Petra PjevacUniversity of Vienna | UniWien · Joint Microbiome Facility
Petra Pjevac
PhD
About
53
Publications
17,611
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,649
Citations
Citations since 2017
Introduction
I'm a microbial ecologist and physiologist focusing on the analysis of functional potential and in situ function of microorganisms in a range of habitats. My research is mainly based on the analysis of (meta)genomic and (meta)transcriptomic data and the integration of these results with physiological and biogeochemical observations.
I'm particularly interested in lithotrophic microorganisms involved in the sulfur and nitrogen cycle in various aquatic and terrestrial environments.
Additional affiliations
December 2018 - present
University of Vienna /Medical University of Vienna, Vienna, Austria
Position
- Researcher
March 2015 - present
June 2014 - February 2015
Publications
Publications (53)
Hot spring biofilms are stable, highly complex microbial structures. They form at dynamic redox and light gradients and are composed of microorganisms adapted to the extreme temperatures and fluctuating geochemical conditions of geothermal environments. In Croatia, a large number of poorly investigated geothermal springs hosts biofilm communities....
Marine and freshwater sponges harbor diverse communities of bacteria with vast potential to produce secondary metabolites that may play an important role in protecting the host from predators and infections. In this work, we initially used cultivation and metagenomics to investigate the microbial community of the freshwater sponge Spongilla lacustr...
The incidence of nephrolithiasis is rising worldwide. Although it is a multifactorial disease, lifestyle plays a major role in its etiology. Another considerable factor could be an aberrant microbiome. In our observational single-center study, we aimed to investigate the composition of bacteria in kidney stones and urine focusing on patients with f...
Purpose: The incidence of nephrolithiasis is rising worldwide. Although it is a multifactorial disease, lifestyle plays a major role in its etiology. Another considerable factor could be an aberrant microbiome. In our observational single-center study, we aimed to investigate the composition of bacteria in kidney stones and urine focusing on patien...
Taurine-respiring gut bacteria produce H 2 S with ambivalent impact on host health. We report the isolation and genomic-ecophysiological characterization of the first taurine-respiring mouse gut bacterium. Taurinivorans muris represents a new widespread species with protective capacity against pathogens and differs from the human gut sulfidogen Bil...
In Croatia, a variety of geothermal springs with a wide temperature range and varied hydrochemical conditions exist, and they may harbor different niches for the distribution of microbial communities. In this study, 19 different sites, mainly located in central and eastern Croatia, were selected for primary characterization of spring hydrochemistry...
Many phycological applications require the growth and maintenance of pure algae cultures. In some research areas, such as biochemistry and physiology, axenic growth is essential to avoid misinterpretations caused by contaminants. Nonetheless, axenicity—defined as the state of only a single strain being present, free of any other organism—needs to b...
Emerging evidence points to a major role of salivary flow and viscoelastic properties in taste perception and mouthfeel. It has been proposed that sweet-tasting compounds influence salivary characteristics. However, whether perceived differences in the sensory properties of structurally diverse sweet-tasting compounds contribute to salivary flow an...
Oxygen (O2) is the ultimate oxidant on Earth and its respiration confers such an energetic advantage that microorganisms have evolved the capacity to scavenge O2 down to nanomolar concentrations. The respiration of O2 at extremely low levels is proving to be common to diverse microbial taxa, including organisms formerly considered strict anaerobes....
Global warming increases soil temperatures and promotes faster growth and turnover of soil microbial communities. As microbial cell walls contain a high proportion of organic nitrogen, a higher turnover rate of microbes should also be reflected in an accelerated organic nitrogen cycling in soil. We used a metatranscriptomics and metagenomics approa...
Premature infants are at substantial risk for suffering from perinatal white matter injury. Though the gut microbiota has been implicated in early-life development, a detailed understanding of the gut-microbiota-immune-brain axis in premature neonates is lacking. Here, we profiled the gut microbiota, immunological, and neurophysiological developmen...
Nitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co-occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics...
Background & Aims
Irritable bowel syndrome (IBS) and inflammatory bowel diseases result in a substantial reduction in quality of life and a considerable socio-economic impact. In IBS, diagnosis and treatment options are limited, but evidence for an involvement of the gut microbiome in disease pathophysiology is emerging. Here we analyzed the preval...
Background: Epidemiological studies suggest that allergy is associated with iron deficiency.
We sought to determine and compare iron and microbial parameters of allergic and non-allergic women without anemia and associated them with their clinical response upon nasal provocation.
