Extension of bundles of cellulose microfibrils on agar surfaces by Acetobacter xylinum

Abstract

The extension of bundles of bacterial cellulose microfibrils on agar surfaces was investigated using pseudoreplicas in the electron microscope. Two classes of bundles were distinguishable; those which were composed of many short individual microfibrils of nearly uniform length (1–3 μ) and those in which there were only a few long microfibrils (> 50 μ). The growth pattern of single straight cellulose microfibrils, the proportion of bundles containing many short microfibrils and the extent of coiling of microfibrils were influenced strongly by the sample of agar used to form the surface. These observations are consistent with the suggestion that the mode of extension of bacterial cellulose microfibrils is sensitive to the concentration of an extracellular precursor in small pools on the agar surface.