FIG. 5.

SDS-PAGE of ArChiA and ArChiB secreted by Arthrobacter sp. strain TAD20. Lanes 1 and 2, 20 μl of the supernatants of cultures grown in the absence of chitin (lane 1) or in the presence of 0.1% colloidal chitin (lane 2). All cultures (10 ml) were grown at 5°C under identical conditions in a medium containing 2 g of yeast extract, 5 g of tryptone, and 33 g of sea salts per liter (pH 7.2). Colloidal chitin was prepared as described by Hsu and Lockwood (17). Lanes 3 and 4, purified ArChiA and ArChiB, respectively. The gel was stained using Coomassie brilliant blue.