FORMATION OF DEOXYINOSINE FROM INOSINE BY WASHID CELL SUSPENSION OF VITAMIN B₁₂-REQUIRING STRAIN OF LACTOBACILLUS LEICHMANNII

Abstract

1. The effects of ribonucleosides or deoxyribonucleosides on the growth rate of Lactobacillus leichmannii were investigated using the ordinary microbioassay technique. It was found that the addition of both vitamin B₁₂ and ribonucleosides resulted in higher growth rate than a single addition of vitamin B₁₂. The finding was quite similar to the case where the addition of both vitamin B₁₂ and thymidine was more active than a single addition of vitamin B₁₂. Further, formation of deoxyribonucleoside was observed after addition of both vitamin B₁₂ and ribonucleosides.
2. Effects of the age of the cells on the deoxyribonucleoside formation were studied, and the best condition for producing the compounds by washed cell suspension of L. leichmannii was studied.
3. 2′-Deoxyribonucleosides were separated from the reaction products and studied chemically and microbiologically. By paper chromatography and bioautography they were separated and identified.
4. Formation of 2′-deoxyribonucleosides from the corresponding ribonucleosides with the washed cell suspension of L. leichmannii at the logarithmic phase of the growth rate was studied.