Preliminary study of a microbeads based histamine detection for food analysis using thermostable recombinant histamine oxidase from Arthrobacter crystallopoietes KAIT-B-007.

We designed and prepared a micro biosensing system consisting of a flow through system with a sub-micro liter injection valve and a sub-micro liter volume bioreactor. An electrochemical detector was combined with the reactor for immediate detections. The volumes of the reactor and the sample loop for the injection were 850 nl and 320 nl, respectively. This paper described about the characteristics of the sensing system in the case of histamine detection for food analysis. Histamine oxidase from KAIT-B-007 was prepared by using a gene recombination technique and they were immobilized with chitosan beads (phi=70-105 microm). The detection less than one minute after injection made possible fast analysis for histamine. The biosensing system also showed a high performance for histamine detection in wide range of 1 microM-1mM. In addition, we practically measured histamine content in raw tuna stored at room temperature and 35 degrees C up to 96 h. As a result of the comparison between our sensing system and HPLC method, there was good agreement. These results show that our microfluidic biosensing system has the potential to assist miniaturization with small sample volume and short determination time for a sequential food analysis.