Tracheid avicelase-treated

Figure 10. Avicelase-treated early -wood tracheid wall evincing partial dissolution of wall substance in S2 near a pit chamber. Scale = 1 fim.

Sprucewood holocellulose was treated with an endo-p-1,4-mannanase isolated from Aspergillus niger and an endo-/3-1,4-xylanase, two avicelases, and a cellobiohydrolase C isolated from Trichoderma viride. The mannanase hydrolyzed about a quarter of the mannan in 2-3 days without xylan or cellulose degradation. The xylanase hydrolyzed about half the xylan with 10% mannan solubilization. The three cellulases hydrolyzed up to 45% of the cellulose and 20% of the xylan, accompanied by 40-70% solubilization of the mannan. Combined xylanase-mannanase treatment hydrolyzed about half the xylan and mannan. Addition of mannanase to to cellulose-treated samples increased the degradation of the cellulose and mannan. Micromorphological studies of the variously treated specimens revealed a loss of substances in P/Slf T, and adjacent zones of S2 of the tracheid wall. 

Avicelases or Cellobiohydrolase C. In holocellulose treated with an avicelase or with cellobiohydrolase C, the degradation of the tracheid wall is very intense. This is mostly concentrated in the Si and adjacent zones of S2 as well as in the tertiary wall region (Figure 9). In the middle part... 

Figure 9. Avicelase-1-treated early-wood tracheid with degradation especially in Si and partially in T. Scale = 1 pm.

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See also in sourсe #XX -- [ , ]

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