Antiquaquibacter oligotrophicus gen. nov., sp. nov., a novel oligotrophic bacterium from groundwater.

In this study, a Gram-stain-positive, non-motile, oxidase- and catalase-negative, rod-shaped, bacterial strain (SG_E_30_P1T) that formed light yellow colonies was isolated from a groundwater sample of Sztaravoda spring, Hungary. Based on 16S rRNA phylogenetic and phylogenomic analyses, the strain was found to form a distinct linage within the family Microbacteriaceae. Its closest relatives in terms of near full-length 16S rRNA gene sequences are Salinibacterium hongtaonis MH299814 (97.72 % sequence similarity) and Leifsonia psychrotolerans GQ406810 (97.57 %). The novel strain grows optimally at 20-28 °C, at neutral pH and in the presence of NaCl (1-2 w/v%). Strain SG_E_30_P1T contains MK-7 and B-type peptidoglycan with diaminobutyrate as the diagnostic amino acid. The major cellular fatty acids are anteiso-C15 : 0, iso-C16 : 0 and iso-C14 : 0, and the polar lipid profile is composed of diphosphatidylglycerol and phosphatidylglycerol, as well as an unidentified aminoglycolipid, aminophospholipid and some unidentified phospholipids. The assembled draft genome is a contig with a total length of 2 897 968 bp and a DNA G+C content of 65.5 mol%. Amino acid identity values with it closest relatives with sequenced genomes of <62.54 %, as well as other genome distance results, indicate that this bacterium represents a novel genus within the family Microbacteriaceae. We suggest that SG_E_30_P1T (=DSM 111415T=NCAIM B.02656T) represents the type strain of a novel genus and species for which the name Antiquaquibacter oligotrophicus gen. nov., sp. nov. is proposed.

Distribution and impacts of contamination by natural and artificial radionuclides in attic dust and urban soil samples from a former industrial Hungarian city: A case study from Salgótarján.

Primordial radionuclides can be found in all environmental compartments. Since coal-fired power plants (CFPP) can be a source of additional radionuclide contamination because coal contains natural radioactive isotopes such as 238U (226Ra) and 232Th. This study investigated the impact of such possible radionuclide contamination from former heavy industrial activities, namely a former local coal-fired power plant, in urban soils and attic dust in Salgótarján, Hungary. Even today, industrial by-products, e.g., coal ash, in this city represent significant threat to its residents. A total of 36 attic dust samples (family houses, kindergartens, churches and blockhouses) were collected and 19 urban soil samples (playgrounds, kindergartens, parks and others) were selected no further than 500 m from the corresponding attic dust sampling sites. Additionally, a coal ash and a brown forest soil sample were also collected to differentiate between the anthropogenic and geogenic sources in the residential area. The sampled houses, built between 1890 and 1990, are considered to be representative sampling sites for long-term accumulations of attic dust. The mean values of the total U, Th and Cs (mg kg-1) concentrations as well as those of K (m/m %) in attic dust and urban soil samples are 2.4, 3.6, 1.7 and 0.6 and 1.1, 4.4, 1.2 and 0.3, respectively, measured using ICP-MS. The mean activity concentrations of 226Ra, 232Th, 40K and 137Cs in attic dust and urban soil samples are 43.3, 34.0, 534.4 and 88.5 and 25.1, 32.8, 386.4 and 5.6 Bq kg-1, respectively, by using a low-background iron chamber with a well-type HPGe and a n-type coaxial HPGe detector. The elemental compositions (U, Th) and activity concentrations (226Ra, 232Th) along with their abundances in coal ash from the CFPP increase in both studied media as the distance of the sampling sites from the CFPP decreases. Two outlier attic dust samples in particular show significantly high activity concentrations of 226Ra: 145 and 143, of 232Th: 83 and 94 Bq kg-1, which can be considered as a proxy of unweathered coal ash. The calculated total absorbed gamma dose rate (D) and annual effective dose (E) received from urban soils indicate that the presence of the CFPP, coal ash cone and slag dumps does not cause an increase in the level of background radiation in Salgótarján. However, the concentrations of the studied radionuclides are much higher (except for 232Th) and exhibit higher degree of variability in the samples of attic dustthan in those of urban soils. The study suggests that attic dust preserves the undisturbed 'fingerprints' of long-term atmospheric deposition thanks to its chemical and physical properties unlike urban soil.

