The influence of carbon nutrition on activation and activities of pectolytic enzyme in cultures of Xanthomonas campestris pv. vignicola

Abstract

Summary In Xanthomonas campestris pv. vignicola the two hydrolases PMG (pectin methyl galacturonase) and PG (polygalacturonase) were best activated at 35°C with 60 min of enzyme-substrate incubation. Both of them were adaptively synthesized with pectin and NaPP. Addition of glucose to either pectin or NaPP enhanced the production of PMG and PG, respectively. Maltose and CMC had adverse influence on PG development. In young cultures pectin transeliminase (PTE) was adaptively synthesized with pectin as the source. In old cultures it was best produced constitutively with CMC as the source. While NaPP increased the capacities of glucose or maltose to activate PTE, it retarded the constitutive ability of CMC to synthesize this enzyme. The other transeliminase, PGTE, was constitutively synthesized in young culture with glucose as the choice carbon source. The addition of NaPP to glucose considerably lowered the constitutive ability of 24-h-old filtrate for activating this enzyme. It had separate synergistic influence on maltose, pectin, or CMC for very prominent level production of PGTE. In young and old cultures the endo-PG activity had preponderance over exo-PG, since NaPP substrate was hydrolysed with more of random cleavage. However, in the older filtrates exo-PG activity, too, picked up gradually.