An Individual Alginate Lyase is Effective in the Disruption of Laminaria Digitata Recalcitrant Cell Wall

Abstract

In the present study, 199 pre-selected Carbohydrate-Active enZymes (CAZymes) and sulfatases were assessed, either alone or in combination, to evaluate their capacity to disrupt Laminaria digitata cell wall, with the consequent release of interesting nutritional compounds. An individual alginate lyase, belonging to the family 7 of polysaccharide lyases (PL7), was shown to be the most efficient in the in vitro degradation of L. digitata cell wall. The alginate lyase treatment, compared to the control, released up to 7.11 g/L of reducing sugars (p < 0.001) and 8.59 mmol/100 g dried alga of monosaccharides (p < 0.001), and reduced cell wall fluorescence intensity by 39.1% after staining with Calcofluor White (p = 0.001). The alginate lyase treatment also released beneficial monounsaturated fatty acids, particularly 18:1c9 (p < 0.001), and decreased the release of saturated fatty acids (p = 0.001). However, no liberation of proteins (p > 0.170) or pigments (p > 0.070) was observed. Overall, these results show the ability of an individual alginate lyase, from PL7 family, to partially degrade L. digitata cell wall under physiological conditions. Therefore, this CAZyme can potentially improve the bioavailability of L. digitata bioactive compounds for monogastric diets, with further application in feed industry.

Temperature-induced variations in dulse (Devaleraea mollis) nutrition provide indirect benefits on juvenile red abalone (Haliotis rufescens) Growth

“…Nevertheless, a subset of studies presents conflicting outcomes, indicating a reduction in nitrogen or protein content in response to warming (Gao et al, 2018;Toth et al, 2020;Lowman et al, 2021). Considering that the structural components of carbohydrates are crucial for seaweed structural integrity and exhibit greater resilience to temperature variations (Costa et al, 2022;Tagliapietra et al, 2022), our carbohydrate findings align with anticipated trends. Seaweed consists of three distinct phyla (Chlorophyta, Rhodophyta, and Phaeophyceae) with deep phylogenetic splits (Raven and Hurd, 2012), potentially explaining the variation of responses documented in literature.…”

Comparing the infection biology and gene expression differences of Plasmodiophora brassicae primary and secondary zoospores

“…The expressions of effectors Pb1 (alginate lyase) and Pb4 (thaumatin family protein) were induced after inoculation with primary and secondary zoospores. Alginate lyase is effective in disrupting recalcitrant cell walls in Laminaria digitata (Costa et al, 2021), and plant cell wall-degrading enzymes secreted by biotrophic plant-pathogenic fungi facilitate their penetration of host plant cells (Gibson et al, 2011). When host cell walls are broken down, the effector may have a crucial role in zoospore infection of root hairs and epidermal cells.…”