Bacillus thuringiensis is a species of aerobic bacteria that lives in soil that creates proteins toxic to some insects (Astuti et. al)
It is used as an insecticide and must be eaten by the insect to work (Astuti et. al)
Primary literature article: Exploration of Bacillus thuringiensis Berl. from soil and screening test its toxicity on insects of Lepidoptera order
Kingdom: Bacteria
Subkingdom: Posibacteria
Phylum: Firmicutes
Class: Bacilli
Oder: Bacillales
Family: Bacillaceae
Genus: Bacillus
Species: Bacillus thuringiensis
(Gervais et. al)
There are different types of Bt that control and terminate different bugs
This bacteria does not harm humans because the toxin proteins are easily digested by our bodies. Humans do not have the correct enzyme to release the harmful effects of Bt.
The bacteria is rod shaped, gram positive, and spore forming
(Gervais et. al)
Bt is found naturally in soil and eats self producing spores. (Gervais et al.)
If Bt is consumed by Manduca sexta (also known as tomato hornworm), it will harm the insect and ultimately terminate it.
(Gervais et al.)
This article studies the origin and toxicity of Bacillus thuringiensis in addition to its effects on insects
The researchers took soil samples from areas around South Sumatra and used larvae to study the effects of the bacteria
A catalyst test was performed to observe the strains of bacteria in the larvae and its effect on their lives
(Astuti et. al)
This table exemplefies the experiments ran on two species of larva
The results indicate to be either negative or positive, meaning it is not effected by Bt or is effected by Bt
The scientists tested many isolates of Bt which varied in P. xllostella
However, S. litura consistenly tested positive for the toxic effect of Bt
(Astuti et. al)
The researchers discovered the bacteria was capable of forming a structure resistant to chemicals, UV, and heat that can grow on its own (aerobically).
This research provided more information on how the bacteria works/effects insects in addition to how the bacteria is self sufficient and resistant to extreme conditions
With this information, they gain a better understanding of how the insecticide can be used for pest control as well as where it takes action in the natural environment affecting other species
(Astuti et. al)
Sources:
DT Astuti, Y Pujiastuti, Suparman SHK , N Damiri, S Nugraha , ER Sembiring, Mulawarman. 2018. “Exploration of Bacillus thuringiensis Berl. from soil and screening test its toxicity on insects of Lepidoptera order.” Conf. Ser.: Earth Environ. Sci. 102 012063.
Gervais, J.; Cocks, M.; Cross, A.; Jenkins, J. 2022. Bacillus thuringiensis (Bt) Fact Sheet; National Pesticide Information Center, Oregon State University Extension Services