Evaluation of the Relationship between Momentum Wakes behind Moving Vehicles and Dispersion of Vehicle Emissions Using Near-Roadway Measurements.

A parameterization of initial vertical dispersion coefficient (σz,init) was developed for incorporation into California line source dispersion model, version 4 (CALINE4) and AMS/EPA regulatory model (AERMOD) to better predict pollutant concentrations near roadways. The momentum wake theory of moving vehicles indicates that both vehicle-induced turbulence (VIT) and dispersion occur in the vehicle wake. Based on a literature review, it is postulated that σz,init near roadways can be estimated using a "wake area model" concept of effective wake area defined as the vehicle height times the wake length, vehicle density, and vehicle type. A total of 523 5-min near-roadway simultaneous measurements (2016-2018) of pollutant concentrations and meteorological and traffic information were used to evaluate the model. Two roadways with distinct fleet composition and simple road configurations were selected for monitoring. The near-roadway σz,init ranged from 1 to 4 m for light-duty vehicles (LDVs) and from 3 to 7 m for fleet-mix (LDVs and heavy-duty vehicles (HDVs)). The results demonstrate that the dispersion contribution from one HDV was 31 times larger than that from one LDV. Calculated pollutant dispersion using the wake area model compared favorably with measurements (R2 = 0.91, slope = 1.07). These results indicate that σz,init varies with vehicle density and HDVs. Pollutant dispersion related to the vehicle wakes can be used to correctly parameterize dispersion models and improve prediction of pollutant concentrations near roadways.

Uncoupling Fermentative Synthesis of Molecular Hydrogen from Biomass Formation in Thermotoga maritima.

When carbohydrates are fermented by the hyperthermophilic anaerobe Thermotoga maritima, molecular hydrogen (H2) is formed in strict proportion to substrate availability. Excretion of the organic acids acetate and lactate provide an additional sink for removal of excess reductant. However, mechanisms controlling energy management of these metabolic pathways are largely unexplored. To investigate this topic, transient gene inactivation was used to block lactate production as a strategy to produce spontaneous mutant cell lines that overproduced H2 through mutation of unpredicted genetic targets. Single-crossover homologous chromosomal recombination was used to disrupt lactate dehydrogenase (encoded by ldh) with a truncated ldh fused to a kanamycin resistance cassette expressed from a native P groESL promoter. Passage of the unstable recombinant resulted in loss of the genetic marker and recovery of evolved cell lines, including strain Tma200. Relative to the wild type, and considering the mass balance of fermentation substrate and products, Tma200 grew more slowly, produced H2 at levels above the physiologic limit, and simultaneously consumed less maltose while oxidizing it more efficiently. Whole-genome resequencing indicated that the ABC maltose transporter subunit, encoded by malK3, had undergone repeated mutation, and high-temperature anaerobic [14C]maltose transport assays demonstrated that the rate of maltose transport was reduced. Transfer of the malK3 mutation into a clean genetic background also conferred increased H2 production, confirming that the mutant allele was sufficient for increased H2 synthesis. These data indicate that a reduced rate of maltose uptake was accompanied by an increase in H2 production, changing fermentation efficiency and shifting energy management.IMPORTANCE Biorenewable energy sources are of growing interest to mitigate climate change, but like other commodities with nominal value, require innovation to maximize yields. Energetic considerations constrain production of many biofuels, such as molecular hydrogen (H2) because of the competing needs for cell mass synthesis and metabolite formation. Here we describe cell lines of the extremophile Thermotoga maritima that exceed the physiologic limits for H2 formation arising from genetic changes in fermentative metabolism. These cell lines were produced using a novel method called transient gene inactivation combined with adaptive laboratory evolution. Genome resequencing revealed unexpected changes in a maltose transport protein. Reduced rates of sugar uptake were accompanied by lower rates of growth and enhanced productivity of H2.

