Characterization of Local Isolates Bacillus thuringiensis from Soil at Bandung City
Ismawati (a*), Herri S. Sastramihardja (b), Ridad Agoes (b)
a) Faculty of Medicine, Universitas Islam Bandung
Jalan Tamansari 22, Bandung 40116, Indonesia
*ismawati[at]unisba.ac.id
b) Faculty of Medicine, Universitas Islam Bandung
Jalan Tamansari 22, Bandung 40116, Indonesia
Abstract
Bacillus thuringiensis is a ubiquitous rod shape Gram-positive bacteria with capability of forming endospores. In the sporulation phase, B.thuringiensis produces crystal proteins coded by cry4 gene which has insecticidal activity (bioinsecticides), including against larvae of mosquitoes. This study had been conducted to get an information about characterization of local isolates B.thuringiensis from soil at Bandung city. This is a descriptive study to find local isolates of B.thuringiensis which have cry4 gene. The media used in this study were Nutrient Agar (NA) and selective media (differential) Luria Bertani (LB) acetate buffer 0.25 M pH 6.8. B.thuringiensis isolates were analyzed by polymerase chain reaction (PCR) method for sensing cry4 genes existence. A total of 22 soil samples from 30 analyzed samples showed positive results containing 61 colonies of suspected B.thuringiensis. PCR results for 61 isolates using BtSpoOA primers showed that 28 isolates contained DNA of B. thuringiensis. Subsequent testing of 28 isolates using Un4 primers showed that there were 7 isolates that had the cry4 gene. It concluded that there are 7 isolates from this study that can be further tested to be developed into bioinsecticides againts larvae of mosquitoes.
Keywords: Bacillus thuringiensis; cry4 gene; bioinsecticides
Topic: Basic and Clinical Medical Sciences