VARIATION IN SHAPE AND ARRANGEMENT OF BACTERIAL FLAGELLA

Abstract
Variation of both flagellar shape and arrangement occurs in 3 distinct types of bacteria. Lateral flagella are produced frequently in young cultures of Aeromonas which produce only polar, monotrichous flagella in older cultures. Individuals with polar, peritrichous and mixed flagellation are found in a culture of a yellow (H2O-insoluble pigment) organism. The polar and lateral flagella show a distinct difference in a curvature. Stable variants could not be obtained. A polar (lophotrichous) to peritrichous type of variation occurs in a culture physiologically classified as Alcaligenes. Various intermediary stages with both types of flagella on the same individual are demonstrated. The peritrichous variant appears to be stable but the lophotrichous variant tends to produce individuals with mixed flagellation and also an occasional individual with peritrichous flagella. The taxonomic implications of these phenomena are discussed. Hypothesis, all flagella may have a polar origin and peritrichously flagellated bacteria are multicellular. 2 observations are made bearing on the evolutionary trend in bacteria from polar flagellated to peritrichous flagellated types.
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