Diversity of bacteria and archaea from two shallow marine hydrothermal vents from Vulcano Island.

To obtain new insights into community compositions of hyperthermophilic microorganisms, defined as having optimal growth temperatures of 80 °C and above, sediment and water samples were taken from two shallow marine hydrothermal vents (I and II) with temperatures of 100 °C at Vulcano Island, Italy. A combinatorial approach of denaturant gradient gel electrophoresis (DGGE) and metagenomic sequencing was used for microbial community analyses of the samples. In addition, enrichment cultures, growing anaerobically on selected polysaccharides such as starch and cellulose, were also analyzed by the combinatorial approach. Our results showed a high abundance of hyperthermophilic archaea, especially in sample II, and a comparable diverse archaeal community composition in both samples. In particular, the strains of the hyperthermophilic anaerobic genera Staphylothermus and Thermococcus, and strains of the aerobic hyperthermophilic genus Aeropyrum, were abundant. Regarding the bacterial community, ε-Proteobacteria, especially the genera Sulfurimonas and Sulfurovum, were highly abundant. The microbial diversity of the enrichment cultures changed significantly by showing a high dominance of archaea, particularly the genera Thermococcus and Palaeococcus, depending on the carbon source and the selected temperature.

Near-roadway monitoring of vehicle emissions as a function of mode of operation for light-duty vehicles.

Determination of the effect of vehicle emissions on air quality near roadways is important because vehicles are a major source of air pollution. A near-roadway monitoring program was undertaken in Chicago between August 4 and October 30, 2014, to measure ultrafine particles, carbon dioxide, carbon monoxide, traffic volume and speed, and wind direction and speed. The objective of this study was to develop a method to relate short-term changes in traffic mode of operation to air quality near roadways using data averaged over 5-min intervals to provide a better understanding of the processes controlling air pollution concentrations near roadways. Three different types of data analysis are provided to demonstrate the type of results that can be obtained from a near-roadway sampling program based on 5-min measurements: (1) development of vehicle emission factors (EFs) for ultrafine particles as a function of vehicle mode of operation, (2) comparison of measured and modeled CO2 concentrations, and (3) application of dispersion models to determine concentrations near roadways. EFs for ultrafine particles are developed that are a function of traffic volume and mode of operation (free flow and congestion) for light-duty vehicles (LDVs) under real-world conditions. Two air quality models-CALINE4 (California Line Source Dispersion Model, version 4) and AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model)-are used to predict the ultrafine particulate concentrations near roadways for comparison with measured concentrations. When using CALINE4 to predict air quality levels in the mixing cell, changes in surface roughness and stability class have no effect on the predicted concentrations. However, when using AERMOD to predict air quality in the mixing cell, changes in surface roughness have a significant impact on the predicted concentrations. IMPLICATIONS: The paper provides emission factors (EFs) that are a function of traffic volume and mode of operation (free flow and congestion) for LDVs under real-world conditions. The good agreement between monitoring and modeling results indicates that high-resolution, simultaneous measurements of air quality and meteorological and traffic conditions can be used to determine real-world, fleet-wide vehicle EFs as a function of vehicle mode of operation under actual driving conditions.

Distension of the toga of Thermotoga maritima involves continued growth of the outer envelope as cells enter the stationary phase.

Thermotoga maritima cells are distinguished by a sheath-like structure called the toga that loosely encloses single or multiple cells. During growth, and particularly at late phases of population growth, the toga distends from the poles of many cells. Little is known about this phenomenon so this study presents basic information about this process. We first provide quantitative data demonstrating that cells showing toga distensions increase in number during growth and that the phenomenon is not due to acidification of their growth medium. Comparisons of the area enclosed by these distended togas to the area of the cytoplasm show that the toga continues to grow as the growth of the cytoplasm ceases. Measuring the expression of many genes involved in toga composition and biosynthesis showed a 5.2-, 7.9- and 3-fold increase in the expression of toga structural protein genes ompB (porin), ompA1 and ompA2 (alpha helical, transperiplasm anchors), respectively. Additionally, expression of the putative pyruvyl transferase gene (csaB) was upregulated 4.4-fold in stationary phase, while the beta barrel assembly factor gene (bamA) showed only a 1.2-fold increase in expression. These findings demonstrate that toga distension is an active process and one that needs further investigation so we can understand the selective forces that operate in high-temperature environments.

