Xylanolytic enzymes have extensive applications in paper, food, and feed, pharmaceutical, and biofuel industries. These industries demand xylanases that are functional under extreme conditions, such as high temperature, acidic/alkaline pH, and others, which are prevailing in bioprocessing industries. Despite the availability of several xylan-hydrolyzing enzymes from cultured microbes, there is a huge gap between what is available and what industries require. DNA manipulations as well as protein-engineering techniques are also not quite satisfactory in generating xylan-hydrolyzing extremozymes. With a compound annual growth rate of 6.6% of xylan-hydrolyzing enzymes in the global market, there is a need for xylanolytic extremozymes. Therefore, metagenomic approaches have been employed to uncover hidden xylanolytic genes that were earlier inaccessible in culture-dependent approaches. Appreciable success has been achieved in retrieving several unusual xylanolytic enzymes with novel and desirable characteristics from different extreme environments using functional and sequence-based metagenomic approaches. Moreover, the Carbohydrate Active Enzymes database includes approximately 400 GH-10 and GH-11 unclassified xylanases. This review discusses sources, characteristics, and applications of xylanolytic enzymes obtained through metagenomic approaches and their amelioration by genetic engineering techniques.

木聚糖分解酶在造纸，食品和饲料，制药和生物燃料工业中具有广泛的应用。这些工业需要在极端条件下起作用的木聚糖酶，例如高温，酸性/碱性pH等，这些条件在生物加工工业中很普遍。尽管可以从培养的微生物中获得几种木聚糖水解酶，但在可获得的酶和工业需要的酶之间仍存在巨大差距。DNA操纵以及蛋白质工程技术在产生木聚糖水解极端酶方面也不太令人满意。在全球市场上，木聚糖水解酶的复合年增长率为6.6％，因此需要木聚糖水解极端酶。因此，宏基因组学方法已被用于发现隐藏的木聚糖分解基因，而这些基因在依赖文化的方法中更是难以获得。在使用功能性和基于序列的宏基因组学方法从不同的极端环境中检索具有新颖和理想特性的几种不常见的木聚糖分解酶方面已取得了明显的成功。此外，碳水化合物活性酶数据库包括大约400个GH-10和GH-11未分类的木聚糖酶。这篇综述讨论了通过宏基因组学方法获得的木聚糖水解酶的来源，特征和应用，以及通过基因工程技术对其的改善。在使用功能性和基于序列的宏基因组学方法从不同的极端环境中检索具有新颖和理想特性的几种不常见的木聚糖分解酶方面已取得了明显的成功。此外，碳水化合物活性酶数据库包括大约400个GH-10和GH-11未分类的木聚糖酶。这篇综述讨论了通过宏基因组学方法获得的木聚糖水解酶的来源，特征和应用，以及通过基因工程技术对其的改善。在使用功能性和基于序列的宏基因组学方法从不同的极端环境中检索出几种具有新颖和理想特性的异常木聚糖水解酶方面，已经取得了明显的成功。此外，碳水化合物活性酶数据库包括大约400个GH-10和GH-11未分类的木聚糖酶。这篇综述讨论了通过宏基因组学方法获得的木聚糖水解酶的来源，特征和应用，以及通过基因工程技术对其的改善。