This review discusses the reaction catalysed, and the structure and function of the cellulase, endo-β-1,4-glucanase and the hemicellulase enzymes, β-1,3-glucanase and endo-β-1,4-mannase that are present in numerous invertebrate groups with a diverse range of feeding specialisations. These range from microbial deposit and filter feeders, micro and macrophagous algal feeders, omnivores to herbivorous leaf litter and wood feeders. Endo-β-1,4-glucanase from glycosyl hydrolase family 9 (GH9) digests cellulose like β-1,4-glucans from a range of materials. As it hydrolyses crystalline cellulose very slowly, it is a poor cellulase. Where tested, the enzyme has dual endo-β-1,4-glucanase and lichenase activity. Its presence does not necessarily indicate the ability of an animal to digest cellulose. It only indicates the ability to digest β-1,4-glucans and its function, which is discussed in this review, should be considered with reference to the substrates present in the diet. β-1,3-glucanase (laminarinase) belongs to glycosyl hydrolase family 16 (GH16) and hydrolyses β-1.3-glucans. These polysaccharides are present in the cell walls of algae, protozoans and yeast, and they also occur as storage polysaccharides within protozoans and algae. Depending on their site of expression, these enzymes may function as a digestive enzyme or may be involved in innate immunity. Enzymes present in the digestive fluids or tissues, would be digestive. Haemolymph GH16 proteins may be involved in innate immunity through the activation of the phenol oxidase system. Insect GH16 proteins expressed within the haemolymph have lost their catalytic residues and function as β-glucan binding proteins. In contrast, crustacean GH16 proteins expressed within the same tissue, have retained the catalytic residues and thus possibly their β-1,3-glucanase activity. The potential function of which is discussed. Endo-β-1,4-mannase from glycosyl hydrolase family 5, subfamily 10 (GH5_10) hydrolyses mannan, glucomannan and galactomannan. These hemicelluloses are present in the cell walls of plants and algae and also function as storage polysaccharides within legume and palm seeds. They are digestive enzymes whose high expression in some species suggests they are a major contributor to hemicellulose digestion. They may also provide the animal with substantial amounts of monosaccharides for energy.

中文翻译：

---

综述：无脊椎动物的纤维素酶（内切β-1,4-葡聚糖酶）和半纤维素酶（内切β-1,3-葡聚糖酶和内切β-1,4-甘露聚糖酶）的结构和功能，其消耗的微生物物质范围广泛，藻类到叶子的凋落物。

这篇综述讨论了催化的反应，以及存在的纤维素酶，内切β-1,4-葡聚糖酶和半纤维素酶，β-1,3-葡聚糖酶和内切β-1,4-甘露聚糖酶的结构和功能。在众多无脊椎动物群体中，有各种不同的饲养专业。这些范围从微生物沉积物和过滤器进料器，微型和巨噬藻类进料器，杂食性到草食性叶子凋落物和木材进料器。糖基水解酶家族9（GH9）的Endo-β-1,4-葡聚糖酶可从多种材料中消化纤维素，如β-1,4-葡聚糖。由于它非常缓慢地水解结晶纤维素，因此它是一种不良的纤维素酶。经测试，该酶具有双重内切β-1,4-葡聚糖酶和地衣酶活性。它的存在并不一定表明动物消化纤维素的能力。它仅表示消化β-1的能力，在本综述中讨论的4-葡聚糖及其功能应参考饮食中存在的底物来考虑。β-1,3-葡聚糖酶（laminarinase）属于糖基水解酶家族16（GH16），可水解β-1.3-葡聚糖。这些多糖存在于藻类，原生动物和酵母的细胞壁中，它们还作为原生动物和藻类中的储存多糖存在。根据它们的表达位点，这些酶可能起消化酶的作用，也可能参与先天免疫。存在于消化液或组织中的酶将具有消化作用。血淋巴GH16蛋白可能通过酚氧化酶系统的激活参与先天免疫。在血淋巴中表达的昆虫GH16蛋白失去了催化残基，并起着β-葡聚糖结合蛋白的作用。相反，在同一组织内表达的甲壳类GH16蛋白保留了催化残基，因此可能保留了其β-1,3-葡聚糖酶活性。讨论了其潜在功能。糖基水解酶家族5（亚家族10（GH5_10））的Endo-β-1,4-甘露聚糖酶水解甘露聚糖，葡甘露聚糖和半乳甘露聚糖。这些半纤维素存在于植物和藻类的细胞壁中，并且还充当豆类和棕榈种子中的贮藏多糖。它们是在某些物种中高表达的消化酶，表明它们是半纤维素消化的主要贡献者。它们还可以为动物提供大量的单糖以获取能量。讨论了其潜在功能。来自糖基水解酶家族5的亚家族-β-1,4-甘露聚糖酶（亚家族10（GH5_10））水解甘露聚糖，葡甘露聚糖和半乳甘露聚糖。这些半纤维素存在于植物和藻类的细胞壁中，并且还充当豆类和棕榈种子中的贮藏多糖。它们是在某些物种中高表达的消化酶，表明它们是半纤维素消化的主要贡献者。它们还可以为动物提供大量的单糖以获取能量。讨论了其潜在功能。糖基水解酶家族5（亚家族10（GH5_10））的Endo-β-1,4-甘露聚糖酶水解甘露聚糖，葡甘露聚糖和半乳甘露聚糖。这些半纤维素存在于植物和藻类的细胞壁中，并且还充当豆类和棕榈种子中的贮藏多糖。它们是在某些物种中高表达的消化酶，表明它们是半纤维素消化的主要贡献者。它们还可以为动物提供大量的单糖以获取能量。它们是在某些物种中高表达的消化酶，表明它们是半纤维素消化的主要贡献者。它们还可以为动物提供大量的单糖以获取能量。它们是在某些物种中高表达的消化酶，表明它们是半纤维素消化的主要贡献者。它们还可以为动物提供大量的单糖以获取能量。