Isolation and Evaluation of Microorganisms from Locally Fermented Foods as Potential Chicken Probiotics

Abstract

Probiotics are living microorganisms that are advantageous to health, particularly in the digestive tract. Probiotics for broilers could promote their growth and protect them from diseases by boosting their immune systems, strengthen their bones, and combat parasites. Antibiotics are commonly used in poultry feed as growth promoters to improve poultry performance. However, antibiotic residues will remain in chicken meat, bones, and organs, which may adversely impact human health. Therefore, this study examined potential chicken probiotics derived from locally fermented foods, such as shrimp paste and soy cake, as substitute to antibiotics. The microbes were cultivated on suitable media after isolating from the previous culture plates. bacteria and yeast were identified as potential probiotics for chickens. The microorganisms underwent in vitro analysis under the conditions mimicking chicken gastrointestinal tract (GIT) conditions at different pH values of 2.5, 3.5, 5, 6.5, 7, 7.5 and 8, temperature of 37°C and in anaerobic condition. Nine yeast and ten bacteria were selected as samples for this study. Their kinetic growth, survivability and biomass were also calculated. Comparisons were conducted on the remaining microorganisms, namely four yeast strains and three bacterial strains, and demonstrated probiotic potential with high specific growth rate, maximum cell concentration, shorter doubling time and higher survivability percentage at pH range from 2.5 to 8.0. The results of toxicity test revealed that some of the pre-selected probiotic prospective strains had produced several toxic compounds that could be harmful to chickens. Finally, based on the results of the investigation, one bacterium, Staphylococcus hominis, and one yeast, Cutaneotrichosporon arboriforme, were chosen to make probiotics for chickens, which were then evaluated in vivo to see how they impacted chicken growth. It was found that chickens supplied with these 2 probiotics boosted the growth of the chicken. In conclusion, based on their growth in the chicken digestive system environment and impacts on chicken growth rate, microbes isolated from locally fermented foods have promise as chicken probiotics.