| dc.description.abstract | Diazotrophs are microorganisms that are able to fix nitrogen from
atmosphere and sometimes used as biological control agents of fungal pathogens
such as Ganoderma boninense. As biological control agent, dizotroph bacteria may
produce the chitinolytic enzymes to lysis fungal cell wall. The aims of this study were
to obtain of chitinolytic diazotrophic bacteria from rhizosphere of oil palm,
screening their antagonistic activity against G. boninense and tested of selected
isolates to the lysis activity their chitinase enzymes agaist cell walls of G. boninense.
The diazotrophs bacteria were isolated from the rhizosphere of oil palm farm of
Universitas Sumatera Utara. Firstly, chitinolytic bacteria was isolated from
rhizosphere samples with chitin agar medium. Then, the positive chitinolytic bacteria
were inoculated to Ashby’s agar medium to confirmation that isolated bacteria were
diazotrophs. The chitinolytic diazotroph bacteria were characterized the morphology
and Gram type. Antagonistic activity of diazotrophics bacteria were tested by dual
culture assay toward G. boninense. The chitinolytics activity of diazotrophic bacteria
was determined qualitatively. The potential isolates of bacteria with chitinolytic and
antagonistic activity were tested for their enzyme activity to lysis of G. boninense cell
wall. About 12 isolates of chitinolytic diazotrophic bacteria were obtain in this
research. All of bacteria was Gram negative and have chitinolytic activity in the
range index between 1.50 until 3.73. The antagonistic test obtained five potential
isolates with percentage of inhibition activity against G. boninense was ranged from
4.1% to 20.2%. Isolates bacteria with the highest chitinolytic activity To 07 were
able to lysis of G. boninense cell wall and released of N-acetyl glucosamine in the
medium. | en_US |
