A comparison of the response of twoBurkholderia fungorumstrains grown as planktonic cells versus biofilm to dibenzothiophene and select polycyclic aromatic hydrocarbons

2016 ◽  
Vol 62 (10) ◽  
pp. 851-860 ◽  
Author(s):  
Nazanin Seyed Khoei ◽  
Marco Andreolli ◽  
Silvia Lampis ◽  
Giovanni Vallini ◽  
Raymond J. Turner
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Laser Scanning ◽  
Living Cells ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Planktonic Cells ◽  
Free Living ◽  
Polycyclic Aromatic ◽  
High Concentrations

In natural environments, bacteria often exist in close association with surfaces and interfaces by establishing biofilms. Here, we report on the ability of Burkholderia fungorum strains DBT1 and 95 to survive in high concentrations of hydrocarbons, and we compare their growth as a biofilm vs. planktonic cells. The 2 compounds tested were dibenzothiophene (DBT) and a mixture of naphthalene, phenanthrene, and pyrene (5:2:1) as representative compounds of thiophenes and polycyclic aromatic hydrocarbons (PAHs), respectively. The results showed that both strains were able to degrade DBT and to survive in the presence of up to a 2000 mg·L−1concentration of this compound both as a biofilm and as free-living cells. Moreover, B. fungorum DBT1 showed reduced tolerance towards the mixed PAHs (2000 mg·L−1naphthalene, 800 mg·L−1phenanthrene, and 400 mg·L−1pyrene) both as a biofilm and as free-living cells. Conversely, biofilms of B. fungorum 95 enhanced resistance against these toxic compounds compared with planktonic cells (P < 0.05). Visual observation through confocal laser scanning microscopy showed that exposure of biofilms to DBT and PAHs altered their structure: high concentrations of DBT triggered an aggregation of biofilm cells. These findings provide new perspectives on the effectiveness of using DBT-degrading bacterial strains in bioremediation of hydrocarbon-contaminated sites.

scholarly journals Residues of Persistent Organic Pollutants (POPs) in Agricultural Soils Adjacent to Historical Sources of Their Storage and Distribution—The Case Study of Azerbaijan

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1815 ◽  
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Karolina Lewińska ◽  
Elton Mammadov ◽  
Anna Karczewska ◽  
Bożena Smreczak ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Environmental Protection Agency ◽  
Agricultural Soils ◽  
The United States ◽  
Natural Soil ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Total Concentrations

The aim of this study was to identify and examine the levels of organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) in soil collected from the surroundings of historical pesticide storage facilities on former agricultural aerodromes, warehouses, and pesticide distribution sites located in the most important agricultural regions in Azerbaijan. The conducted research included determination of three groups of POPs (occurring together), in the natural soil environment influenced for many years by abiotic and biotic factors that could have caused their transformations or decomposition. In this study, soil samples were collected in 21 georeferenced points located in the administrative area of Bilasuvar, Saatly, Sabirabad, Salyan and Jalilabad districts of Azerbaijan. Soil chemical analysis involved determination of organochlorine compounds (OCP): hexachlorocyclohexanes (HCHs) (three isomers α-HCH, β-HCH and γ-HCH) and dichlorodiphenyltrichloroethanes (DDTs) (six congeners 2,4′DDT; 4,4′DDT; 2,4′DDE; 4,4′DDE; 2,4′DDE; and 4,4′DDE); polycyclic aromatic hydrocarbons (PAHs): 16 compounds from the United States Environmental Protection Agency US EPA list and, PCBs (seven congeners identified with the following IUPAC numbers: 28, 52, 101, 118, 138, 153, and 180). Our research showed that OCPs reached the highest concentration in the studied areas. The total concentrations of OCPs ranged from 0.01 to 21,888 mg∙kg−1 with significantly higher concentrations of Σ6DDTs (0.01 μg kg−1 to 21880 mg kg−1) compared to ΣHCH (0.14 ng kg−1 to 166.72 µg kg−1). The total concentrations of PCBs in the studied soils was varied from 0.02 to 147.30 μg·kg−1 but only PCB138 and PCB180 were detected in all analyzed samples. The concentrations of Σ16 PAHs were also strongly diversified throughout the sampling areas and ranged from 0.15 to 16,026 mg kg−1. The obtained results confirmed that the agricultural soils of Azerbaijan contained much lower (up to by three orders of magnitude) concentrations of PCBs and PAHs than DDT. It is supported by the fact that PCBs and PAHs were not directly used by agriculture sector and their content results from secondary sources, such as combustion and various industrial processes. Moreover, the high concentrations of PAHs in studied soils were associated with their location in direct neighborhood of the airport, as well as with accumulation of contaminants from dispersed sources and long range transport. The high concentrations of pesticides confirm that deposition of parent OCPs have occurred from obsolete pesticide landfills.

