Gabriel Costa

Evaluation of antimicrobial properties

of MAG

09/11/2009

IntroductionAimMethodsResultsProblemsConclusionAcknowledgments

Out

line

Introduction

IntroductionMonoacylglycerols

CARACHTERISTICS• Partial esters of glycerol • Non-ionic surface-active compounds• Biodegradability

APPLICATION• Food, cosmetic, textile, plastic industry, etc.

PREPARATION• Interesterification• Hydrolysis of triacylglycerols• Fatty acid addition to glycidol

IntroductionNisin

CARACHTERISTICS• Polycyclic peptide antibacterial with 34 aminoacids• Rare example of a broad-spectrum bacteriocin (effective against gram positives and gram negatives)

APPLICATION• Food industry as food preservative

PREPARATION• Fermentation using Lactococcus lactis

Aim

Evaluate antimicrobial effect of monoacylglycerol

Lauric acid Palmitic acidAdamantanecarboxylic

acid

Aim

Nisin

Evaluate of antimicrobial effect of monoacylglycerol

Lauric acid Palmitic acidAdamantanecarboxylic

acid

Aim

Nisin

MAG A

Methods

Glycidol acid:glycidol (1:1,8)

1-Adamantanecarboxylic acid +

toluene (8ml per 1 gram)

Lauric acid or

palmitic acid

glass reactor with a temperature-stabilized jacket

Purification and Filtration

96 ⁰C 30 minutes

MethodsPreparation of MAG

Solvent system Non-solvent system

Chromium (III) acetate hydroxide0,5% w/w

96 ⁰C 30 minutes

96 ⁰C 120 minutes

MethodsAntimicrobial assay

Salmonella enterica ssp. Enterica ser. Enteritidis CCM 4420

Micrococcus luteus CCM 732

Gram +

1. Bacillus subtilis2. Staphylococcus aureus3. Bacillus cereus4. Micrococcus luteus5. Enterococcus Faecalis

Gram -

1. Escherichia coli2. Citrobacter freundii3. Serratia marcescens4. Salmonella enterica5. Pseudomonas aeruginosa

MethodsAntimicrobial assay

Salmonella enterica ssp. Enterica ser. Enteritidis CCM 4420

Micrococcus luteus CCM 732

Gram +

1. Bacillus subtilis2. Staphylococcus aureus3. Bacillus cereus4. Micrococcus luteus5. Enterococcus Faecalis

Gram -

1. Escherichia coli2. Citrobacter freundii3. Serratia marcescens4. Salmonella enterica5. Pseudomonas aeruginosa

Incubation in plate readerAbsorbance readings (600nm)

Growth curves

MethodsAntimicrobial assay

200 µl MPB with MAG + 5 µl of bacterial suspension

Every 30 minutes24 hours

Dilution of MAG in MPB(25 - 1500 µl/ml)

Results

ResultsGram +

ResultsGram +

ResultsGram +

ResultsBacillus subtilis

ResultsBacillus subtilis

41%

ResultsBacillus cereus

ResultsPetri dishes

1. MAG A of Iva - 1000 µg/ml2. MAG A of Gabriel - 1000 µg/ml3. Nisin - 500 µg/ml4. MAG A of Iva + Nisin – 100MAG + 300N µg/ml5. MAG A of Gabriel + Nisin - 100MAG + 300N µg/ml6. MAG Lauric - 1000 µg/ml7. MAG A of Gabriel + Nisin - 200MAG + 200N µg/ml

Used to confirm the results

Problems

ProblemsWe always have...

MAG A• Did not work the first time• 10 days to realize and prepare

another one

PLATE READER• Light bulb burned out•Could not test MAG of palmitic acid•Could not test mix (Nisin + MAG) in gram negative bacterias

Conclusions

Conclusions

COMBINATION• Probable synergistic effect between nisin and MAG• Other combinations are possibly effective• Part of nisin could be replaced by MAG to reduce costs

Acknowledgments

Acknowledgments

Eva SvobodováLenka PlechačováOlga HaukováHanka Miklíková

Special acknowledgments