Exploring the relationship between metal(loid) contamination rate, physicochemical conditions, and microbial community dynamics in industrially contaminated urban soils.

Increasing metal(loid) contamination in urban soils and its impact on soil microbial community have attracted considerable attention. In the present study, the physicochemical parameters and the effects of twelve metal(loid) pollution on soil microbial diversity, their ecotoxic effects, and human health risk assessment in urban soils with different industrial background were studied in comparison with an unpolluted forest soil sample. Results showed that urban soils were highly contaminated, and metal(loid) contamination significantly influenced structure of the soil microbial communities. In all samples the bacterial community was dominated by Proteobacteria, and on the level of phyla characteristic differences were not possible to observe between polluted and control sampling sites. However, clear differences emerged at class and genus level, where several rare taxa disappeared from contaminated urban soils. Simper test results showed that there is 71.6 % bacterial OTU and 9.5 % bacterial diversity dissimilarity between polluted and control samples. Ratio of Patescibacteria, Armatimonadetes, Chlamydiae, Fibrobacteres, and Gemmatimonadetes indicated a significant (p < 0.05) positive correlation with soil Zn, Cr, Pb, Sn, Cu, Mn content, suggest that metal(loid)s strongly influence the structure of microbial community. In contrast, the presence of metal(loid) contamination in urban soils has been found to significantly reduce the population of Archaeal communities. This can be attributed to the depletion of organic matter caused by contamination that reached a minimum of 0.5 m/m% for nitrate and 0.9 m/m% for total organic carbon. The values of urban soil pH were close to neutral, ranging from 5.9 to 8.3. The findings of ecotoxicology test are alarming, as all the studied urban soil sites were cytotoxic to soil microorganisms, and in one site metal(loid) contamination reached genotoxic level. Moreover, all the metal(loid) contaminated sites pose severe and persistent health risk to children, highlighting the urgent need for effective measures to mitigate metal(loid) pollution in urban areas.

The Impact of Anti-Inflammatory Drugs on the Prokaryotic Community Composition and Selected Bacterial Strains Based on Microcosm Experiments.

Non-steroidal anti-inflammatory drugs (NSAIDs) are increasingly recognized as potential environmental contaminants that may induce toxicity in aquatic ecosystems. This 3-week microcosm experiment explores the acute impacts of NSAIDs, including diclofenac (DCF), ibuprofen (IBU), and acetylsalicylic acid (ASA), on bacterial communities using a wide range of these substances (200-6000 ppm). The results showed that the NSAID-treated microcosms had higher cell count values than control samples, though the diversity of microbial communities decreased. The isolated heterotrophic bacteria mostly belonged to Proteobacteria, particularly Klebsiella. Next-generation sequencing (NGS) revealed that NSAIDs altered the structure of the bacterial community composition, with the proportion of Proteobacteria aligning with the selective cultivation results. Bacteria had higher resistance to IBU/ASA than to DCF. In DCF-treated microcosms, there has been a high reduction of the number of Bacteroidetes, whereas in the microcosms treated with IBU/ASA, they have remained abundant. The numbers of Patescibacteria and Actinobacteria have decreased across all NSAID-treated microcosms. Verrucomicrobia and Planctomycetes have tolerated all NSAIDs, even DCF. Cyanobacteria have also demonstrated tolerance to IBU/ASA treatment in the microcosms. The archaeal community structure was also impacted by the NSAID treatments, with Thaumarchaeota abundant in all microcosms, especially DCF-treated microcosms, while Nanoarchaeota is more typical of IBU/ASA-treated microcosms with lower NSAID concentrations. These results indicate that the presence of NSAIDs in aquatic environments could lead to changes in the composition of microbial communities.

Activity concentration of 137Cs in undisturbed attic dust collected from Salgótarján and Ózd (northern Hungary).

