• C. N. Ngamau Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
  • V. N. Matiru Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
  • C. W. Muthuri Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
  • A. Tani Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, Japan
Keywords: Endophytic bacteria, diazotrophic endophytes, phosphate-solubilizing microorganisms (PSM), banana


This study was conducted with the aim of isolating and identifying banana endophytic bacteria on the basis of their
potential as biological fertilizer. Banana materials were collected from five different geographical regions to
enhance diversity. Isolation of bacteria was done using five (5) different isolation media and the isolates were
characterized on the basis of their morphology, biochemical and molecular characteristics. A total of 214 bacterial
isolates were obtained and characterized. Microorganism profiling was done using MALDI-TOF/MS and the isolates
were clustered into 53 genotypes. Based on their functional characteristics, 43 isolates were selected for 16S rRNA
gene sequencing. The 43 strains showed varied levels of positive nitrogenase activity as measured by the acetylene
reduction assay and 37 strains were observed to solubilize phosphates by the formation of visible dissolution halos
on agar plates (NBRIP medium). Siderophore production of the isolates was determined using Chrome Azurol S
(CAS) agar plates and all the isolates were observed to be positive for siderophore production with 3 strains
showing distinctively high level of production. Using the 16S rRNA gene sequencing, the 43 strains were identified
as Serratia spp. (17 strains), Pseudomonas spp. (12 strains), Enterobacter spp. (4 strains), Rahnella spp. (4 strains),
Raoultella spp. (2 strains), Bacillus spp. (1 strain), Klebsiella spp. (1 strain), Yersinia spp. (1 strain) and Ewingella
spp. (1 strain). In conclusion, banana endophytic bacteria were successfully isolated and identified, and some of
the isolates showed potential of being biological fertilizers. However, greenhouse and field investigations are
necessary to confirm this potentiality.