John F Stolz

• PhD
• Managing Director at Duquesne University

The MopB superfamily constitutes a repertoire of metalloenzymes that are central to enduring mysteries in microbiology, from the origin of life and how microorganisms and biogeochemical cycles have coevolved over deep time to how anaerobic life adapted to increasing concentrations of O 2 during the transition from an anoxic to an oxic world. Our wo...

Management of oil and gas (O&G) waste streams from extraction of unconventional reservoirs challenges the sustainable development of these reservoirs. Landfilling of waste materials is an emerging strategy for uncon-ventional O&G waste disposal. However, the effectiveness of effluent management systems designed for historical landfill waste streams...

Much of what we know about the history of life on Earth has been gleaned from the rock record. Stromatolites, fossil and living, have been instrumental for reconstructing that history (Awramik, 2006). The earliest fossil stromatolites have been found in rocks dated at over 3.4 Ga (Allwood et al., 2006) but span almost the entirety of geologic time...

The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the...

The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the...

The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the...

The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the...

One of the largest assemblages of living marine microbialites, with shapes and sizes analogous to ancient structures, is found along the margins of Hamelin Pool, Shark Bay, Western Australia. An investigation of microbial mats on the surfaces of these structures using petrographic analysis, light, and scanning electron microscopy identified the in...

Microbialites and peloids are commonly associated throughout the geologic record. Proterozoic carbonate megafacies are composed predominantly of micritic and peloidal limestones often interbedded with stromatolitic textures. The association is also common throughout carbonate ramps and platforms during the Phanerozoic. Recent investigations reveal...

The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the...

The development of unconventional oil and gas shales using hydraulic fracturing and directional drilling is currently a focal point of energy and climate change discussions. While this technology has provided access to substantial reserves of oil and gas, the need for large quantities of water, emissions, and infrastructure raises concerns over the...

We have isolated a chlorophyll-d-containing cyanobacterium from the intertidal field site at Moss Beach, on the coast of Central California, USA, where Manning and Strain (1943) originally discovered this far-red chlorophyll. Here, we present the cyanobacterium’s environmental description, culturing procedure, pigment composition, ultrastructure, a...

Life has been a powerful geologic force, shaping the world as we know it today. Microbes in particular have played a crucial role in this transformation, through their metabolic diversity and mineral interactions. Microbes use over 50 elements, including metals and metalloids, for a variety of cellular functions including structure, energy generati...

The resurgence of oil and gas extraction in the Appalachian Basin has resulted in an excess of oil and gas brines in Pennsylvania, West Virginia, and Ohio. Primarily driven by unconventional development, this expansion has also impacted conventional wells and consequently, created economic pressure to develop effective and cheap disposal options. U...

Selenium is an essential trace element whose compounds are widely metabolized by organisms from all three domains of life. Moreover, phylogenetic evidence indicates that selenium species, along with iron, molybdenum, tungsten, and nickel, were metabolized by the last universal common ancestor (LUCA) of all cellular lineages, primarily for the synth...

Microbes and metals are intricately linked in a complex relationship. Many microbial pathways rely on metals for functionality, including enzymatic machinery (co-factors in key enzymes), dissimilatory reduction in energy generation (as alternative electron acceptors in anaerobic respiration) and biomineralization. Some metals share very close physi...

Selenium is an essential trace element for organisms from all three domains of life. Microorganisms in particular, mediate reductive transformations of selenium that govern the element's mobility and bioavailability in terrestrial and aquatic environments. Selenium metabolism is not just ubiquitous, but an ancient feature of life likely extending b...

Mononuclear molybdoenzymes of the dimethyl sulfoxide reductase (DMSOR) family catalyze a number of reactions essential to the carbon, nitrogen, sulfur, arsenic, and selenium biogeochemical cycles. These enzymes are also ancient, with many lineages likely predating the divergence of the last universal common ancestor into the Bacteria and Archaea do...

Primary production in Mono Lake, a hypersaline soda lake rich in dissolved inorganic arsenic, is dominated by Picocystis strain ML. We set out to determine if this photoautotrophic picoplankter could metabolize inorganic arsenic and in doing so form unusual arsenolipids (e.g., arsenic bound to 2-O-methyl ribosides) as reported in other saline ecosy...

The arsenate respiratory reductase serves as the terminal electron acceptor in dissimilatory arsenate reduction. The enzyme, Arr, is a heterodimer with a large catalytic subunit, ArrA, and a smaller electron transfer subunit, ArrB. It was initially purified from Chrysiogenes arsenatis and subsequently from the Firmicute Bacillus selenitireducens ,...

