• Microbiology and Biotechnology Letters
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• v.14 no.4
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• pp.329-334
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• 1986

Bacillus thuringiensis serovar israelensis H 14 strain was cultured in 4 different fermentation M-media and then measured the rates of their growths and the productions of endotoxin crystals front the media. Out of the four M-media the production of endotoxin crystals and spores was maximal in M-4 medium (pH 9). The wet weight of the cells grown in the 150$m{\ell}$ culture was approximately 3.901g and the number of viable spores was 1.53$\times$10$^{12}$ per nil and the ratio of the endotoxin over the total cell weight was 18.54%. The generation time was about 89.3 minutes in the M-1 medium, 124.1 minutes in the M-2, 97 minutes in the M-3, 130.8 minutes in the M-4. The proper pHs for the production of the endotoxin appeared to be 6.5 to 7.5.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.177-182
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• 1996

Effects of 14 carbohydrates supplied as carbon sources on cell growth and sporulation of, and the production of insecticidal crystal proteins by Bacillus thuringiensis strains were investigated in liquid cultures. Strains grew well in media containing any one of the 14 carbohydrates supplied, reaching maximum cell densities of $10^7{\sim}10^8\;cells/ml$ in 16.7 to 22 hours after inoculation depending on the strain. Spores first appeared in 16.7 to 24.7 hours after inoculation, and 80% sporulation was reached in 28 to 51.3 hours after inoculation depending on the strain. No change in pH of media was observed after cell multiplication. The production of total protein was highest when supplied with sucrose and was lowest with starch. More insecticidal crystal proteins were produced when supplied with glucose, lactose, maltose, or sucrose. The amount of insecticidal crystal proteins produced by the strains was proportional to that of the total protein. The relative amount of individual insecticidal crystal protein species produced by B.t. kurstaki and B.t. israelensis was not influenced by the carbohydrates supplied.

• Korean journal of applied entomology
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• v.28 no.3
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• pp.167-174
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• 1989

A confined field assessment on the integrated control of vector mosquitoes (Anopheles sinen- sis and Culex tritaent'orhynchus) was conducted by timely treatment of Bacillus thuringiensis(H-14) formulation in the presence of larvivorous fish (Aplocheilus lalipes) in natural rice fields of $30,000M^2$ at Yongam, South Korea Cholla Province from July through October in 1988. In presence of larvivorous fish (Aplocheilus) at lower density of 0.6 fish per $M^2$ water surface, mosquito vector control rates ranged 55. 0~57. 6% from July through August, and when the mosquio density started to increase with over 10 larvae on the average per sample, B.t.(H-14) formulation treatment at the rate of 1. 0 Kg/ha made 100% vectors reduc¬tion in 24 hours, the control sustained above 98% until the test was terminated on October 11th. In the fish introduced rice paddies with Aphyocypris chinensis at the density of above 1. 5 fish per $M^2$, a satisfactory degree of vector control was obtained by 88. 2~96. 7% in 2 week period until September 21st. In the absence of larvivorous fishes, B.t. (H-14) treatment made 100% control in 24 hours, however, vector population rebound appeared in day 7, required to make additional treatment to suppress population down.