Salkowski's reagent test as a primary screening index for functionalities of rhizobacteria isolated from wild dipterocarp saplings growing naturally on medium-strongly acidic tropical peat soil.

Rhizobacteria isolated from wild dipterocarp saplings in Central Kalimantan, Indonesia, were subjected to Salkowski's reagent test, which is often used in detecting indolic substances. Among 69 isolates grown in a low-nitrogen medium supplemented with L-tryptophan (TRP), culture fluids of 29 strains were positive to the test, in which 17 bacteria turned red and other 10 pink. All the red type rhizobacteria actively converted TRP into tryptophol (TOL), while some yielded indole-3-acetic acid (IAA) with TOL production.

Burkholderia vietnamiensis isolated from root tissues of Nipa Palm (Nypa fruticans) in Sarawak, Malaysia, proved to be its major endophytic nitrogen-fixing bacterium.

Root-associating bacteria of the nipa palm (Nypa fruticans), preferring brackish-water affected mud in Sarawak, Malaysia, were investigated. In a comparison of rhizobacterial microbiota between the nipa and the sago (Metroxylon sagu) palm, it was found that the nipa palm possessed a group of Burkholderia vietnamiensis as its main active nitrogen-fixing endophytic bacterium. Acetylene reduction by the various isolates of B.