This section will highlight the biodegradability aspect of Bt toxin while also disclosing if Bt toxin is endotoxin or exotoxin. Other aspects targeted would be:
- Is Bt toxin an insecticide?
- Why is Bt toxin regarded as the safest insecticide?
- What are the applications and uses of Bt toxin?
- Is Bt toxin endotoxin?
- Is Bt toxin biodegradable?
- FAQs
Is Bt toxin endotoxin or exotoxin and is it biodegradable?
Bt toxin is produced from a bacterium called Bacillus thuringiensis and therefore, it is regarded as biodegradable. It is an endotoxin and hence is a lipopolysaccharide in nature
The Bt toxin is used as an insecticide with a wide variety of other applications as well that include anti-cancer activities and the production of useful biopolymers.
Bt toxin is regarded as one of the safest insecticides and as per EPA, there are no hazardous or harmful effects of Bt toxin on life and human health. Insecticides such as DDT may cause eggshell thinning, bioaccumulation, and soil and water pollution.
Is Bt toxin an insecticide?
This section will cover the basic introduction to what Bt toxin is. If one guesses from the name, one may wonder that Bt toxin is some kind of harmful material because of the word toxin.
However, it is not the case. Yes, Bt toxin is an insecticide. In fact, it is regarded as one of the safest insecticides.
The main problem with insecticides is that the effects of insecticides are not just limited to the target organisms. Rather, non-target organisms are also affected by most of the common day insecticides. This results in more harm than good.
When it comes to the issue of insecticide, the disclosure of DDT becomes imperative. DDT is also an insecticide which was introduced somewhere in the 1940s and till the 1970s it was commonly used.
Due to the varied applications of DDT, it was found in almost every store and every house because everyone liked DDT. This was chiefly because of the versatile uses of DDT.
However, it was later discovered that what was regarded as a friend was actually a foe. Many harmful effects of DDT were discovered such as bioaccumulation and thinning of eggshells.
The effects of DDT were reciprocated at many levels of the food chains and many habitats were either altered or destroyed by the negative implications of DDT.
Therefore, the need for harmless insecticides has always been there. Many claim that Bt toxin is an answer to all such needs.
Before we proceed any further, let us understand what insecticides are. As per the definition, insecticide is a type of pesticide that is intended to either harm or kill one or more specie(s) of insects. Insecticides may achieve their function in a variety of ways.
Insecticides may be of different types. These may include:
- Organic
- Synthetic
- Inorganic
- Miscellaneous
The most common insecticides are the following:
- Sevin garden insecticides
- Malathion
- Boric Acid roach powder
- Thuricide HPC
- Neemix 4.5
Why is Bt toxin regarded as the safest insecticide?
Common pesticides or insecticides may introduce us to a number of environmental and medical problems because non-target organisms (including humans) can also be affected by the effects of insecticides.
The common negative effects rendered by most of the insecticides are:
- Highly persistent pollutants
- Eggshell thinning
- Loss of life
- Bioaccumulation in various ecosystems
- Breeding failure
- Infiltration into the food chains and food webs
- Nausea
- Tremors
- Cancer
- Reproductive problems
- Tumours
- Developmental abnormalities
- Neuro Complications
- Vertigo
- dizziness
- Neurological anomalies
As it can be seen that the effects of conventional insecticides are not just limited to organisms but are also reciprocated to humans and other forms of life, as well.
These negative effects are the very reason why Bt toxin is highly regarded. This is because there are no such implications for Bt toxin. But what Bt toxin is in the first place?
Bt is a soil-dwelling, gram-positive bacterium. There are two types of bacteria namely gram-positive and gram-negative. This is a classification system to better understand and approach the issue and idea of bacteria.
A toxin is any substance or material that may prove to be hazardous or lethal to any particular set of organisms.
Bt toxin is a toxin that is produced by the bacterium Bacillus thuringiensis. This toxin can be used as a natural and biological insecticide because Bt toxin is known to kill insects that may cause harm to crops and vegetation.
It is claimed that the invention of Bt toxin as an insecticide has been a major one because it is regarded as one of the best available microbial insecticides that are effective against a plethora of insects.
Another factor that really makes Bt toxin a remarkable discovery is the ability or capacity of Bt toxin to be genetically modified to cater to the increased resistance in insects.
In this way, Bt toxin has the capacity to never get obsolete and will keep on tackling the issue of insects and pests that cause loss of financial substantiality and loss of crops.
What are the applications and uses of Bt toxin?
This section can be explained through two frames. One is what are the effects that are not caused by Bt toxin but would have been caused by its counterparts. The other factor is the direct applications of Bt toxin.
Insecticides are known to cause a lot of damage to crops, substantiality, economy, and the environment. A number of these effects already have been rummaged in the previous sections.
Let us further probe into this matter. To further deepen our understanding of insecticides, there was a study conducted in 2009. In the study, about 356 workers were exposed to the effects of insecticides. It was seen that all the workers showed adverse medical signs.
The workers showed significant neurological impacts. The ECG and LDH of the workers also came in different ways that implied the possibility of cardiotoxicity.
The implications were not only restricted to medical symptoms but were also expanded to neurological, psychological and behavioural symptoms and anomalies.
It was also studied that by exposure to insecticides there was a significant rise and increase in fertility and reproductive complications.
Humans are not the only species that are affected by the detrimental impacts of insecticides such as DDT. Many other spices are also affected.
For example, insecticides may bioaccumulate at various levels of food chains where they may stem medical complications.
Insecticides are also associated with thinning of eggshells of birds due to which birds are not rightly protected leading to death. If the effects are not tampered with, it could lead to the endangerment of species too.
Insecticides are also known to pollute waterways and land soil. Further, the effects of insecticides on aquatic species are also well-stanced.
