Journal of Pure and Applied MicrobiologyVol. 8 No. Special Edition Nov. 2014

Assay of Antagonistic Bacteria of Single Isolate and Combination to Control Seedling-off in Chili Seed caused by Fusarium oxysporum

Dwi Suryanto1, Muhammad Asril1, Erman Munir1 and Emmy Harso Kardhinata2

1Department of Biology, Faculty of Mathematics and Natural Sciences, University of Sumatera Utara, Medan, Indonesia 20155. 2Department of Agroecotechnology, Faculty of Agriculture, University of Sumatera Utara, Medan, Indonesia 20155.

Received on 11 July 2013 and accepted on 20 November 2013

 

ABSTRACT

Single isolate and combination of chitinolytic and non-chitinolytic bacteria were assayed to know their ability in reducing chili seedling-off caused by Fusarium oxysporum. Eight antagonistic bacterial isolates i.e. Bacillus sp. BK13, Alcaligenes sp. BK14, Enterobacter sp. BK15, Citrobacter sp. BK16, and Bacillus sp. BK17 showing chitinolytic activity, and Pseudomonas sp. KM01, Alcaligenes sp. KM02, and Serratia sp. KM04 with no chitinolytic activity were assayed to inhibit F. oxysporum and Candida albicans growth in vitro. All isolates showed varied ability in inhibiting the fungal growth, in which Enterobacter sp. BK15 and Bacillus sp. BK13 inhibited the most. Inhibition assay on C. albicans indicated that non-chitinolytic bacterial isolates is likely to produce other toxic metabolic compounds. Single isolate of Enterobacter sp. BK15 and combination of Bacillus sp. BK13+Serratia sp. KM04 as well showed to reduce more chili seedling-off. All treatments produce higher seedling height and seedling dry-weight than that of isolate-free seeds planted in fungus-inoculated soil but one, Enterobacter sp. BK15+Pseudomonas sp. KM01.

Keywords : Antagonistic bacteria, Candida albicans, chili seed, Fusarium oxysporum, seedling-off.