The main difference between Bacillus cereus and Bacillus thuringiensis is that Bacillus cereus does not contain genes coding for insecticidal toxins, whereas Bacillus thuringiensis has genes coding for insecticidal toxins in plasmids.
Bacillus cereus and Bacillus thuringiensis are two types of rod-shaped bacteria that are Gram-positive. Generally, they are facultative anaerobes.
Key Areas Covered
1. What are Bacillus Cereus
– Definition, Features, Importance
2. What are Bacillus Thuringiensis
– Definition, Features, Importance
3. Similarities – Bacillus Cereus and Bacillus Thuringiensis
– Outline of Common Features
4. Difference Between Bacillus Cereus vs Bacillus Thuringiensis
– Comparison of Key Differences
Key Terms
Bacillus Cereus, Bacillus Thuringiensis
What is Bacillus Cereus
Bacillus cereus is another species of Bacillus species that is Gram-positive and rod-shaped. The bacterium occurs in the soil, food, and marine sponges. In general, some strains of Bacillus cereus are harmful and cause foodborne illnesses. Bacillus cereus cause illnesses due to its spore-forming nature. But, other strains show mutualism with certain plants. Some are beneficial as probiotics. However, the main importance of endospores of Bacillus cereus is their ability to tolerate unfavorable environmental conditions.
Figure 1: Endospore Staining Bacillus Cereus
Furthermore, Bacillus cereus is a facultative anaerobic bacterium that has numerous virulence factors. Some of the virulence factors include phospholipase C, sphingomyelinase, cereulide, and metalloproteases. The strains of Bacillus cereus are mesophilic, and therefore, the optimal temperature of the bacterium is 25 °C and 37 °C. They are also neutralophilic, and therefore, the optimal pH of Bacillus cereus is neutral pH. Another importance of Bacillus cereus is the formation of biofilms. This bacterium presents a large challenge to the food industry due to its capability to contaminate food.
What is Bacillus Thuringiensis
Bacillus thuringiensis is a soil-dwelling bacterium that has a rod shape. It is the most commonly used biological pesticide worldwide. In general, it occurs in the gut of caterpillars of different moths and butterflies. Apart from that, Bacillus thuringiensis also occurs in aquatic environments, leaf surfaces, animal feces, flour mills, insect-rich environments, and grain-storage facilities. Bacillus thuringiensis is parasitic on other moths. It forms crystal proteins known as delta endotoxins having insecticidal actions. Therefore, Bacillus thuringiensis is important as an insecticide in genetically-modified crops such as Bt corn.
Figure 2: Bacillus Thuringiensis
Moreover, the production of Bt is by regrowing the spores. The spores of the Bacillus thuringiensis are toxic to the larvae of insects. On that account, Bt is a natural source of insecticides called biopesticides. It tends to have fewer risks than typical human-made pesticides. Target insects of Bt include fly family, beetle family, butterfly family, and mosquitoes.
Similarities Between Bacillus Cereus and Bacillus Thuringiensis
- Bacillus cereus and Bacillus thuringiensis are two types of Bacillus species.
- They are rod-shaped bacteria that belong to the family Bacillaceae.
- They are facultative anaerobes.
- Both form oval endospores.
Difference Between Bacillus Cereus and Bacillus Thuringiensis
Definition
Bacillus cereus refers to a facultatively anaerobic, toxin-producing gram-positive bacterium found in soil, vegetation, and food, while Bacillus thuringiensis refers to a gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide.
Occurrence
Bacillus cereus occurs in soil, food, and marine sponges, while Bacillus thuringiensis is a soil-dwelling bacterium.
Insecticidal Toxins
Moreover, Bacillus cereus does not contain genes coding for insecticidal toxins, whereas Bacillus thuringiensis has genes coding for insecticidal toxins in plasmids.
Importance
Bacillus cereus causes food poisoning, while Bacillus thuringiensis naturally occurs in the gut of caterpillars.
Uses
Bacillus cereus is important as probiotics, while Bacillus thuringiensis has genes coding for the insecticidal toxins in plasmids.
Conclusion
In brief, Bacillus cereus and Bacillus thuringiensis are two types of rod-shaped bacteria that belong to the family Bacillaceae. Generally, Bacillus cereus occurs in soil, food, and marine sponges, causing food poisoning. However, some strains of Bacillus cereus are important as probiotics. In comparison, Bacillus thuringiensis is a soil-dwelling bacterium, occurring in the gut of caterpillars. It also has genes coding for insecticidal toxins in plasmids. Therefore, the main difference between Bacillus cereus and Bacillus thuringiensis is their importance.
References:
- Helgason E, Okstad OA, Caugant DA, Johansen HA, Fouet A, Mock M, Hegna I, Kolstø AB. Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis–one species on the basis of genetic evidence. Appl Environ Microbiol. 2000 Jun;66(6):2627-30. doi: 10.1128/AEM.66.6.2627-2630.2000. PMID: 10831447; PMCID: PMC110590.
Image Courtesy:
- “Bacillus cereus endospore stain” By T. Nims – Own work (CC BY- SA 4.0) via Commons Wikimedia
- “Bacillus thuringiensis.” By Dr. Sahay – Own Work (CC BY-SA 3.0) via Commons Wikimedia
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