scholarly journals Comparative Proteomics of Marinobacter sp. TT1 Reveals Corexit Impacts on Hydrocarbon Metabolism, Chemotactic Motility, and Biofilm Formation

2020 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Saskia Rughöft ◽  
Nico Jehmlich ◽  
Tony Gutierrez ◽  
Sara Kleindienst

The application of chemical dispersants during marine oil spills can affect the community composition and activity of marine microorganisms. Several studies have indicated that certain marine hydrocarbon-degrading bacteria, such as Marinobacter spp., can be inhibited by chemical dispersants, resulting in lower abundances and/or reduced biodegradation rates. However, a major knowledge gap exists regarding the mechanisms underlying these physiological effects. Here, we performed comparative proteomics of the Deepwater Horizon isolate Marinobacter sp. TT1 grown under different conditions. Strain TT1 received different carbon sources (pyruvate vs. n-hexadecane) with and without added dispersant (Corexit EC9500A). Additional treatments contained crude oil in the form of a water-accommodated fraction (WAF) or chemically-enhanced WAF (CEWAF; with Corexit). For the first time, we identified the proteins associated with alkane metabolism and alginate biosynthesis in strain TT1, report on its potential for aromatic hydrocarbon biodegradation and present a protein-based proposed metabolism of Corexit components as carbon substrates. Our findings revealed that Corexit exposure affects hydrocarbon metabolism, chemotactic motility, biofilm formation, and induces solvent tolerance mechanisms, like efflux pumps, in strain TT1. This study provides novel insights into dispersant impacts on microbial hydrocarbon degraders that should be taken into consideration for future oil spill response actions.

2021 ◽  
Vol 9 (6) ◽  
pp. 1200
Author(s):  
Gareth E. Thomas ◽  
Jan L. Brant ◽  
Pablo Campo ◽  
Dave R. Clark ◽  
Frederic Coulon ◽  
...  

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zulfa Al Disi ◽  
Samir Jaoua ◽  
Dhabia Al-Thani ◽  
Saeed Al-Meer ◽  
Nabil Zouari

Weathering processes change properties and composition of spilled oil, representing the main reason of failure of bioaugmentation strategies. Our purpose was to investigate the metabolic adaptation of hydrocarbon-degrading bacteria at harsh conditions to be considered to overcome the limitations of bioaugmentation strategies at harsh conditions. Polluted soils, exposed for prolonged periods to weathered oil in harsh soils and weather conditions, were used. Two types of enrichment cultures were employed using 5% and 10% oil or diesel as sole carbon sources with varying the mineral nitrogen sources and C/N ratios. The most effective isolates were obtained based on growth, tolerance to toxicity, and removal efficiency of diesel hydrocarbons. Activities of the newly isolated bacteria, in relation to the microenvironment from where they were isoalted and their interaction with the weathered oil, showed individual specific ability to adapt when exposed to such factors, to acquire metabolic potentialities. Among 39 isolates, ten identified ones by 16S rDNA genes similarities, including special two Pseudomonas isolates and one Citrobacter isolate, showed particularity of shifting hydrocarbon-degrading ability from short chain n-alkanes (n-C12–n-C16) to longer chain n-alkanes (n-C21–n-C25) and vice versa by alternating nitrogen source compositions and C/N ratios. This is shown for the first time.


2008 ◽  
Vol 2008 (1) ◽  
pp. 537-539
Author(s):  
Seungjoon Chung ◽  
Jaclyn Gandee ◽  
Makram T. Suidan ◽  
Albert D. Venosa

ABSTRACT Oil spill cleanup in wetlands is problematic because of the limited remediation techniques that can be applied in such environments. The use of sorbents to clean up oil spills presents many advantages due to simplicity of approach and the inexpensive nature of these materials. Furthermore, sorbents can be used not only as wicking agents but also as microbial media that mediate hydrocarbon biodegradation. Once a sorbent is applied to an impacted wetland, it absorbs the contaminating oil. It retains the oil for a sufficient length of time to allow biodegradation of hydrocarbons by indigenous bacteria under aerobic conditions. In addition, plant-derived organic sorbents are biodegradable, thus leaving no permanent residue. Ammoniated bagasse is one of the biodegradable organic sorbents that contain nitrogen as a nutrient needed to support the activity of oil degrading bacteria. In this study, we evaluated the effectiveness of sorbents in wicking oil from the subsurface of oil-contaminated sediments under various conditions. Several microcosms were prepared to simulate saturated wetland environments. Glass cylinders, 10 cm in diameter and 10 cm in height, enclosed these microcosms. Each microcosm was layered in the following sequence (from the bottom to the top): a clean sand layer, an oiled-sand layer, and an overlying sorbent layer. Sand, sorbent, and water were sterilized prior to use to ensure that no biodegradation occurs during the experiment. The different conditions included: 2 particle sizes of sand (20 × 30 and 60 × 80 U.S. Mesh), 2 levels of oil contamination (25% and 75% of saturation), 3 water levels (at the oiled-layer/clean sand interface, at the oiled-layer/sorbent-layer interface, and at the sorbent-layer/air interface), and 2 levels of sorbent (presence or absence). Oil wicking experiments were performed in airtight microcosms for a period of 3 months. At the termination of an experiment, each layer of the microcosms was separated and samples were taken. Samples were extracted with dichloromethane and quantified by gas chromatography/mass spectrometry (GC-MS). Mass balances in each microcosm were established in terms of total petroleum hydrocarbons (TPH). TPH includes alkanes (C10-C35); pristane; phytane; hopane; 2-, 3-, and 4-ring PAHs; and pyrogenic PAHs (5- & 6-rings). The TPH change in each layer from time zero to 3 months was used to determine the effectiveness of the sorbent under each condition tested.


