show Abstracthide AbstractTo better understand bacterial community and metabolism under N-deficient condition, 634 nitrate-utilizing bacteria were isolated from 154 seawater samples (0-200m) at 22 stations in the photic zone of the Western North Pacific Ocean (WNPO) using selective media and a culture-dependent method. 29 isolates of 94 representative nitrate-utilizing isolates were confirmed to be nitrate-reducers.