Naslov
The various coexistence of enterobacteria with Lactobacillus brevis L62 in mixed cultures

Autori
Butorac, Ana ; Mrvčić, Jasna ; Stehlik-Tomas, Vesna ; Gjuračić, Krešimir ; Bačun-Družina, Višnja

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Book of Abstracts / Vujaklija, Dušica ; Pigac, Jasenka ; Hađina, Suzana ; Kosalec, Ivan - Zagreb : Hrvatsko mikrobiološko društvo, 2008, 135-135

ISBN
978-953-96567-7-3

Skup
The various coexistence of enterobacteria with Lactobacillus brevis L62 in mixed cultures, 4th Croatian Congress of Microbiology with International Participation

Mjesto i datum
Zadar, Hrvatska, 24.09.2008. - 27.09.2008

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
GASP phenotypes; Escherichia coli; Salmonella enterica; Lactobacillus brevis

Sažetak
Understanding the patterns of occurrence of microbial populations in food is a problem of determining the actual niche of the organism present, especially identification and quantity of pathogen microorganisms. During prolonged starvation stress expressions the Growth Advantage in Stationary Phase (GASP) phenomenon is manifested depending on the appearance of new mutations in the population of nonsporogenic bacteria. Previously in a typical GASP competition experiment, we found moderate GASP phenotype in mixed cultures of 1-day-old Lactobacillus brevis L62 and 10-days– old Escherichia coli and Salmonella enterica serovar Typhimurium wild type as a numerical minority (1:10 or 1 ; 100 vol/vol) at 30  C under semianaerobic condition. The goal of this investigation was to analyze mixed populations of 1-day-old and 3-days-old L. brevis and enterobacteria E. coli or S. enterica during the prolonged period of carbon starvation due to the evaluation of their coexistence at 37  C. To determine relative fitness of bacterium in mixed cultures we used selective minimal M9, Simmons citrate and MRS with nalidixic acid plates for E. coli, S. enterica and L. brevis cells, respectively. The L. brevis strain is resistant even to high concentration of nalidixic acid. Restriction analysis of the episomal genetic elements detected in this strain suggested the presence of at least three individual plasmids ranging from 7 to 25 kb in size. In bacterial mixtures of two used enterobacteria with L. brevis different GASP phenotypes have been found. The mixed cultures of 1-day-old S. enterica with 1-day-old or 3-days-old L. brevis cells as majority showed strong GASP phenotype. However, in mixtures of same age of E. coli and L. brevis cells, weak GASP phenotype has occurred. Investigating bacterial trait in mixed cultures serves as an excellent model for studying the cell competition and evolution under stress condition.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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