Cellulases from Insects
Cellulases from Insects
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DOI：
10.1007/10_2013_206
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发表时间：
2013-01-01
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影响因子：
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通讯作者：
Twyman, Richard M.
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文献类型：
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作者：
Fischer, Rainer;Ostafe, Raluca;Twyman, Richard M.
目前，生物乙醇是通过含糖和淀粉作物的发酵生产的，但废弃植物生物质是一个更丰富的来源，因为糖可以直接从纤维素中提取。生物质制乙醇过程中的限制性步骤之一是将纤维素降解为可发酵的糖（糖化）。这目前依赖于使用细菌和/或真菌纤维素酶，其在生物精炼条件下往往具有低活性并且容易被抑制。一些昆虫以植物生物质为食，可以有效地降解纤维素以产生葡萄糖作为能源。虽然昆虫最初被认为需要与细菌和真菌的共生关系来分解纤维素，但网翅目（Dictyoptera）、直翅目（Orthoptera）和鞘翅目（Coleoptera）中的几个物种现在已被证明在中肠或唾液腺中产生它们自己的纤维素酶，并且在其他目中已鉴定出推定的纤维素酶基因。昆虫纤维素酶通常与肠道中共生微生物群提供的纤维素酶协同工作，以实现有效的纤维素分解。本文讨论了昆虫纤维素酶的研究现状，并提出了寻找新型酶和提高其效率的策略。
Bioethanol is currently produced by the fermentation of sugary and starchy crops, but waste plant biomass is a more abundant source because sugars can be derived directly from cellulose. One of the limiting steps in the biomass-to-ethanol process is the degradation of cellulose to fermentable sugars (saccharification). This currently relies on the use of bacterial and/or fungal cellulases, which tend to have low activity under biorefinery conditions and are easily inhibited. Some insect species feed on plant biomass and can efficiently degrade cellulose to produce glucose as an energy source. Although insects were initially thought to require symbiotic relationships with bacteria and fungi to break down cellulose, several species in the orders Dictyoptera, Orthoptera, and Coleoptera have now been shown to produce their own cellulases in the midgut or salivary glands, and putative cellulase genes have been identified in other orders. Insect cellulases often work in concert with cellulases provided by symbiotic microbiota in the gut to achieve efficient cellulolysis. We discuss the current status of insect cellulases and potential strategies that could be used to find novel enzymes and improve their efficiency.