title: High throughput automated colorimetric method for the screening of l-lactic acid producing microorganisms.
abstract: Lactic acid is a valuable and fully degradable organic acid with promising applications in poly-lactic acid production (Taskila S and Ojamo, 2013 [1]). Despite their efficiency, the cost of the current lactic acid bio-processes is still an obstacle to this application (Miller et al., 2011 [2]). To ameliorate lactic acid producing strains, researchers are using mutations and metabolic engineering techniques, as well as medium optimization. All these studies necessitate a good and high throughput screening method. Currently, researchers mostly use HPLC methods which often necessitate sample preparation, are not stereospecific and do not allow high throughput. To help optimizing l-lactic acid production, we developed a high throughput colorimetric method inspired by the blood l-lactic acid detection method used for diagnosis (Lin et al., 1999 [3]).•Two sequential enzymatic reactions using l-lactate oxidase, peroxidase and ABTS (2,2'-azino-di-[3-ethylbenzthiazoine-sulfonate]), a chromogenic peroxidase substrate, are used to quantify l-lactate between 13.8 and 90 mg/l.•The accuracy of the method was ascertained before automation.•The method was successfully applied for the direct determination of l-lactate content in fungal culture supernatants.
authors.affiliation: INRA, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France ; Aix Marseille Université, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France ; ARD, Agro-Industry Research and Development, F-51100 Pômacle, France.
authors.forename: Nadège
authors.initials: N
authors.lastname: Liaud
authors.affiliation: INRA, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France ; Aix Marseille Université, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France.
authors.forename: David
authors.initials: D
authors.lastname: Navarro
authors.affiliation: Yelen, 10 boulevard Tempête, F-13820 Ensues la redonne, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vidal
authors.affiliation: INRA, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France ; Aix Marseille Université, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Sigoillot
authors.affiliation: INRA, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France ; Aix Marseille Université, UMR1163 Biotechnology and Biodiversity of Fungi, F-13288 Marseille, France.
authors.forename: Sana
authors.initials: S
authors.lastname: Raouche
keywords: ABTS, 2,2′-azino-di-[3-ethylbenzthiazoine-sulfonate]; Automated assays; Automated screening for lactic acid production; Bacteria; Colorimetric; Fungi; HRP, horseradish peroxidase; LA, l-lactate concentration; LLOD, lower limit of detection; LLOQ, lower limit of quantification; LOD, l-lactate oxidase; Screening; l-Lactate oxidase; l-Lactic acid