Mononuclear molybdenum enzymes catalyze a variety of reactions that are essential in the cycling of nitrogen, carbon, arsenic, and sulfur. For decades, the structure and function of these crucial enzymes have been investigated to develop a fundamental knowledge for this vast family of enzymes and the chemistries they carry out. Therefore, obtaining...

Arsenic is a toxin, ranking first on the Agency for Toxic Substances and Disease Registry and the Environmental Protection Agency Priority List of Hazardous Substances. Chronic exposure increases the risk of a broad range of human illnesses, most notably cancer; however, there is significant variability in arsenic‐induced disease among exposed indi...

Identifying the types of contamination and their sources in surface and groundwater is fundamental for effective protection of private and public source waters. Here we employed mass ratio analyses of a variety of anion and cation pairs to characterize flowback, produced water, and mine drainage. These endmembers were used to evaluate the source co...

Unconventional natural gas extraction by hydraulic fracturing requires millions of gallons of water and generates flowback water, produced water and recycled fluids of varying chemical composition. Ion chromatography (IC) is a relatively low cost and efficient means to determine the anionic composition, however, the wide range in anionic content of...

Hal.ar.se.na.ti.bac ' ter. Gr. n. hals, halos, salt, N.L. n. arsenas, ‐atis , arsenate, N.L. masc. n. bacter , rod; N.L. masc. n. Halarsenatibacter , the salty, arsenate‐respiring rod. Firmicutes / Clostridia / Halanaerobiales / Halanaerobiaceae / Halarsenatibacter The genus Halarsenatibacter is classified into the family Halanaerobiaceae , order H...

Selenium is an essential element for life, with Se(IV) reduction a key step in its biogeochemical cycle. This report identifies for the first time a dissimilatory Se(IV) reductase, Srr, from a known selenite-respiring bacterium, the haloalkalophilic Bacillus selenitireducens strain MLS10. The work extends the versatility of the complex iron-sulfur...

Campylobacter jejuni, a human gastrointestinal pathogen, uses nitrate for growth under microaerophilic conditions using periplasmic nitrate reductase (Nap). The catalytic subunit, NapA, contains two prosthetic groups, an iron sulfur cluster and a molybdenum cofactor. Here we describe the cloning, expression, purification, Michaelis-Menten kinetics...

Hamelin Pool, Shark Bay, Western Australia, is home to the largest and most diverse assemblage of living marine stromatolites, with shapes and sizes comparable to ancient structures. A recent field-intensive program revealed seasonally ephemeral occurrences of modern dendrolitic microbial mats forming in intertidal, low energy settings. Dominated b...

A number of prokaryotes are capable of employing arsenic oxy-anions as either electron acceptors [arsenate; As(V)] or electron donors [arsenite; As(III)] to sustain arsenic-dependent growth ('arsenotrophy'). A subset of these microorganisms function as either chemoautotrophs or photoautotrophs, whereby they gain sufficient energy from their redox m...

Three novel strains of photosynthetic bacteria from the family Ectothiorhodospiraceae were isolated from soda lakes of the Great Basin Desert, USA by employing arsenite (As(III)) as the sole electron donor in the enrichment/isolation process. Strain PHS-1 was previously isolated from a hot spring in Mono Lake, while strain MLW-1 was obtained from M...

The Gaia Hypothesis, proposed 50 years ago, posits that the Earth's biosphere, atmosphere, hydrosphere, and lithosphere interact as a cybernetic system, maintaining the long-term habitability of the planet. The resulting chemical composition of the atmosphere, oceans, and crust is unique as compared to the other planets of our solar system, and due...

A recent field-intensive program in Shark Bay, Western Australia provides new multi-scale perspectives on the world’s most extensive modern stromatolite system. Mapping revealed a unique geographic distribution of morphologically distinct stromatolite structures, many of them previously undocumented. These distinctive structures combined with chara...

Chronic exposure to arsenic in drinking water causes cancer and non-cancer diseases. However, mechanisms for chronic arsenic-induced pathogenesis, especially in response to lower exposure levels, are unclear. In addition, the importance of health impacts from xeniobiotic-promoted microbiome changes is just being realized and effects of arsenic on t...

The involvement of prokaryotes in the redox reactions of arsenic occurring between its +5 [arsenate; As(V)] and + 3 [arsenite; As(III)] oxidation states has been well established. Most research to date has focused upon circum-neutral pH environments (e.g., freshwater or estuarine sediments) or arsenic-rich “extreme” environments like hot springs an...

