Finally, experiments were carried out using cellulase, which cleaves β-glucosidic bonds of cellulose. Partial cleavage of D3G to DON (about 11% after 3 h, about 15% after 18 h) was observed after cellulase treatment. We suspect this activity is due to co-occurrence of β-glucosidases (cellobiase) from Trichoderma, rather than to a side activity of an endo- or exo-cellulase. This is in good agreement ATM/ATR cancer with the results gained using Aspergillus cellobiase, which yielded the highest conversion of about 60% after 3 h and 73% after 18 h. Forty-seven different bacterial strains, isolated from guts, were examined towards their ability to hydrolyze
D3G. B. bifidum, B. longum, C. freundii, E. avium, E. selleck chemicals llc coli, L. amylovorus, L. crispatus, L. fermentum, L. gasseri, L. paracasei and L. rhamnosus showed no activity. E. casseliflavus, E. faecalis, and E. gallinarum liberated minor amounts of DON (1–8% after 8 h) from D3G. However, E. cloacae, E. durans, E. faecium, E. mundtii but also L. plantarum
and B. adolescentis efficiently cleaved D3G, releasing up to 62% DON after 8 h ( Table 2). Up to now, data regarding the toxicological relevance of D3G were lacking. Our results indicate that D3G is resistant to acidic conditions. It is, therefore, extremely unlikely that D3G can be hydrolyzed into DON in the stomach of mammals. Pretty much the same results were gained using digestive enzymes in vitro, suggesting that D3G will most likely pass unchanged also through the small intestine. For instance amylase, which is produced in the salivary glands and the pancreas and able to
cleave the α-glucosidic bonds of starch, showed no potential to hydrolyze D3G. β-Glucosidase is expressed in human liver, kidney, spleen and gut ( Berrin et al., 2002) and plays an important role in the hydrolysis of plant glucosides like flavones, isoflavones, flavanones, flavonoles or cyanogenic glucosides like amygdalin. However, there are several naturally occurring glucosides that cannot be cleaved by hCBG, including D3G. The position of the glucose in the molecule Immune system is of importance as, e.g. quercetin-7-glucoside can be cleaved by hCBG in contrast to quercetin-3-glucoside ( Berrin et al., 2002). β-Glucuronidase can be found in human plasma and at high levels also in the placenta. The available snail β-glucuronidase showed virtually no hydrolytic activity towards D3G. Therefore, the snail gut β-glucuronidase enzyme mixture, which is frequently used to liberate DON from DON-glucuronic acid conjugates in urine and other tissue samples is unsuitable for hydrolysis of D3G in grain samples for analytical purposes. While enzymes encoded by the human genome seem to be of no relevance, microbial inhabitants of the intestines are providing a rich source of hydrolytic enzymes. Cellulase is produced by a variety of microorganisms found in the gut of ruminants.