Milk and milk products. Determination of the minimal inhibitory concentration (MIC) of antibiotics applicable to bifidobacteria and non-enterococcal lactic acid bacteria (LAB)

ABSTRACT: Sausages are highly susceptible to microbial spoilage. Lactic acid bacteria (LAB) is the main group of spoilage bacteria in vacuum packed cooked sausages. To control microbial growth natural antimicrobials have been used as food preservatives. The aim of this study was to identify strains of lactic acid bacteria isolated from spoiled commercial Calabresa sausages and use them in an in vitro challenge with the natural antimicrobials, nisin (NI) and ε-poly-L-lysine (ε-PL). Mass spectrometry identification of LAB isolated from sausages using MALDI-TOF revealed a predominance of L. plantarum in the LAB population. RAPD-PCR of L. plantarum strains showed four different genetic profiles. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of NI and ε-PL, alone and in combination, against a pool of different profiles L. plantarum were determined. MIC of NI and ε-PL were 0.468 mg/ L and 75 mg/ L; respectively, whereas MBC of NI and ε-PL were 12.48 mg/L and 150 mg/L, respectively. The combined effect of NI and ε-PL was determined using concentrations at 1/4 and 1/8 of individual MICs. Synergistic effect was confirmed at both concentrations showing a fractional inhibitory concentration index of 0.5 and 0.2, respectively. The combination of NI and ε-PL at a small concentration of 0.05 mg/L and 9.375 mg/L, respectively, showed inhibitory effect towards spoilage L. plantarum Results show the potential of the combined use of NI and ε-PL to control sausage spoilage-associated with lactobacilli.

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Identification of some lactic acid bacteria from two Zimbabwean fermented milk products

World Journal of Microbiology and Biotechnology ◽

10.1007/bf01200939 ◽

1990 ◽

Vol 6 (2) ◽

pp. 178-186 ◽

Cited By ~ 16

Author(s):

Sara B. Feresu ◽

M. I. Muzondo

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Fermented Milk ◽

Milk Products ◽

Fermented Milk Products

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The Inhibition of wine microorganisms by silver nanoparticles

Potravinarstvo Slovak Journal of Food Sciences ◽

10.5219/1604 ◽

2021 ◽

Vol 15 ◽

pp. 995-1004

Author(s):

Aleš Vavřiník ◽

Kateřina Štůsková ◽

Adrian Alumbro ◽

Methusela Perrocha ◽

Lenka Sochorová ◽

...

Keyword(s):

Silver Nanoparticles ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Gluconobacter Oxydans ◽

Lactobacillus Brevis ◽

Inhibitory Effect ◽

Silver Particles ◽

Acetobacter Aceti ◽

Inhibition Zones

The presented work aimed to study the inhibition using nanoparticles produced by the green synthesis in selected acetic acid and lactic acid bacteria, which are related to viticulture. The degree of ability to eliminate silver particles produced by green syntheses was determined using the plate method on Petri dishes. This is done using two different approaches - the method of direct application of the solution to the surface of the inoculated medium (determination of inhibition zones) and the method of application using nanoparticles to the inoculated medium. Gluconobacter oxydans (CCM 3618) and Acetobacter aceti (CCM 3620T) were studied from acet acetic bacteria. The lactic acid bacteria were Lactobacillus brevis (CCM 1815) and Pediococcus damnosus (CCM 2465). The application of silver nanoparticles was always in concentrations of 0, 0.0625, 0.125, 0.25, 0.5, and 1 g.L-1. All applied concentrations of silver nanoparticles showed an inhibitory effect on the monitored microorganisms. Silver particles could be used in wine technology for their antibacterial effects, mainly to inhibit microorganisms during vinification, as a substitute for sulfur dioxide.

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