Silage inoculants consisting of primarily Lactobacillus plantarum, are widely used to ensure that lactic acid bacteria dominate the fermentation of water soluble carbohydrates (WSC) during the ensilage process. Previous studies have shown that the supplementation of ensiled forage crops with cellulases can also improve the quality of silage through i) increasing the generation of WSC, and therefore ensuring an adequate supply of substrate for L. plantanim; ii) Partial hydrolysis of the plant cell wall increasing the rate of cellulose hydrolysis within the rumen. From the above discussion it is apparent that the use of an L.plantarum strain, with the capacity to hydrolyse cellulose, could be beneficial in the ensiling process. No celluloytic lactic bacterium has been isolated from microbial ecosystems. However, the advent of recombinant DNA technology affords us the possibility of engineering a cellulolytic derivative of L. plantarum. This report describes progress towards this objective.