TY  - JOUR
T1  - Effect of Dissolved Oxygen on the Growth, Sporulation
and Larvicidal Activity of Bacillus sphaericus 2362
A1  - Abdul Karim, Mohamed Ismail
LA  - English
LA  - English
PB  - Universiti Putra Malaysia Press
YR  - 1996
UL  - http://discoverylib.upm.edu.my/discovery/Record/oai:psasir.upm.edu.my:3217
AB  - Bacillus sphaericus produces bacterial protein toxin capable of killing larvae of mosquitoes which spread diseases such as filariasis, encephalitis and
malaria. In batch culture, a maximum spore count of 2.9 x 109/ml media was obtained after 48 h cultivation. In continuous culture, a dilution rate
of 0.10 hr- I was found to give a higher spore count than 0.15 h- 1 and 0.2 h- I dilution rates. Kinetic studies on dissolved oxygen (DO) levels showed that
20,50 and 100% gave rapid formation of free spores, whilst 5% DO gave
poor results. Cells grown at 5, 20 and 50% DO levels gave comparable
values of mosquito-larvicidal activity while those grown at 100% DO were
significantly less toxic.
ER  -