Green macroalgae, e.g., Ulva lactuca, are valuable bioactive sources of nutrients; but algae recalcitrant cell walls, composed of a complex cross-linked matrix of polysaccharides, can compromise their utilization as feedstuffs for monogastric animals. This study aimed to evaluate the ability of pre-selected Carbohydrate-Active enZymes (CAZymes) and sulfatases to degrade U. lactuca cell walls and release nutritive compounds. A databank of 199 recombinant CAZymes and sulfatases was tested in vitro for their action towards U. lactuca cell wall polysaccharides. The enzymes were incubated with the macroalga, either alone or in combination, to release reducing sugars and decrease fluorescence intensity of Calcofluor White stained cell walls. The individual action of a polysaccharide lyase family 25 (PL25), an ulvan lyase, was shown to be the most efficient in cell wall disruption. The ulvan lyase treatment, in triplicate measures, promoted the release of 4.54 g/L (P < 0.001) reducing sugars, a mono- and oligosaccharides release of 11.4 and 11.2 mmol/100 g of dried alga (P < 0.01), respectively, and a decrease of 41.7% (P < 0.001) in cell wall fluorescence, in comparison to control. The ability of ulvan lyase treatment to promote the release of nutritional compounds from alga biomass was also evaluated. A release of some monounsaturated fatty acids was observed, particularly the health beneficial 18:1c9 (P < 0.001). However, no significant release of total fatty acids (P > 0.05), proteins (P = 0.861) or pigments (P > 0.05) was found. These results highlight the capacity of a single recombinant ulvan lyase (PL25 family) to incompletely disrupt U. lactuca cell walls. This enzyme could enhance the bioaccessibility of U. lactuca bioactive products with promising utilization in the feed industry.

大型绿色藻类，例如石莼，是宝贵的生物活性营养来源；但藻类顽固的细胞壁由复杂的多糖交联基质组成，可能会影响其作为单胃动物饲料的利用。本研究旨在评估预先选择的碳水化合物活性酶 (CAZymes) 和硫酸酯酶降解莴苣细胞壁并释放营养化合物的能力。体外测试了 199 种重组 CAZymes 和硫酸酯酶的数据库对乳果细胞壁多糖的作用。将这些酶单独或组合地与大型藻类一起孵育，以释放还原糖并降低 Calcoflor White 染色细胞壁的荧光强度。多糖裂解酶家族 25 (PL25)（一种绿藻硫化多糖裂解酶）的单独作用被证明是破坏细胞壁最有效的。绿藻硫化多糖处理一式三份，促进了 4.54 g/L ( P < 0.001) 还原糖的释放，单糖和寡糖释放量为 11.4 和 11.2 mmol/100 g 干藻 ( P < 0.01)，与对照相比，细胞壁荧光分别减少了 41.7% ( P < 0.001)。还评估了绿藻硫化多糖处理促进藻类生物质释放营养化合物的能力。观察到一些单不饱和脂肪酸的释放，特别是对健康有益的 18:1c9 ( P < 0.001)。然而，没有发现总脂肪酸（ P > 0.05）、蛋白质（ P =0.861）或色素（ P > 0.05）的显着释放。 这些结果强调了单一重组绿藻硫化多糖裂解酶（PL25 家族）不完全破坏U. actuca细胞壁的能力。这种酶可以提高乳果生物活性产品的生物可及性，在饲料工业中具有广阔的应用前景。