Substrate adaptabilities of Thermotogae mannan binding proteins as a function of their evolutionary histories.

The Thermotogae possess a large number of ATP-binding cassette (ABC) transporters, including two mannan binding proteins, ManD and CelE (previously called ManE). We show that a gene encoding an ancestor of these was acquired by the Thermotogae from the archaea followed by gene duplication. To address the functional evolution of these proteins as a consequence of their evolutionary histories, we measured the binding affinities of ManD and CelE orthologs from representative Thermotogae. Both proteins bind cellobiose, cellotriose, cellotetraose, ß-1,4-mannotriose, and ß-1,4-mannotetraose. The CelE orthologs additionally bind ß-1,4-mannobiose, laminaribiose, laminaritriose and sophorose while the ManD orthologs additionally only weakly bind ß-1,4-mannobiose. The CelE orthologs have higher unfolding temperatures than the ManD orthologs. An examination of codon sites under positive selection revealed that many of these encode residues located near or in the binding site, suggesting that the proteins experienced selective pressures in regions that might have changed their functions. The gene arrangement, phylogeny, binding properties, and putative regulatory networks suggest that the ancestral mannan binding protein was a CelE ortholog which gave rise to the ManD orthologs. This study provides a window on how one class of proteins adapted to new functions and temperatures to fit the physiologies of their new hosts.

Ultrafine-Particle Emission Factors as a Function of Vehicle Mode of Operation for LDVs Based on Near-Roadway Monitoring.

This paper presents ultrafine-particle (UFP) emission factors (EFs) as a function of vehicle mode of operation (free flow and congestion) using (1) concurrent 5 min measurements of UFPs and carbon monoxide (CO) concentration, wind speed and direction, traffic volume and speed near a roadway that is restricted to light-duty vehicles (LDVs) and (2) inverse dispersion model calculations. Short-term measurements are required to characterize the highly variable and rapidly changing UFP concentration generated by vehicles. Under congestion conditions, the UFP vehicle EFs increased from 0.5 × 10(13) to 2 × 10(13) (particles km(-1) vehicle(-1)) when vehicle flow increased from 5500 to 7500 vehicles/h. For free-flow conditions, the EF is constant at 1.5 × 10(13) (particles km(-1) vehicle(-1)). The analysis is based on the assumption that air-quality models adequately describe the dilution process due to both traffic and atmospheric turbulence. The approach used to verify this assumption was to use an emission factor model to determine EFs for CO and then estimate dilution factors using measured CO concentrations. This procedure eliminates the need to rely only on air quality models to generate dilution factors. The EFs are suitable for fleet emissions under real-world traffic conditions.

Thermotoga lettingae can salvage cobinamide to synthesize vitamin B12.

