Lactobacillus plantarum is an attractive candidate for bioprocessing of lignocellulosic biomass due to its high metabolic variability such as its ability to ferment both pentoses and hexoses as well as its high acid tolerance often utilized in industrial processes. This bacterium also grow naturally on biomass, however, it lacks the inherent ability to deconstruct lignocellulosic substrates. In this communication, we introduced L. plantarum with a potent cellulase and xylanase from a highly active cellulolytic bacterium, using newly developed competent plasmids for efficient secretion of heterologous proteins or for anchoring to the cell wall. Three distinct approaches were evaluated: 1) secretion of free enzymes, 2) anchoring enzymes on the bacterial cell surface, and 3) integrated on the outer surface of L. plantarum into designer cellulosome complexes, via a chimaeric scaffoldin. The latter will bear two divergent cohesins that can thus selectively integrate both enzymes and a carbohydrate-binding module (CBM) for substrate targeting. The enzymatic activities of the three different approaches on the degradation of a wheat straw substrate were assessed and compared.
