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Bioprocess Biosyst Eng (2015) 38:671680 DOI 10.1007/s00449-014-1306-2
ORIGINAL PAPER
Gluconic acid production from sucrose in an airlift reactor using a multi-enzyme system
Agnes Cristina Oliveira Mafra Felipe Fernando Furlan
Alberto Colli Badino Paulo Waldir Tardioli
Received: 13 July 2014 / Accepted: 10 October 2014 / Published online: 19 October 2014 Springer-Verlag Berlin Heidelberg 2014
Abstract Sucrose from sugarcane is produced in abundance in Brazil, which provides an opportunity to manufacture other high-value products. Gluconic acid (GA) can be produced by multi-enzyme conversion of sucrose using the enzymes invertase, glucose oxidase, and catalase. In this process, one of the byproducts is fructose, which has many commercial applications. This work concerns the batch mode production of GA in an airlift reactor fed with sucrose as substrate. Evaluation was made of the inuence of temperature and pH, as well as the thermal stability of the enzymes. Operational conditions of 40 C and pH 6.0 were selected, based on the enzymatic activity proles and the thermal stabilities. Under these conditions, the experimental data could be accurately described by kinetic models. The maximum yield of GA was achieved within3.8 h, with total conversion of sucrose and glucose and a volumetric productivity of around 7.0 g L-1 h-1.
Keywords Gluconic acid Fructose Sucrose
Airlift bioreactors Batch processing Multi-enzyme
bioconversion
Introduction
Gluconic acid (GA) and its salts are widely used in the pharmaceutical, food, detergent, textile, leather, photographic, and concrete industries [1, 2]. The future of most of these applications is largely dependent on the commercial availability of gluconates.
A variety of different processes are available for the production of GA, including chemical, electrochemical, biochemical (fermentation and enzymatic), and bioelectrochemical techniques [3, 4]. Fermentation is most commonly used industrially for the conversion of glucose into GA [4]. Nevertheless, the fermentation process has a number of disadvantages, such as the need for rigorous aseptic procedures and cell separation, as well as the formation of byproducts, amongst others [5]. On the other hand, the enzymatic route does not present these drawbacks and is a promising alternative for the industrial production of GA [2]. GA production by the enzymatic route has already been reported in the literature. However, most studies have used glucose as the raw material. Nakao et al. [6] reported the immobilization of...