As a result of these effects, we have Bt toxin. It may have the following applications. These applications adhere to the second aspect of the uses of Bt toxin.
- Toxic against mites
- Toxic against nematodes
- Toxic against ticks
- Effective against pathogenic and harmful bacterial
- Effective against pathogenic and harmful fungi
- Anti-cancer activities
- Biosynthesis of nanoparticles
- Production and assimilation of biopolymers
- Production of helpful bioproducts
Is Bt toxin endotoxin? (3 differences between endotoxin and exotoxin)
When it comes to toxins, there are two types of toxins that are usually categorised. One is endotoxin and the other is exotoxin.
You may wonder about the difference between the two. This section will shed light on the difference between endo and exo toxin and will also disclose what type of toxin Bt toxin is.
The primary difference between endotoxins and exotoxins is that the latter is liberated when the bacteria die. Endotoxins are part of the outer membrane of the cell and are lipopolysaccharides in nature.
Exotoxin, on the contrary, is a protein-based toxin secreted by bacteria as a part of its growth and metabolism. Therefore, it can be guessed that exotoxins are:
- Highly antigenic
- Highly toxic
- Has high enzymatic activity
Based on the introduction of Bt toxin, it is very easy to guess that Bt toxin is an endotoxin because it is regarded as a safe insecticide.
Is Bt toxin biodegradable?
Biodegradability is defined as the process of breakdown of waste into simpler products by the action of microbes and enzymes. The term biodegradability is coined from two terms. These are bio and degradation.
Bio means life and degradation means the breakdown into simpler materials. This breakdown is very essential because it is a parameter to ensure that there is no waste generation and no waste accumulation.
If there is waste accumulation, there will be pollution and natural habitats will be disrupted. A common example of biodegradation can be the spoilage of food or rotting vegetables.
Biodegradability can also be analogised to the Earth’s dustbin because it is a process to treat and segregate waste. Biodegradability ensures that the waste gets back to the system and is properly utilised.
However, not all waste is biodegradable. When it comes to biodegradability, there are two types of waste that are present. These include biodegradable and non-biodegradable waste.
Biodegradable waste is the type of waste which can be degraded by the action of microbes and enzymes over a short period of time. Regarding this type, there is a general rule of thumb that biodegradable waste is mostly sourced from natural sources.
Examples of biodegradable waste include plant waste, animal waste, sewage, manure, waste from slaughterhouses et cetera.
Next, we have non-biodegradable waste. This type of waste is mostly sourced from non-natural sources such as the products of fossil fuels. This type of waste won’t degrade readily by the action of microbes.
It is claimed that this type of waste may require even a thousand years to degrade. Therefore, it will lead to waste accumulation and negative impacts. Because of this, non-biodegradable waste is of more significant concern to environmentalists as compared to biodegradable waste.
Examples of non-biodegradable waste include synthetic plastics, synthetic fibres, epoxies, hazardous waste, nuclear waste, electronic waste et cetera.
Based on this detail, it can be said that since Bt toxin is sourced from nature (bacterium) it is easily biodegradable. There is no facet of non-naturality when it comes to Bt toxin.
Conclusion
It is concluded that Bt toxin is produced from a bacterium called Bacillus thuringiensis and therefore, it is regarded as biodegradable. It is an endotoxin and hence is a lipopolysaccharide in nature
The Bt toxin is used as an insecticide with a wide variety of other applications as well that include anti-cancer activities and the production of useful biopolymers.
Bt toxin is regarded as one of the safest insecticides and as per EPA, there are no hazardous or harmful effects of Bt toxin on life and human health. Insecticides such as DDT may cause eggshell thinning, bioaccumulation, and soil and water pollution.
Frequently Asked Questions: Is Bt toxin endotoxin or exotoxin and is it biodegradable?
Why is Bt toxin better than other pesticides?
It is better because it does affect non-target organisms and also it has the capacity to genetically change to cater for improved pest and insect resistance.
What are Bt crops?
Bt crops are those crops that have the gene of Bt engineered in their gene pool. As a result, Bt crops do not require the Bt bacteria to make the Bt toxin. They are made inherently capable of that.
References
- Entomology Society of America. (May 2018). Is Bt safe for Humans to Eat? Retrieved from: https://www.entsoc.org/sites/default/files/files/Science-Policy/2018/ESA-Factsheet-Bt.pdf
- Aktar, W., Sengupta, D., & Chowdhury, A. (2009). Impact of pesticides use in agriculture: their benefits and hazards. Interdisciplinary toxicology, 2(1), 1-12.
- US EPA. Insecticides. Retrieved from: https://www.epa.gov/caddis-vol2/insecticides
- Jouzani, G. S., Valijanian, E., & Sharafi, R. (2017). Bacillus thuringiensis: a successful insecticide with new environmental features and tidings. Applied microbiology and biotechnology, 101(7), 2691-2711.
- Soberón, M., Pardo-López, L., López, I., Gómez, I., Tabashnik, B. E., & Bravo, A. (2007). Engineering modified Bt toxins to counter insect resistance. Science, 318(5856), 1640-1642.
- Mendelsohn, M., Kough, J., Vaituzis, Z., & Matthews, K. (2003). Are Bt crops safe?. Nature biotechnology, 21(9), 1003-1009.
- Huesing, J., & English, L. (2004). The impact of Bt crops on the developing world.
- Popoff, M. R. (2018). “Bacterial Toxins” Section in the Journal Toxins: A Fantastic Multidisciplinary Interplay between Bacterial Pathogenicity Mechanisms, Physiological Processes, Genomic Evolution, and Subsequent Development of Identification Methods, Efficient Treatment, and Prevention of Toxigenic Bacteria. Toxins, 10(1), 44.