Characteristics and in vitro antibacterial activity of lactobacillus acidophilus fncc-0051 probiotic microspheres against propionibacterium acnes atcc 11827

Lactobacillus acidophilus FNCC-0051 is a probiotic which contains bacteriocin metabolites, lactic acid, and organic acid which are effective as antibacterial for acne treatment. This study aims to encapsulate probiotic, characterise and determine the antibacterial activity of L. acidophilus FNCC-0051 at pH 4.5 and 6.0. The probiotic microspheres were made using ionic gelation aerosolization technique with 2% sodium alginate and 1.0 M CaCl₂. The characterization included surface morphology, size, moisture content, swelling index, and viability. Antibacterial activity was carried out by diffusion method using Propionibacterium acnes ATCC 11827. Activity was determined by inhibition zone diameter every 1 hour for 6 hours. Results showed that the microsphere was spherical with smooth surface with a size of 1.7841 ± 0.0253 µm. Moisture content was 3.38 ± 0.18% and the swelling index at pH 4.5 and pH 6.0 were 384.29% and 507.37%, respectively within 6 hours. The results of inhibition zone diameter measurement against Propionibacterium acnes at pH 4.5 for 6 hours were 10.11 ± 1.07; 12.16 ± 1.25; 15.73 ± 2.36; 18.81 ± 3.20; 22.99 ± 2.38; and 30.74 ± 5.24 mm. while the inhibition zone diameter at pH 6.0 were 20.98 ± 2.41; 25.58 ± 2.40; 31.04 ± 3.57; 36.09 ± 2.62; 40.47 ± 2.12; and 48.38 ± 4.73 mm. Swelling capacity at pH 6.0 was higher than at pH 4.5. Therefore, the released probiotics were higher at pH 6 and caused a higher antibacterial activity at pH 6.0 than at pH 4.5.