Safe and sustainable systems for food-grade fermentations by genetically modified lactic acid bacteria

The last decade has seen a great increase in innovative improvements of lactic acid bacteria used in industrial food fermentations. In order to allow the genetically modified lactic acid bacteria to reach the market place, their novel genetic combinations should be selected, stably maintained, and expressed using food-grade systems that are safe, stable, and sustainable. This paper aims to review the food-grade systems that have been constructed with specific attention for self cloning approaches, and focuses on recent developments on food-grade selection markers, chromosome inactivation, stabilization, and amplification strategies, as well as approaches for controlled gene expression. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.