Conversion of pentoses to @entity1068 by XXXX and fungi.

@entity6122 @entity26 @entity27753 @entity505 @entity375 @entity1068 @entity413
Fermentation of @entity6122 is of interest in enhancing the yield of @entity1068 obtainable from lignocellulosic hydrolysates. Such hydrolysates can contain both pentoses and hexoses, and while technology to convert hexoses to @entity1068 is well established, the fermentation of pentoses had been problematical. To overcome the difficulty, @entity375 and fungi have been sought and identified in recent years that can convert @entity6122 into @entity1068 . However, operation of their cultures in the presence of the @entity27753 to obtain rapid and efficient @entity1068 production is somewhat more complex than in the archetype alcoholic fermentation, @entity375 on @entity413 . The complexity stems, in part, from the association of @entity1068 accumulation in cultures where @entity6122 is the sole @entity505 source with conditions that limit growth, by @entity26 in particular, although limitation by other nutrients might also be implicated. Aspects of screening for appropriate organisms and of the parameters that play a role in determining culture variables, especially those associated with @entity1068 productivity, are reviewed. Performance with @entity6122 as sole @entity505 source, in sugar mixtures, and in lignocellulosic hydrolysates is discussed. A model that involves biochemical considerations of @entity6122 metabolism is presented that rationalizes the effects of @entity26 on cultures where @entity6122 is the sole @entity505 source, notably effects of the specific rate of @entity26 use on the rate and extent of @entity1068 accumulation. Alternate methods to direct fermentation of @entity6122 have been developed that depend on its prior isomerization to @entity6122 , followed by fermentation of the pentulose by certain @entity375 and fungi. Factors involved in the biochemistry, use, and performance of these methods, which with some organisms involves sensitivity to @entity26 , are reviewed.
