Estimation of Fungal Contamination of Cereal Grains as Determined by Measuring Glucosamine Concentration

Abstract

Estimation of fungal contamination of cereal grains as determined by measuring glucosamine concentration. Can. J. Anim. Sci. 69:235-245.The degree of fungal contamination of a grain or feed sample can be estimated from the determination of its glucosamine (GlcN) content, using a modified amino acid analysis procedure. A sample (100 mg) was hydrolyzed in 6 N HCI for 7 h at 121'C, evaporated to dryness, reconstituted in citrate buffer and applied to an ion exchange column of an amino acid analyzer. Hydrolysis conditions were optimized for the recovery of GlcN, released Polymers of a second compound, galactosamine (GalN), have also been found in the walls of some species .The techniques currently used for chitin analysis generally involve colorimetric methods such as that of Ride and Drysdale (1912)

Growth kinetics of Myceliophthora thermophila M.7·7 in solid‐state cultivation

“…The influence of the mycelium age on NAG concentration is not a consensus in literature since it depends on the organism considered (Rotter et al . 1989; Di Lena et al . 1994; Scotti et al .…”

“…Hence, the conversion factor NAG/biomass was 19Á3 mg of NAG per gram of biomass, estimated from the slope of the fitted curve. The influence of the mycelium age on NAG concentration is not a consensus in literature since it depends on the organism considered (Rotter et al 1989;Di Lena et al 1994;Scotti et al 2001;Onuma et al 2019); therefore, this influence was tested determining NAG content in samples cultivated at 24-h intervals up to 120 h. Table 1 shows there was no influence of cultivation time on NAG concentration. These experiments have been carried out independently and the obtained variation coefficient (VC) was always under 10%, a reasonable value for biological experiments.…”

Effects of different cereal and oilseed substrates on the growth and production of toxins by Aspergillus alutaceus and Penicillium verrucosum

“…Estimation of Fungal Biomass, Ochratoxin A, Ochratoxin B, and Citrinin. Fungal biomass (glucosamine content) was measured according to the procedure described by Rotter et al (1989). Ground samples (10 g each) for mycotoxin analysis were extracted with CHCI3-O.I H3PO4 (20:1 v/v) and subjected to reverse-phase thin-layer chromatography (RPTLC) for cleanup.…”

“…Also, the time course relationship between the production of these toxins and degree of fungal growth as estimated by the concentration of glucosamine has not been determined. Rotter et al (1989) has recently demonstrated that the glucosamine content of cereal grains provides a good estimate of degree of fungal contamination. The current studies were carried out to better establish the nature of these interrelationships.…”

Modification of the Glucosamine Method for the Quantification of Fungal Contamination

“…GlcN mine (GlcN), a hydrolysis product of chitin analysis was performed as detailed by Rotter in fungal cell walls. Previously, Rotter et al et al (1989). (1989) described a modified amino acid ana-A neutralization procedure was tested as a lytical procedure based on methods described substitute for the acid evaporation step and the by Stahmann et al (1975), Wu and Stahmann recovery of GlcN compared to that obtained (1975) and Hubbard etal.…”