A Preliminary Study on Probiotic Characteristics of Sporosarcina spp. for Poultry Applications

Probiotics are well known for their wide range of beneficial activities. However, recent use of probiotic Bifidobacterium, Enterococcus, and Lactobacillus spp. has been plagued by certain disadvantages such as complex growth requirements, high maintenance cost, susceptibility to the gastrointestinal environment, pathogenic gene transfer, non-standardized dosage, cell lysis at extreme acidic pH, widespread antibiotic resistance, and lower bacterial viability due to the lack of spore formation. Therefore, spore-forming bacteria belonging to Sporosarcina genus such as pasteurii, globispora, and psychrophila were assessed for probiotic characteristics such as biofilm formation, intestinal adhesion, acid and bile tolerance, antibiotic sensitivity, and anti-pathogenic activity. This ensures bacterial viability under gastrointestinal conditions and enabled the same to colonize effectively in the intestinal lumen (in vitro). The bacterial cell counts ranging from 6.59 to 6.91 log(CFU/mL) was observed for Sporosarcina spp. after 16 h. This indicated that there is no significant difference in the cell counts (P-value = 0.90). The cell counts of Sporosarcina spp. ranging from 5.57 to 5.93 log(CFU/mL) displayed strong acid tolerance at pH 2. They were also viable at higher bile (0.5%) concentration. Among the Sporosarcina spp., pasteurii showed better tolerance (6.90 log(CFU/mL)) even after 16 h. Among the selected bacteria, Sporosarcina psychrophila was more susceptible to teicoplanin and meropenem with an inhibition zone of 30 mm. Maximum antagonistic activity was observed against Serratia marcescens (with inhibition zone up to 15 mm). Our results suggest that bacteria belonging to Sporosarcina genus possess all the required characteristics to be used as potential poultry probiotics.