Black pepper (
Piper nigrum
L.) is a climbing vine known for its pungent fruit used as a spice worldwide. The aim of this
study was to evaluate the available P content in the native soils where pepper is grown as a crop plant. The native population
of phosphate solubilising microbes (PSM) was studied from the rhizosphere of
P. nigrum plants grown in the Western
Ghats of Karnataka, India. A variety of phosphate solubilising bacteria and fungi were isolated from the rhizosphere soil
samples. Phosphate solubilising capacity of different isolates was studied on Pikovskaya's medium. The isolates were
tested for their phosphate solubilising capacity
in vitro with three different phosphate sources, tricalcium phosphate (TCP),
potassium dihydrogen phosphate (KHP), and rock phosphate (RP) in the concentrations 2.5, 5.0 and 7.5 g L
-1. The three
phosphate sources were solubilised by the isolates in varying proportions. The dominant PSM flora obtained from the
samples included
Bacillus
and
Aspergillus
. The study showed that PSM utilised the three phosphate sources TCP, KHP,
and RP with considerable variability. The phosphatase activity of the isolates showed that the predominant microorganisms
were
Bacillus subtilis
(5.33 U mL
-1) and
Aspergillus (11.5 U mL
-1). The predominant organisms were identified up to
molecular level.