Toxicity of bacillus thuringiensis subsp. kurstaki strain HD-1 against insect larvae
4
Issued Date
1991
Copyright Date
1991
Resource Type
Language
eng
File Type
application/pdf
No. of Pages/File Size
xvi, 97 leaves : ill.
Access Rights
open access
Rights
ผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้า
Rights Holder(s)
Mahidol University
Bibliographic Citation
Thesis (M.Sc. (Microbiology))--Mahidol University, 1991.
Suggested Citation
Sukon Tantipaibulvut Toxicity of bacillus thuringiensis subsp. kurstaki strain HD-1 against insect larvae. Thesis (M.Sc. (Microbiology))--Mahidol University, 1991.. Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/103430
Title
Toxicity of bacillus thuringiensis subsp. kurstaki strain HD-1 against insect larvae
Alternative Title(s)
ความเป็นพิษของเชื้อแบคทีเรีย Bacillus thurin giensis สายพันธุ์ kurstaki HD-1 ต่อหนอนศัตรูพืช
Author(s)
Abstract
B. thuringiensis subsp. kurstaki HD-1 contains two types of proteinaceous crystals, that is a bipyramidal crystal (M(,r) = 134 kDa), which is toxic to lepidopteran larvae, and a cuboidal crystal (M(r) = 65 kDa), which is toxic to dipteran larvae. In order to study the toxicities of these toxin, the purified crytals must be obtained. Vigorous shaking in 0.2 M NaCl was used to produce purified crystals containing impurities of 1.3% spores from cultures of B. thuringiensis subsp kurstaki HD-1. Bioassays of these crystals were done against Spodoptera exigua and Aedes aegypti larvae in parallel with the sample derived from cultures washing in distilled water and/or the sample derived from cultures washing in 1 M. NaCl. When S. exigua larvae were used, the sample derived from cultures washing in 1 M NaCl gave highest toxicity than others. This sample gave LC(,50) = 62 crystals/mm(,2) diet surface in first instar larvae to 1291 crystals/mm(2) diet surface in fifth instar larvae. While the purified crystals gave the least toxicity, it gave LC(,50) = 207 crystals/mm(2) diet surface against first instar larvae to 32,734 crystals/mm(2) diet surface in fifth instar larvae. When mosquito larvae were used to test all of these specimens the purified crystals was the most effective one when it was compared with the crude preparations. The LC(,50) was 3,682 crystals/ml against early instar larvae and 23,550 crystals/ml against late instar larvae. When the intact crystals were solubilized in 2% 2-mercaptoethanol at pH 10, the 134-kDa protein was recovered. After this protein was removed, the residue was solubilized in 0.1 M NaOH and the 65-kDa protein was obtained. The toxicity of these proteins were tested against third instar larvae of S. exigua and second instar larvae of Ae. aegypti. The 139-kDa protein could kill S. exigua larvae with 2 folds higher activity than that of the intact crystal. The 65-kDa protein could kill Ae. aegypti larvae with 10 folds higher activity than those of the intact crystals. However, this protei
Description
Microbiology (Mahidol University 1991)
Degree Name
Master of Science
Degree Level
Master's degree
Degree Department
Faculty of Science
Degree Discipline
Microbiology
Degree Grantor(s)
Mahidol University