Open AccessBioefficacy of Serratia marcescens isolated from entomopathogenic nematodes (EPN) and their secondary metabolite prodigiosin against Spodoptera litura
Author(s) -
Huong Hoai Nguyen,
Kha Hoang Anh Nguyen
Publication year - 2015
Publication title -
khoa học công nghệ
Language(s) - English
Resource type - Journals
ISSN - 1859-0128
DOI - 10.32508/stdj.v18i2.1140
Subject(s) - spodoptera litura , serratia marcescens , prodigiosin , biology , microbiology and biotechnology , bioassay , spodoptera , biological pest control , botany , larva , biochemistry , escherichia coli , gene , genetics , recombinant dna
Bacterial strain SH1 was isolated from entomopathogenic nematodes (EPN) Heterorhabditis indica CP16 released from insect cavaders (Spodoptera litura). Their identification by API 20E Kit as well as by 16S rDNA sequencing showed that it belongs to the species Serratia marcescens. The isolate expressed the toxicity to Spodoptera litura. In the injection assay more than 65 % insects were killed after 10 h at 23 cfu/insect; in the ingestion assay (droplet on leaf surface), more than 50 % insects were killed after 72 h at 170 cfu/cm2. The red pigment produced by the isolate SH1 was confirmed to be one of its secondary metabolites – prodigiosin based on its color, UV/VIS spectra và ESI-MS results. When injected to Spodoptera litura at a dose of 422 ng/insect, the active compound killed approximately 65 % insects after 10 h of treatment, and in the ingestion assay (droplet on the leaf surface) at a dose of 27.66 ng/cm2 killed approximately 90 % insects after 120 h of treatment.