Author(s):  
Alexander Ermolov ◽  
Alexander Ermolov

International experience of oil spill response in the sea defines the priority of coastal protection and the need to identify as most valuable in ecological terms and the most vulnerable areas. Methodological approaches to the assessing the vulnerability of Arctic coasts to oil spills based on international systems of Environmental Sensitivity Index (ESI) and geomorphological zoning are considered in the article. The comprehensive environmental and geomorphological approach allowed us to form the morphodynamic basis for the classification of seacoasts and try to adapt the international system of indexes to the shores of the Kara Sea taking into account the specific natural conditions. This work has improved the expert assessments of the vulnerability and resilience of the seacoasts.


2021 ◽  
Vol 13 (12) ◽  
pp. 6585
Author(s):  
Mihhail Fetissov ◽  
Robert Aps ◽  
Floris Goerlandt ◽  
Holger Jänes ◽  
Jonne Kotta ◽  
...  

The Baltic Sea is a unique and sensitive brackish-water ecosystem vulnerable to damage from shipping activities. Despite high levels of maritime safety in the area, there is a continued risk of oil spills and associated harmful environmental impacts. Achieving common situational awareness between oil spill response decision makers and other actors, such as merchant vessel and Vessel Traffic Service center operators, is an important step to minimizing detrimental effects. This paper presents the Next-Generation Smart Response Web (NG-SRW), a web-based application to aid decision making concerning oil spill response. This tool aims to provide, dynamically and interactively, relevant information on oil spills. By integrating the analysis and visualization of dynamic spill features with the sensitivity of environmental elements and value of human uses, the benefits of potential response actions can be compared, helping to develop an appropriate response strategy. The oil spill process simulation enables the response authorities to judge better the complexity and dynamic behavior of the systems and processes behind the potential environmental impact assessment and thereby better control the oil combat action.


2021 ◽  
Vol 14 (5) ◽  
pp. 414
Author(s):  
Neda Aničić ◽  
Uroš Gašić ◽  
Feng Lu ◽  
Ana Ćirić ◽  
Marija Ivanov ◽  
...  

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.


2020 ◽  
Vol 8 (3) ◽  
pp. 344 ◽  
Author(s):  
Urška Ribič ◽  
Jernej Jakše ◽  
Nataša Toplak ◽  
Simon Koren ◽  
Minka Kovač ◽  
...  

Staphylococcus epidermidis cleanroom strains are often exposed to sub-inhibitory concentrations of disinfectants, including didecyldimethylammonium chloride (DDAC). Consequently, they can adapt or even become tolerant to them. RNA-sequencing was used to investigate adaptation and tolerance mechanisms of S. epidermidis cleanroom strains (SE11, SE18), with S. epidermidis SE11Ad adapted and S. epidermidis SE18To tolerant to DDAC. Adaptation to DDAC was identified with up-regulation of genes mainly involved in transport (thioredoxin reductase [pstS], the arsenic efflux pump [gene ID, SE0334], sugar phosphate antiporter [uhpT]), while down-regulation was seen for the Agr system (agrA, arC, agrD, psm, SE1543), for enhanced biofilm formation. Tolerance to DDAC revealed the up-regulation of genes associated with transporters (L-cysteine transport [tcyB]; uracil permease [SE0875]; multidrug transporter [lmrP]; arsenic efflux pump [arsB]); the down-regulation of genes involved in amino-acid biosynthesis (lysine [dapE]; histidine [hisA]; methionine [metC]), and an enzyme involved in peptidoglycan, and therefore cell wall modifications (alanine racemase [SE1079]). We show for the first time the differentially expressed genes in DDAC-adapted and DDAC-tolerant S. epidermidis strains, which highlight the complexity of the responses through the involvement of different mechanisms.


2021 ◽  
pp. 117424
Author(s):  
Ali Akbari ◽  
Carolyn David ◽  
Arshath Abdul Rahim ◽  
Subhasis Ghoshal

2013 ◽  
Vol 1498 ◽  
pp. 73-78 ◽  
Author(s):  
N. Gozde Durmus ◽  
Erik N. Taylor ◽  
Kim M. Kummer ◽  
Thomas J. Webster

ABSTRACTBiofilms are a major source of medical device-associated infections, due to their persistent growth and antibiotic resistance. Recent studies have shown that engineering surface nanoroughness has great potential to create antibacterial surfaces. In addition, stimulation of bacterial metabolism increases the efficacy of antibacterial agents to eradicate biofilms. In this study, we combined the antibacterial effects of nanorough topographies with metabolic stimulation (i.e., fructose metabolites) to further decrease bacterial growth on polyvinyl chloride (PVC) surfaces, without using antibiotics. We showed for the first time that the presence of fructose on nanorough PVC surfaces decreased planktonic bacteria growth and biofilm formation after 24 hours. Most importantly, a 60% decrease was observed on nanorough PVC surfaces soaked in a 10 mM fructose solution compared to conventional PVC surfaces. In this manner, this study demonstrated that bacteria growth can be significantly decreased through the combined use of fructose and nanorough surfaces and thus should be further studied for a wide range of antibacterial applications.


2021 ◽  
Vol 9 (10) ◽  
pp. 6423-6431
Author(s):  
Xieji Lin ◽  
Yue Dong ◽  
Xiaohong Chen ◽  
Haiyan Liu ◽  
Zhaobin Liu ◽  
...  

It is the first time that metallasilsesquioxanes are introduced into the synthesis of porous carbon nanosheets. Lithium hepta(i-butyl)silsesquioxane trisilanolate is a multifunctional precursor for both carbon sources and templates with different dimensions.


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