Students from the BIMS 4491 Advanced Microbiology course presented their posters at a come and go reception this morning. These students conducted research this fall on how heat affects survival of bacterial spores produced in rich and poor growth media using a several wild-type and genetically-modified/engineered bacteria. It was an amazing amount of good work, and the students designed and completed the study from start to finish with excellent results.
Matt Durham, Jonathan Urbanczyk, and Kee’Twana Williams studied Bacillus thuringiensis (Bt), a spore-forming bacterium of economic importance because of the insecticidal crystal it produces. Their work compared heat resistance of natural and engineered strains of Bt and its non-crystal producing relative, soil microbe Bacillus cereus (Bc). Though they worked together in the lab, each looked at a different aspect of the project. Durham compared the spores of several natural varieties of Bt and Bc for heat resistance when grown in a rich medium (brain-heart infusion agar, BHI) vs. in a poor medium (soil extract agar, SEA). He found that in every case spores produced in the rich medium were far less heat resistant than those produced in SEA. Rich media seem to generate weaker spores. Urbanczyk compared wild-type, crystal-producing Bt with plasmid-cured, acrystalliferous strains. His work found that the crystal’s absence did not have a bearing on heat resistance, though the means of plasmid curing did influence resistance. Again, engineered strains were not as heat resistant when grown on BHI as on SEA. Williams looked at Bc strains which had been engineered to produce Bt crystals. It was found that introducing crystal protein did not appear to change the heat resistance of spores from that observed for wild-type strains. Again, BHI-produced spores were less heat resistant than those from SEA.
On tap next for the three will be research conferences and the pooling of their data and observations to produce a paper that will be submitted for publication this spring.
Students in the class were (see photo, from left to right) Matthew Durham, Jonathan Urbanczyk, KeeKee Williams, and Dr. Gary Wilson.
Great job!
