Complete Genome Sequences of Polynucleobacter sp. Subcluster PnecA Strains SHI2 and SHI8, Isolated from an Oligotrophic-Dystrophic Lake in Japan.

Members of the genus Polynucleobacter belonging to the subcluster PnecA comprise freshwater bacterioplankton with worldwide distribution. Here, we report the complete genome sequences of two Polynucleobacter sp. strains (PnecA), SHI2 and SHI8, isolated from the surface water of an oligotrophic-dystrophic lake in a humid continental climate in Japan.

Determination of hydrazine in air by liquid chromatography/tandem mass spectrometry combined with precolumn derivatization.

In this study, we developed a determination method for hydrazine in the air. Hydrazine was derivatized with p-dimethyl amino benzaldehyde (DBA) to yield p-dimethylaminobenzalazine, which was subjected to liquid chromatography-electrospray tandem mass spectrometry (LC/MS/MS) analysis. The derivative exhibited good sensitivity in the LC/MS/MS analysis, and its instrument detection limit and instrument quantification limit were 0.003 and 0.008 ng/mL, respectively. The air sample was collected using an air sampler equipped with a peristaltic pump at 0.2 L/min for 8 h. We demonstrated that a silica cartridge impregnated with DBA and 1,2-bis(4-pyridyl) ethylene can collect hydrazine in the air stably. The mean recovery rates in outdoor and indoor locations were 97.6% and 92.4%, respectively. Further, the method detection and quantification limits were 0.1 and 0.4 ng/m3, respectively. The proposed method does not require any pretreatment and/or concentration step, enabling high-throughput analyses.

Complete Genome Sequences of Three Polynucleobacter sp. Subcluster PnecC Strains, KF022, KF023, and KF032, Isolated from a Shallow Eutrophic Lake and a River in Japan.

The genus Polynucleobacter subcluster PnecC consists of bacteria representing the ubiquitous taxon of freshwater bacterioplankton. Here, we report the complete genome sequences of three Polynucleobacter sp. (PnecC) strains, namely, KF022, KF023, and KF032, which were isolated from surface water of a temperate shallow eutrophic lake and its inflow river in Japan.

Complete Genome Sequences of Three Limnohabitans sp. (Lhab-A3) Strains, INBF002, TEGF004, and MORI2, Isolated from Two Lakes and a River in Japan.

Freshwater bacterioplankton of the genus Limnohabitans represent a dominant group that has worldwide distribution. Here, we report the complete genome sequences of three Limnohabitans sp. (Lhab-A3 tribe) strains, i.e., INBF002, TEGF004, and MORI2, which were isolated from surface water samples from two shallow eutrophic lakes and a river in Japan.

Complete Genome Sequence of Aurantimicrobium sp. Strain INA4, Isolated from an Oligotrophic Lake in Japan.

The globally distributed freshwater bacterioplankton of the genus Aurantimicrobium belong to the tribe Luna2. Here, we report the complete genome sequence of Aurantimicrobium sp. strain INA4, which was isolated from an oligotrophic lake surface water in Japan.

Novel automated identification and quantification database using liquid chromatography quadrupole time-of-flight mass spectrometry for quick, comprehensive, cheap and extendable organic micro-pollutant analysis in environmental systems.

In order to protect human health and the environment, highly efficient, low-cost, labor-saving, and green analysis of toxic chemicals are urgently required. To achieve this objective, we have developed a novel database-based automated identification and quantification system (AIQS) using LC-QTOF-MS. Since the AIQS uses retention times (RTs), exact MS and MS-MS spectra, and calibration curves of 484 chemicals registered in the database instead of the use of standards, the targets can be determined with low-cost in a short time. The AIQS uses Sequential Window Acquisition of All Theoretical Fragment-ion Spectra as an acquisition method by which we can obtain accurate MS and MS-MS spectra of all detectable substances in a sample with minimal interference from co-eluted peaks. Identification is certainly done using RTs, mass error, ion ratios (a precursor to two product ions), and accurate MS and MS-MS spectra. Consequently, the chance of misidentification is very low even in dirty samples. To examine the accuracy of the AIQS, two collaborative tests were conducted. The first test used 208 pesticide standards at two concentrations (10 and 100 ng mL-1) using 7 instruments, and showed that average trueness was 106 and 95.2%, respectively, with relative standard deviations of 90% of the test compounds below 30%. The second collaborative study involved 5 laboratories carrying out recovery tests on 200 pesticides using 10 river waters. The average recovery was 71.6%; this was 15% lower than that using purified water probably due to the matrix effects. The average relative standard deviation was 30% worse than that of measurement of the standards. Both the recovery and reproducibility, however, satisfied the criteria of Analytical Method Validity Guidelines, Ministry of Health, Labour and Welfare, Japan. Instrument detection limits of 96% of the registered compounds are below 10 pg. The AIQS allows for easy addition of new substances and retrospective analysis after their addition. The results applied to actual samples showed that the AIQS has sufficient identification and quantification performance as a target screening method for a large number of substances in environmental samples.

