As discussed earlier, the role and importance of VA is very essential in bio — ligninolysis. It is generally synthesized de novo from glucose via shikimate pathway at the early stage of secondary metabolism in parallel with the LiPs production. The biosynthetic pathway for VA was performed with 14 C isotope trapping exper­iments in the ligninolytic fungus P. chrysosporium (ATCC 34541); and concluded that the pathway proceeds as follows: Phenylalanine ^ cinnamic acid ^ Benzoate/ Benzaldehyde ^ VA [115, 123]. In P. chrysosporium, VA production is induced by nitrogen-limitation, whereas in Bjerkandera sp., the nitrogen element does not have any significant regulatory effect on the VA biosynthesis [124]. Furthermore, LiPs action on non-phenolic residue of lignin can be enhanced by addition of VA in bio­logical pretreatment of lignocellulose. As per Hammel et al. [115], VA protects LiPs against H2O2-mediated inactivation reaction (rate limiting step) in the LiPs catalytic cycle reaction (Fig. 1.2) and it has been proposed that VA act, in vivo as a stabilizer for the enzymes.