title: Improving succinic acid production by Actinobacillus succinogenes from raw industrial carob pods.
abstract: Carob pods are an inexpensive by-product of locust bean gum industry that can be used as renewable feedstock for bio-based succinic acid. Here, for the first time, unprocessed raw carob pods were used to extract a highly enriched sugar solution, afterwards used as substrate to produce succinic acid using Actinobacillus succinogenes. Batch fermentations containing 30g/L sugars resulted in a production rate of 1.67gSA/L.h and a yield of 0.39gSA/g sugars. Taking advantage of A. succinogenes' metabolism, uncoupling cell growth from succinic acid production, a fed-batch mode was implemented to increase succinic acid yield and reduce by-products formation. This strategy resulted in a succinic acid yield of 0.94gSA/g sugars, the highest yield reported in the literature for fed-batch and continuous experiments, while maintaining by-products at residual values. Results demonstrate that raw carob pods are a highly efficient feedstock for bio-based succinic acid production.
authors.affiliation: REQUIMTE, DQ/FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.
authors.forename: Margarida
authors.initials: M
authors.lastname: Carvalho
authors.affiliation: REQUIMTE, DQ/FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal. Electronic address: christophe.roca@fct.unl.pt.
authors.forename: Christophe
authors.initials: C
authors.lastname: Roca
authors.affiliation: REQUIMTE, DQ/FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal.
authors.forename: Maria A M
authors.initials: MA
authors.lastname: Reis
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000188:Actinobacillus / Q000378:metabolism*; D002241:Carbohydrates / Q000737:chemistry*; D003362:Cost-Benefit Analysis; D007887:Fabaceae / Q000737:chemistry; D005285:Fermentation; D005524:Food Technology; D005561:Formates / Q000737:chemistry; D005685:Galactans / Q000737:chemistry*; D007218:Industrial Microbiology; D007700:Kinetics; D008351:Mannans / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*; D019802:Succinic Acid / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D002241:Carbohydrates; D005561:Formates; D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D014867:Water; C030544:formic acid; D019802:Succinic Acid; D019342:Acetic Acid; C017471:locust bean gum
keywords: Actinobacillus succinogenes; Carob pods; Fed-batch fermentation; Succinic acid