Related Experiment Videos
Urea-mercaptoethanol-soluble protein from spores of Bacillus thuringiensis and other species
Abstract:
Treatment with urea-mercaptoethanol of purified spores of Bacillus thuringiensis, other Bacillus species, and Clostridium roseum solubilizes a protein fraction between 5 and 12% of the dry weight of the spores. This fraction behaves identically to the crystal protein of B. thuringiensis on acrylamide-gel electrophoresis. The protein from all of the Bacillus species shows partial homology with crystal protein, using the Ouchterlony immunodiffusion technique. A further fraction, similar in amount, can be removed from spores of B. thuringiensis by the addition of sodium lauryl sulfate to the urea-mercaptoethanol. Spores of B. thuringiensis extracted in these ways show no difference when compared to untreated spores with respect to viability or resistance to heat and ultraviolet-irradiation. The extracted spores do show differences in their germination requirements and their susceptibility to phase-darkening by lysozyme. It is concluded that an urea-mercaptoethanol-soluble protein or class of protein is a widespread component of bacterial spores, possibly located in the spore coat, and that this protein may be related to the crystal protein of B. thuringiensis.
Insights
A protein fraction solubilized from bacterial spores using urea-mercaptoethanol is widespread and may relate to crystal proteins. This extraction did not affect spore viability or resistance.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Bacterial spores possess protective layers and unique proteins.
- Bacillus thuringiensis produces crystal proteins with insecticidal properties.
Purpose of the Study:
- To investigate the presence and characteristics of urea-mercaptoethanol-soluble proteins in bacterial spores.
- To determine the relationship between these proteins and the crystal proteins of Bacillus thuringiensis.
Main Methods:
- Solubilization of spore proteins using urea-mercaptoethanol and sodium lauryl sulfate.
- Analysis of protein fractions using acrylamide-gel electrophoresis.
- Immunological comparison with crystal proteins via Ouchterlony immunodiffusion.
Main Results:
- A protein fraction (5-12% of dry weight) was solubilized from various bacterial spores.
- This fraction showed identical behavior to Bacillus thuringiensis crystal protein on electrophoresis.
- Homology was observed between extracted proteins and crystal proteins across Bacillus species.
Conclusions:
- A widespread urea-mercaptoethanol-soluble protein component exists in bacterial spores, potentially in the spore coat.
- This protein may be related to the crystal protein of Bacillus thuringiensis.
- Spore extraction altered germination and lysozyme susceptibility but not viability or resistance.