A test for collecting bacterial cell fraction of high vitamin B_<12> content was conducted using Sharples super centrifuge in the night soil treatment plant at Kotoura in Okayama Prefecture. The yield of bacterial cell fraction after 60 minutes operation averaged 480 g (15% moisture), corresponding to 0.1% on a dry basis toward the amount of the supernatant treated. Vitamin B_<12> content in 28 kinds of the samples determined with E. coli and Ochromonas malhamensis averaged 24.5 and 16.5μg/g, respectively. That is to say, about 70% of vitamin B_<12> activity obtained might be due to that active for animals. At any rate, further investigation is desirable on the collection methods.