Microbiological Survey in Two Arctic Fjords: Total Bacterial Number and Biomass Comparison of Hornsund and Kongsfjorden

2015 ◽  
pp. 115-126 ◽  
Author(s):  
Agnieszka Kalinowska ◽  
Anetta Ameryk ◽  
Katarzyna Jankowska
Keyword(s):  
Bacterial Number ◽  
Total Bacterial Number ◽  
Arctic Fjords

scholarly journals A model-based analysis identifies differences in phenotypic resistance between in vitro and in vivo: implications for translational medicine within tuberculosis

2020 ◽  
Vol 47 (5) ◽  
pp. 421-430
Author(s):  
Oskar Clewe ◽  
Alan Faraj ◽  
Yanmin Hu ◽  
Anthony R. M. Coates ◽  
Ulrika S. H. Simonsson
Keyword(s):  
Drug Effect ◽  
Drug Effects ◽  
Bacterial Number ◽  
Natural Growth ◽  
In Vivo Models ◽  
Phenotypic Resistance ◽  
Total Bacterial Number

Abstract Proper characterization of drug effects on Mycobacterium tuberculosis relies on the characterization of phenotypically resistant bacteria to correctly establish exposure–response relationships. The aim of this work was to evaluate the potential difference in phenotypic resistance in in vitro compared to murine in vivo models using CFU data alone or CFU together with most probable number (MPN) data following resuscitation with culture supernatant. Predictions of in vitro and in vivo phenotypic resistance i.e. persisters, using the Multistate Tuberculosis Pharmacometric (MTP) model framework was evaluated based on bacterial cultures grown with and without drug exposure using CFU alone or CFU plus MPN data. Phenotypic resistance and total bacterial number in in vitro natural growth observations, i.e. without drug, was well predicted by the MTP model using only CFU data. Capturing the murine in vivo total bacterial number and persisters during natural growth did however require re-estimation of model parameter using both the CFU and MPN observations implying that the ratio of persisters to total bacterial burden is different in vitro compared to murine in vivo. The evaluation of the in vitro rifampicin drug effect revealed that higher resolution in the persister drug effect was seen using CFU and MPN compared to CFU alone although drug effects on the other bacterial populations were well predicted using only CFU data. The ratio of persistent bacteria to total bacteria was predicted to be different between in vitro and murine in vivo. This difference could have implications for subsequent translational efforts in tuberculosis drug development.

scholarly journals Large Fraction of Dead and Inactive Bacteria in Coastal Marine Sediments: Comparison of Protocols for Determination and Ecological Significance

2002 ◽  
Vol 68 (7) ◽  
pp. 3509-3513 ◽  
Author(s):  
G. M. Luna ◽  
E. Manini ◽  
R. Danovaro
Keyword(s):  
Marine Sediments ◽  
Nutrient Enrichment ◽  
Large Fraction ◽  
Bacterial Number ◽  
Bacterial Cells ◽  
Turnover Rates ◽  
Bacterial Counts ◽  
Total Bacterial Number ◽  
Cell Counts ◽  
Active Bacteria

ABSTRACT It is now universally recognized that only a portion of aquatic bacteria is actively growing, but quantitative information on the fraction of living versus dormant or dead bacteria in marine sediments is completely lacking. We compared different protocols for the determination of the dead, dormant, and active bacterial fractions in two different marine sediments and at different depths into the sediment core. Bacterial counts ranged between (1.5 ± 0.2) × 108 cells g−1 and (53.1 ± 16.0) × 108 cells g−1 in sandy and muddy sediments, respectively. Bacteria displaying intact membrane (live bacterial cells) accounted for 26 to 30% of total bacterial counts, while dead cells represented the most abundant fraction (70 to 74%). Among living bacterial cells, nucleoid-containing cells represented only 4% of total bacterial counts, indicating that only a very limited fraction of bacterial assemblage was actively growing. Nucleoid-containing cells increased with increasing sediment organic content. The number of bacteria responsive to antibiotic treatment (direct viable count; range, 0.3 to 4.8% of the total bacterial number) was significantly lower than nucleoid-containing cell counts. An experiment of nutrient enrichment to stimulate a response of the dormant bacterial fraction determined a significant increase of nucleoid-containing cells. After nutrient enrichment, a large fraction of dormant bacteria (6 to 11% of the total bacterial number) was “reactivated.” Bacterial turnover rates estimated ranged from 0.01 to 0.1 day−1 but were 50 to 80 times higher when only the fraction of active bacteria was considered (on average 3.2 day−1). Our results suggest that the fraction of active bacteria in marine sediments is controlled by nutrient supply and availability and that their turnover rates are at least 1 order of magnitude higher than previously reported.

scholarly journals Total bacterial number concentration in free tropospheric air above the Alps

Aerobiologia ◽  
2012 ◽  
Vol 29 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Y. Xia ◽  
F. Conen ◽  
C. Alewell
Keyword(s):  
Number Concentration ◽  
Bacterial Number ◽  
Total Bacterial Number ◽  
The Alps

scholarly journals Spectral Characterization of Dissolved Organic Matter in Seawater and Sediment Pore Water from the Arctic Fjords (West Svalbard) in Summer

