Effects of combined treatment of sodium hypochlorite/ionizing radiation and addition of vitamin b ₁ on microbial flora of oyster and short-necked clam

To determine the synergistic disinfection effect of the combined treatments of sodium hypochlorite (NaClO), irradiation, and vitamin B ₁, the bactericidal effects of the treatments on natural microflora of oyster and short-necked clam were investigated. Then, bacteria isolated from the samples were identified by 16S rDNA sequencing. Oyster and short-necked clam were mainly contaminated with Vibrio spp. and Bacillus spp. Total number of aerobic bacteria ranged from 10 ² to 10 ⁴ colony forming units (CFU)/g initially. More than 100 mg/L of NaClO with 1000mg/L vitamin B ₁ and 2kGy irradiation treatment for oyster and short-necked clam can reduce the total aerobic bacteria to the level of lower than a detection limit (10 CFU/g). Synergistic effects were observed for all combined treatment against natural microflora. The results suggest that a significant synergistic benefit can be achieved by a combination of NaClO-ionizing radiation treatment with the addition of vitamin B ₁ to reduce the microbial population contaminated in oyster and short-necked clam.