L-aspartic acid is a non-essential amino acid with applications in the chemical, pharmaceutical and food products. It is produced by chemical synthesis or biological, though the former has disadvantages, most prominently the racemic mixture produced. In this paper we use the native strain of Pseudomonas fluorescens and fumaric acid as a source of carbon and energy. The first step was to adapt the organism itself in a solid medium, partially replacing the source of carbon and energy from 20% to 80% in those presenting outstanding growth. The second stage was performed in liquid fermentation, in which adjustments were made from 1% to 8%, showing turbidity to 7%. Later there were the curves of biomass, substrate consumption and product training and followed the model of Monod. The maximum concentration obtained from L-aspartic acid was approximately 1.5 mM