We recently reported that the Thermotogales acquired the ability to synthesize vitamin B12 by acquisition of genes from two distantly related lineages, Archaea and Firmicutes (K. S. Swithers et al., Genome Biol. Evol. 4:730-739, 2012). Ancestral state reconstruction suggested that the cobinamide salvage gene cluster was present in the Thermotogales' most recent common ancestor. We also predicted that Thermotoga lettingae could not synthesize B12 de novo but could use the cobinamide salvage pathway to synthesize B12. In this study, these hypotheses were tested, and we found that Tt. lettingae did not synthesize B12 de novo but salvaged cobinamide. The growth rate of Tt. lettingae increased with the addition of B12 or cobinamide to its medium. It synthesized B12 when the medium was supplemented with cobinamide, and no B12 was detected in cells grown on cobinamide-deficient medium. Upstream of the cobinamide salvage genes is a putative B12 riboswitch. In other organisms, B12 riboswitches allow for higher transcriptional activity in the absence of B12. When Tt. lettingae was grown with no B12, the salvage genes were upregulated compared to cells grown with B12 or cobinamide. Another gene cluster with a putative B12 riboswitch upstream is the btuFCD ABC transporter, and it showed a transcription pattern similar to that of the cobinamide salvage genes. The BtuF proteins from species that can and cannot salvage cobinamides were shown in vitro to bind both B12 and cobinamide. These results suggest that Thermotogales species can use the BtuFCD transporter to import both B12 and cobinamide, even if they cannot salvage cobinamide.

Novel inositol catabolic pathway in Thermotoga maritima.

myo-inositol (MI) is a key sugar alcohol component of various metabolites, e.g. phosphatidylinositol-based phospholipids that are abundant in animal and plant cells. The seven-step pathway of MI degradation was previously characterized in various soil bacteria including Bacillus subtilis. Through a combination of bioinformatics and experimental techniques we identified a novel variant of the MI catabolic pathway in the marine hyperthermophilic bacterium Thermotoga maritima. By using in vitro biochemical assays with purified recombinant proteins we characterized four inositol catabolic enzymes encoded in the TM0412-TM0416 chromosomal gene cluster. The novel catabolic pathway in T. maritima starts as the conventional route using the myo-inositol dehydrogenase IolG followed by three novel reactions. The first 2-keto-myo-inositol intermediate is oxidized by another, previously unknown NAD-dependent dehydrogenase TM0412 (named IolM), and a yet unidentified product of this reaction is further hydrolysed by TM0413 (IolN) to form 5-keto-l-gluconate. The fourth step involves epimerization of 5-keto-l-gluconate to d-tagaturonate by TM0416 (IolO). T. maritima is unable to grow on myo-inositol as a single carbon source. The determined in vitro specificity of the InoEFGK (TM0418-TM0421) transporter to myo-inositol-phosphate suggests that the novel pathway in Thermotoga utilizes a phosphorylated derivative of inositol.

Reconstructed ancestral Myo-inositol-3-phosphate synthases indicate that ancestors of the Thermococcales and Thermotoga species were more thermophilic than their descendants.

The bacterial genomes of Thermotoga species show evidence of significant interdomain horizontal gene transfer from the Archaea. Members of this genus acquired many genes from the Thermococcales, which grow at higher temperatures than Thermotoga species. In order to study the functional history of an interdomain horizontally acquired gene we used ancestral sequence reconstruction to examine the thermal characteristics of reconstructed ancestral proteins of the Thermotoga lineage and its archaeal donors. Several ancestral sequence reconstruction methods were used to determine the possible sequences of the ancestral Thermotoga and Archaea myo-inositol-3-phosphate synthase (MIPS). These sequences were predicted to be more thermostable than the extant proteins using an established sequence composition method. We verified these computational predictions by measuring the activities and thermostabilities of purified proteins from the Thermotoga and the Thermococcales species, and eight ancestral reconstructed proteins. We found that the ancestral proteins from both the archaeal donor and the Thermotoga most recent common ancestor recipient were more thermostable than their descendants. We show that there is a correlation between the thermostability of MIPS protein and the optimal growth temperature (OGT) of its host, which suggests that the OGT of the ancestors of these species of Archaea and the Thermotoga grew at higher OGTs than their descendants.

Complete genome sequence of the thermophilic, piezophilic, heterotrophic bacterium Marinitoga piezophila KA3.

Marinitoga piezophila KA3 is a thermophilic, anaerobic, chemoorganotrophic, sulfur-reducing bacterium isolated from the Grandbonum deep-sea hydrothermal vent site at the East Pacific Rise (13°N, 2,630-m depth). The genome of M. piezophila KA3 comprises a 2,231,407-bp circular chromosome and a 13,386-bp circular plasmid. This genome was sequenced within Department of Energy Joint Genome Institute CSP 2010.

