Who isolated Bacillus radicicola, the organism responsible for N fixation in 1888

Bacillus radicicola is the organism responsible for Nitrogen fixation and was isolated by M. W. Beijerinck in 1888. This bacteria was discovered as it produces root nodules for fixation.
He observed the motile "swarmer" stage as well as the branching forms, that were developing the nodules for fixing atmospheric nitrogen.