Se.le.ni.hal.an.ae.ro.bac'ter. Gr. n. selene moon; N.L. n. selenium element 34; Gr. n. hals, halos salt; Gr. pref. an not; Gr. n. aer air; N.L. masc. n. bacter the masc. equivalent of Gr. neut. n. baktron a staff or rod; N.L. masc. n. Selenihalanaerobacter the salty anaerobic selenium rod. Firmicutes / “Clostridia” / Halanaerobiales / Halobacteroid...

Sul.fu.ro.spi.ril' lum . L. n. sulfur sulfur; Gr. n. spira a spiral; M.L. neut. n. Sulfurospirillum a spirillum that reduces elemental sulfur. Proteobacteria / Epsilonproteobacteria / Campylobacterales / Campylobacteraceae / Sulfurospirillum Slender, vibrioid to spirally curved rods, 0.1–0.5 × 1.0–3 µm. May form helical chains of two or more cells....

The Appalachian Basin is home to three major shales, the Upper Devonian, Marcellus, and Utica. Together, they contain significant quantities of tight oil, gas, and mixed hydrocarbons. The Marcellus alone is estimated to contain upwards of 500 trillion cubic feet of natural gas. The extraction of these deposits is facilitated by a combination of hor...

Flowback and produced wastewaters from unconventional hydraulic fracturing during oil and gas explorations typically brings to the surface Naturally Occurring Radioactive Materials (NORM), predominantly radioisotopes from the U238 and Th232 decay chains. Traditionally, radiological sampling are performed by sending collected small samples for labor...

Reports of ground water contamination in a southwestern Pennsylvania community coincided with unconventional shale gas extraction activities that started late 2009. Residents participated in a survey and well water samples were collected and analyzed. Available pre-drill and post-drill water test results and legacy operations (e.g., gas and oil wel...

Alkaliphilus oremlandii strain OhILAs, a gram-positive bacterium, has been shown to ferment lactate as well as use arsenate and roxarsone as a terminal electron acceptor. This study examines the proteome expressed under four growth conditions to further elucidate the bacterial metabolism of inorganic and organic arsenic. The four growth conditions...

The nitrate anion is a simple, abundant and relatively stable species, yet plays a significant role in global cycling of nitrogen, global climate change, and human health. Although it has been known for quite some time that nitrate is an important species environmentally, recent studies have identified potential medical applications. In this respec...

Microbialites are the most abundant macrofossils of the Precambrian. Decline in microbialite abundance and diversity during the terminal Proterozoic and early Phanerozoic has historically been attributed to the concurrent radiation of complex metazoans. Similarly, the apparent resurgence of microbialites in the wake of Paleozoic and Mesozoic mass e...

Hydraulic fracturing activities generate fluids commonly known as flowback and produced water. They have different chemical compositions that should be analyzed to evaluate a probable effect on ecosystems and for proper management such as wastewater treatment or recycling. We have devised a methodology that provides routine rapid determination of 3...

A major challenge for the bioremediation of toxic metals is the co-occurrence of nitrate, as it can inhibit metal transformation. Geobacter metallireducens, Desulfovibrio desulfuricans, and Sulfurospirillum barnesii are three soil bacteria that can reduce chromate [Cr(VI)] and nitrate, and may be beneficial for developing bioremediation strategies....

A haloalkaliphilic sulfate-respiring bacterium, strain SLSR-1, was isolated from a lactate-fed stable enrichment culture originally obtained from the extreme environment of Searles Lake, California. The isolate proved capable of growth via sulfate-reduction over a broad range of salinities (125-330 g/L), although growth was slowest at salt-saturati...

Stromatolites are laminated organosedimentary structures formed by microbial communities, principally cyanobacteria although eucaryote phototrophs may also be involved in the construction of modern stromatolites. In this study, productivity and photophysiology of communities from stromatolites (laminated) and thrombolites (nonlaminated) were analys...

Arsenotrophy, growth coupled to autotrophic arsenite oxidation or arsenate respiratory reduction, occurs only in the prokaryotic domain of life. The enzymes responsible for arsenotrophy belong to distinct clades within the DMSO reductase family of molybdenum-containing oxidoreductases: specifically arsenate respiratory reductase, ArrA, and arsenite...

##Assembly-Data-START## Assembly Method :: GAP v. version4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

##Assembly-Data-START## Assembly Method :: GAP4 v. version 4 Sequencing Technology :: Sanger dideoxy sequencing ##Assembly-Data-END##

Concerns have been raised about our recent study describing a bacterium that can grow using arsenic (As) instead of phosphorus (P). Our data suggested that As could act as a substitute for P in major biomolecules in this organism. Although the issues raised are of investigative interest, we contend that they do not invalidate our conclusions. We ar...

