Biochemical Characterization of Lactic Acid Bacteria from the Small Intestine of Piglets as Possible Probiotic Strains

Abstract

Abstract A major problem the pig farms are facing today is the use of industrial probiotics that can harm both the animals and the consumers. Thus, the main objective of this study was the selection, characterization, and identification of the Lactobacillus sp strains from the small intestine of piglets as possible probiotic strains. Eight animals were divided into two groups – one with four 21-day-old piglets and the other with four 40-day-old ones. Descriptive statistics were applied. Once the sowing was done, the strains found in the small intestine were isolated according to their morphology. Eight strains were found, and basic biochemical tests were carried out, such as gram staining. All eight strains were Bacilli-positive and the catalase, oxidase, and KOH tests were negative. Next, biochemical tests were carried out for the identification of each isolated strain, such as the acidification test in which the longer hours of acidification lead to a considerable decrease in pH while a 0.3% growth in the bile. Moreover, strain 6 had greater resistance to the bile while strain 5 had a lower resistance. Using the bile and carbohydrate fermentation, the following lactobacillus species were identified: Lactobacillus fermentarun, L. delbrueck ii, L. reuteri, L. casei, L. acidiphilus, L. brevis, L. johnsonii, and L. plantarun. The authors conclude that isolated strains can be used as probiotics if they meet the minimum CFU/gr and recommend conducting other biochemical tests such as the API 50 CHL tests for better identification.

Keywords

• lactobacillus sp., piglets, lactic acid, bacteria, small intestine.