (8 species), Eustigmatophyta (1 species) and Cyanobacteria (52 species). Classes Bacillariophyceae, Chlorophyceae, and Cyanophyceae were considered polymorphic among the leaders. 11 species of algoflora involved in algoflora of the consortium have been specified as well. The most widely distributed algoflora in soil samples were of the genera Chlamydomonas (20 species), Eunotia (17 species), Phormidium (11 species), Pinnularia (11 species), Tetracystis (10 species), Leptolyngbya (9 species), Nitzschia (9 species), Chlorococcum (8) species, Nostoc (7) species and Oscillatoria (6 species) were dominant flora in all soil samples. Frequency percentage algoflor showed that from all of the soil, the maximum quantities of algoflora and cianobacteria in marsh soil that was 65.49%, in sod - podzolic soil 34.51%, in yell soil 19.88, in red soil 18.71%, the lowest frequency of occurrence of algoflora and cianobacteria was shown in urban soil 9.35%. Due to seasonal changes in soil and air temperature, there are 71 species (41.52%) in spring, 65 (38.95%) in summer, 78 (45.61%) in autumn, and 53 (30.99%) in winter. A lower level of biological activity in the urban soils was found. Morphometric trait differences in test objects activated on the soil samples have been observed. The study was found specialized species of Algal-cyanobacterial communitiesfrom each ecotype of soil. The soil samples collected from polluted sites were more affected by waste water which affected the population densities of Algal-cyanobacterial communities. Found that Adjara support a large and diverse community of Algal-cyanobacterial on soil, many species of which are previously undiscovered and undescribed. On this basis, works of longer duration and more intensive sampling are needed to obtain data regarding Algal-cyanobacterial communities, with more attention to specific variables such as microclimate, soil moisture, soil type, soil pH and vegetation types.

A critical review of soil algae as a crucial soil biological component of high ecological and economic significance.

Aero-terrestrial algae are ecologically and economically valuable bioresources contributing to carbon sequestration, sustenance of soil health, and fertility. Compared to aquatic algae, the literature on subaerial algae is minimal, including studies of distinctive habitats such as forest soils, agricultural fields, deserts, polar regions, specific subaerial zones, artificial structures, and tropical soils. The primary goal here was to identify the gaps and scope of research on such algae. Accordingly, the literature was analyzed per sub-themes, such as the "nature of current research data on terrestrial algae," "methodological approaches," "diversity," "environmental relationships," "ecological roles," and "economic significance." The review showed there is a high diversity of algae in soils, especially members belonging to the Cyanophyta (Cyanobacteria) and Chlorophyta. Algal distributions in terrestrial environments depend on the microhabitat conditions, and many species of soil algae are sensitive to specific soil conditions. The ecological significance of soil algae includes primary production, the release of biochemical stimulants and plant growth promoters into soils, nitrogen fixation, solubilization of minerals, and the enhancement and maintenance of soil fertility. Since aero-terrestrial habitats are generally stressed environments, algae of such environments can be rich in rare metabolites and natural products. For example, epilithic soil algae use wet adhesive molecules to fix them firmly on the substratum. Exploring the ecological roles and economic utility of soil and other subaerial algae could be helpful for the development of algae-based industries and for achieving sustainable soil management.

Comparative analysis of soil ecosystems of protected and artificially created beech forests

