had alterations of the nucleotide sequence of rluD gene. Table 3 shows
a summary of mutations found in nine mutants; three base changes
leading to amino acid changes, four base changes leading to the
nonsense codon, two deletions of one base leading to the occurrence
of the nonsense codon due to the frame shift of translation. Thus, six
mutations out of nine knocked out the function of rluD gene, and
these results support that the neomycin resistance to neomycin may
be the results of the loss of rluD gene function in B. bifidum YIT 4007.