Preliminary Characterization of the Probiotic Properties of a Bacterial Strain for Used in Monogastric Nutrition

Abstract

This study aimed to evaluate some probiotic properties of Bacillus subtilis ATCC 6051a. The phenotypic profile, resistance to pH by simulated gastric juice (pH 2 and 3), bile salts by simulated intestinal fluid, survivability (%), heat and antibiotics tolerance were investigated. The strain is a Gram-positive, rod-shaped bacteria, arranged in short chains or in small irregular pairs with the ability to produce spores. Good viability at pH 2 and 3, with a survival of more than ≥80%, was found. In the presence of bile salts 0.3%, over 4 h, the strain exhibited a survival ≥85%. At 80°C, for 120 min., the strain showed good growth (9.04 log CFU/ml). Results were sensitive to most antibiotics, with a highly susceptible (between 16 – 25 mm) to erythromycin, clindamycin, amoxicillin, chloramphenicol, ciprofloxacin, amikacin and kanamycin. The strain was found to be sensitive to vancomycin, gentamicin, and tetracycline. The present research demonstrated that Bacillus subtilis ATCC 6051a can survive under gastrointestinal conditions, which involves them to future in vitro and in vivo probiotic studies.

Effect of Bacillus subtilis on growth performance, bone mineralization, and bacterial population of broilers fed with different protein sources

“…(2013) found that BS can secrete pathogen-suppressive substances that have bacteriostatic action on common pathogens such as Staphylococcus aureus and E. coli which were highly sensitive to sample concentrate, and the bacteriostatic effect is equivalent to normal antibiotics. Therefore, our results suggest that the dietary inclusion of BS (ATCC 6051a strain) based on in vitro enzyme production profiles ( Dumitru et al., 2019 ) contributed to enhance performance and bone quality as well as improve GIT microbial balance in broiler consuming SBM and CWP diets.…”

“…These results support the previous reports that other strains of BS, or a probiotic with a predominance of BS, improved BWG and FCR of broiler chicks ( Jeong and Kim, 2014 ; Li et al., 2016 ; Gao et al., 2017 ; Mahmoud et al., 2017 ; Zhen et al., 2018 ; Flores et al., 2019 ). The reasons for the improvement in BWG and FCR of broilers fed a BS probiotic supplement were probably because of the increased FI or to the ability to produce some extracellular enzymes such as amylase, protease, and lipase ( Dumitru et al., 2019 ) that improved nutrient digestibility. Another possible reason is that Bacillus spp .…”

“…The bacterial strain was grown in a nutrient medium (g/L: tryptone 10; meat extract 5; sodium chloride 5; pH medium 7.2 ± 2 before autoclaving) and incubated in a shaker-incubator (200 rpm) at 37°C for 24 h in aerobic conditions as reported previously by Dumitru et al. (2018 , 2019) . The inoculum was analyzed by serial 10-fold dilutions using phosphate buffered saline solution ( PBS ), and then, 1 mL from 10 −10 to 10 −12 was placed on nutrient agar medium (g/L: tryptone 5; meat extract 3; bacteriological agar 5; distilled water).…”

“…B. subtilis a nonpathogenic bacteria are spore-forming, and the genus has been considered as one of the most successful probiotic bacteria in poultry nutrition because of its resistance to a wide range of temperatures during the feed manufacturing process and long-term storage at ambient temperature and survive the low pH, bile, and other antimicrobial molecules in the gastrointestinal tract ( GIT ) of the host ( Sen et al., 2012 ; Alloui et al., 2013 ; Goodarzi Boroojeni et al., 2016 ; Mahmoud et al., 2017 ; Dumitru et al., 2019 ). Dietary supplementation with BS increases the abundance of beneficial bacteria, decrease of pathogens, and improve growth performance ( GP ) and carcass quality in broiler chickens ( Li et al., 2016 ; Bai et al., 2017 ; Gao et al., 2017 ; Mahmoud et al., 2017 ; Reis et al., 2017 ; Flores et al., 2019 ).…”

Effect of dietary orange and grapefruit peel on growth performance, health status, meat quality and intestinal microflora of broiler chickens

“…The bacteria determined from intestinal microflora were incubated aerobically at 37 C for 48 h. Escherichia coli (E. coli; biotype b-hemolytic) and Salmonella spp. was analysed as reported by Dumitru et al (2019). The viable counts of Lactobacillus spp.…”