Peculiarities of soil ecosystems (algae, microbiocenosis, agrochemical and agrophysical characteristics) of the Uholsko-Shirokoluzhanskyi beech relict forests of the Carpathian Biosphere Reserve, as well as artificial European beech (Fagus sylvatica L.) plantations located on the botanical and geographical plots "Ukrainian Carpathians" of the M.M. Gryshko National Botanical Garden of NAS of Ukraine. Soil samples were collected from May to September during 2020–2021. The species composition of soil microalgae, the number of ecological and trophic groups of microorganisms, agrophysical and agrochemical characteristics of soils were analyzed. The predominance of green algae with a significant diversity of green flagellates and the complete absence of cyanobacteria are typical features of forest soils. The small number of detected species (12 in beech relict forests and 15 in artificial beech plantations) indicates shaded forest ecosystems which are typical for beech forests. Despite common features, the species composition of soil algae of both phytocenoses is quite different. The soils under the beech relict forests are characterized by a significant predominance of green algae, among which essential number of Trebouxiophyceae representatives with aerophytic ecology were found. It indicates the mountainous nature of the soil algal flora. Soils under artificial beech plantations are characterized by a richer species diversity and predominance of Chlorophyceae representatives, which is typical for lowland forests. A characteristic feature of protected and artificially created beech forests was the relative high number of micromycetes. Correlation analysis of research results showed a positive relationship between algal diversity and the abundance of two eco-trophic groups of microorganisms: actinomycetes and ammonifiers. In addition, the growth of algal diversity was positively correlated with the content of Ca and Mg, and negatively with the content of P.

Johansenicoccus eremophilus gen. et sp. nov., a novel evolutionary lineage in Chlorophyceae with unusual genomic features

Background – Green algae are a diverse group of photosynthetic eukaryotes, yet are still vastly understudied compared to land plants. For many years, green algae were characterized based on their morphology and life cycles. More recently, phylogenetic and genomic analyses have been added to the phycological toolkit for a better understanding of algal biodiversity and evolutionary history. Material and methods – A desert strain of green algae was isolated from Joshua Tree National Park (JTNP) in southern California as part of a larger biodiversity survey. The alga’s nuclear rRNA genes as well as the chloroplast genome were sequenced, annotated, and analysed in addition to a morphological assessment. Results – Morphologically this strain is especially similar to Pseudomuriella and Rotundella, and its lipid profile resembles that of other soil algae, but phylogenomic analyses demonstrate that it is a distinct evolutionary lineage in Chlorophyceae. The alga exhibits several unusual genomic features, the most remarkable being its highly derived yet apparently functional nuclear rRNA genes, 18S and 28S. Both genes are GC-rich and bear many compensatory base changes to maintain a similar secondary structure to that of other green algae. The chloroplast genome has a distinct gene order and repeat arrangement from other published green algal plastomes, but contains the expected genes and also provides phylogenetically informative data. Conclusion – We conclude that the strain be placed into a new species and genus in the class Chlorophyceae, and propose the name Johansenicoccus eremophilus for this new taxon. Johansenicoccus eremophilus exemplifies science’s insufficient understanding of the range of genomic variations among inconspicuous soil algae.

Seasonal variation in soil algal community structure in different forest plantations in subtropic China.

Algae exert great impact on soil formation and biogeochemical cycling. However, there is no full understanding of the response of soil algal community structure to the seasonal fluctuations in temperature and moisture and changes of soil physicochemical properties across different forests. Here, based on 23S rRNA gene sequencing, we analyzed soil algal community structure in four different forest plantations in two seasons and examined soil physiochemical properties. The results showed the significantly seasonal variation in soil algal community structure, with the higher overall diversity in summer than in winter. In addition, there existed significant correlations between soil algae (species composition, relative abundance, diversity index) and physicochemical properties (pH, total phosphorus, organic matter and nitrate nitrogen), suggesting that edaphic characteristics are also largely responsible for the variation in soil algal community. Nevertheless, the seasonal variation in algal community structure was greater than the variation across different forest plantations. This suggest temperature and moisture are more important than soil physicochemical properties in determining soil algal community structure. The findings of the present study enhance our understanding of the algal communities in forest ecosystems and are of great significance for the management and protection of algal ecosystem.

Unrecognized diversity and distribution of soil algae from Maritime Antarctica (Fildes Peninsula, King George Island).

