Effect of Probiotics on the Removal of Aflatoxin B1 in Phosphate Buffer Solutionution

• Main Authors: Hsiao-Hui Chou, 周曉蕙
• Other Authors: Chihwei P. Chiu
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/50980047241646431697

碩士 === 輔仁大學 === 食品營養學系 === 91 === The objectives of this study were to evaluate the removal of aflatoxin B1 (AFB1) by Bifidobacterium spp., Lactobacillus spp. and Streptococcus thermophilus in phosphate buffer solution (PBS). Factors influencing the elimination of including concentration of AFB1, pH, the temperature, reaction time, and purity of bacterial cell wall were also investigated. The bacterial precipitated pellets obtained from centrifugation of growth broths of Bifidobacterium spp., Lactobacillus spp. and Streptococcus thermophilus were suspended in pH 7 PBS containing 5 ppm AFB1, and incubated at 37℃ for 4h. After centrifugation, AFB1 residue in the supernatant was measured by HPLC. Results showed that the higher removal of AFB1 by Bifidobacterium spp. was observed. The amount of AFB1 removal increased with increasing AFB1 in PBS, whereas the percentage of AFB1 removal decreased when AFB1 in PBS was up to 10 ppm. Maximum removal of AFB1 was obtained in PBS at pH 7. The efficacy of AFB1 removal decreased with prolonged reaction time and was independent of reaction temperature. The whole cells, crude cell walls and purified cell walls of B. infantis CCRC14633 and B. adolescentis CCRC14606 had ability to remove AFB1. The purified cell walls showed better removal of AFB1 than whole cells and crude cell walls. The cells and cell walls were treated individually with chemical reagents, including sodium hydroxide (NaOH), hydrochloric acid (HCl), trichloroacetic acid (TCA), sodium dodecyl sulfate (SDS), sodium metaperiodate, and with heat, including boiling at 100℃ for 15 minutes and autoclaving at 121℃ for 15 minutes. After treatment, the bacterial suspensions were centrifuged and the supernatants were analyzed for total carbohydrate and protein. The precipitated cells or cell walls were used to remove AFB1. The relationships between carbohydrate or protein contents in supernatant after chemical or heat treatment of cells and cell walls and the removal of AFB1 were examined. Treatment of chemicals and heat enhanced the ability of cells or cell walls to remove AFB1. Better removal of AFB1 was achieved by 2% sodium dodecyl sulfate and sodium metaperiodate treatments. The relation of AFB1 removal to carbohydrate and protein contents in supernatant varied with bacterial strains. In conclusion, maximum removal of AFB1 could be obtained by B. adolescentis CCRC14606 cell walls which had undergone chemical or heat treatment to reduce more carbohydrate and retain more protein.