Screening of Potential Probiotic Lactic Acid Bacteria from Be-tong Chicken

Abstract

Food safety is very important. In order to avoid undesirable results of antibiotics and growth promoting agents, probiotic has been used in economic animals including poultry husbandry. This research studied the probiotic properties of 145 strains of lactic acid bacteria (LAB) isolated from crop, small and large intestinal tract of Be-tong chicken. According to the primary screen method for acid tolerance, twenty-two isolates exhibited the acid tolerance with survival higher than 50% at pH 2 for 2 hours. These 22 strains were then incubated in simulated gastrointestinal tract. Thirteen strains including F/Cr 01007, F/Cr 01008, A/Cr 04002, A/Si 04001, A/Si 04002, A/Si 04014, A/Si 04015, S/Si 04024, A/Li 04008, A/Li 05011, F/Si 06001, A/Cr 07010 and A/Li 07003 showed the tolerance with survival ranging from 51.66 to 88.59%. Eleven strains had more over 90.28 and 82.89% hydrophobicity in xylene and toluene, respectively. The antibiotic resistance of these LAB showed that F/Cr 01007, A/Si 04002, S/Si 04024, A/Li 04008, A/Li 05011, F/Si 06001 and A/Cr 07010 had high survival under the simulated gastrointestinal tract and high cell surface hydrophobicity could tolerate to 5-9 antibiotics. These 7 strains were identified as Lactobacillus reuteri with the 99% similarity by 16S rDNA sequence analysis. This research study indicates that it is possible to use Lactobacillus reuteri from gastrointestinal tract of Be-tong chicken as effective probiotic.