Eukaryotic algae in the top few centimeters of fellfield soils of ice-free Maritime Antarctica have many important effects on their habitat, such as being significant drivers of organic matter input into the soils and reducing the impact of wind erosion by soil aggregate formation. To better understand the diversity and distribution of Antarctic terrestrial algae, we performed a pilot study on the surface soils of Meseta, an ice-free plateau mountain crest of Fildes Peninsula, King George Island, being hardly influenced by the marine realm and anthropogenic disturbances. It is openly exposed to microbial colonization from outside Antarctica and connected to the much harsher and dryer ice-free zones of the continental Antarctic. A temperate reference site under mild land use, SchF, was included to further test for the Meseta algae distribution in a contrasting environment. We employed a paired-end metabarcoding analysis based on amplicons of the highly variable nuclear-encoded ITS2 rDNA region, complemented by a clone library approach. It targeted the four algal classes, Chlorophyceae, Trebouxiophyceae, Ulvophyceae, and Xanthophyceae, representing key groups of cold-adapted soil algae. A surprisingly high diversity of 830 algal OTUs was revealed, assigned to 58 genera in the four targeted algal classes. Members of the green algal class Trebouxiophyceae predominated in the soil algae communities. The major part of the algal biodiversity, 86.1% of all algal OTUs, could not be identified at the species level due to insufficient representation in reference sequence databases. The classes Ulvophyceae and Xanthophyceae exhibited the most unknown species diversity. About 9% of the Meseta algae species diversity was shared with that of the temperate reference site in Germany. In the small portion of algal OTUs for which their distribution could be assessed, the entire ITS2 sequence identity with references shows that the soil algae likely have a wide distribution beyond the Polar regions. They probably originated from soil algae propagule banks in far southern regions, transported by aeolian transport over long distances. The dynamics and severity of environmental conditions at the soil surface, determined by high wind currents, and the soil algae's high adaptability to harsh environmental conditions may account for the high similarity of soil algal communities between the northern and southern parts of the Meseta.

Effect of Blue-Green Algae in Soils with Different Texture: (b) on Microbial Communities of Soils

Effect of Blue-Green Algae in Soils with Different Texture: (b) on Microbial Communities of Soils

Effect of Blue-Green Algae in Soils with Different Texture: (a) on Enhancement Growth and Yield of Wheat Plant

Effect of Blue-Green Algae in Soils with Different Texture: (a) on Enhancement Growth and Yield of Wheat Plant

Biochar as a Green Sorbent for Remediation of Polluted Soils and Associated Toxicity Risks: A Critical Review

Soil contamination with organic contaminants and various heavy metals has become a global environmental concern. Biochar application for the remediation of polluted soils may render a novel solution to soil contamination issues. However, the complexity of the decontaminating mechanisms and the real environment significantly influences the preparation and large-scale application of biochar for soil ramification. This review paper highlights the utilization of biochar in immobilizing and eliminating the heavy metals and organic pollutants from contaminated soils and factors affecting the remediation efficacy of biochar. Furthermore, the risks related to biochar application in unpolluted agricultural soils are also debated. Biochar production conditions (pyrolysis temperature, feedstock type, and residence time) and the application rate greatly influence the biochar performance in remediating the contaminated soils. Biochars prepared at high temperatures (800 °C) contained more porosity and specific surface area, thus offering more adsorption potential. The redox and electrostatic adsorption contributed more to the adsorption of oxyanions, whereas ion exchange, complexation, and precipitation were mainly involved in the adsorption of cations. Volatile organic compounds (VOCs), dioxins, and polycyclic aromatic hydrocarbons (PAHs) produced during biochar pyrolysis induce negative impacts on soil alga, microbes, and plants. A careful selection of unpolluted feedstock and its compatibility with carbonization technology having suitable operating conditions is essential to avoid these impurities. It would help to prepare a specific biochar with desired features to target a particular pollutant at a specific site. This review provided explicit knowledge for developing a cost-effective, environment-friendly specific biochar, which could be used to decontaminate targeted polluted soils at a large scale. Furthermore, future study directions are also described to ensure a sustainable and safe application of biochar as a soil improver for the reclamation of polluted soils.

