Enzymatic and chemical treatment limits on the controlled solubilization of brewers' spent grain.

The enzymatic hydrolysis of brewers' spent grain (BSG) has been investigated through treatment with commercial carbohydrases and proteases. Resultant residues were then chemically fractionated and delignified. Enzymatic treatments released 25-30% of the BSG mass and yielded precursors suitable for subsequent conversion to potentially value-added products. Controlled chemical fractionation selectively solubilized arabinoxylan but with no differences apparent due to prior enzyme treatment. The loss of non-polysaccharide components during alkali treatment suggests the presence of a high proportion of alkali-soluble lignin. Further delignification of the alkali-insoluble residues and further chemical fractionation released the remaining hemicellulose, to yield a residue which was >90% cellulose. Further knowledge of the properties and interaction between BSG polymers will facilitate an improved enzyme-assisted total deconstruction of BSG and hence the exploitation of its biomass.

Genetic divergence detected by ISSR markers and characterization of microsatellite regions in Mytilus mussels.

The wide distribution of microsatellites in mussels of the Mytilus edulis complex (Mytilidae) enables the analysis of inter-simple-sequence repeat (ISSR) markers. The aim of this investigation was to assess genetic differentiation in six sampling localities distributed along the European Atlantic coast to expose the potential of these markers in genetic studies requiring the detection of low polymorphism and as a source of sequences for developing microsatellite markers. We detected low genetic structuring within each member of the Mytilus edulis complex. Nei and Li distances and AMOVA clustered the individuals studied into two groups. On the basis of these results two sampling localities coming from the M. edulis x M. galloprovincialis mosaic hybrid zone in Western Europe were assigned to one species. On the other hand, mussels of a sampling locality in the Baltic Sea were not significantly different from a pure M. edulis locality supporting an extensive introgression of M. edulis in these individuals. Finally, 148 microsatellites were found in the sequences of 51 ISSR markers, and two polymorphic microsatellite markers were developed.