Genes for the major structural components of Thermotogales species' togas revealed by proteomic and evolutionary analyses of OmpA and OmpB homologs.

The unifying structural characteristic of members of the bacterial order Thermotogales is their toga, an unusual cell envelope that includes a loose-fitting sheath around each cell. Only two toga-associated structural proteins have been purified and characterized in Thermotoga maritima: the anchor protein OmpA1 (or Ompα) and the porin OmpB (or Ompß). The gene encoding OmpA1 (ompA1) was cloned and sequenced and later assigned to TM0477 in the genome sequence, but because no peptide sequence was available for OmpB, its gene (ompB) was not annotated. We identified six porin candidates in the genome sequence of T. maritima. Of these candidates, only one, encoded by TM0476, has all the characteristics reported for OmpB and characteristics expected of a porin including predominant ß-sheet structure, a carboxy terminus porin anchoring motif, and a porin-specific amino acid composition. We highly enriched a toga fraction of cells for OmpB by sucrose gradient centrifugation and hydroxyapatite chromatography and analyzed it by LC/MS/MS. We found that the only porin candidate that it contained was the TM0476 product. This cell fraction also had ß-sheet character as determined by circular dichroism, consistent with its enrichment for OmpB. We conclude that TM0476 encodes OmpB. A phylogenetic analysis of OmpB found orthologs encoded in syntenic locations in the genomes of all but two Thermotogales species. Those without orthologs have putative isofunctional genes in their place. Phylogenetic analyses of OmpA1 revealed that each species of the Thermotogales has one or two OmpA homologs. T. maritima has two OmpA homologs, encoded by ompA1 (TM0477) and ompA2 (TM1729), both of which were found in the toga protein-enriched cell extracts. These annotations of the genes encoding toga structural proteins will guide future examinations of the structure and function of this unusual lineage-defining cell sheath.

Genome sequence of the mesophilic Thermotogales bacterium Mesotoga prima MesG1.Ag.4.2 reveals the largest Thermotogales genome to date.

Here we describe the genome of Mesotoga prima MesG1.Ag4.2, the first genome of a mesophilic Thermotogales bacterium. Mesotoga prima was isolated from a polychlorinated biphenyl (PCB)-dechlorinating enrichment culture from Baltimore Harbor sediments. Its 2.97 Mb genome is considerably larger than any previously sequenced Thermotogales genomes, which range between 1.86 and 2.30 Mb. This larger size is due to both higher numbers of protein-coding genes and larger intergenic regions. In particular, the M. prima genome contains more genes for proteins involved in regulatory functions, for instance those involved in regulation of transcription. Together with its closest relative, Kosmotoga olearia, it also encodes different types of proteins involved in environmental and cell-cell interactions as compared with other Thermotogales bacteria. Amino acid composition analysis of M. prima proteins implies that this lineage has inhabited low-temperature environments for a long time. A large fraction of the M. prima genome has been acquired by lateral gene transfer (LGT): a DarkHorse analysis suggests that 766 (32%) of predicted protein-coding genes have been involved in LGT after Mesotoga diverged from the other Thermotogales lineages. A notable example of a lineage-specific LGT event is a reductive dehalogenase gene-a key enzyme in dehalorespiration, indicating M. prima may have a more active role in PCB dechlorination than was previously assumed.

Vitamin B(12) synthesis and salvage pathways were acquired by horizontal gene transfer to the Thermotogales.