Phyllosphere eukaryotic microalgal communities in rainforests: Drivers and diversity

Phyllosphere algae are common in tropical rainforests, forming visible biofilms or spots on plant leaf surfaces. However, knowledge of phyllosphere algal diversity and the environmental factors that drive that diversity is limited. The aim of this study is to identify the environmental factors that drive phyllosphere algal community composition and diversity in rainforests. For this purpose, we used single molecule real-time sequencing of full-length 18S rDNA to characterize the composition of phyllosphere microalgal communities growing on four host tree species (Ficus tikoua, Caryota mitis, Arenga pinnata, and Musa acuminata) common to three types of forest over four months at the Xishuangbanna Tropical Botanical Garden, Yunnan Province, China. Environmental 18S rDNA sequences revealed that the green algae orders Watanabeales and Trentepohliales were dominant in almost all algal communities and that phyllosphere algal species richness and biomass were lower in planted forest than in primeval and reserve rainforest. In addition, algal community composition differed significantly between planted forest and primeval rainforest. We also found that algal communities were affected by soluble reactive phosphorous, total nitrogen, and ammonium contents. Our findings indicate that algal community structure is significantly related to forest type and host tree species. Furthermore, this study is the first to identify environmental factors that affect phyllosphere algal communities, significantly contributing to future taxonomic research, especially for the green algae orders Watanabeales and Trentepohliales. This research also serves as an important reference for molecular diversity analysis of algae in other specific habitats, such as epiphytic algae and soil algae.

Soil algae as a potential carrier for nanoplastics: Adsorption and internalization of nanoplastics in algal cells.

Although plastics are widely distributed in soil environments, few studies have assessed their effects on different test species. In this study, the responses (adsorption or internalization) of two green algal species (Chlorococcum infusionum and Chlamydomonas reinhardtii) to nanoplastics in soil were evaluated via microscopic analysis for nine weeks; additionally, the effects of polystyrene (PS) nanoplastics on their photosynthetic activity and growth were assessed. The results showed that PS nanoplastics and C. infusionum or C. reinhardtii cells were aggregated with the formation of palmelloid colonies; additionally, internalization of PS nanoplastics to C. reinhardtii cells was verified. However, no significant effects of PS nanoplastics on photosynthetic activity and growth of soil algae were observed. Algae were more likely to be threatened by plastic aggregation in the soil environment than in the aquatic environment due to the formation of a mucilaginous sheath on their cell. Our results highlighted that soil algae are a potential carrier of nanoplastics to other organisms in the food chain due to plastic aggregation through adsorption or internalization. This study will enhance our understanding of nanoplastic distribution in soil algae.

Participation of Rossiulus kessleri (Diplopoda, Julida) in the Formation of Algae Assemblages of Urbanized Territories

Epi- and endozoochory are well explored phenomena that contribute to the distribution patterns of plant seeds, spores or fruits by vertebrates. It is less known how soil algae may be redistributed due to analogous interactions. We describe the participation of saprophage Rossiulus kessleri (Julidae, Diplopoda) in soil algae redistribution. The research was carried out in a park area of a large industrial megacity in the Dnipro steppe region (Ukrainian North Steppe subzone), Dnipro city. Research material was collected according to zoological and algological methods. The leaf litter of tree species (ash maple Acer negundo, Italian poplar Populus deltoides, locust Robinia pseudoacacia, European white elm Ulmus laevis, Norway maple Acer platanoides) and living diplopods were collected within 1 m2 quadrats along transects. Millipedes were maintained without feeding for five days, after which they were fed with the litter collected previously. Identification of algoflora was conducted in washes from the surface of diplopods’ bodies, its gut washes, in diplopods’ excretions and leaf litter washes. In the leaf litter, as R. kessleri’s feeding base, 14 soil algae species were identified—Nostoc punctiforme, Bracteacoccus minor, Mychonastes homosphaera, Neospongiococcum sp., Chlamydomonas sp., Chlorella vulgaris, Stichococcus bacillaris, Pseudococcomyxa simplex, Desmococcus olivaceus, Trebouxia spp., Klebsormidium flaccidum, Nephrodiella phaseolus, Navicula pelliculosa and Vischeria magna. In body surface washes, five soil algae species were identified, in gut washes seven algae species were found, while in excretions, just four were observed. It was established that not all algae species from the gut washes of R. kessleri were present in excretions. The presence of some representatives of soil algae, for example, Chlorella vulgaris and Vischeria magna, in natural park litter, body surface washes, gut washes and in excretions of R. kessleri, suggests that the given species pass through the diplopod’s gut and stay undamaged. This indicates that soil saprophage R. kessleri contributes to the dispersal of some soil algae representatives through epi- and endozoochory. Our results represent novel contributions to the knowledge of zoochory. It was shown that animals can be involved in dispersal of not only plant parts but also entire organisms, although it is unknown at what scale diplopods contribute to the diversity and dispersal of algae.

