TITLE:
Characterization of Novel Alkaliphilic Isolate of Bacillus mannanilyticus, Strain IB-OR17, Displaying Chitinolytic and Antifungal Activities
AUTHORS:
A. I. Melentiev, N. F. Galimzianova, E. A. Gilvanova, E. A. Shchelchkova, L. Yu. Kuzmina, T. F. Boyko, N. G. Usanov, G. E. Aktuganov
KEYWORDS:
Bacillus mannanilyticus, Alkaliphilic Bacteria, Bacilli, 16S rRNA, Chitinase, β-Mannanase, Antifungal Activity, Microbial Antagonism
JOURNAL NAME:
Advances in Microbiology,
Vol.4 No.8,
June
17,
2014
ABSTRACT: The novel alkaliphilic strain, designated as Bacillus sp. IB-OR17 and isolated from soda lake sediments, was
identified and characterized. Isolated strain demonstrated slight antifungal
activity against some plant pathogen fungi that are capable to grow under
alkaline conditions. Based on its morphological, physiological and biochemical
characteristics as well as on 16S rRNA gene analysis data, Bacillus sp. IB-OR17 were related to alkaliphilic species B. mannanilyticus. Such as type species, Bacillus sp. IB-OR17 produced
extracellular β-mannanase but
additionally it displayed also chitinolytic activity which is a new property
reported for this species. Bacillus sp. IB-OR17 grew in pH range 8.0 - 11.0 with maximal intensity under 9.0 - 10.0
but not showed halophilic properties (growth limit under NaCl concentrations
Bacillus sp. IB-OR17 produced chitinase(s) in presence of colloidal
chitin as main carbon source and sodium carbonate (0.25% - 1.0%) demonstrating
high enzyme yield under enough low concentrations of the substrate (0.20%).
Unlike chitinase, β-mannanase was
constitutively produced by Bacillus sp. IB- OR17 in presence of various substrates including crab shell chitin.
Probable involvement of the enzymes in antifungal activity of Bacillus sp. IB-OR17 is discussed
shortly in terms of further researches and application of this strain.