The availability of genome sequences of Thermotogales species from across the order allows an examination of the evolutionary origins of phenotypic characteristics in this lineage. Several studies have shown that the Thermotogales have acquired large numbers of genes from distantly related lineages, particularly Firmicutes and Archaea. Here, we report the finding that some Thermotogales acquired the ability to synthesize vitamin B(12) by acquiring the requisite genes from these distant lineages. Thermosipho species, uniquely among the Thermotogales, contain genes that encode the means to synthesize vitamin B(12) de novo from glutamate. These genes are split into two gene clusters: the corrinoid synthesis gene cluster, that is unique to the Thermosipho and the cobinamide salvage gene cluster. The corrinoid synthesis cluster was acquired from the Firmicutes lineage, whereas the salvage pathway is an amalgam of bacteria- and archaea-derived proteins. The cobinamide salvage gene cluster has a patchy distribution among Thermotogales species, and ancestral state reconstruction suggests that this pathway was present in the common Thermotogales ancestor. We show that Thermosipho africanus can grow in the absence of vitamin B(12), so its de novo pathway is functional. We detected vitamin B(12) in the extracts of T. africanus cells to verify the synthetic pathway. Genes in T. africanus with apparent B(12) riboswitches were found to be down-regulated in the presence of vitamin B(12) consistent with their roles in B(12) synthesis and cobinamide salvage.

Mesotoga prima gen. nov., sp. nov., the first described mesophilic species of the Thermotogales.

A novel mesophilic member of the Thermotogales, strain MesG1.Ag.4.2, was isolated from sediments from Baltimore Harbor, MD, USA. The strain grew optimally at 37 °C with a doubling time of 16.5 h on xylose. Carbohydrates and proteinaceous compounds supported growth and pentoses were preferred over hexoses. The strain was strictly anaerobic and growth was slightly stimulated by thiosulfate, sulfite, and elemental sulfur. The G + C content of its genomic DNA was 45.3 mol%. Strain MesG1.Ag.4.2 and Kosmotoga olearia lipids were analyzed. Strain MesG1.Ag.4.2 contained no long-chain dicarboxylic acids and its major phospholipid was lyso-phosphatidylserine. Long-chain dicarboxylic acids were found in K. olearia and its major phospholipid was cardiolipin, a lipid not yet reported in Thermotogales species. Phylogenetic analyses of its two 16S rRNA genes placed strain MesG1.Ag.4.2 within the bacterial order Thermotogales. Based on the phylogenetic analyses and its low optimal growth temperature, it is proposed that the strain represents a novel species of a new genus within the family Thermotogaceae, order Thermotogales. The name Mesotoga prima gen. nov., sp. nov. is proposed. The type strain of M. prima is MesG1.Ag.4.2 (= DSM 24739 = ATCC BAA-2239).

Genome sequence of Kosmotoga olearia strain TBF 19.5.1, a thermophilic bacterium with a wide growth temperature range, isolated from the Troll B oil platform in the North Sea.

Kosmotoga olearia strain TBF 19.5.1 is a member of the Thermotogales that grows best at 65°C and very well even at 37°C. Information about this organism is important for understanding the evolution of mesophiles from thermophiles. Its genome sequence reveals extensive gene gains and a large content of mobile genetic elements. It also contains putative hydrogenase genes that have no homologs in the other member of the Thermotogales.

Genome sequence of Thermotoga sp. strain RQ2, a hyperthermophilic bacterium isolated from a geothermally heated region of the seafloor near Ribeira Quente, the Azores.

Thermotoga sp. strain RQ2 is probably a strain of Thermotoga maritima. Its complete genome sequence allows for an examination of the extent and consequences of gene flow within Thermotoga species and strains. Thermotoga sp. RQ2 differs from T. maritima in its genes involved in myo-inositol metabolism. Its genome also encodes an apparent fructose phosphotransferase system (PTS) sugar transporter. This operon is also found in Thermotoga naphthophila strain RKU-10 but no other Thermotogales. These are the first reported PTS transporters in the Thermotogales.

Odor emission rate estimation of indoor industrial sources using a modified inverse modeling method.

