An experimental study of cellulose and hemicellulose degradation in the alimentary canal of the American cockroach

Abstract

Artificial diets containing [¹⁴C]cellulose and [¹⁴C]hemicellulose were prepared and fed to adult females. During the first 300 h after ingestion, ¹⁴CO₂ was recovered equivalent to about 73% (cellulose) and 48% (hemicellulose) of the label ingested. For both polysaccharides the rate of ¹⁴CO₂ evolution peaked 20–40 h after feeding and label was acquired by hemolymph trehalose. The evolution of ¹⁴CO₂ from labelled cellulose was sharply reduced when antibiotics were supplied in the diet either with the labelled polysaccharide or before its ingestion. When each polysaccharide was introduced into the lumen of the cannulated colon in vitro, degradation occurred and acid- and heat-stable labelled material appeared in the incubation medium. It is proposed that cellulose and hemicellulose are potentially of nutritional significance in this insect and that the hindgut may be an important site of degradation.