Validation of the paper-disc soil method using soil alga Chlorococcum infusionum to quantitatively determine the toxicity of heavy metals

The paper-disc soil method is a soil algal bioassay used to assess soil water transfer in polluted soils. Although this ecotoxicological method was first established in 2016 to assess soil pollution, quantitative toxicity assessments of Cu- or Ni-treated soil and in situ or ex situ soils polluted with other heavy metals (HMs) have not been widely conducted. In this study, the paper-disc soil method was validated under different test conditions. The validated paper-disc soil method was used to quantitatively investigate the toxicity of four HMs (As, Cd, Cr, and Zn). Based on the results, the test species, initial inoculation concentration in the algal-dispersed solution, water content, light intensity, and exposure duration were proposed as Chlorococcum infusionum, 3 × 106 cells/mL in Bold's basal medium, 80% water-holding capacity, 4000 ± 500 lx, and 6 days, respectively. The toxicity of HMs was quantified using the validated paper-disc soil method, and the half-maximal effective concentration values for biomass were calculated as 22.49 (21.26–23.78) mg Cr/kg dry weight (dw) soil, 42.72 (38.64–47.24) mg Cd/kg dw soil, 57.79 (55.46–60.21) mg As/kg dw soil, and 183.06 (175.38–191.06) mg Zn/kg dw soil. The paper-disc soil method using the soil alga C. infusionum was validated by quantitatively evaluating the test conditions and toxicity of HMs. Our results provide important quantitative toxicity data for soil algae exposed to HMs and a basis for standardizing the paper-disc soil method using soil algae.

Persistence and Exposure Assessment of Insecticide Indoxacarb Residues in Vegetables.

Indoxacarb, a promising new generation insecticide, is gaining popularity among vegetable growers in West Bengal, India, for controlling a large number of insects. However, it may simultaneously also increase the risk of contamination in the edible portions of the vegetables. This study was planned to analyze the persistence behavior of indoxacarb in cabbages, tomatoes, and soil. Moreover, indoxacarb residue contents were estimated to assess both the dietary and soil ecological risks associated with the application of the same. The experimental location was important because West Bengal is the leading vegetables producing state in India. Indoxacarb was found to dissipate quickly with a half-life ranging between 1.55 and 2.76 days, irrespective of the vegetable, dose, and season, and the safe waiting period was very less. The findings indicate that both vegetables can be safely consumed 1 day after the final spray. However, the risk to soil algae is predicted to be unacceptably high, which needs to be studied extensively.

Anti-Inflammatory Extract from Soil Algae Chromochloris zofingiensis Targeting TNFR/NF-κB Signaling at Different Levels

