Maceration of Clover and Grass Leaves by Lachnospira multiparus.

A strain of Lachnospira multiparus, a pectin-hydrolyzing bacterium from the rumen, was incubated in nutrient media in the presence of surface-disinfected clover leaflets. When the culture flasks containing the leaflets together with Lachnospira were shaken after overnight incubation, extensive maceration of the leaflets was seen, although uninoculated control leaflets remained intact during a similar treatment. Examination of inoculated leaflets by transmission electron microscopy showed extensive invasion of intercellular areas of the mesophyll tissue but only minor invasion of vascular tissue. Cutting the leaves before incubation greatly increased the ability of L. multiparus to colonize and macerate the leaflets. Similar experiments with grass leaves are also described, and the possible role of maceration in the digestion of plant material in the rumen is discussed. Although Lachnospira stains gram variable and often gram negative, the ultrastructure of the cell wall was that of a gram-positive bacterium.