This guideline is from another university, but can serve as a helpful guide for formulating/writing a thesis proposal.
Bacteria with cytoskeletons/evolutionary tree
Biofilm formation in disease, the environment, or industry
Quorum sensing: how bacteria communicate
Development in prokaryotes- spore formation, Caulobacter, Myxococcus, Streptomyces
Life in extreme environments
Extraterrestrial life
Biodegradation of anthropogenic compounds (PCB's, dioxins pesticides, etc.) by bacteria
Evolution of life
Antibiotic/antiviral resistance mechanisms
How to prevent antibiotic resistance
Antibacterial products
Symbiotic relationships between bacteria and other organisms
Viable, but non-culturable organisms
Source:https://www.science.smith.edu/