1-34: Cellulolytic activity of microbes isolated from the guts of wood-feeding beetles in Indonesia

Larvae of several orders of insects can feed on lignocellulosic materials such as wood, and rely on gut microbes to degrade the complex polymers to simpler carbohydrates.  These insect larvae include wood-feeding beetles, woodwasps, and carpenterworm moths. In a quest for novel cellulases and other useful activities, we have cultured bacteria, filamentous fungi and yeasts from the guts of wood-feeding larval insects in a rain forest in Indonesia.  Larvae were gathered from tunnels in decaying logs, dissected, and gut contents plated to cultivate bacteria or fungi.  Microbes were identified by ribosomal sequencing.  Insect larvae were identified by sequencing the DNA barcode (the mitochondrial gene COX1). Insect larval families included Passalidae, Cerambycidae, Scarabaeidae, and Cossidae, which are all well-known wood-feeding insect families.  Many yeasts isolated from insect guts were species known to be associated with beetles or decaying wood, such as Pichia stipitis, Candida novakii, Wickerhamomyces alni, Candida ergastensis, and Pichia scolyti.  Thirteen novel species of yeasts were identified.  Yeasts, bacteria and filamentous fungi were screened for degradation of carboxymethylcellulose, AZCL-conjugated substrates, and fermentation of cellobiose or xylose.  Our preliminary screening showed that 42 filamentous fungi, 3 yeasts and 2 bacteria were able to degrade carboxymethylcellulose. Genetic analysis is underway to identify genes responsible for novel activities.