Digestive enzyme spectra in crustacean decapods (Paleomonidae, Portunidae and Penaeidae) feeding in the natural habitat

Abstract

This work describes the pro¢le of ¢ve proteases and four carbohydrases from the crustacean decapods Macrobrachium australiense (Holthuis), Scylla serrata (Forskal), Portunus pelagicus (Linnaeus), Penaeus esculentus, Penaeus plebejus (Hess) and Metapenaeus bennettae (Racck & Dall), feeding in the natural habitat, in order to provide an indication of their digestive capabilities. The results raised the following points. First, species from each family showed a particular suite of digestive enzymes. Second, the activity of cellulase from M. australiensis and S. serrata, using AZCL-HE cellulose as the substrate, was around 90% higher than that observed with AZO-CM cellulose. However, for P. pelagicus and P. esculentus, the enzyme activity was better with AZO-CM cellulose. Third, M. australiense displayed the highest ratio of amylase to protease activity. In contrast, Portunidae species, P. pelagicus and S. serrata showed the lowest ratios. Fourth, comparison of the laminarinase activity of M. bennettae and P. esculentus in October (Spring) and December (early Summer) showed a sig-ni¢cant decrease in December. Finally, the wide distribution of digestive enzymes in these crustaceans may re£ect di¡erent feeding habits and habitats.

A glycosyl hydrolase family 16 gene is responsible for the endogenous production of β-1,3-glucanases within decapod crustaceans

“…A GHF16 β-1,3-glucanase was also expressed within the midgut gland of other amphibious and terrestrial decapods species, and this suggests that expression of this gene is widespread amongst the decapod crustacea. This would explain the high β-1,3-glucanase activities observed in the digestive fluid and midgut glands of numerous crustacean species (Sova et al, 1970) (Suzuki et al, 1987;Omondi and Stark, 1995;Figueiredo et al, 2001;Johnston and Freeman, 2005;Figueiredo and Anderson, 2009). 4.3.…”

“…β-1,3-glucanase activities are present in the digestive fluid of the carnivorous decapods Scylla serrata and Portunus pelagicus (Figueiredo and Anderson, 2009). S. serrata and P. pelagicus consume animal material in the form of molluscs, crustaceans and polychaete worms (Figueiredo and Anderson, 2009). In these species, the β-1,3-glucanase would not function as a digestive enzyme as these species do not consume significant amounts of β-1,3-glucans.…”

“…β-1,3-glucans are also present in other organisms such as diatoms, protozoans and fungi (Bull and Chesters, 1966;Piavaux, 1977;Bacic et al, 1988;Ruiz-Herrera, 1992;Terra and Ferreira, 1994;Pesentseva et al, 2008). In species such as Petrolisthes elongatus and Metapenaeus bennetae that consume algae and possess high activities of β-1,3-glucanase, this enzyme would hydrolyse and thus digest β-1,3-glucans to produce mainly glucose (Johnston and Freeman, 2005;Allardyce and Linton, 2008;Figueiredo and Anderson, 2009). …”

“…However stimulation of the prophenol oxidase system within the digestive fluid has yet to be demonstrated and thus the primary function of the protein may be to hydrolyse cell walls. β-1,3-glucanase activities are present in the digestive fluid of the carnivorous decapods Scylla serrata and Portunus pelagicus (Figueiredo and Anderson, 2009). S. serrata and P. pelagicus consume animal material in the form of molluscs, crustaceans and polychaete worms (Figueiredo and Anderson, 2009).…”

“…Laminarinase or β-1,3-glucanase is a ubiquitous digestive hemicellulase enzyme that is present at high activities within the digestive fluid of aquatic and terrestrial crustaceans (Sova et al, 1970;Suzuki et al, 1987;Omondi and Stark, 1995;Figueiredo et al, 2001;Linton and Greenaway, 2004;Johnston and Freeman, 2005;Figueiredo and Anderson, 2009;Linton et al, 2009). It catalyses the hydrolysis of β-1,3-glycosidic bonds within β-1,3-glucans such as laminarin and callose.…”