Degradation of pectic substances in green flax fibre by Erwinia carotovora

SUMMARY In this paper, we report that Erwinia carotovora can perform controlled biological pectinolysis of green flax fibre. The degradation of pectic substances is considered a key step during this process and is estimated by determining the cation exchange capacity (CEC). A CEC characteristic of a ‘good retting degree’, is reached after 20 h incubation, whatever the tested temperature and initial pectate lyase activity of the bacterial culture. Similar results are obtained after only 4 h, at a temperature of 45°C and the pectate lyase activity is greater than 2 nmol ml‐1 min‐1. The linear relationship between the CEC and the weight loss of green fibre which is established, allows us to estimate an equivalent weight of 1000 g eq‐1 for the solubilised polymers.