Dynabeads protein G antibody conjugates combined with modified brain heart infusion broth for the enrichment and separation of Bacillus cereus in artificially contaminated vegetables

作者：Wei Shuai; Forghani Fereidoun; Park Youn Seo; Park Byung Jae; Seo Kun Ho; Oh Deog Hwan^*

来源：Food Science and Biotechnology, 2016, 25(3): 941-947.

DOI：10.1007/s10068-016-0154-z

• Bacillus cereus
• immunomagnetic separation
• Dynabeads (R) protein G
• enrichment

A modified brain heart infusion (MBHI) broth and a protocol of immunomagnetic separation (IMS) using antibody-coated Dynabeads(A (R)) protein G were developed for the enrichment and separation of Bacillus cereus in artificially contaminated vegetable samples. The MBHI consisted of BHI and 0.34 g/L magnesium sulfate, 12.08 g/L sodium pyruvate, 1.82 g/L yeast extract, and polymyxin B. The amount of immunomagnetic beads (IMBs) and immunoreaction time were optimized. The capture efficiency was 58.32% with 0.4 mg IMBs when the immunoreaction time was 20 min. Capture of B. cereus by IMBs did not interfere with competing flora. Pre-enrichment IMS was validated with four B. cereus strains in artificially contaminated baby sprouts, bean sprouts, lettuce, and spinach at two levels (similar to 0.1 and similar to 1 CFU/g). We were able to detect and isolate B. cereus in 40/40 samples of vegetables contaminated at 0.1 CFU/g with IMS after 6 h of enrichment in MBHI.

• 出版日期2016-6