Microbial diversity in heavy-metal polluted waters

Indigenious water microflora as well as the presence of metal- and xenobiotic biotransforming bacteria were investigated in waters near the KCM Pb-Zn smelter, South Bulgaria. Content of As, Hg, Cd, Mn, Pb, Cu and Zn exceeded in times the maximum permission standart. Absence of some microbial groups demonstrated a change in the microbial community structure in the region. Ecotoxicology test ISO/DIS 10712.2 displayed toxic environmental effect of the polluted waters, especially one of them which demonstrated 72 % of ecotoxicity. More than 20 ecologically relevant new bacteria were cultured. Three of them demonstrated tolerance to Cd, Cu and Mn and five- a tolerance to 2,4-dichlorphenoxyacetic acid. Our result revealed that the heavy metal pollutions reduced the microbial diversity in the studied waters, are ecotoxic as well as that some of newly isolated bacteria possess a capacity for a clean-up biotechnologies in the region. . 1, . 2, 2., 3, 3, .

Culture-Dependent Approach for Determining Microbial Diversity in Soils from KCM/AGRIA Region

Significant shifting of the microbial communities structure was detected in three metal-polluted soils collected around the Pb-Zn smelter KCM and the agrochemicals factory AGRIA, situated near the town of Plovdiv, Bulgaria. Industrial-, dumpsite- and agricultural soils were contaminated with As: 7.5-52.9 mg/kg; Hg: 0.086-0.404 mg/kg; Cd: 2.3-71.1 mg/kg; Mn: 742-1510 mg/kg; Pb: 138-2560 mg/kg; Cu: 32-268 mg/kg and Zn: 293-4490 mg/kg. Remarcable ecological disturbance was found in the agricultural soil using ecotoxicological test with type strain Pseudomonas putida DSM 50026 (ISO 10712). In order to assess ecologically relevant bacteria over twenty soil bacterial isolates were cultured. Six of them possess tolerance to one or more heavy metals. Four of the isolates demonstrated herbicide tolerance to 2,4-dichlorphenoxiacetic acid. Our results suggest that the microbial community responds to long-term metal- and pesticides contamination through changes in microbial community structure and selection for resistance. *** and.

Long-Distance LIDAR Mapping Schematic for Fast Monitoring of Bioaerosol Pollution over Large City Areas

Light detection and ranging (LIDAR) atmospheric sensing is a major tool for remote monitoring of aerosol pollution and its propagation in the atmosphere. Combining LIDAR sensing with ground-based aerosol monitoring can form the basis of integrated air-quality characterization. When present, biological atmospheric contamination is transported by aerosol particles of different size known as bioaerosol, whose monitoring is now among the basic areas of atmospheric research, especially in densely-populated large urban regions, where many bioaerosol-emitting sources exist. Thus, promptly identifying the bioaerosol sources, including their geographical coordinates, intensities, space-time distributions, etc., becomes a major task of a city monitoring system. This chapter argues in favor of integrating a LIDAR mapping schematic with in situ sampling and characterization of the bioaerosol in the urban area. The measurements, data processing, and decision-making aimed at preventing further atmospheric contamination should be performed in a near-real-time mode, which imposes certain demands on the typical LIDAR schematics, including long-range sensing as a critical parameter, especially over large areas (10 – 100 km2). In this chapter, we describe experiments using a LIDAR schematic allowing near-real-time long-distance measurements of urban bioaerosol combined with its ground-based sampling and physicochemical and biological studies

Oxydation de l'arsenic chez Cenibactérium arsenoxidans (Applications potentielles dans la biorémédiation des eaux contaminées par l'arsenic)

STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Diversity and biocide susceptibility of fungal assemblages dwelling in the Art Gallery of Magura Cave, Bulgaria

Magura Cave, north-western Bulgaria, possesses valuable rock-art paintings made with bat guano and dated from the period between the Eneolithic and Bronze Ages. Since 2008, the Art Gallery is closed to the general public in order to protect the paintings from vandalism, microclimatic changes caused by visitors and artificial illumination, and the consequent growth of fungi and phototrophs. Nevertheless, some tourist visits are allowed under the supervision of cave managers. This study provides the first scientific report on cultivable fungal assemblages dwelling different substrata in the Art Gallery. A total of 78 strains, belonging to 37 OTUs (Ascomycota 81%, Zygomycota 13%, Basidiomycota 5%), were isolated in the study. This fungal diversity was clearly dominated by Penicillium (50% of strains) and Aspergillus (13%). The most relevant visible fungal colonies were detected in sediments rich in bat guano, where, besides Penicillium, other guanophilic fungi such as Mucor, Mortierella, Trichosporon and Trichoderma were dominant. Conversely, scarce fungi were detected on rock surface of painted walls. Based on the biocide susceptibility assay, octylisothiazolinone (OIT) and benzalkonium chloride (BAC) were effective inhibiting the in vitro growth of dominant fungal species in Magura Cave, when applied at concentrations ranged from 100 to 1,000 mg/L. These data provide a valuable knowledge about Magura fungi, and exemplify a type of preliminary test that may be conducted before planning any biocide treatment. However, considering the irreversible effects of biocides on the ecological balance in caves, and the low fungal contamination in painted walls of Magura Cave, there is no reason to use conventional biocides in this cave. Further studies, monitoring microbial communities and microclimatic parameters, should be conducted to improve the knowledge on microbial ecology in Magura Cave and possible human impacts, as well as to allow the early detection of potential microbial outbreaks