Farnesol inhibits planktonic cells and antifungal-tolerant biofilms of Trichosporon asahii and Trichosporon inkin

2019 ◽  
Vol 57 (8) ◽  
pp. 1038-1045 ◽  
Author(s):  
Rossana de Aguiar Cordeiro ◽  
Lívia Maria Galdino Pereira ◽  
José Kleybson de Sousa ◽  
Rosana Serpa ◽  
Ana Raquel Colares Andrade ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Inhibitory Effect ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Planktonic Cells ◽  
Trichosporon Asahii ◽  
Trichosporon Species ◽  
Biofilm Development ◽  
Systemic Infections

Abstract Trichosporon species have been considered important agents of opportunistic systemic infections, mainly among immunocompromised patients. Infections by Trichosporon spp. are generally associated with biofilm formation in invasive medical devices. These communities are resistant to therapeutic antifungals, and therefore the search for anti-biofilm molecules is necessary. This study evaluated the inhibitory effect of farnesol against planktonic and sessile cells of clinical Trichosporon asahii (n = 3) andTrichosporon inkin (n = 7) strains. Biofilms were evaluated during adhesion, development stages and after maturation for metabolic activity, biomass and protease activity, as well as regarding morphology and ultrastructure by optical microscopy, confocal laser scanning microscopy, and scanning electron microscopy. Farnesol inhibited Trichosporon planktonic growth by 80% at concentrations ranging from 600 to 1200 μM for T. asahii and from 75 to 600 μM for T. inkin. Farnesol was able to reduce cell adhesion by 80% at 300 μM for T. asahii and T. inkin at 600 μM, while biofilm development of both species was inhibited by 80% at concentration of 150 μM, altering their structure. After biofilm maturation, farnesol decreased T. asahii biofilm formation by 50% at 600 μM concentration and T. inkin formation at 300 μM. Farnesol inhibited gradual filamentation in a concentration range between 600 and 1200 μM. Farnesol caused reduction of filament structures of Trichosporon spp. at every stage of biofilm development analyzed. These data show the potential of farnesol as an anti-biofilm molecule.

Distribution of polycyclic aromatic hydrocarbons in snow particulates around Longyearbyen and Barentsburg settlements, Spitsbergen

Polar Record ◽  
2016 ◽  
Vol 52 (6) ◽  
pp. 645-659 ◽  
Author(s):  
Anna Abramova ◽  
Sergei Chernianskii ◽  
Nataly Marchenko ◽  
Elena Terskaya
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Snow Cover ◽  
Aromatic Hydrocarbons ◽  
Airborne Particulate Matter ◽  
Svalbard Archipelago ◽  
Wide Range ◽  
Polycyclic Aromatic ◽  
High Concentrations ◽  
Snow Mass ◽  
Southwest Part

ABSTRACTContamination of snow cover has been investigated in the Longyearbyen (78°13 N, 15°38 E) and Barentsburg (78°3 N, 14°12 E) areas, which are situated in the southwest part of Spitsbergen (Svalbard archipelago). Snow cover was sampled in two winter seasons, 2012–2013 and 2013–2014, at 54 locations within potentially contaminated areas. Sampling incorporated the whole snow mass and was combined with morphological observations as well as thickness and density measurements. Meltwater and suspended solids were further analysed for a wide range of contaminants including polycyclic aromatic hydrocarbons (PAHs) and macro-ions. Results were contrasted with previous studies measuring the release of contaminants from snow to soil cover. It was shown in keeping with earlier studies that PAH contributions are associated with airborne particulate matter. The results, in contrast to earlier studies further demonstrated that the high concentrations of contaminants in both settlements are attributed to local sources due to combustion and industrial activity.

scholarly journals Temperature-Regulated Formation of Mycelial Mat-Like Biofilms by Legionella pneumophila

2006 ◽  
Vol 72 (2) ◽  
pp. 1613-1622 ◽  
Author(s):  
Zhenyu Piao ◽  
Chun Chau Sze ◽  
Oksana Barysheva ◽  
Ken-ichiro Iida ◽  
Shin-ichi Yoshida
Keyword(s):  
Legionella Pneumophila ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
C Cells ◽  
Planktonic Cells ◽  
Legionnaires Disease ◽  
Novel Strategy ◽  
Glass Surfaces

ABSTRACT Fifty strains representing 38 species of the genus Legionella were examined for biofilm formation on glass, polystyrene, and polypropylene surfaces in static cultures at 25°C, 37°C, and 42°C. Strains of Legionella pneumophila, the most common causative agent of Legionnaires' disease, were found to have the highest ability to form biofilms among the test strains. The quantity, rate of formation, and adherence stability of L. pneumophila biofilms showed considerable dependence on both temperature and surface material. Glass and polystyrene surfaces gave between two- to sevenfold-higher yields of biofilms at 37°C or 42°C than at 25°C; conversely, polypropylene surface had between 2 to 16 times higher yields at 25°C than at 37°C or 42°C. On glass surfaces, the biofilms were formed faster but attached less stably at 37°C or 42°C than at 25°C. Both scanning electron microscopy and confocal laser scanning microscopy revealed that biofilms formed at 37°C or 42°C were mycelial mat like and were composed of filamentous cells, while at 25°C, cells were rod shaped. Planktonic cells outside of biofilms or in shaken liquid cultures were rod shaped. Notably, the filamentous cells were found to be multinucleate and lacking septa, but a recA null mutant of L. pneumophila was unaffected in its temperature-regulated filamentation within biofilms. Our data also showed that filamentous cells were able to rapidly give rise to a large number of short rods in a fresh liquid culture at 37°C. The possibility of this biofilm to represent a novel strategy by L. pneumophila to compete for proliferation among the environmental microbiota is discussed.

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