Due to the Chernobyl nuclear power plant accident, contaminated air masses, containing 137Cs, were widely propagated across all of Europe. Cesium-137 is easily adsorbed on aerosol particles as it returns to the lithosphere/pedosphere/via wet and dry deposition in the form of a radioactive fallout component. Following the nuclear accident, primary attention was paid to agricultural areas and less to urban environments. Our 137Cs activity study using undisturbed attic dust samples has been carried out from two residential areas (city of Salgótarján and Ózd) in northern Hungary, approx. 1000 km away from Chernobyl. A total of 61 attic dust samples were collected in 2016 and 2018 from houses (>30 years) functioning as family house, kindergarten, blockhouse and church. Activity concentration of 137Cs was determined for 1-2 g homogenized (<125 µm) attic dust samples in a low background iron chamber with a well-type HPGe detector. The mean 137Cs activity concentrations in attic dust samples are 88.5 ± 5.1 Bq kg-1 and 87.8 ± 4.5 Bq kg-1 in Salgótarján and Ózd, respectively. The dependence between 137Cs activities and the age of the houses was found to be significant (p=0.02), which could be explained by Chernobyl nuclear accident-causing elevated activity concentrations in location built prior to the accident. Three outliers in Ózd (>223 Bq kg-1), are probably related to the first rainfall event after the Chernobyl accident. Isotopic landscapes (isoscapes) of 137Cs were derived for both cities by means of kriging interpolation. In Salgótarján the 137Cs activity concentrations were higher than in Ózd which might have been due to redistribution loadings and local topographical features. We concluded that components of attic dust are highly useful indicators of home exposure to pollution events and remain detectable after several decades.

Szabonella alba gen. nov., sp. nov., a motile alkaliphilic bacterium of the family Rhodobacteraceae isolated from a soda lake.

A Gram-stain-negative, oxidase- and catalase-positive, rod-shaped, creamy white coloured bacterial strain, DMG-N-6T, was isolated from a water sample of Lake Ferto/Neusiedler See (Hungary). Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain forms a distinct linage within the family Rhodobacteraceae. Its closest relatives are Tabrizicola alkalilacus DJCT (96.76% similarity) and Tabrizicola piscis K13M18T (96.76%), followed by Tabrizicola sediminis DRYC-M-16T (96.69 %), Rhodobacter sediminicola JA983T (96.62 %), Tabrizicola aquatica RCRI19T (96.47 %) and Cereibacter johrii JA192T (96.18 %). The novel bacterial strain favours an alkaline environment (pH 8.0-12.0) and grows optimally at 18-28°C in the presence of 2-4 % (w/v) NaCl. Cells of DMG-N-6T were motile by a single subpolar flagellum. Bacteriochlorophyll a was not detected. The predominant respiratory quinone was ubiquinone Q-10. The major cellular fatty acid was C18:1 ω7c. The polar lipid profile comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, an unidentified phospholipid and five unidentified lipids. The assembled draft genome of strain DMG-N-6T had 52 contigs with a total length of 4 219 778 bp and a G+C content of 64.3 mol%. Overall genome-related indices (ANI <77.8 %, AAI <69.0 %, dDDH <19.6 %) with respect to close relatives were all significantly below the corresponding threshold to demarcate bacterial genus and species. Strain DMG-N-6T (=DSM 108208T=NCAIM B.02645T) is strongly different from its closest relatives and is suggested as the type strain of a novel species of a new genus in the family Rhodobacteraceae, for which the name Szabonella alba gen. nov., sp. nov. is proposed.

Whole genome sequence analysis of Cupriavidus campinensis S14E4C, a heavy metal resistant bacterium.

