Cultivation of novel Atribacterota from oil well provides new insight into their diversity, ecology, and evolution in anoxic, carbon-rich environments.

BACKGROUND: The Atribacterota are widely distributed in the subsurface biosphere. Recently, the first Atribacterota isolate was described and the number of Atribacterota genome sequences retrieved from environmental samples has increased significantly; however, their diversity, physiology, ecology, and evolution remain poorly understood. RESULTS: We report the isolation of the second member of Atribacterota, Thermatribacter velox gen. nov., sp. nov., within a new family Thermatribacteraceae fam. nov., and the short-term laboratory cultivation of a member of the JS1 lineage, Phoenicimicrobium oleiphilum HX-OS.bin.34TS, both from a terrestrial oil reservoir. Physiological and metatranscriptomics analyses showed that Thermatribacter velox B11T and Phoenicimicrobium oleiphilum HX-OS.bin.34TS ferment sugars and n-alkanes, respectively, producing H2, CO2, and acetate as common products. Comparative genomics showed that all members of the Atribacterota lack a complete Wood-Ljungdahl Pathway (WLP), but that the Reductive Glycine Pathway (RGP) is widespread, indicating that the RGP, rather than WLP, is a central hub in Atribacterota metabolism. Ancestral character state reconstructions and phylogenetic analyses showed that key genes encoding the RGP (fdhA, fhs, folD, glyA, gcvT, gcvPAB, pdhD) and other central functions were gained independently in the two classes, Atribacteria (OP9) and Phoenicimicrobiia (JS1), after which they were inherited vertically; these genes included fumarate-adding enzymes (faeA; Phoenicimicrobiia only), the CODH/ACS complex (acsABCDE), and diverse hydrogenases (NiFe group 3b, 4b and FeFe group A3, C). Finally, we present genome-resolved community metabolic models showing the central roles of Atribacteria (OP9) and Phoenicimicrobiia (JS1) in acetate- and hydrocarbon-rich environments. CONCLUSION: Our findings expand the knowledge of the diversity, physiology, ecology, and evolution of the phylum Atribacterota. This study is a starting point for promoting more incisive studies of their syntrophic biology and may guide the rational design of strategies to cultivate them in the laboratory. Video Abstract.

[Pollution Characteristics of Heavy Metals in PM2.5 Near Highway].

In this study, we evaluate the pollution characteristics of heavy metals in particulate matter with diameters less than 2.5 µm (PM2.5) near highways. Three rounds of cluster sampling of PM2.5 were conducted on three highways, Changzhang, Changtong, and Wenhou, in peri-urban areas near Nanchang from March to August 2018. The sampling sites included service areas, toll stations, tunnels, and areas near the highway. The concentrations of six heavy metals including Cu, Zn, Pb, Cd, Cr, and Ni in PM2.5 were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The pollution and distribution of heavy metals in PM2.5 near the highway were analyzed, and that pollution characteristics and the level of possible ecological jeopardy were assessed by using the Geoaccumulation Index and Potential Risk Index methods. No significant difference was observed in PM2.5 or in heavy metals in PM2.5 along highways with different traffic flow, but they differed significantly in among highway settings in the following order:super-long tunnels > long tunnels and area near the highway > service areas and toll stations. The heavy metal concentration in highways decreased in the following order:Zn (3.8 µg·m-3) > Pb (10.2×10-2 µg·m-3) > Cr (6.8×10-2 µg·m-3) > Cu (3.5×10-2 µg·m-3) > Ni (1.5×10-2 µg·m-3) > Cd (0.1×10-2 µg·m-3). In accordance with the influence of temperature and precipitation, PM2.5 and heavy metals in PM2.5 showed significant variations among the monitoring months. The PM2.5 concentration had a significant negative correlation with atmospheric temperature. We observed that PM2.5 concentration was significantly lower from May to August than from March to April. The Zn concentration in PM2.5 was more significant from May to August than from March to April. Pearson analysis showed a significant positive correlation between Zn in PM2.5 with atmospheric temperature because elevated temperatures could aggravate wear and tear and metallic corrosion, which then prompts the emission of Zn. According to the Geoaccumulation Index and Potential Ecological Jeopardy Index, the level of pollution associated with heavy metals of PM2.5 manifested in the following order:Zn and Cd > Pb > Cu > Ni and Cr. The pollution and degree of jeopardy associated with Zn and Cd were the most severe in the assessment criteria; therefore, the pollution by these elements and the sources of traffic should be noted in air pollution control plans. Super long tunnels, long tunnels, and areas near highways showed greater levels of pollution and higher potential ecological jeopardy than service areas and toll stations. The degree of pollution in densely populated service areas and toll stations was consistent across partially urban areas.

Identifying the Pollution Characteristics of Atmospheric Polycyclic Aromatic Hydrocarbons Associated with Functional Districts in Ningbo, China.

Duplicate polyurethane foam based passive air samplers (PUF-PAS) were deployed at seven sites in Ningbo from November 1, 2014 to October 31, 2015 and were used to analyze 15 priority polycyclic aromatic hydrocarbons (PAHs). Higher benzo[a]pyrene toxic equivalent concentrations were observed in the industrial areas during wintertime. Correspondence analysis (CA) was used to characterize the PAH congener profiles associated with each functional district and their temporal variations. It showed that different PAH composition profiles and seasonal variations were observed in mountain, rural area and residential areas; and different industrial layouts also led to different properties of PAH congener emissions. Higher levels of PAHs were observed around oil refinery in summer and at mountainous areas in winter, which might be attributed to the evaporation of petroleum and the impact of local biomass burning. This study also demonstrated that the factors influencing the representativeness of a site could be more clearly understood using PUF-PAS and CA analysis.