摘要：The ability of representative oral microorganisms to degrade biopolymers, such as collagen, chondroitin-4-sulphate, hyaluronic acid, heparin and proteins was investigated using both native and synthetic substrates. Porphyromonas gingivalis and Bacteroides heparinolyticus were the only species which had heparinase activity. Hydrolysis of hyaluronic acid and chondroitin-4-sulphate was detected in P. gingivalis irrespective of the method used. Both enzymes were largely cell associated and increased up to 120 h. Hyaluronic acid and chondroitin-4-sulphate degradation was detected in B. melaninogenicus, B. oralis, Fusobacterium nucleatum, Capnocytophaga ochracea and Veillonella parvula by a spectrophotometric assay but not by a plate method. Collagenase activity was mainly associated with P. gingivalis; activity was largely extracellular and reached a maximum after 96 h. Several other species such as the black-pigmented bacteroides, F. nucleatum and C. ochracea showed very weak activity. All species tested except B. oralis possessed some proteolytic activity against gelatin, casein and skimmed milk. Fluorometnc and chromogenic substrates which contained an arginine residue were readily hydrolysed.Keywords: Oral flora; Hydrolytic enzymes; Periodontal disease; Gram-negative anaerobes.
