Fig. 7

Diagram of the wood block and selected sample positions for morphological analysis by scanning electron microscopy (top). Electron micrographs of cross-sections of the wood block (bottom): a untreated sample at the center middle location, b 4-min pretreated sample at the edge middle location, c 4-min pretreated sample at the outside top middle location, d 18-min pretreated sample at the edge middle location, e 18-min pretreated sample at the center top location, and f 18-min pretreated sample at the center middle location. Red arrows lignin aggregates. Scale bar 2 μm