The microbiological assay is one of the most common methods for biotin determination, which generally uses biotin-dependent L. plantarum ATCC 8014. The growth of microorganisms in the presence of biotin was evaluated by turbidity optical density of the assay solution at 610 nm, which is known as a turbidimetric assay. We developed a new improved bioassay for biotin levels using ATP production in L. plantarum. The standard curve was linear in the range from 0.01 to 800 pg/ml and the detection levels of this assay as low as 50 pg/ml could be realized. The intra-assay precision test revealed that the reproducibility of duplicates was within 8%. These findings suggest that this ATP assay is more sensitive and simple for the determination of biotin than the classic turbidimetric assay, thus making it appropriate for clinical laboratory use.
