Identifikasi Molekuler Bakteri Pengurai Kitin Serangga dan Karakterisasi Enzim Kitinasenya

Abstract

Rhizobacteria have beneficial effects for plant growth as phytostymulator, biofertilizer, and biocontrol agent. Our previous study showed that rhizobacteria of I.5, I.21, and II.14 isolates produced chitinases. The enzymes could degrade chitin of leaf miner (Aphis gossypi) and white fly (Bemisia tabaci). This research was conducted to identify the bacteria based on 16S r-RNA gene sequences and to characterize protein of chitinase from selected rhizobacteria. PCR amplification of 16S rRNA gene yielded DNA fragments of 1300 bp for each isolate. Based on sequences of the 16S rRNA gene, I.5 isolate was similar to Bacillus sp. with similarity percentage of 88% and I.21 and II.14 isolates were similar to B. cereus with similarity percentage of 93% and 91% respectively. Zymogram analyses showed that molecular weight of chitinase from I.21 isolate was 145 kDA and 168 kDa. However, no protein bands were showed in zymogram analyses of I.5 and II.14 isolates. Three chitinolytic bacteria have an opportunity to be used as natural biocontrols and bioinsecticides.