Growth of Escherichia coli, Pichia pastoris and Bacillus cereus in the Presence of the Ionic Liquids [BMIM][BF4] and [BMIM][PF6] and Organic Solvents

Abstract

The influence of the two most commonly used ionic liquids (1-butyl-3-methyl imidazolium tetrafluoroborate, [BMIM][BF(4)], 1-butyl-3-methyl imidazolium hexafluorophosphate, [BMIM][PF(6)]) and three selected organic solvents (dimethylsulfoxide, ethanol, methanol) on the growth of Escherichia coli, Pichia pastoris and Bacillus cereus was investigated. [BMIM][BF(4)] was toxic at 1% (v/v) on all three microorganisms. The minimal inhibitory concentration (MIC) of [BMIM][BF(4)] on E. coli growth was between 0.7 and 1% (v/v). In contrast, [BMIM][PF(6)] was less toxic for P. pastoris and B. cereus, whereas E. coli was not able to tolerate [BMIM][PF(6)] (MIC value: 0.3-0.7% v/v). Growth of P. pastoris was unaffected by [BMIM][PF(6)] at 10% (v/v). Similar results were found for dimethylsulfoxide. Thus, ionic liquids (ILs) can have substantial inhibitory effects on the growth of microorganisms, which should be taken into account for environmental reasons as well as for the use of ILs as co-solvents in biotransformations.

Antimicrobial properties and thermal stability of polycarbonate modified with 1‐alkyl‐3‐methylimidazolium tetrafluoroborate ionic liquids

“…20 Thus, it was found that both ILs have substantial inhibitory effects on the growth of E. coli bacteria. The minimal inhibitory concentrations of the said ILs on E. coli growth was between 0.7 and 1% (v/v), whereas no further bacterial growth was observed in the presence of 4% (v/v) of IL.…”

“…The minimal inhibitory concentrations of the said ILs on E. coli growth was between 0.7 and 1% (v/v), whereas no further bacterial growth was observed in the presence of 4% (v/v) of IL. 20 Although 1-butyl-3-methyl imidazolium hexafluorophosphate is water immiscible, thorough shaking of the culture ensured direct contact of the bacterial cells and IL. It should also be noted that polyesters (PET, PBT) internally modified with imidazolim ILs showed pronounced antibacterial activity at low ILs content (2%).…”

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

“…The toxicity of certain ILs can also inhibit enzymatic activity of microorganisms due to accumulation in cell membranes (Matsumoto et al 2004;Pham et al 2010;Romero et al 2008). Some ILs also have been shown to inhibit cell growth and cell viability for various microorganisms (Ganske and Bornscheuer 2006;Jing et al 2014;Pernak et al 2003;Pfruender et al 2006;Sendovski et al 2010). Many challenges associated with IL toxicity must be overcome before ILs can be utilized at the commercial scale (Egorova and Ananikov 2014).…”

Application of a Recombinant Escherichia coli Whole‐Cell Catalyst Expressing Hydroxynitrile Lyase and Nitrilase Activities in Ionic Liquids for the Production of (S)‐Mandelic Acid and (S)‐Mandeloamide

“…Several reports described that growth of E. coli is severely impaired in the presence of even low concentrations of ionic liquids and that many ionic liquids even possess an antimicrobial activity. [8,12,13] On the other hand, it was shown by Pfruender et al (2006) that in a resting cell situation even the addition of 20% (v/v) of Bmim PF 6 for 5 h had no detrimental effect on the survival of the cells and that this (and other) ionic liquid(s) exhibited complete biocompatibility. [9] There are also only very few publications which described the utilisation of recombinant E. coli strains for biotransformation reactions in the presence of ionic liquids.…”