Methods: Female subjects (27 allergics, 24 non-allergic) donated bl...
In microbiome research, phylogenetic and functional marker gene amplicon sequencing is the most commonly-used community profiling approach. Consequently, a plethora of protocols for the preparation and multiplexing of samples for amplicon sequencing have been developed. Here, we present two economical high-throughput gene amplification and sequenci...
Nitrification, the oxidation of ammonia to nitrate, is an essential process in the biogeochemical nitrogen cycle. The first step of nitrification, ammonia oxidation, is performed by three, often co-occurring guilds of chemolithoautotrophs: ammonia-oxidizing bacteria (AOB), archaea (AOA), and complete ammonia oxidizers (comammox). Substrate kinetics...
Ammonia-oxidizing bacteria (AOB) of the betaproteobacterial genera Nitrosomonas and Nitrosospira are key nitrifying microorganisms in many natural and engineered ecosystems. Since many AOB remain uncultured, fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes has been one of the most widely used approaches to study t...
Microorganisms in coastal sediments are fundamental for ecosystem functioning, and regulate processes relevant in global biogeochemical cycles. Still, our understanding of the effects anthropogenic perturbation and pollution can have on microbial communities in marine sediments is limited. We surveyed the microbial diversity, and the occurrence and...
Ammonia-oxidizing bacteria (AOB) of the betaproteobacterial genera Nitrosomonas and Nitrosospira are key nitrifying microorganisms in many natural and engineered ecosystems. Since many AOB remain uncultured, fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes has been one of the most widely used approaches to study t...
Fertilizers are added to crops in order to produce enough food to feed the human population. Fertilizers provide crops with nutrients like potassium, phosphorus, and nitrogen, which allow crops to grow bigger, faster, and to produce more food. Nitrogen in particular is an essential nutrient for the growth of every organism on Earth. Nitrogen is all...
The discovery of comammox in the genus Nitrospira changes our perception of nitrification. However, genomes of comammox organisms have not been acquired from full-scale WWTPs, and very little is known about their survival strategies and potential metabolisms in complex wastewater treatment systems. Here, four comammox metagenome-assembled genomes a...
Nitrification, the oxidation of ammonia via nitrite to nitrate, is a key process in marine nitrogen (N) cycling. Although oceanic ammonia and nitrite oxidation are balanced, ammonia-oxidizing archaea (AOA) vastly outnumber the main nitrite oxidizers, the bacterial Nitrospinae. The ecophysiological reasons for this discrepancy in abundance are uncle...
Nitrification is a ubiquitous microbially mediated process in the environment and an essential process in engineered systems such as wastewater and drinking water treatment plants. However, nitrification also contributes to fertilizer loss from agricultural environments, increasing the eutrophication of downstream aquatic ecosystems, and produces t...
Desulfosporosinus fructosivorans strain 63.6F T is a strictly anaerobic, spore-forming, sulfate-reducing bacterium isolated from marine sediment in the Baltic Sea. Here, we report the draft genome sequence of D. fructosivorans 63.6F T .
Desulfosporosinus sp. strain Sb-LF was isolated from an acidic peatland in Bavaria, Germany. Here, we report the draft genome sequence of the sulfate-reducing and lactate-utilizing strain Sb-LF.
Sulfide‐driven anoxygenic photosynthesis is an ancient microbial metabolism that contributes significantly to inorganic carbon fixation in stratified, sulfidic water bodies. Methods commonly applied to quantify inorganic carbon fixation by anoxygenic phototrophs, however, cannot resolve the contributions of distinct microbial populations to the ove...
Fluorescence in situ hybridization (FISH) with rRNA-targeted oligonucleotide probes is a key method for the detection of (uncultured) microorganisms in environmental and medical samples. A major limitation of standard FISH protocols, however, is the small number of phylogenetically distinct target organisms that can be detected simultaneously. In t...
Nitrous oxide (N2O) and nitric oxide (NO) are atmospheric trace gases that contribute to climate change and affect stratospheric and ground-level ozone concentrations. Ammonia oxidizing bacteria (AOB) and archaea (AOA) are key players in the nitrogen cycle and major producers of N2O and NO globally. However, nothing is known about N2O and NO produc...
Anoxygenic phototrophic sulfide oxidation by green and purple sulfur bacteria (PSB) plays a key role in sulfide removal from anoxic shallow sediments and stratified waters. Although some PSB can also oxidize sulfide with nitrate and oxygen, little is known about the prevalence of this chemolithotrophic lifestyle in the environment. In this study, w...