This publication presents a broad range of current topics and techniques in the exciting field of environmental biogeochemistry. In addition, it examines emerging developments and applications and forecasts future research directions. This book is divided into three parts: Environments, Processes, and New Technologies. Readers will find a broad ran...

Life is mostly composed of the elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus. Although these six elements make up nucleic acids, proteins, and lipids and thus the bulk of living matter, it is theoretically possible that some other elements in the periodic table could serve the same functions. Here, we describe a bacterium, str...

Phylogenetically diverse microorganisms metabolize arsenic despite its toxicity and are part of its robust iogeochemical cycle. Respiratory arsenate reductase is a reversible enzyme, functioning in some microbes as an arsenate reductase but in others as an arsenite oxidase. As(III) can serve as an electron donor for anoxygenic photolithoautotrophy...

Clostridial species predominate in both chicken gastrointestinal tract as well as litter where the organoarsenical roxarsone (3-nitro 4-hydroxybenzenearsonic acid) is anaerobically transformed releasing the more recognized toxic inorganic arsenic. 2D-gel electrophoresis and mass spectrometry were used to evaluate the changes in protein expression o...

The modern marine stromatolites at Highborne Cay, Bahamas are inhabited by diverse surface microbial communities. Although these communities are most often dominated by cyanobacteria (e.g., Schizothrix gebeleinii, Solentia sp., Oscillatoria sp. etc.), diatoms can be abundant and have been implicated in stromatolite biogenesis. We have identified tw...

Arsenic is a toxic element that occurs naturally in the environment. Microorganisms have detoxification pathways that involve the expulsion of arsenite from the cytoplasm. The genes encoding these processes, including acr3(2), have been well studied in laboratory. However, comparatively less is known of detoxification genes in the environment. Here...

Flat laminated microbial mats are complex microbial ecosystems that inhabit a wide range of environments (e.g., caves, iron springs, thermal springs and pools, salt marshes, hypersaline ponds and lagoons, methane and petroleum seeps, sea mounts, deep sea vents, arctic dry valleys). Their community structure is defined by physical (e.g., light quant...

If you were asked to speculate about the form extra-terrestrial life on Mars might take, which geomicrobial phenomenon might you select as a model system, assuming that life on Mars would be ‘primitive’? Give your reasons.At the end of my senior year at Rensselaer Polytechnic Institute in 1968, I took Professor Ehrlich's final for his Geomicrobiolo...

Mono Lake sediment slurries incubated with lactate and tellurite [Te(IV)] turned progressively black with time because of the precipitation of elemental tellurium [Te(0)]. An enrichment culture was established from these slurries that demonstrated Te(IV)-dependent growth. The enrichment was purified by picking isolated black colonies from lactate/T...

An intensive multi-year field study of the modern marine stromatolites atHighborne Cay, Bahamas has identified a variety of microbial communities thatcolonize the stromatolite surfaces. They include both bacterial and diatom dominatedcommunities. The "classic" microbial communities are those described by Reid et al.(2000). They include Schizothrix...

The haloalkaliphilic bacterium Alkalilimnicola ehrlichii is capable of anaerobic chemolithoautotrophic growth by coupling the oxidation of arsenite (As(III)) to the reduction of nitrate and carbon dioxide. Analysis of its complete genome indicates that it lacks a conventional arsenite oxidase (Aox), but instead possesses two operons that each encod...

Tens of millions of people in Southeast Asia drink groundwater contaminated with naturally occurring arsenic. How arsenic is released from the sediment into the water remains poorly understood. Here, we show in laboratory experiments that phosphate-limited cells of Burkholderia fungorum mobilize ancillary arsenic from apatite. We hypothesize that a...

2 Abstract: Facultative anaerobic bacteria capable of reducing arsenate and selenate oxyanions were isolated from water and sediment samples collected from sites contaminated with industrial and agricultural wastes from Kafr el Dawar and Edko (Behera Governorate) and from kafr el Zayat (Gharbeya Governorate). Microbiological analysis and heavy meta...

Phylogenetic analysis indicates that microbial arsenic metabolism is ancient and probably extends back to the primordial Earth. In microbial biofilms growing on the rock surfaces of anoxic brine pools fed by hot springs containing arsenite and sulfide at high concentrations, we discovered light-dependent oxidation of arsenite [As(III)] to arsenate...