Burga Braun

Investigation of the microbial degradation of phenazone-type drugs and their metabolites by natural biofilms derived from river water using liquid chromatography/tandem mass spectrometry (LC-MS/MS)

The degradation of the pharmaceuticals phenazone and metamizole, two pyrazolone-derivates in widespread use, using biofilms created by natural organisms from the national park Unteres Odertal, Germany, were investigated. An analytical method based on LC-MS/MS was optimised to determine the substances phenazone and methylaminoantipyrine (MAA), the hydrolysis product of metamizole (also known as dipyrone), as well as their metabolites 1,5-dimethyl-1,2-dehydro-3-pyrazolone (DP), acetaminoantipyrine (AAA), formylaminoantipyrine (FAA) and 4-aminoantipyrine (AA). Performance characteristics of the method were evaluated in terms of recovery, standard deviation, coefficient of variation, method detection limits (MDL) and method quantification limits (MQL). Degradation studies of phenazone and MAA were conducted using a laboratory-scale continuous flow biofilm reactor fed with different nutrient media and with variable hydraulic retention times of 24 and 32 h. MAA was degraded rapidly to FAA and AA, while phenazone was not degraded under the prevailing conditions even after 32 h. By operating the bioreactor in batch mode to study the phenazone degradation potential of the biofilm under limiting nutrient conditions, an elimination rate of 85% phenazone was observed, but because of the slow elimination rate and aerobic conditions, the metabolite DP was not detected. In additional batch experiments using bacterial isolates from the natural biofilm to decompose phenazone, some bacterial strains were able to form DP from phenazone in marginal concentrations over the sampling period of eight weeks. Obviously, the microorganisms need a reasonably long time to adapt their metabolisms to enable the removal of phenazone from water samples.

Detection of iron-depositing Pedomicrobium species in native biofilms from the Odertal National Park by a new, specific FISH probe

Iron-depositing bacteria play an important role in technical water systems (water wells, distribution systems) due to their intense deposition of iron oxides and resulting clogging effects. Pedomicrobium is known as iron- and manganese-oxidizing and accumulating bacterium. The ability to detect and quantify members of this species in biofilm communities is therefore desirable. In this study the fluorescence in situ hybridization (FISH) method was used to detect Pedomicrobium in iron and manganese incrusted biofilms. Based on comparative sequence analysis, we designed and evaluated a specific oligonucleotide probe (Pedo 1250) complementary to the hypervariable region 8 of the 16S rRNA gene for Pedomicrobium. Probe specificities were tested against 3 different strains of Pedomicrobium and Sphingobium yanoikuyae as non-target organism. Using optimized conditions the probe hybridized with all tested strains of Pedomicrobium with an efficiency of 80%. The non-target organism showed no hybridization signals. The new FISH probe was applied successfully for the in situ detection of Pedomicrobium in different native, iron-depositing biofilms. The hybridization results of native bioflims using probe Pedo_1250 agreed with the results of the morphological structure of Pedomicrobium bioflims based on scanning electron microscopy.

Unraveling the microbial community of a cold groundwater catchment system

The abundance, diversity and composition of bacterial communities in water wells with low groundwater temperatures were assessed. The drinking water catchment system, equipped with subsurface groundwater treatment for iron- and manganese removal, is located within a continental influenced veldt landscape type in eastern Russia, close to the border to China. In this study, the bacterial communities in 22 different water wells of the catchment system were analyzed and correlated to operating conditions and environmental factors. The investigated bacterial treated and groundwater populations differed from those in central European groundwater. Large variations between the investigated samples were observed, and DGGE profiles of water samples from the beginning and the end of the abstraction phases revealed two distinct fingerprint clusters with about 82% similarity to each other corresponding to the operation mode of the wells. Sequence data analysis from 454 pyrosequencing indicated Rhodoferax and Gallionella as the most abundant genera within the catchment system. The abundance of the OTU Methylotenera was statistically significant when correlated to the beginning of the abstraction phases, while no indicator OTUs could be determined for the end of the pumping phases. ACK-M1 cluster was proofed as indicator OTU for operating wells, whereas the Gallionella OTUs were correlated with non operating wells. Well operation and resultant oxygen entry could serve as factors that altered the bacterial community structure and composition the most. Quantitative PCR analysis showed that genes related to the iron-reducing Rhodoferax genus were present in nearly all of the samples. This study clearly showed an alteration within the bacterial communities dependent on the operation mode of the water wells.

Complete Genome Sequence of “Candidatus Viadribacter manganicus” Isolated from a German Floodplain Area

ABSTRACT Iron- and manganese-depositing bacteria occur in many soils and all water systems, and their biogenic depositions of ochre in technical systems may cause severe clogging problems and monetary losses. “Candidatus Viadribacter manganicus” is a small coccoid, iron- and manganese-depositing bacterium isolated from the Lower Oder Valley National Park, Germany.

Neutrophilic Iron-Depositing Microorganisms

Neutrophilic iron-depositing microorganisms include various groups of bacteria, algae, and protozoa. The most striking feature of these microorganisms is their ability to precipitate ferric iron around their cells and colonies in many different forms. Growth of these microorganisms has various practical implications, for example, formation of iron ore in many parts of the world, aging of water wells, and clogging of drinking water pipes. Morphological description of many genera and species of iron-depositing bacteria by microscopy dates back to the nineteenth century, but only very few pure cultures of bacteria such as Leptothrix discophora and Gallionella ferruginea have been obtained in the last decades. Therefore, little has been known on the physiology or phylogeny of these bacteria.

Draft Genome Sequence of Strain R_RK_3, an Iron-Depositing Isolate of the Genus Rhodomicrobium , Isolated from a Dewatering Well of an Opencast Mine

ABSTRACT Rhodomicrobium sp. strain R_RK_3 is an iron-depositing bacterium from which we report the draft genome. This strain was isolated from ochrous depositions of a mining well pump in Germany. The Illumina NextSeq technique was used to sequence the genome of the strain.

Bakterienprofile in natürlichen und technischen Ökosystemen

The increased use of xenobiotica has led to their accumulation in soils, water bodies and ground water as a result of insufficient removal by sewage plants. Bacteria are able to break down or transform a variety of chemicals due to the great diversity of their degradation pathways. Their occurrence and activity is an important research theme in environmental engineering. 16S amplicon and transcriptome sequencing are powerful tools to investigate the diversity and function of bacterial populations.

Draft Genome Sequence of Rheinheimera sp. Strain SA_1 Isolated from Iron Backwash Sludge in Germany

ABSTRACT Rheinheimera sp. strain SA_1 is an iron-depositing bacterium for which we report a draft genome sequence. Strain SA_1 was isolated from iron backwash sludge of a waterworks in Germany. The Illumina MiSeq technique was used to sequence the genome of the strain.