Research Article Open Access

Chitinolytic Bacteria Isolated from Chili Rhizosphere: Chitinase Characterization and Its Application as Biocontrol for Whitefly (Bemisia tabaci Genn.)

Nisa Rachmania Mubarik1, Irni Mahagiani1, Amaryllis Anindyaputri1, Sugeng Santoso2 and Iman Rusmana1
  • 1 Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Jalan Agatis, Dermaga, Bogor 16628, Indonesia
  • 2 Department of Plant Protection, Faculty of Agricultural, Bogor Agricultural University, Dermaga, Bogor 16628, Indonesia

Abstract

Problem statement: Chitin, a common constituent of insect exoskeleton, could be hydrolyzed by chitinase. The research was conducted to screen chitinolytic rhizobacteria isolated from rhizosphere of chilli pepper and to determine their chitinase activity in degrading chitin of whitefly, Bemisia tabaci Genn. (Hemiptera: Aleyrodidae). Whitefly is recognized as an important pest on many crops including chilli pepper. Approach: Screening and molecular identification based on 16S rRNA sequence of chitinolytic isolates, chitinase productions, measurement of chitinase activity, characterization of chitinase and effect of the chitinase treatment on whitefly were studied. Results: A total of 25 isolates of rhizobacteria formed a clear zone on solid chitin media. Two isolates, i.e., I.5 and I.21 isolates had the highest chitinolytic index. Based on sequence of 16S rRNA gene, the isolates of I.5 and I.21 were identified as Bacillus sp. and Bacillus cereus, respectively. The highest chitinolytic index and specific activity of I.5 isolate was 0.94 and 0.11 U mg-1 proteins, respectively. Maximum production of I.5 chitinase was occured after 36 h cultivation at 30°C and pH 7.0. The highest chitinolytic index and specific activity of I.21isolate was 0.75 and 0.114 U mg-1 proteins, respectively. Maximum production of I.21 chitinase was occured after 36 h cultivation at 55°C and pH 7.0. Cell culture and crude enzyme of the isolates were tested on chitin of B. tabaci and the effect was observed using a microscope and sterile water was used as a negative control. Hydrolytic observation showed that crude enzyme of I.21 isolate could degrade chitin of B. tabaci exoskeleton and the activity was better than that of I.5 isolate. Conclusion: Chitinase produced by Bacillus cereus I.21 strain has potential application as biocontrol agents for B. tabaci.

American Journal of Agricultural and Biological Sciences
Volume 5 No. 4, 2010, 430-435

DOI: https://doi.org/10.3844/ajabssp.2010.430.435

Submitted On: 25 August 2010 Published On: 11 November 2010

How to Cite: Mubarik, N. R., Mahagiani, I., Anindyaputri, A., Santoso, S. & Rusmana, I. (2010). Chitinolytic Bacteria Isolated from Chili Rhizosphere: Chitinase Characterization and Its Application as Biocontrol for Whitefly (Bemisia tabaci Genn.). American Journal of Agricultural and Biological Sciences, 5(4), 430-435. https://doi.org/10.3844/ajabssp.2010.430.435

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Keywords

  • Rhizobacteria
  • chitinase
  • biocontrol
  • Bemisia tabaci Genn