Chitinolytic enzymes produced by ovine rumen bacteria.
Two strains of clostridia, isolated from the rumen fluid of sheep as potential antagonists toward anaerobic fungi showed a complete array of chitinolytic enzymes. Enzyme tests in cultures demonstrated endochitinase, exochitinase, N-acetyl-glucosaminidase, chitosanase and chitin deacetylase activities mainly in the extracellular fractions. In all samples, the highest was the activity of exochitinase (600-1100 nmol mL-1 h-1); the activity of endochitinase (280-500 nmol mL-1 h-1) was also significant. Chitinases were stimulated in the presence of reducing compounds and no dependence on cations was observed. In both strains different isoforms of chitinases of molar mass 36-96 kDa were detected. The chitinases from our isolates lyzed cell walls of anaerobic fungi in vitro and inhibited the activity of fungal beta-1,4-endoglucanases. Of the two bacteria examined, one was more effective in both antifungal effects.
Kopecný
J
J
Institute of Animal Physiology and Genetics, Academy of Sciences, Czech Republic, 104 00 Prague 10-Uhrínĕves, Czechia. kopecny@iapg.cas.cz
Hodrová
B
B
D000693:Anaerobiosis; D000818:Animals; D000898:Antibiosis; D002473:Cell Wall / Q000378:metabolism; D002480:Cellulase / Q000037:antagonists & inhibitors; D002688:Chitinases / Q000378:metabolism*; D003013:Clostridium / Q000201:enzymology*; D003470:Culture Media; D020088:Neocallimastix / Q000378:metabolism; D012417:Rumen / Q000382:microbiology*; D012756:Sheep / Q000382:microbiology*
D003470:Culture Media; D002688:Chitinases; D002480:Cellulase