A pyruvated mannose-specific xanthan lyase involved in xanthan degradationby Paenibacillus alginolyticus XL-1

The xanthan-degrading bacterium Paenibacillus alginolyticus XL-1, isolated from soil, degrades approximately 28% of the xanthan molecule and appears t o leave the backbone intact. Several xanthan-degrading enzymes were excrete d during growth on xanthan, including xanthan lyase. Xanthan lyase producti on was induced by xanthan and inhibited by glucose and low-molecular-weight enzymatic degradation products from xanthan. A xanthan lyase with a molecu lar mass of 85 kDa and a pI of 7.9 was purified and characterized. The enzy me is specific for pyruvated mannosyl side chain residues and optimally act ive at pH 6.0 and 55 degrees C.