Methylmercury inhibits growth and induces membrane changes in Pseudomonas putida

Vodovnik, Maša (author), Bistan, Mirjana (author), Zorec, Maša (author), Marinšek-Logar, Romana (author)

A bacterial model system (Pseudomonas putida DSM 50026) was used in this research to assess toxicity of the environmentally relevant concentrations of mercury species (MeHg and Hg(II)) that represent important pollutants of aquatic ecosystems at sites of industrial or mining activities. In addition to direct monitoring of bacterial growth, we also analyzed fatty acid profiles of exposed and non-exposed cultures to determine possible toxic effects manifested on membrane level. The results showed that exposure of P. putida to Hg(II) in concentrations of 0.2-200 g/L did not have any significant effects on growth nor fatty acid composition of exposed bacterial culture. On the other hand, when bacteria were exposed to up to 1600-times lower concentrations of MeHg (0.12-12.5 g/L), growth inhibition as well as significant changes in fatty acid composition were detected. Observed adaptive membrane changes due to MeHg exposure were similar to those associated with responses to organic solvents and some other membrane-disrupting compounds.

• Language: English
• Keywords: micorbiology, environmental protection, bacteria, Pseudomonas putida, aquatic ecosystems, pollution, mercury, methylmercury, growth inhibition, membrane adaptation, cis-trans isomerization
• Work type: Not categorized
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Year: 2010
• Number of pages: Str. 87-93
• Numbering: Letn. 96, št. 2
• PID: 20.500.12556/RUL-15713
• UDC: 579
• ISSN on article: 1581-9175
• COBISS.SI-ID: 2792840
• Publication date in RUL: 11.07.2014

Record is a part of a journal

• Title: Acta agriculturae Slovenica
• Shortened title: Acta agric. Slov.
• Publisher: Biotehniška fakulteta
• ISSN: 1581-9175
• COBISS.SI-ID: 213840640

Secondary language

• Language: Slovenian

Abstract

V raziskavi smo na bakterijskem modelu (Pseudomonas putida DSM 50026) analizirali strupenost okoljskih koncentracij anorganske (Hg(II)) in organske (MeHg) oblike živega srebra, ki predstavljata pomembna vira onesnaenja vodnih ekosistemov v bliini nekaterih industrijskih in rudarskih območij. Poleg neposrednega spremljanja bakterijske rasti smo analizirali tudi maščobnokislinske profile izpostavljenih bakterijskih kultur in jih primerjali s tistimi, ki živosrebrovima spojinama niso bili izpostavljeni. Rezultati so pokazali, da izpostavitev P. putida Hg(II) v koncentracijah med 0,2 in 200 g/L ne inhibira rasti, niti ne vpliva na maščobnokislinsko sestavo bakterijskih membran. Nasprotno pa je izpostavitev celic do 1600-krat nižjim koncentracijam MeHg povzročila tako upočasnitev rasti kot tudi prilagoditvene spremembe na membranskem nivoju. Slednje so bile podobne kot tiste, opaene ob izpostavitvi bakterij organskim topilom in nekaterim drugim spojinam, ki motijo integriteto membran.

• Keywords: mikrobiologija, varstvo okolja, bakterije, Pseudomonas putida, vodni ekosistemi, onesnaževanje, živo srebro, metil živo srebro, inhibicija rasti, membranska adaptacija, cis-trans izomerizacija