Metal‐sulfides are wide‐spread in marine benthic habitats. At deep‐sea hydrothermal vents they occur as massive sulfide chimneys formed by mineral precipitation upon mixing of reduced vent fluids with cold oxygenated sea water. While microorganisms inhabiting actively venting chimneys and utilizing compounds supplied by the venting fluids are well...
Chemoautotrophic bacteria belonging to the genus Sulfurimonas (class Campylobacteria) were previously identified as key players in the turnover of zero‐valence sulfur, a central intermediate in the marine sulfur cycle. S. denitrificans was further shown to be able to oxidize cyclooctasulfur (S8). However, at present the mechanism of activation and...
At hydrothermal vent sites, chimneys consisting of sulfides, sulfates, and oxides are formed upon contact of reduced hydrothermal fluids with oxygenated seawater. The walls and surfaces of these chimneys are an important habitat for vent-associated microorganisms. We used community proteogenomics to investigate and compare the composition, metaboli...
Ammonia-oxidizing archaea (AOA) within the phylum Thaumarchaeota are the only known aerobic ammonia oxidizers in geothermal environments. Although molecular data indicate the presence of phylogenetically diverse AOA from the Nitrosocaldus clade, group 1.1b and group 1.1a Thaumarchaeota in terrestrial high-temperature habitats, only one* enrichment...
The facultative anaerobic chemoorganoheterotrophic alphaproteobacterium Telmatospirillum siberiense 26-4b1 was isolated from a Siberian peatland. We report here a 6.20-Mbp near-complete high-quality draft genome sequence of T. siberiense that reveals expected and novel metabolic potential for the genus Telmatospirillum , including genes for sulfur...
Ammonia-oxidizing archaea (AOA) within the phylum Thaumarchaea are the only known aerobic ammonia oxidizers in geothermal environments. Although molecular data indicate the presence of phylogenetically diverse AOA from the Nitrosocaldus clade, group 1.1b and group 1.1a Thaumarchaea in terrestrial high-temperature habitats, only one enrichment cultu...
paragraph
Nitrification, the oxidation of ammonia (NH3) via nitrite (NO2⁻) to nitrate (NO3⁻), is a key process of the biogeochemical nitrogen cycle. For decades, ammonia and nitrite oxidation were thought to be separately catalyzed by ammonia-oxidizing bacteria (AOB) and archaea (AOA), and by nitrite-oxidizing bacteria (NOB). The recent discovery o...
Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be catalyzed by the concerted activity of ammonia- and nitrite-oxidizing microorganisms. Only recently, complete ammonia oxidizers (“comammox”), which oxidize ammonia to nitrate on their own, were identified in the bacterial genus Nitrospira, previously as...
Molecular hydrogen (H2) is the key intermediate in the anaerobic degradation of organic matter. Its removal by H2-oxidizing microorganisms is essential to keep anaerobic degradation energetically favorable. Sulfate-reducing microorganisms (SRM) are known as the main H2 scavengers in anoxic marine sediments. Although the community of marine SRM has...
At deep-sea hydrothermal vents, primary production is carried out by chemolithoautotrophic microorganisms, with the oxidation of reduced sulfur compounds being a major driver for microbial carbon fixation. Dense and highly diverse assemblies of sulfur-oxidizing bacteria (SOB) are observed, yet the principles of niche differentiation between the dif...
Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be catalyzed by the concerted activity of ammonia- and nitrite-oxidizing microorganisms. Only recently, complete ammonia oxidizers (‘comammox’), which oxidize ammonia to nitrate on their own, were identified in the bacterial genus Nitrospira , previously k...
To date, very little is known about the bacterial core community of marine sediments. Here we study the environmental distribution, abundance and ecogenomics of the gammaproteobacterial Woeseiaceae/JTB255 marine benthic group. A meta-analysis of published work shows that the Woeseiaceae/JTB255 are ubiquitous and consistently rank among the most abu...
Iron redox reactions play an important role in carbon remineralization, supporting large microbial communities in iron-rich terrestrial and aquatic sediments. Stratified water columns with comparably low iron concentrations are globally widespread, but microbial iron cycling in these systems has largely been ignored. We found evidence for unexpecte...
Marine sediments are the largest carbon sink on earth. Nearly half of dark carbon fixation in the oceans occurs in coastal sediments, but the microorganisms responsible are largely unknown. By integrating the 16S rRNA approach, single-cell genomics, metagenomics and transcriptomics with (14)C-carbon assimilation experiments, we show that uncultured...
Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be a two-step process catalysed by chemolithoautotrophic microorganisms oxidizing either ammonia or nitrite. No known nitrifier carries out both steps, although complete nitrification should be energetically advantageous. This functional separation has puz...
Most stratified sulfidic holomictic lakes become oxygenated after annual turnover. In contrast, Lake Rogoznica, on the eastern
Adriatic coast, has been observed to undergo a period of water column anoxia after water layer mixing and establishment of
holomictic conditions. Although Lake Rogoznica's chemistry and hydrography have been studied extensi...
Diffuse hydrothermal fluids often contain organic compounds such as hydrocarbons, lipids and organic acids. Microorganisms consuming these compounds at hydrothermal sites are so far only known from cultivation-dependent studies. To identify potential heterotrophs without prior cultivation we combined microbial community analysis with short-term inc...
Sulfide 'chimneys' characteristic of seafloor hydrothermal venting are diverse microbial habitats. (13) C/(12) C ratios of microbial lipids have rarely been used to assess carbon assimilation pathways on these structures, despite complementing gene- and culture-based approaches. Here, we integrate analyses of the diversity of intact polar lipids (I...
http://elib.suub.uni-bremen.de/edocs/00103759-1.pdf
Zero-valence sulfur (S(0) ) is a central intermediate in the marine sulfur cycle and forms conspicuous accumulations at sediment surfaces, hydrothermal vents and in oxygen minimum zones. Diverse microbes grow with S(0) , but those consuming S(0) in the environment are largely unknown. We identified possible key players in S(0) -turnover on native o...
Projects
Projects (3)
The investigation of the Bacteria and Archaea inhabiting geothermal systems has been critical to our understanding of the diversity and history of life on Earth. In recent years, the advent of genome sequencing has opened a window into the genomic potential and metabolic activity of the global microbiome. The genomes of >300 000 Bacteria and >3000 Archaea have provided key insights into, for example, their evolution and role in biogeochemical cycles, their modes of pathogenesis and antimicrobial resistance and the genetic determinants underlying their biotechnological potential. Therefore, metagenomic datasets derived directly from environmental DNA can provide novel, unprecedented insights into microbial community structure, function and metabolic capacity. The bioprospecting of enzymes that operate under extreme conditions is of particular interest for many biotechnological and industrial processes. In Croatia, one such environment, geothermal springs, are almost entirely unexplored and represent a potential source of microbial species, novel pathways, and enzymes. The main objective of the proposal is using highly parallel quantitative SSU rRNA gene sequencing, SSU cDNA amplicon sequencing and reverse-transcription quantitative PCR, as well as metagenomic and metatranscriptomics to analyze the microbial community composition, dynamics, and function, as well as biotechnological perspectives in Croatia’s numerous geothermal springs. The collaboration and networking with top level European scientist will contribute to the further development quality and competitiveness of microbial ecology research in Croatia. The results of the project will be visible through a stronger future cooperation with biotechnology companies which will have a strong impact on the development of bio-based industries in Croatia.
We use molecular methods (16S rRNA gene sequencing, fluorescence in situ hybridization, metagenomic, metaproteomic, intact polar lipid analysis, stable isotope tracer methods) to unravel the composition, diversity and function of microbial communities colonizing deep-see hydrothermal vent (HTV) sites.
Sulfur-oxidizing microorganisms, offten the dominant primary producers at deep-sea HTV sites, are of particular interest. Where possible, we try to integrate results from HTV sites with data from other marine environments, to generate and develop global, habitat independent concepts of diversification and niche differentiation amongst sulfur-oxidizing chemotrophs.
Nitrogen cycle scene has just been shaken up by the entrance of ‘comammox’, Nitrospira bacteria able to perform complete nitrification (Daims et al. 2015, Nature 528). This was previously thought to involve the oxidation of ammonia into nitrite by ammonia oxidisers (AO), further oxidised into nitrate by nitrite oxidising bacteria (NOB), which also include members of the Nitrospira genus. A decade before, AO were supposed to be bacteria (AOB) only, when archaeal AO (AOA) were found; significant contribution of AOA, initially considered as accessory, to nitrification was since then repetitively shown. Now, exploring the ecology of comammox and their interaction with ammonia oxidisers in soils, where nitrification affects fertilisation yield, nitrate leaching and nitrous oxide emissions, is crucial for agricultural and environmental fields.