Changes in the cell envelope structure of Clostridium sp. strain EM1 during massive production of α-amylase and pullulanase

Abstract

Marked changes in cell envelope structure were observed when Clostridium sp. strain EM1 cells grown in continuous culture under glucose limitation were compared with cells grown under starch limitation. The increase in the level of extracellular α-amylase and pullulanase during starch-limited growth was parallelled by degradation of the cell-envelope layer and the formation of blebs and a high number of vesicles, which apparently originated from the cytoplasmic membrane. These vesicles were covered by a delicate layer of small particles and were shown to be released into the culture fluid. It is assumed that the overproduction of enzyme destined to remain associated with the cells led to these changes. © 1987.