Characterization of intestinal lactobacilli as putative probiotic candidates

Abstract

Aims: To use antioxidative activity and antagonistic properties of lactobacilli against selected pathogens and members of the normal microflora as a basis for screening probiotic candidates. Methods and Results: Antagonistic activity of lactobacilli against target bacteria in both microaerobic and anaerobic environments was tested. Production of antagonistic metabolites (ethanol, hydrogen peroxide (H 2 O 2 ), acetic, lactic and succinic acid) by lactobacilli as well as their total antioxidative activity were assessed. In general, the lactobacilli tested were most effective against Gram-negative bacteria and their antagonistic activity was strainspecific. However, obligately heterofermentative lactobacilli had the strongest activity when tested in a microaerobic environment. Additionally, facultatively heterofermentative lactobacilli were equally effective in either milieu and produced significant levels of acetic and lactic acid. Moreover, obligately homofermentative lactobacilli had high H 2 O 2 production and total antioxidative activity but weak antagonistic activity. Conclusions: Antioxidative and antagonistic activity of intestinal lactobacilli is strain-specific but typically can be related to their fermentation type which may be used for rapidly screening large numbers of lactobacilli for probiotic candidates. Significance and Impact of the Study: This study represents the first report on the utilization of group characteristics to screen lactobacilli intended for specific probiotic use. Such uses include the targeting of particular gut niches and pathogens as well as allowing for long-term benefits to the host.

Physicochemical, microbiological and spoilage analysis of probiotic processed cheese analogues with reduced emulsifying salts during refrigerated storage

“…Madureira et al (2011) stated that the dominant inhibitory effect of probiotics was typically bacteriostatic namely lower rates of increase in the viable numbers of contaminant bacteria throughout storage. Addition of the probiotics by the decreasing pH facilitates diffusion of antimicrobial compounds (organic acids such as lactic and acetic acids), and co-aggregates them with contaminant microorganisms (Annuk et al 2003). Table 2 illustrated a numerical scoring system for the macroscopic and sensory assessment of the spoilage of processes cheeses stored for 60 days at 4°C.…”

“…The addition of 10 7 and 10 8 CFU/g of B. coagulans spores can be proposed to prevent spoilage of the processed cheese analogues, so that the slight levels of off-odors and off-flavors were formed in the probiotic cheeses only on day 60, but the products were still acceptable (Table 2). This fact can be a reasonable result of the pH reduction, preservative effects of organic acids produced by converting lactose and low counts of coliforms and yeasts/ molds present in the final product (Setlow et al 1977;Annuk et al 2003;Buriti et al 2005a, b).…”

Cholesterol reduction in vitro by novel probiotic lactic acid bacterial strains of Enterococcus isolated from healthy infants stool

“…Additionally, several cultural conditions such as media composition, pH, temperature, and inoculum size may change the metabolic pathways by altering pyruvate metabolism and external electron acceptors resulted in different end-products (Axelsson, 1998;Annuk et al, 2003).…”

Potential probiotic of Lactobacillus johnsonii LT171 for chicken nutrition

“…Tel: +98 261 2248082. Fax: +98 261 2246752. inhibitory activity toward any species or isolate of the genus Lactobacillus (Annuk et al, 2003). Hence this research was conducted to investigate the most important properties of L. johnsonii LT171, an indegenus poultry-derived isolate, for potential probiotic.…”