Sporulation of Bacillus subtilis (natto) KFP 4 isolated from Takahashi natto starter derived from food extracts
2007
Mitsuboshi, S.(Kyoritsu Women's Univ., Tokyo (Japan)) | Obitsu, R. | Otsuki, M. | Katsumata, M. | Kita, R. | Watanabe, S. | Tanaka, T. | Muramatsu, K. | Kiuchi, K.
We investigated the sporulation of vegetative cells of Bacillus subtilis (natto) KFP 4, isolated from commercial Takahashi natto starter. When the temperature of culture plates was increased from 37 deg C to 40 deg C, the spore number (/ml) after sporulation treatment was observed to increase, and the number of spores was maximized by using cells from the second culture day. In a previous study, the addition of 0.01 mmol/l Mnsup(2+) to the culture medium increased the spore ratio (ratio of spore number to whole cell number) from 72% (data obtained in a previous study) to more than 90%. In the present study, as inorganic Mnsup(2+) was not permitted as a food additive, we prepared extracts from four foods with high Mnsup(2+) content: dry sea lettuce, raw and dry green laver, and poppy seeds. By adding these extracts to the medium we could achieve a spore ratio of more than 90%. There were no large differences in organoleptic test results for natto produced with starters prepared from four kinds of food extracts.
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