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 Carbohy-drate-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).How-ever,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.

Mónica M.Costa;Luís B.Pio;Pedro Bule;Vania A.Cardoso;Marlene Duarte;Cristina M.Alfaia;Diogo F.Coelho;Joana A.Brás;Carlos M.G.A.Fontes;José A.M.Prates

CHSA-Centro de Investiga??o Interdisciplinar em Sanidade Animal,Faculdade de Medicina Veterinária,Universidade de Lisboa,Alto da Ajuda,1300-477 Lisboa,Portugal;NZYTech-Genes and Enzymes,Estrada do Pa?o do Lumiar,Campus do Lumiar,Edificio E,1649-038 Lisboa,Portugal

动物营养（英文）

[1]Mónica M.Costa;Luís B.Pio;Pedro Bule;Vania A.Cardoso;Marlene Duarte;Cristina M.Alfaia;Diogo F.Coelho;Joana A.Brás;Carlos M.G.A.Fontes;José A.M.Prates-.Recalcitrant cell wall of Ulva lactuca seaweed is degraded by a single ulvan lyase from family 25 of polysaccharide lyases)[J].动物营养（英文）,2022(02):184-192

Recalcitrant,ulvan,lyases,feedstuffs,monogastric,Carbohy,enZymes,sulfatases,databank,Calcofluor,PL25,triplicate,1c9

cell,Ulva,lactuca,seaweed,degraded,by,single,from,family,Green,macroalgae,are,valuable,bioactive,sources,nutrients,but,recalcitrant,walls,composed,complex,cross,linked,matrix,polysaccharides,compromise,their,utilization,animals,This,study,aimed,ability,pre,selected,drate,Active,CAZymes,release,nutritive,compounds,recombinant,was,tested,vitro,action,towards,enzymes,were,incubated,either,alone,combination,reducing,sugars,decrease,fluorescence,intensity,White,stained,individual,shown,most,efficient,disruption,treatment,measures,promoted,oligosaccharides,dried,respectively,comparison,control,nutritional,biomass,also,evaluated,some,monounsaturated,fatty,acids,observed,particularly,health,beneficial,How,ever,significant,total,proteins,pigments,found,These,results,highlight,capacity,incompletely,could,enhance,bioaccessibility,products,promising,industry

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