A comparison of the insoluble residues produced by the Klason lignin and acid detergent lignin procedures

Abstract

Two methods-Klason lignin (KL) and acid detergent lignin ( A D L F for determining lignin concentration in plants were compared using stem material from lucerne (Medicago satioa L), cocksfoot (Dactylis glomerata L) and switchgrass (Panicurn virgatum L), at three stages of maturity, and leaf samples from lucerne and cocksfoot. For all forages, KL values were higher than ADL values. Lucerne samples, which had crude protein levels twice that of the grass species, had KL values that were only 30-40% higher than ADL values; in grasses, KL values were 200-300% greater than ADL values. The addition of nitrogenous materials (bovine serum albumin, lysine, and ammonium sulfate) to commercial xylan and cellulose did not result in additional KL residue. Pyrolysis-GC-MS revealed that both residues appeared to be similar to the orginal plant lignin and did not appear to be contaminated with carbohydrate or protein. The higher values for grass KL residues were not due to protein contamination or incomplete hydrolysis of carbohydrates, but were more likely due to the solubilization of lignin components by the ADL treatment. KL values may give a more accurate quantification of the total lignin within forage plants.

Protein contamination on Klason lignin contents in tropical grasses and legumes

“…These values reinforce that protein correction is mandatory to accurately estimate KL contents in tropical forages. The pattern obtained here agrees with previous assessment of protein contamination on KL in tropical forages (Gomes et al, 2011), but disagrees with Hatfield et al (1994), who found that CP content in samples is not correlated with the degree of protein contamination in lignin residues. At least part of the greater protein contamination in legumes can be traced back to the greater tannin content of this group, which favors the formation of insoluble complexes with the protein components of forages (Van Soest, 1994 Considering that protein contamination is relevant for KL estimates, a procedure for protein correction must be recommended to correctly obtain lignin content and to estimate more reliable relationships between rate and extent of cell degradation in the rumen.…”

Fermentable sugars by chemical hydrolysis of biomass

“…The brown residue remaining after two-stage corn stover hydrolysis likely includes lignin, insoluble polysaccharides, any insoluble hydrolysis byproducts, protein, and ash. We have not yet characterized the lignin byproduct, but it is likely to resemble lignin produced by other acid hydrolysis processes, e.g., Klason lignin (43,52).…”

Implicações do período de crescimento na composição química e digestão dos tecidos de cultivares de capim-elefante (Pennisetum purpureum Schumach.)

“…Para a determinação da lignina, adotou-se o mé-todo descrito por THEANDER e WESTERLUND (1986) e HATFIELD et al (1994), por intermédio do qual amostras de 100 mg (1 mm) foram submetidas à pré-hidrólise, durante uma hora, à temperatura ambiente, com a adição de 1,5 mL de ácido sulfúrico 72% (12M). Em seguida, a solução foi diluída para 0,4 M com a adição de 43,5 mL de água destilada, quando a amostra foi submetida à nova hidrólise (1 hora, 120 ±1 o C), na mesma autoclave já descrita e utilizada para a determinação de FDN.…”