Inflammatory skin diseases, including atopic dermatitis (AD) and psoriasis, are increasing in populations worldwide. The treatment of patients with AD and other forms of skin inflammation is mainly based on the use of topical corticosteroids or calcineurin inhibitors, which can cause significant side effects with long-term use. Therefore, there is a great need for the development of more effective and less toxic anti-inflammatory agents suitable for the treatment of chronic skin lesions. Here, we screened a number of strains from the ASIB 505 terrestrial algae collection and identified a green algae Chromochloris zofingiensis with pronounced anti-inflammatory properties. We found that a crude nonpolar extract of C. zofingiensis (ID name NAE_2022C), grown upon nitrogen deprivation, acts as a bioactive substance by inhibiting TNFR/NF-κB responses in human skin keratinocyte HaCaT cells. We also found that NAE_2022C suppressed the secretion of pro-inflammatory cytokine tumor necrosis factor α (TNFα) and several Th1- and Th2-related chemokines in a reconstituted human epidermis. The TNFR/NF-κB pathway analysis showed multiple inhibitory effects at different levels and disclosed a direct targeting of IKKβ by the extract. Bioassay-guided fractionation followed by high-resolution mass spectrometry detected diacylglyceryl-trimethylhomoserine (DGTS), Lyso-DGTS (LDGTS), 5-phenylvaleric acid, theophylline and oleamide as leading metabolites in the active fraction of NAE_2022C. Further analysis identified betaine lipid DGTS (32:0) as one of the active compounds responsible for the NAE_2022C-mediated NF-κB suppression. Overall, this study presents an approach for the isolation, screening, and identification of anti-inflammatory secondary metabolites produced by soil algae.

Soil algae enzymes and their biotechnological applications

At present time, most of the enzymes are derived from biological sources, including plants, animals, microalgae, algae, and other microorganisms. Microorganism enzymes, among the others, account for the biggest part of application and demand in industries. These enzymes from soil microorganisms are very essential not only for soil fertility but also for biotechnological significance. Soil enzymes from microalage, comprising Amylase, Carbonic anhydrase, Galactosidase, Laccase, L-Asparaginase, Lipase, Peroxidase, Phytase, Protease, and Superoxide dismutase attract a considerable amount of attention for themselves in various industries. Most of the enzymes mentioned above have a great potential for their application in biotechnology and agriculture. Majority of such enzymes are known for their versatility and countless applications in various fields; thus, performing research on these enzymes in the future would be auspicious. This review paper presents an overview of the potential of soil algae enzymes in fields like biotechnology, medicine and agriculture, and also provides areas for advancement in researches related to this field.

Видовий склад водоростей солоних приморських водойм Приазовського національного природного парку

The paper is devoted to the researches of species composition and taxonomic structure of algae in the saline coastal reservoirs of the Pryazov National Natural Park (PNNP). It is established that species composition of algae in the studied reservoirs under modern conditions includes 153 species. These species represented 7 divisions, 11 classes, 32 orders, 61 families, 92 genera. The highest species richness at the level of divisions showed Cyanoprokaryota (43.8% of the total number of species), Bacillariophyta (32.0%) and Chlorophyta (20.9%). These divisions include 148 species and form the basis of the species composition in the studied water bodies. The leading orders of algae in the researched reservoirs were Oscillatoriales and Synechococcales (23 and 20 species respectively). The most diversely represented families were: Oscillatoriaceae (13 species), Nostocaceae, Leptolyngbyaceae, Naviculaceae (8 each), Microcoleaceae, Bacillariaceae (7 each). The top list of the genera by this parameter: Leptolyngbya (6 species), Lyngbya, Nostoc, Phormidium, Nitzschia (5 each), Calothrix, Kamptonema, Cocconeis, Navicula (4each).The highest frequency of occurrence among the identified species had also diatoms, cyanoprokaryotes and green algae: Halamphora coffeiformis (5.26%), Lyngbya aestuarii (4.21%), Cladophora siwaschensis (3.51%), Hantzschia amphioxys (3.33%), Nodularia harveyana (2.98%).Our researches demonstrate that species composition of algae of the studied saline coastal reservoirs of PNNP is quite impoverished in comparison with the partial soil algae flora, as well as the species list of algae of the freshwater reservoirs and seas of Ukraine. Specific features of the taxonomic composition of the saline coastal reservoirs are manifested in the association of organisms of fresh, marine and terrestrial habitats.

