Monday, April 29, 2013
Exhibit Hall
A biological method of removing or modifying lignin could reduce or eliminate the high energy and chemical inputs and enable lower cost, environmentally friendly biofuel production. The microorganisms in rainforest soils have developed enzymatic systems for the rapid turnover of plant organic matter. The goal of the present research was to discover and characterize novel lignin-degrading enzymes from microorganisms including bacteria and fungi present in rainforest soil. More than 500 fungal isolates were screened for their ability to grow on Kraft lignin and to transform the dye Remazol brilliant blue R (RBBR). The activities of three ligninolytic enzymes, manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase, were measured during growth in Vogel’s medium. Four of these fungal isolates, P1H9, P2C1, P2C3, and P3E7, produced higher ligninolytic enzyme activities than the other isolates. These were further characterized using phenolic substrates, Kraft lignin and lignin model dimers, and poplar biomass. Furthermore, the enzymes responsible for these ligninolytic activities have been isolated and characterized.