scholarly journals Discovery of a Modified Transcription Factor Endowing Yeasts with Organic-Solvent Tolerance and Reconstruction of an Organic-Solvent-Tolerant Saccharomyces cerevisiae Strain

2008 ◽  
Vol 74 (13) ◽  
pp. 4222-4225 ◽  
Author(s):  
Ken Matsui ◽  
Shinya Teranishi ◽  
Shohei Kamon ◽  
Kouichi Kuroda ◽  
Mitsuyoshi Ueda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factor ◽  
Organic Solvent ◽  
Carbonyl Compounds ◽  
Solvent Tolerance ◽  
Wild Type ◽  
Organic Solvent Tolerance ◽  
Organic Solvent Tolerant ◽  
Solvent Tolerant ◽  
Wild Type Yeast

ABSTRACT Organic-solvent tolerance in Saccharomyces cerevisiae strain KK-211, which was first isolated as an organic-solvent-tolerant strain, depends on point mutation (R821S) of the transcription factor Pdr1p. The integration of the PDR1 R821S mutation into wild-type yeast results in organic-solvent tolerance, and the PDR1 R821S mutant can reduce carbonyl compounds in organic solvents.

Organic solvent-tolerant mutants of Pseudomonas aeruginosa display multiple antibiotic resistance

1999 ◽  
Vol 45 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Xian-Zhi Li ◽  
Keith Poole
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Organic Solvent ◽  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Environmental Pollutants ◽  
Multidrug Resistant ◽  
Solvent Tolerance ◽  
Organic Solvent Tolerance ◽  
Organic Solvent Tolerant ◽  
Solvent Tolerant

Organic solvent-tolerant mutants of Pseudomonas aeruginosa selected in the presence of hexane exhibited increased resistance to a variety of structurally unrelated antimicrobial agents, including beta-lactams, fluoroquinolones, chloramphenicol, tetracycline, and novobiocin, a phenotype typical of nalB multidrug-resistant mutants. Western immunoblotting with antibodies specific to components of the three known multidrug efflux systems in P. aeruginosa demonstrated that the solvent-tolerant mutants displayed increased expression of the MexAB-OprM system and decreased expression of the MexEF-OprN system. Sequence analysis of mexR, the repressor gene of mexAB-oprM efflux operon, identified a nonsense mutation and a point mutation in the mexR genes of two solvent-tolerant mutants. These results emphasize the importance of the MexAB-OprM efflux system in organic solvent tolerance and the ability of environmental pollutants to select bacteria with a medically relevant antibiotic-resistant phenotype.Key words: Pseudomonas aeruginosa, organic solvent tolerance, multidrug resistance, MexAB-OprM efflux pump, mexR gene.

scholarly journals Duration of Outpatient Fecal Colonization Due to Escherichia coli Isolates with Decreased Susceptibility to Fluoroquinolones: Longitudinal Study of Patients Recently Discharged from the Hospital

2006 ◽  
Vol 50 (11) ◽  
pp. 3939-3943 ◽  
Author(s):  
Ebbing Lautenbach ◽  
Pam Tolomeo ◽  
Xiangqun Mao ◽  
Neil O. Fishman ◽  
Joshua P. Metlay ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Longitudinal Study ◽  
Organic Solvent ◽  
Hospital Discharge ◽  
Antibiotic Use ◽  
Resistance Mechanisms ◽  
Solvent Tolerance ◽  
Organic Solvent Tolerance ◽  
Organic Solvent Tolerant ◽  
Solvent Tolerant

ABSTRACT Among 10 subjects colonized with Escherichia coli isolates with reduced susceptibility to fluoroquinolones, the median duration of colonization following hospital discharge was 80 days (range, 8 to 172 days). Colonization was longer for isolates demonstrating organic-solvent tolerance than for isolates that were not organic-solvent tolerant (151 versus 29 days, respectively; P = 0.07) but was not associated with other resistance mechanisms, demographics, or antibiotic use.

ABC transporters and cell wall proteins involved in organic solvent tolerance in Saccharomyces cerevisiae

2013 ◽  
Vol 165 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Nao Nishida ◽  
Naoki Ozato ◽  
Ken Matsui ◽  
Kouichi Kuroda ◽  
Mitsuyoshi Ueda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Organic Solvent ◽  
Abc Transporters ◽  
Solvent Tolerance ◽  
Cell Wall Proteins ◽  
Organic Solvent Tolerance

scholarly journals Biochemical and Structural Characterization of Cross-Linked Enzyme Aggregates (CLEAs) of Organic Solvent Tolerant Protease

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 55 ◽  
Author(s):  
Muhammad Syafiq Mohd Razib ◽  
Raja Noor Zaliha Raja Abd Rahman ◽  
Fairolniza Mohd Shariff ◽  
Mohd Shukuri Mohamad Ali
Keyword(s):  
Structural Analysis ◽  
Organic Solvent ◽  
Average Diameter ◽  
Relative Activity ◽  
Biochemical Properties ◽  
Biochemical Interaction ◽  
Organic Solvent Tolerant ◽  
Random Aggregate ◽  
Solvent Tolerant ◽  
The Stability

Cross-linked enzyme aggregates (CLEAs) is an immobilization technique that can be used to customize enzymes under an optimized condition. Structural analysis on any enzyme treated with a CLEA remains elusive and has been less explored. In the present work, a method for preparing an organic solvent tolerant protease using a CLEA is disclosed and optimized for better biochemical properties, followed by an analysis of the structure of this CLEA-treated protease. The said organic solvent tolerant protease is a metalloprotease known as elastase strain K in which activity of the metalloprotease is measured by a biochemical interaction with azocasein. Results showed that when a glutaraldehyde of 0.02% (v/v) was used under a 2 h treatment, the amount of recovered activity in CLEA-elastase was highest. The recovered activity of CLEA-elastase and CLEA-elastase-SB (which was a CLEA co-aggregated with starch and bovine serum albumin (BSA)) were at an approximate 60% and 80%, respectively. The CLEA immobilization of elastase strain K allowed the stability of the enzyme to be enhanced at high temperature and at a broader pH. Both CLEA-elastase and CLEA-elastase-SB end-products were able to maintain up to 67% enzyme activity at 60 °C and exhibiting an enhanced stability within pH 5–9 with up to 90% recovering activity. By implementing a CLEA on the organic solvent tolerant protease, the characteristics of the organic solvent tolerant were preserved and enhanced with the presence of 25% (v/v) acetonitrile, ethanol, and benzene at 165%, 173%, and 153% relative activity. Structural analysis through SEM and dynamic light scattering (DLS) showed that CLEA-elastase had a random aggregate morphology with an average diameter of 1497 nm.

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