Identification of nitrogen-fixing enterobacteria from living Sassafras (Atherosperma moschatum Labill.) trees

Nitrogen-fixing enterobacteria (Enterobacter agglomerans and Citrobacter freundii) were commonly found associated with the microflora of stained Sassafras (Atherosperma moschatum Labill.) in forests of SE Tasmania. However, their populations never exceeded 3× 10⁴ cells g⁻¹ dry wood and comprised at most 3% of the total bacterial flora. Bacterial colonization of the wood appeared to coincide with that by non-hymenocetous fungi: bacteria were never isolated in significant numbers from wood not infected with fungi. The contribution of the N₂-fixing flora to the N economy of the habitat is considered to be negligible.