The bacterial reproduction process of binary fission differs from mitosis in that:
Binary fission represents prokaryotic division program fundamentally distinct from eukaryotic mitosis in mechanism and regulation. Initiation begins with replication of single circular chromosome from unique origin oriC proceeding bidirectionally via replisomes containing DNA polymerase III. Segregation of origins is mediated by ParABS partitioning system and SMC condensin complexes moving DNA toward opposite poles as cell elongates via MreB-guided peptidoglycan insertion. Division site selection uses precise regulatory systems: oscillating MinCDE proteins concentrate MinC inhibitor at poles preventing polar Z-ring assembly, and nucleoid occlusion proteins SlmA in E. coli and Noc in B. subtilis bind chromosomal DNA blocking FtsZ polymerization over nucleoids, ensuring tubulin homolog FtsZ assembles into contractile Z-ring only at mid-cell between separated chromosomes. FtsZ then recruits FtsA, ZipA, FtsQ, FtsL, FtsW and FtsI transpeptidase that synthesize septal wall and drive constriction via GTP hydrolysis. No microtubule spindle, kinetochores, centrosomes or chromosome condensation occurs, and daughters are monoploid identical cells, making absence of spindle the defining difference from mitosis.
Ref: Madigan et al., Brock Biology of Microorganisms, 16th ed., Chapter 4: Binary Fission and Absence of Spindle Apparatus.