Odor emission rates are commonly measured in the laboratory or occasionally estimated with inverse modeling techniques. A modified inverse modeling approach is used to estimate source emission rates inside of a postdigestion centrifuge building of a water reclamation plant. Conventionally, inverse modeling methods divide an indoor environment in zones on the basis of structural design and estimate source emission rates using models that assume homogeneous distribution of agent concentrations within a zone and experimentally determined link functions to simulate airflows among zones. The modified approach segregates zones as a function of agent distribution rather than building design and identifies near and far fields. Near-field agent concentrations do not satisfy the assumption of homogeneous odor concentrations; far-field concentrations satisfy this assumption and are the only ones used to estimate emission rates. The predictive ability of the modified inverse modeling approach was validated with measured emission rate values; the difference between corresponding estimated and measured odor emission rates is not statistically significant. Similarly, the difference between measured and estimated hydrogen sulfide emission rates is also not statistically significant. The modified inverse modeling approach is easy to perform because it uses odor and odorant field measurements instead of complex chamber emission rate measurements.

Ligands of thermophilic ABC transporters encoded in a newly sequenced genomic region of Thermotoga maritima MSB8 screened by differential scanning fluorimetry.

The chromosome of Thermotoga maritima strain MSB8 was found to have an 8,870-bp region that is not present in its published sequence. The isolate that was sequenced by The Institute for Genomic Research (TIGR) in 1999 is apparently a laboratory variant of the isolate deposited at the Deutsche Sammlung von Mikroorganismen und Zellkulturen (DSM 3109) in 1986. This newly sequenced region from the DSMZ culture was located between TM1848 (cbp, cellobiose phosphorylase) and TM1847 (the 3' end of a truncated ROK regulator). The new region contained seven genes: a beta glucosidase gene (bglA), three trehalose ABC transporter genes (treEFG), three xylose ABC transporter genes (xylE2F2K2), and the 5' end of a gene encoding the ROK regulator TM1847. We present a new differential scanning fluorimetry method using a low pH that was necessary to screen potential ligands of these exceptionally thermostable periplasmic substrate-binding proteins. This method showed that trehalose, sucrose, and glucose stabilized TreE, and their binding was confirmed by measuring changes in intrinsic fluorescence upon ligand binding. Binding constants of 0.024 µM, 0.300 µM, and 56.78 µM at 60°C, respectively, were measured. XylE2 ligands were similarly determined and xylose, glucose, and fucose bound with K(d) (dissociation constant) values of 0.042 µM, 0.059 µM, and 1.436 µM, respectively. Since there is no discernible phenotypic difference between the TIGR isolate and the DSMZ isolate despite the variance in their genomes, we propose that they be called genomovars: T. maritima MSB8 genomovar TIGR and T. maritima MSB8 genomovar DSM 3109, respectively.

Comparison of two dynamic measurement methods of odor and odorant emission rates from freshly dewatered biosolids.

Odor and odorant emission rates from freshly dewatered biosolids in a dewatering building of a Water Reclamation Plant (WRP) are measured using the EPA flux chamber and wind tunnel methods. Experimental results are compared statistically to test whether the two methods result in similar emission rates when experiments are performed under field conditions. To the best of our knowledge the literature is void of studies comparing the two methods indoors. In this paper the two methods are compared indoors where the wind velocity and air exchange rate are pertinent field conditions and can be measured. The difference between emission rates of odor and hydrogen sulfide measured with the two methods is not statistically significant (P values: 0.505 for odor, 0.130 for H(2)S). It is concluded that both methods can be used to estimate source emissions but selection of the most effective or efficient method depends on prevailing environmental conditions. The wind tunnel is appropriate for outdoor environments where wind effects on source emissions are more pronounced than indoors. The EPA flux chamber depends on the air exchange rate of the chamber, which simulates corresponding conditions of the indoor environment under investigation and is recommended for estimation of indoor pollution sources.