Complete Genome Sequences of Rhodoluna sp. Strains KAS3 and KACHI23, Isolated from Lake and River Surface Water.

The genus Rhodoluna belongs to the ubiquitous freshwater bacterioplankton tribe Luna1-A2. Here, we report the complete sequences of Rhodoluna sp. strains KAS3 and KACHI23, which were isolated from freshwater lake and river surface water in Japan.

Whole-Genome Sequence of Sediminibacterium sp. Strain TEGAF015, Isolated from a Shallow Eutrophic Freshwater Lake in Japan.

The genus Sediminibacterium comprises bacteria representing the ubiquitous taxa of freshwater bacterioplankton. Here, we report the whole-genome sequence of Sediminibacterium sp. strain TEGAF015, isolated from a shallow eutrophic freshwater lake in Japan.

Complete Genome Sequence of Aquiluna sp. Strain KACHI24, Isolated from River Surface Water.

The globally distributed bacterioplankton of the genus Aquiluna belong to the tribe Luna1-A1. Here, we report the complete genome sequence of Aquiluna sp. strain KACHI24, which was isolated from river surface water in Japan.

Non-target environmental analysis by liquid chromatography/high-resolution mass spectrometry with a product ion and neutral loss database.

Despite the increasing detection of emerging substances in the environment, the identity of most are left unknown due to the lack of efficient identification methods. We developed a non-target analysis method for identifying unknown substances in the environment by liquid chromatography/high-resolution mass spectrometry (LC/HRMS) with a product ion and neutral loss database (PNDB). The present analysis describes an elucidation method with elemental compositions of the molecules, product ions, and corresponding neutral losses of the unknown substance: (1) with the molecular formula, possible molecular structures are retrieved from two chemical structure databases (PubChem and ChemSpider); then (2) with the elemental compositions of product ions and neutral losses, possible partial structures are retrieved from the PNDB; and finally, (3) molecular structures that match the possible partial structures are listed in order of number of hits. A molecular structure with a higher number of hits is more similar to the structure of the analyzed substance. The performance of the non-target method was evaluated by simulated analysis of 150 LC/HRMS spectra registered in MassBank. First, all substances of the same mass data (41/41) and 68% (39/57) of the mass data of the same substances not registered in the PNDB were elucidated. It was demonstrated that 14% (7/52) and 31% (16/52) of the substances with no mass spectral data registered in the PNDB were obtained at the first and within the fifth place, respectively. Owing to the fact that 10 of the total hits occurred in product ions and neutral losses, almost 50% of the substances evaluated with this method were placed at the top 4 positions in the similarity ranking. Importantly, the proposed method is effective for analyzing mass spectral data that has not been registered in the PNDB and thus is expected to be used for a variety of non-target analyses.

Distribution characteristics of methylsiloxanes in atmospheric environment of Saitama, Japan: Diurnal and seasonal variations and emission source apportionment.

The large production volume of methylsiloxanes (MSs), combined with their high mobility/volatility and persistence, is a matter of concern from the atmospheric pollution perspective. Therefore, we evaluated of the concentrations and emission sources of MSs, including 7 cyclic methylsiloxanes (D3-D9; CMSs, the number refers to the number of Si-O bonds) and 13 linear methylsiloxanes (L3-L15; LMSs) in ambient air collected from Saitama, Japan. This is a first study regarding the evaluation of 20 methylsiloxanes in the Japanese atmosphere. We improved the air sampling methodology by determination the stability of D5 during a 7-d air sampling and arbitrary sample storage period using polystyrene-divinyl benzene copolymer sorbent (Sep-Pak plus PS-2). We analyzed air samples for MSs seasonally collected from nine locations in Saitama, including urban, suburban, rural, and mountainous areas. The mean CMS and LMS concentrations were 358 ng m-3 and 13.4 ng m-3, respectively. The D5 concentrations were distributed widely, with high concentrations in urban/suburban populous areas and dispersed at low concentrations in surrounding areas (north and mountainous areas). We analyzed 7-d air samples collected every week over a year and found apparent seasonal and periodic trends in the CMS concentrations. In the diurnal sampling campaign, we observed periodic fluctuations in ambient CMSs, with an inverse relationship with the atmospheric boundary layer development during the day. Backward trajectories and the prevailing wind direction during the sampling period indicated that the specific profiles of D4 observed in fall/winter weeks and north of Saitama could be ascribed to northwestward air-mass advection. We employed a novel approach in estimating CMSs emission sources and source apportionment by using non-negative matrix factorization (NMF). The concentration matrix was divided successfully into two factors (emission sources) namely, personal care and household products and industrial activities.

Thermal mineralization behavior of PFOA, PFHxA, and PFOS during reactivation of granular activated carbon (GAC) in nitrogen atmosphere.

