<i>In Vitro</i> Screening and Selection of Probiotic Lactic Acid Bacteria Isolated from Spontaneously Fermenting Kunu-Zaki

Abstract

The present study was conducted to determine the pro-biotic properties in vitro of the lactic acid bacteria isolated from spontaneously fermenting kunu-zaki. Kunu-zaki was processed using composite, non composite, germinated and ungerminated Digitaria exilis (Fonio), Sorghum bicolor (Sorghum) and Pennisetum americanum (Millet) cereals. A total of 150 LAB isolates were obtained from all the fermenting slurries. These 150 LAB isolates were screened for their ability to grow at pH 3.0, resistance against bile salt and ability to inhibit reference test pathogens. Out of these 150 LAB isolates; 21 exhibited good probiotic properties. All the 21 isolates were further identified to specie and subspecies level using standard API50CHL system with all 21 showing good survival (P < 0.05) in a pH 3.0 buffered medium and subsequent resistance to 0.3% bile. The LAB isolates which survived these conditions consisted of 18 Lactobacillus species, 2 Pediococcus species and 1 Lactococcus specie. These LAB species were further examined for antimicrobial activity against the growth of reference pathogens Staphylococcus aureus 25923, Escherichia coli 25922, Pseudomonas aeruginosa 27853 and Enterococcus faecalis 29212. All 21 LAB species exhibited good inhibition of all test reference pathogens except Lactobacillus fructivorans, Lactococcus lactis sp lactis and L. fermentum which however, showed no zone of inhibition against the growth of E. faecalis. Kunu-zaki made from composite un-germinated Sorghum bicolor (Sorghum) and Pennisetum americanum (Millet) cereal grains contained the highest percentage (52%) of LAB species which showed good probiotic criteria in vitro. Non composite ungerminated cereals accounted for 33% of the total probiotic LAB isolates whilst the germinated non composite and composite cereals recorded the lowest percentage (10%) and (5%) of probiotic LAB respectively. The results of this research study showed that the LAB species isolated from wild fermentation of kunu-zaki beverage fulfilled the criteria for in vitro screening of probiotic characteristics. These LAB species possed potential for further use as probiotic in human preparations and suggested the use of kunu-zaki made from ungerminated composite sorghum and millet grains as a natural probiotic drink.

Probiotic potential Streptomyces species from the grains of pearl millet (Pennisetum glaucum)

“…The main aim of using probiotic strains should be to beneficially affect the gut microbial composition and functionality. Oluwajoba et al (2013) reported similar results on lactic acid bacteria (LAB). The same authors noted that LAB, isolated from millet grains and fermented products, inhibited human pathogens such as S. aureus 25923, E. coli 25922, Pseudomonas aeruginosa 27853 and Enterococcus faecalis 29212.…”

Probiotic Potential of Lactic Acid Bacteria Ch-2 Isolated from Chuli Characterization of Potential Probiotic Lactic Acid Bacteria- Pediococcus acidilactici Ch-2 Isolated from Chuli- A Traditional Apricot Product of Himalayan Region for the Production of Novel Bioactive Compounds with Special Therapeutic Properties

“…Probiotics are able to do coaggregation with pathogens will effectively inhibit and kill pathogenic bacteria as antimicrobial compounds produced can move directly on pathogens [43]. The antimicrobial action of probiotic bacteria is reportedly due to their potential to produce lactic acid, H 2 O 2 and antimicrobial peptides (bacteriocins) [44]. Mandal et al [45] studied the antagonistic potential of P. acidilactici LAB5 against some food spoilage and human pathogenic bacteria and proved the antagonistic efficacy of antibacterial substance secreted by the strain i.e.…”

Isolation of Gram-positive Bacteria from Different Sources and Evaluation of their Probiotic Properties

“…The MRS agar was used for isolation of L. acidophilus and B. bifidum while L. lactis and B. subtilis were isolated by M 17 medium and Nutrient agar, respectively. Each sample was diluted serially 10-fold in phosphate buffer saline and then was inoculated on required medium [10]. The inoculated plates were incubated at 37°C for 48 h. The macroscopic appearance of the isolated colonies including colonies ' shape, color, and texture was examined.…”

“…Briefly, for each bacterial culture, 10 5 CFU of culture product was inoculated in selective broths supplemented with 0.0% and 0.3% (w/v) concentrations of bile salts. The cultures were incubated at 37°C for 24 h. Plate count method was used to evaluate the survival of isolated bacterial species [10].…”

“…For each isolated bacterial species, 5 log10 CFU (10 5 CFU) of culture product was poured into each broth and was incubated for 2 h at 37°C. The plate count method was used to evaluate the survival of the isolated bacterial species [10].…”