Mineralization of ¹⁴ C-Ring-Labeled Synthetic Lignin Correlates with the Production of Lignin Peroxidase, not of Manganese Peroxidase or Laccase

Abstract

Recently, Mn(II) has been shown to induce manganese peroxidases (MnPs) and repress lignin peroxidases (LiPs) in defined liquid cultures of several white rot organisms. The present work shows that laccase is also regulated by Mn(II). We therefore used Mn(II) to regulate production of LiP, MnP, and laccase activities while determining the effects of Mn(II) on mineralization of ring-labeled synthetic lignin. At a low Mn(II) level, Phanerochaete chrysosporium and Phlebia brevispora produced relatively high titers of LiPs but only low titers of MnPs. At a high Mn(II) level, MnP titers increased 12to 20-fold, but LiPs were not detected in crude broths. P. brevispora formed much less LiP than P. chrysosporium, but it also produced laccase activity that increased more than sevenfold at the high Mn(II) level. The rates of synthetic lignin mineralization by these organisms were similar and were almost seven times higher at low than at high Mn(II). Increased synthetic lignin mineralization therefore correlated with increased LiP, not with increased MnP or laccase activities.

Physiology and molecular biology of the lignin peroxidases of Phanerochaete chrysosporium

“…These data not only indicated for the first time that the LiPs play a dominant role in lignin degradation but also showed that a strain of P. chrysosporium which lacked LiP activity could still degrade lignin, albeit to a minor extent. These conclusions were independently corroborated by later studies of Bonnarme and Jeffries [39] and Perez and Jeffries [45], who observed that LiP production is completely suppressed in the presence of high levels of Mn(II) and that only 10-11% of the lignin degradation occurs in such a medium, as compared to an identical medium with low levels of Mn(II) in which both LiPs and MnPs are produced. The above results further indicated that LiP production in P. chrysosporium is regulated differently, at least in some aspects, from MnP production and that LiPs play a dominant role in mineralizing synthetic [14C]lignin in liquid cultures.…”

The effect of manganese on the production of Phanerochaete flavido-alba ligninolytic peroxidases in nitrogen limited cultures

“…3E). In analogous chromatographic conditions in P. chrysosporium [15,20] and Bjerkandera spp. [17] cultures, LiP peaks exhibiting lower retention time than those showing MnP activity has been described.…”

“…Fast protein liquid chromatography (FPLC) of haemproteins was performed according to Perez and Je¡ries [15]. Peak detection was monitored at 280 nm (for total proteins) and at 405 nm (for haemproteins).…”

Lignin-modifying enzymes from selected white-rot fungi: production and role from in lignin degradation

“…The production of LiP correlates, i.e. is simultaneous with the degradation of JaC-[Ring]-DHP to 14CO2 in P. radiata [28] and in P. chrysosporium [62]. Apparently, high evolution of 14CO, from 14C-[Ring]-labeIled DHP is in good correlation with the production of LiP in the cultures, provided that the fungus produces MnP.…”