Applicability Evaluation of Soil Algae Pipe Assay in Silver Nanoparticle-Contaminated Soils

Due to pervasive and resilient soil contaminants, heterogeneously contaminated soil poses unpredictable potential threats to ecosystems. In this study, the extension of a previously developed soil algae pipe assay for evaluating heterogeneously contaminated soil under an open system is described. The assay can be used in soil that is heterogeneously contaminated with silver nanoparticles in combination with the examination of morphological changes (e.g., in vivo chlorophyll a, cell granularity, cell size, and mucilaginous sheath) and lipid contents. In addition, we attempted to extend the exposure duration under an open system. We evaluated the applicability of this soil algae pipe assay using green alga Chlamydomonas reinhardtii exposed to heterogeneous and homogeneous polyvinylpyrrolidone capping silver nanoparticles in contaminated soils. The results demonstrated that this method is an applicable bioassay that can be employed to better evaluate soil algal toxicity under an open system, with significant changes in the measured endpoints. The developed assay showed decent predictivity, which can be a useful tool when evaluating heterogeneous soil algae contamination.

Algae and cyanobacteria in soils polluted with heavy metals (Northwest Russia, Murmansk region)

The analysis of algae and cyanobacteria in Albic Podzols affected by emissions of the copper–nickel plant Pechenganikel in the forest-tundra of the Arctic region was carried out. The main pollutants contained in the emissions and entering the soil are sulfur compounds and heavy non-ferrous metals. Algae and cyanobacteria were identified in soil samples collected in three zones differing in their distance from the pollution source: the zone of strong pollution (at a distance of 3 km southwest from the source of the emission), the zone of medium pollution (5-7 km), and the zone of weak pollution (16-25 km). In total, 61 species of eukaryotic algae and 2 species of cyanobacteria were found. In the studied soils, several species of algae were found with a high frequency, apparently resistant to unfavorable natural and anthropogenic factors: Chloromonas sp., Neocystis brevis, Parietochloris alveolaris, Pseudococcomyxa simplex, Stichococcus bacillaris, Interfilum terricola, Leptosira cf. obovata, Myrmecia bisecta, Nostoc muscorum. Algae from the Chlorophyta division predominated in all soils studied. Yellowgreen algae and diatoms were found only in the zone of strong pollution and were represented by a very small number of species. The presence of Microthamnion kuetzingianum, which is resistant to high acidity and heavy metals concentration, can be useful as an indicator of severe heavy metal contamination. Our study confirmed sensitivity of Vischeria magna to soil contamination with heavy metals. In long-term aspect, the species diversity of algae has increased by 35% in the soils influenced by the Pechenganikel plant in comparison with the data obtained 30 years ago, which probably indicates a certain decrease in anthropogenic load on the adjacent territories.

Soil microorganisms in the urban ecosystems of the russian subarctic (Murmansk region, Apatity)

A comprehensive study of the quantitative and qualitative parameters of soil microfungi, bacteria and algae communities in the Apatity city, located in the subarctic zone of Russia, was carried out for the first time. Urban soil samples were taken from various landuse zones (residential, recreational) and compared to arable and forest soils. In the residential zone, a decrease in the number of microfungi in the topsoil horizon to 1.1 thous. CFU/g compared to 22.7 thous. CFU/g in forest soil was revealed. In the residential zone, an increase was found in the number of saprotrophic bacteria to 7.8 million cells g-1 and oligotrophic to 10.9 million cells g-1 compared to 2.6 million cells g-1 and 1.8 million cells g-1 respectively in forest soils. In the recreational zone, the number of soil microorganisms was similar to that in the forest. A decrease in the species diversity of microfungi in the soil of the residential zone and an increase in the diversity of soil algae were revealed. Among the dominant species of fungi in urban soils, atypical species, including pathogenic ones for humans (Penicillium dierckxii, Stachybotris echinatus, Fusarium sp.), were found. In the algal community, diatoms, yellow-green algae, and cyanobacteria appeared in urban soils in comparison with forest soil. As a result of changes in the quantitative and qualitative indicators of soil microbial communities, a decrease in the enzymatic activity of soils has been noted. This may indicate a weakening of the ecosystem functions of urban soils and an increase in the degree of toxicity for living organisms and humans.