Changes in biotin levels during production of natto, Japanese fermented soybean

Abstract

<p><span style="font-family: Times New Roman;"><span style="font-size: medium;">The change of biotin level during production of natto (Japanese fermented soybean) was investigated in this study. </span><span style="font-size: medium;">The total biotin level was measured by an agar plate bioassay using </span><em><span style="font-size: medium;">Lactobacillus plantarum</span></em><span style="font-size: medium;"> ATCC 8014.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">The total biotin level decreased during water soaking, but increased after the fermentation of soybeans using </span><em><span style="font-size: medium;">Bacillus subtilis</span></em><span style="font-size: medium;"> var. </span><em><span style="font-size: medium;">natto</span></em><span style="font-size: medium;"> (</span><em><span style="font-size: medium;">B. natto</span></em><span style="font-size: medium;">) and reached a maximum level.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">The increase of total biotin was not affected by Asp, Arg, and Ile which promoted the growth of </span><em><span style="font-size: medium;">L. plantarum</span></em><span style="font-size: medium;"> in high concentrations. </span><span style="font-size: medium;"> </span><span style="font-size: medium;">The peak level of biotin in the fermented soybeans was significantly higher than that of dry soybeans.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">The fermented soybeans at the biotin peak level were adequate for food.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">In addition, we detected 9 and 4 biotinylated polypeptides in the soybeans and </span><em><span style="font-size: medium;">B. natto</span></em><span style="font-size: medium;"> used in this study, respectively.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">We speculated that the increase of biotin level may depend on the increase of the 4 biotinylated polypeptides and free biotin in </span><em><span style="font-size: medium;">B. natto</span></em><span style="font-size: medium;">.</span></span></p>