Abstract: The invention is concerned with a new microorganism, named PO 7111 strain belonging to the family of Pseudomonacea, and with a process of converting fumaric acid into L-aspartic acid using said microorganism. In a first step the microorganism is cultivated in aerobian conditions in a nutritive medium containing sources of carbon, phosphorus, nitrogen, and oligo-elements and in a second step fumaric acid is introduced into said medium, the conversion being carried for 12-16 hours at a pH between 6 and 12 and at a temperature between 30.degree. and 60.degree.C.