Cupriavidus sp. are model organisms for heavy metal(loid) resistance and aromatic compound's degradation studies and these characteristics make them a perfect candidate for biotechnological purposes. Bacterial strain S14E4C (identified as Cupriavidus campinensis) was isolated from a playground by enrichment method in a 0.25 mM containing medium. The analysis revealed that this bacterium is able to tolerate high concentrations of heavy metal(loid)s: Cd up to 19.5 mM, Pb to 9 mM, Hg to 5.5 mM and As to 2 mM in heavy metal(loid) salt containing nutrient medium. The whole genome data and analysis of the type strain of C. campinensis CCUG:44526T have not been available so far, thus here we present the genome sequencing results of strain S14E4C of the same species. Analysis was carried out to identify possible mechanisms for the heavy metal resistance and to map the genetic data of C. campinensis. The annotation pipelines revealed that the total genome of strain S14E4C is 6,375,175 bp length with a GC content of 66.3% and contains 2 plasmids with 295,460 bp (GC content 59.9%) and 50,483 bp (GC content 63%). In total 4460 coding sequences were assigned to known functions and 1508 to hypothetical proteins. Analysis proved that strain S14E4C is having gene clusters such as czc, mer, cus, chr, ars to encode various heavy metal resistance mechanisms that play an important role to survive in extreme environments.

Phragmitibacter flavus gen. nov., sp. nov. a new member of the family Verrucomicrobiaceae.

The Gram-stain-negative, aerobic, non-motile, oxidase- and catalase-positive, rod-shaped yellow-coloured bacterial strain MG-N-17T was isolated from a water sample of Lake Ferto/Neusiedler See (Hungary). Results of phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain forms a distinct linage within the family Verrucomicrobiaceae of the phylum Verrucomicrobia, and its closest relatives are Verrucomicrobium spinosum DSM 4136T (94.38 %) and Roseimicrobium gellanilyticum DC2a-G7T (91.55 %). The novel bacterial strain prefers a weak alkaline environment and grows optimally between 22-28 °C in the absence of NaCl. The major isoprenoid quinones are MK-10, MK-11, MK-12 and MK-9. The major cellular fatty acids are anteiso-C15 : 0, C16 : 0, C16 : 1ω5c and iso-C14 : 0. The polar lipid profile contains phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, two unidentified phospholipids and four unidentified glycolipids. The assembled draft genome of strain MG-N-17T had 44 contigs with an N50 value 348255 nt, 56.5× genome coverage, total length of 5 910 933 bp and G+C content of 56.9 mol%. Strain MG-N-17T (=DSM 106674T=NCAIM B.02643T) is proposed as the type strain of a new genus and species in the family Verrucomicrobiaceae, for which the name Phragmitibacter flavus gen. nov., sp. nov. is proposed.

Fertoeibacter niger gen. nov., sp. nov. a novel alkaliphilic bacterium of the family Rhodobacteraceae.

Three Gram-stain-negative, non-motile, oxidase- and catalase-positive, rod-shaped, black, facultative phototrophic bacterial strains, RG-N-1aT, DMA-N-7a and RA-N-9 were isolated from the water sample from Lake Ferto/Neusiedler See (Hungary). Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the strains form a distinct linage within the family Rhodobacteraceae and their closest relatives are Tabrizicola piscis K13M18T (96.32%) followed by Cypionkella psychrotolerans PAMC 27389T (96.25%). The novel bacterial strains prefer alkaline environments and grow optimally at 23-33 °C in the presence of NaCl (1-2 w/v%). Bacteriochlorophyll a was detected. Cells contained exclusively ubiquinone Q-10. The major cellular fatty acids were C18 : 1ω7c, C19 : 1iso ω5c, C18 : 0 3-OH and C18 : 1ω7c 11-methyl. The polar lipid profile contains diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, an unidentified phospholipid and four unidentified lipids. The assembled draft genome of RG-N-1aT had 33 contigs with N50 values 315 027 nt, 96× genome coverage, total length of 4 326 551 bp and a DNA G+C content of 64.9%. Genome-based calculations (genome-to-genome distance and DNA G+C percentage) and pairwise amino acid identity (AAI <73.5%) indicate that RG-N-1aT represents a novel genus. RG-N-1aT (=DSM 108317T=NCAIM B.02647T) is suggested as the type strain of a novel genus and species in the family Rhodobacteraceae, for which the name Fertoeibacter niger gen. nov., sp. nov. is proposed.