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 202
Author(s):  
Meilian Chen ◽  
Ji-Hoon Kim ◽  
Sungwook Hong ◽  
Yun Kyung Lee ◽  
Moo Hee Kang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pore Water ◽  
Phytoplankton Bloom ◽  
Ocean Surface ◽  
The Arctic ◽  
Sediment Pore Water ◽  
Ice Edge ◽  
Accumulation Trend ◽  
Arctic Fjords

Fjords in the high Arctic, as aquatic critical zones at the interface of land-ocean continuum, are undergoing rapid changes due to glacier retreat and climate warming. Yet, little is known about the biogeochemical processes in the Arctic fjords. We measured the nutrients and the optical properties of dissolved organic matter (DOM) in both seawater and sediment pore water, along with the remote sensing data of the ocean surface, from three West Svalbard fjords. A cross-fjord comparison of fluorescence fingerprints together with downcore trends of salinity, Cl−, and PO43− revealed higher impact of terrestrial inputs (fluorescence index: ~1.2–1.5 in seawaters) and glaciofluvial runoffs (salinity: ~31.4 ± 2.4 psu in pore waters) to the southern fjord of Hornsund as compared to the northern fjords of Isfjorden and Van Mijenfjorden, tallying with heavier annual runoff to the southern fjord of Hornsund. Extremely high levels of protein-like fluorescence (up to ~4.5 RU) were observed at the partially sea ice-covered fjords in summer, in line with near-ubiquity ice-edge blooms observed in the Arctic. The results reflect an ongoing or post-phytoplankton bloom, which is also supported by the higher levels of chlorophyll a fluorescence at the ocean surface, the very high apparent oxygen utilization through the water column, and the nutrient drawdown at the ocean surface. Meanwhile, a characteristic elongated fluorescence fingerprint was observed in the fjords, presumably produced by ice-edge blooms in the Arctic ecosystems. Furthermore, alkalinity and the humic-like peaks showed a general downcore accumulation trend, which implies the production of humic-like DOM via a biological pathway also in the glaciomarine sediments from the Arctic fjords.

PCBs, HCB and PAHs in the seawater of Arctic fjords – Distribution, sources and risk assessment

2021 ◽  
Vol 164 ◽  
pp. 111980
Author(s):  
Anna Pouch ◽  
Agata Zaborska ◽  
Mikołaj Mazurkiewicz ◽  
Aleksandra Winogradow ◽  
Ksenia Pazdro
Keyword(s):  
Risk Assessment ◽  
Arctic Fjords

Nematode biomass and morphometric attributes as biological indicators of local environmental conditions in Arctic fjords

2016 ◽  
Vol 69 ◽  
pp. 368-380 ◽  
Author(s):  
Katarzyna Grzelak ◽  
Marta Gluchowska ◽  
Klaudia Gregorczyk ◽  
Aleksandra Winogradow ◽  
Jan Marcin Weslawski
Keyword(s):  
Environmental Conditions ◽  
Biological Indicators ◽  
Arctic Fjords

scholarly journals Producing Drink like Grafted Milk from Chickpeas and Evaluation of its Qualitative Properties

2020 ◽  
Vol 10 (03) ◽  
pp. 374-377
Author(s):  
Ibtihal Ismail Muhammad Al-Ani
Keyword(s):  
Room Temperature ◽  
Extraction Efficiency ◽  
Ph Value ◽  
Bacterial Number ◽  
Qualitative Properties ◽  
Product Density ◽  
Ph Values ◽  
Extraction Volume ◽  
Refrigerator Temperature ◽  
Soda Solution

The present study aimed to study the possibility of producing a drink that looks like grafted milk by using chickpeas and evaluate its physical, chemical, microbial, and sensory properties. The result showed the superiority of F treatment (soaking 100 grams of chickpeas at the refrigerator temperature 4ºC for 12 hours) over the rest seven treatments in extraction efficiency, which was 70%, while, it was 50.5% in H treatment (soaking 100 grams of chickpeas in the heated water at 60ºC for 30 minutes). The highest value of the product density was after water and flavorings addition in the D treatment (soaking 100 grams chickpeas in 0.05 soda solution at 60ºC for 30 minutes), and it was 0.97 g cm-3, compared with the lowest density 0.57 g cm-3 in A treatment (soaking 100 grams chickpeas in 0.05 soda solution at room temperature 25ºC for 12 hours). pH values were highest in A treatment compared with the other treatments, and its value was 7.66 in the 1st and 2nd day, after dissolving in a refrigerator at 4ºC, and then, for 5 minutes at room temperature 30ºC. The lowest value in the D treatment was 6.45 on the 1st day, and 6.87 on the 2nd day in the G treatment. On the 3rd day, the highest pH value was 7.13 in the D treatment, and the lowest value 6.79 was in the E treatment. pH highest value was 6.2 on the 4th day in A treatment. From the last results, it may be concluded that F treatment was the best in extraction efficiency, the final product density, and less total bacterial number, after dissolving for 5 days at refrigerator temperature 4ºC, and then, at room temperature 30ºC for 3 and 48 hours incubation. The best extraction volume and pH were in A treatment.

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