Effects of warming on the degradation and production of low-molecular-weight labile organic carbon in an Arctic tundra soil

ABSTRACT Degradation of petroleum hydrocarbons was monitored in microcosms with diesel fuel-contaminated Arctic tundra soil incubated for 48 days at low temperatures (−5, 0, and 7°C). An additional treatment was incubation for alternating 24-h periods at 7 and −5°C. Hydrocarbons were biodegraded at or above 0°C, and freeze-thaw cycles may have actually stimulated hydrocarbon biodegradation. Total petroleum hydrocarbon (TPH) removal over 48 days in the 7, 0, and 7 and −5°C treatments, respectively, was 450, 300, and 600 μg/g of soil. No TPH removal was observed at −5°C. Total carbon dioxide production suggested that TPH removal was due to biological mineralization. Bacterial metabolic activity, indicated by RNA/DNA ratios, was higher in the middle of the experiment (day 21) than at the start, in agreement with measured hydrocarbon removal and carbon dioxide production activities. The total numbers of culturable heterotrophs and of hydrocarbon degraders did not change significantly over the 48 days of incubation in any of the treatments. At the end of the experiment, bacterial community structure, evaluated by ribosomal intergenic spacer length analysis, was very similar in all of the treatments but the alternating 7 and −5°C treatment.

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Sphingoaurantiacus polygranulatus gen. nov., sp. nov., isolated from high-Arctic tundra soil, and emended descriptions of the genera Sandarakinorhabdus, Polymorphobacter and Rhizorhabdus and the species Sandarakinorhabdus limnophila, Rhizorhabdus argentea and Sphingomonas wittichii

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.000677 ◽

2016 ◽

Vol 66 (1) ◽

pp. 91-100 ◽

Cited By ~ 26

Author(s):

MyongChol Kim ◽

OkChol Kang ◽

Yumin Zhang ◽

Lvzhi Ren ◽

Xulu Chang ◽

...

Keyword(s):

Arctic Tundra ◽

High Arctic ◽

Tundra Soil ◽

Sphingomonas Wittichii ◽

Arctic Tundra Soil

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Removal of Natural Organic Matter (NOM) from Drinking Water Supplies by Ozone-Biofiltration

Water Science & Technology ◽

10.2166/wst.1999.0466 ◽

1999 ◽

Vol 40 (9) ◽

pp. 157-163 ◽

Cited By ~ 29

Author(s):

Raymond M. Hozalski ◽

Edward J. Bouwer ◽

Sudha Goel

Keyword(s):

Molecular Weight ◽

Organic Matter ◽

Organic Carbon ◽

Natural Organic Matter ◽

Laboratory Experiments ◽

Low Molecular Weight ◽

Batch Experiments ◽

Toc Removal ◽

High Molecular Weight Material ◽

Effects Of Temperature

Removal of natural organic matter (NOM) in biofilters can be affected by many factors including NOM characteristics, use of pre-ozonation, water temperature, and biofilter backwashing. Laboratory experiments were performed and a biofilter simulation model was developed for the purpose of evaluating the effects of each of these factors on NOM removal in biofilters. Four sources of NOM were used in this study to represent a broad spectrum of NOM types that may be encountered in water treatment. In batch experiments with raw NOM, the removal of organic carbon by biodegradation was inversely proportional to the UV absorbance (254 nm)-to-TOC ratio and directly proportional to the percentage of low molecular weight material (as determined by ultrafiltration). The extent and rate of total organic carbon (TOC) removal typically increased as ozone dose increased, but the effects were highly dependent on NOM characteristics. NOM with a higher percentage of high molecular weight material experienced the greatest enhancement in biodegradability by ozonation. The performance of laboratory-scale continuous-flow biofilters was not significantly affected by periodic backwashing, because backwashing was unable to remove large amounts of biomass from the filter media. Model simulations confirmed our experimental results and the model was used to further evaluate the effects of temperature and backwashing on biofilter performance.

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Dyadobacter sandarakinus sp. nov., isolated from Arctic tundra soil, and emended descriptions of Dyadobacter alkalitolerans, Dyadobacter koreensis and Dyadobacter psychrophilus

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.005103 ◽

2021 ◽

Vol 71 (11) ◽

Author(s):

Yongping Zhang ◽

Xiaoya Peng ◽

Kun Qin ◽

Jia Liu ◽

Qiang Xu ◽

...

Keyword(s):

Type Species ◽

Arctic Tundra ◽

Rrna Gene ◽

Aerobic Bacterium ◽

Tundra Soil ◽

Unidentified Phospholipid ◽

Polar Lipid Profile ◽

Content Type ◽

Link Type ◽

Arctic Tundra Soil

Strain Q3-56T, isolated from Arctic tundra soil, was found to be a Gram-stain-negative, yellow-pigmented, oxidase- and catalase-positive, non-motile, non-spore-forming, rod-shaped and aerobic bacterium. Strain Q3-56T grew optimally at pH 7.0 and 28 °C. The strain could tolerate up to 1 % (w/v) NaCl with optimum growth in the absence of NaCl. The strain was not sensitive to oxacillin and ceftazidime. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Q3-56T belonged to the genus Dyadobacter . Strain Q3-56T showed the highest sequence similarities to Dyadobacter luticola T17T (96.58 %), Dyadobacter ginsengisoli Gsoil 043T (96.50 %), Dyadobacter flavalbus NS28T (96.43 %) and Dyadobacter bucti QTA69T (96.43 %). The predominant respiratory isoprenoid quinone was identified as MK-7, The polar lipid profile of strain Q3-56T was found to contain one phosphatidylethanolamine, three unidentified aminolipids, three unidentified lipids and one unidentified phospholipid. The G+C content of the genomic DNA was determined to be 49.1 mol%. The main fatty acids were summed feature 3 (comprising C16 : 1 ω7c/C16 : 1 ω6c), iso-C15 : 0, C16 : 1 ω5c and iso-C16 : 1 3-OH. On the basis of the evidence presented in this study, a novel species of the genus Dyadobacter , Dyadobacter sandarakinus sp. nov., is proposed, with the type strain Q3-56T (=CCTCC AB 2019271T=KCTC 72739T). Emended descriptions of Dyadobacter alkalitolerans , Dyadobacter koreensis and Dyadobacter psychrophilus are also provided.

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Lack of Correlation between Turnover of Low-Molecular-Weight Dissolved Organic Carbon and Differences in Microbial Community Composition or Growth across a Soil pH Gradient

Applied and Environmental Microbiology ◽

10.1128/aem.02870-10 ◽

2011 ◽

Vol 77 (8) ◽

pp. 2791-2795 ◽

Cited By ~ 31

Author(s):

Johannes Rousk ◽

Philip C. Brookes ◽

Helen C. Glanville ◽

David L. Jones

Keyword(s):

Molecular Weight ◽

Microbial Community ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Community Composition ◽

Soil Ph ◽

Predictive Power ◽

Microbial Community Composition ◽

Low Molecular Weight ◽

Soil C

ABSTRACTWe studied how soil pH (pHs 4 to 8) influenced the mineralization of low-molecular-weight (LMW)-dissolved organic carbon (DOC) compounds, and how this compared with differences in microbial community structure. The mineralization of LMW-DOC compounds was not systematically connected to differences in soil pH, consistent with soil respiration. In contrast, the microbial community compositions differed dramatically. This suggests that microbial community composition data will be of limited use in improving the predictive power of soil C models.

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