Isolation and identification of fenobucarb degrading bacteria from Pangalengan farm land

Abstract

The long term excessive use of pesticides can lead to their residues accumulation in the soils. Soil microbes were considered to convert the residues into harmless compounds, however the indigenous soil microbes having those beneficial properties are limited. Therefore this study aimed to isolate, select and identify the fenobucarb insecticide-degrading bacteria from agricultural soils. The soil samples were collected from the vegetable fields in Pangalengan, West Java, Indonesia. Isolation of the bacteria was conducted using Nitrate Mineral Salt Agar suplemented by 100 ppm of a fenobucarb. The bacteria isolates were selected based on its hypersensitive response, haemolytic activity, and its ability to degrade fenobucarb. The selected isolates was identified base on sequences of 16S rRNA gene. Twenty nine bacteria were isolated from four soil samples and 23 of the isolates were not potentially phytopathogenic and non haemolytic. The best three isolates that could degrade 94.2%, 94.5% and 95.47% fenobucarb residue are B41, B54 and B83 isolates, respectively. The 16S rDNA Sequence analysis showed that B41 and B83 isolates have 100% similarity to Bacillus thuringiensis MYBT 18426B54, while B54 isolate has 99% similarity to Bacillus luciferensis LMG 18422. These isolates are potential to be developed as a bioremediation agent.