Tracking bacterial growth in liquid media and a new bacterial life model.
By increasing viscosity of liquid media above 8.4 centipoise (cp) i.e. 0.084 g * cm(-1) * s(-1), individual growth and family formation of Escherichia coli was continuously observed in real-time for up to 6 h. The observations showed primarily unidirectional growth and reproduction of E. coli and suggested more than one reproduction in the observed portion of E. coli life span. A new bacterial life model is proposed: each bacterium has a stable cell polarity that ultimately transforms into two bacteria of different generations; the life cycle of a bacterium can contain more than one reproduction cycle; and the age of a bacterium should be defined by its experienced chronological time. This new bacterial life model differs from the dominant concepts of bacterial life but complies with all basic life principles based on direct observation of macroorganisms.
Liu
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Department of Microbiology and Immunology, MCP Hahnemann University, Philadelphia, PA 19129, USA.