Waste disposal site is one of the important sinks of chemicals. A significant amount of perfluoroalkyl and polyfluoroalkyl substances (PFASs) such as perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexanoic acid (PFHxA) have been brought into it. Because of their aqueous solubility, PFASs are released to landfill effluent waters, from which PFASs are efficiently collected by adsorption technique using granular activated carbon (GAC). The exhausted GAC is reactivated by heating processes. The mineralization of PFASs during the reactivation process was studied. Being thermally treated in N2 atmosphere, the recovery rate of mineralized fluorine and PFC homologues including short-chained perfluorocarboxylic acids was determined. If the reagent form of PFOA, PFHxA, and PFOS were treated at 700 °C, the recovery of mineralized fluorine was less than 30, 46, and 72 %, respectively. The rate increased to 51, 74, and 70 %, if PFASs were adsorbed onto GAC in advance; moreover, addition of excess sodium hydroxide (NaOH) improved the recovery to 74, 91, and 90 %. Residual PFAS homologue was less than 1 % of the original amount. Steamed condition did not affect destruction. The significant role of GAC was to suppress volatile release of PFASs from thermal ambient, whereas NaOH enhanced destruction and retained mineralized fluorine on the GAC surface. Comparing the recovery of mineralized fluorine, the degradability of PFOS was considered to be higher than PFOA and PFHxA. Whole mass balance missing 9~26 % of initial amount suggested formation of some volatile organofluoro compounds beyond analytical coverage.

Use of high-resolution mass spectrometry to identify precursors and biodegradation products of perfluorinated and polyfluorinated compounds in end-user products.

Structural identification of perfluoroalkyl and polyfluoroalkyl substances found in end-user products and their biodegradation products was performed using ultra-high resolution mass spectrometry. Little attention has so far been paid to the environmental burden of perfluorooctane sulfonate and perfluorooctanoic acid from compounds with a molar mass of ~2,000. Analysis of end-user waterproofing and stain repellent products revealed the presence of numerous ions with molar masses ranging from 1,000 to 2,000 and complex mass spectra. Ultra-high resolution mass spectrometry determined the accurate mass of the observed ions, allowing the cleavage position and fragment structure to be determined. The precursor structures were determined based on reconstitution of the retrieved fragments. Products of fluorochemical manufacturers before voluntary regulation comprised compounds with plural perfluorooctyl chains. In the current product lines, compounds comprising perfluorobutyl chains were detected. Biodegradation tests using activated sludge revealed that biodegradation products consistent with those reported previously were generated even from complex end-user products. For example, the biodegradation test revealed the formation of N-ethyl perfluorooctane sulfonamido acetic acid and various fluorotelomer acids in the samples. The results of the present study suggest that the environmental burden of these compounds should be reevaluated.

Discharge of perfluorinated compounds from rivers and their influence on the coastal seas of Hyogo prefecture, Japan.

The aim of this study was to investigate 12 perfluorinated compounds (PFCs) including perfluorinated carboxylates (C4-C12) and perfluorinated alkyl sulfonates (C4, C6, and C8) in river and seawater samples to determine contamination levels in the aquatic environment of Hyogo prefecture, Japan. High levels of perfluorohexanoic acid (PFHxA; 2300-16,000 ng/L) were detected in the Samondogawa River at Tatsumi Bridge downstream of a PFC production facility; this location also had the highest mass flow rate of PFCs (3900-29,000 kg/y). Widespread contamination of coastal waters was confirmed with PFHxA as the dominant compound. Perfluorooctanoic acid was also prevalent in coastal waters. The concentration of PFHxA in coastal seawater and the distance from the mouth of the Samondogawa River were inversely related. This discharge of high concentrations of PFHxA from the Samondogawa River may have affected concentrations of PFCs in Osaka Bay.

Perfluorinated compounds in sediment samples from the wastewater canal of Pancevo (Serbia) industrial area.

Perfluoroalkyl sulfonates (PFSAs) and perfluoroalkyl carboxylates (PFCAs) were analyzed in sediment samples from the wastewater canal draining the industrial complex of Pancevo, Serbia (oil refinery, petrochemical plant, and fertilizer factory). The canal is directly connected to Europe's second largest river, the Danube, which drains its water into the Black Sea. Perfluorooctane sulfonate (PFOS) up to 5.7ngg(-1) dry weight (dw) and total Perfluorinated compounds (PFCs) up to 6.3ngg(-1) dw were detected. Compared to other reports, high levels of PFOS were found, even though PFCs are not used in the industrial production associated with this canal. The PFOS concentration in water was recalculated using the adsorption coefficient, KOC from literature. Using the average output of wastewater from the canal, a mass load of 1.38kg PFOS per year discharged in the Danube River has been calculated, which undoubtedly points to the contribution to global persistent organic pollution of surface waters originating from this industrial place.