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Biotechnol Lett (2012) 34:611618 DOI 10.1007/s10529-011-0833-z
REVIEW
Riboavin production by Ashbya gossypii
Tatsuya Kato Enoch Y. Park
Received: 11 November 2011 / Accepted: 9 December 2011 / Published online: 21 December 2011 Springer Science+Business Media B.V. 2011
Abstract Riboavin is an important nutrient for humans and animals. Industrial production has shifted completely from chemical synthesis to microbial fermentation. First generation riboavin production was improved by a combination of traditional muta-genesis and genetic engineering, and isolated strains have been used in industry. As the DNA genome of riboavin producers has the potential to reveal new technologies, DNA microarray, proteomic and metabolic analyses have been applied to the analysis of hyper-riboavin producers. In this review, disparity mutagenesis technology is introduced as a means of improving riboavin production by Ashbya gossypii. DNA microarray, proteomic and metabolic analyses of this high riboavin producer are discussed, as well as recent riboavin production trends, costs and future improvements.
Keywords Ashbya gossypii DNA microarray
Metabolic ux Riboavin
Introduction
Riboavin, also called vitamin B2, is an essential component for cellular metabolism because it is a precursor of avin mononucleotide (FMN) and avin adenine dinucleotide (FAD), which are co-factors of dehydrogenases and oxidoreductases. Microorganisms and plants can produce riboavin endogenously, but animals and humans cannot synthesize it, so it must be supplied by foods and dietary supplements. Riboavin has in the past been produced by either chemical synthesis or biosynthesis. Industrial riboavin production has been achieved mainly by fermentation using microorganisms. Microbial fermentation is economically less expensive than chemical synthesis. The fungi Ashbya gossypii and Eremotheciumashbyii, the yeast Candida famata and the bacterium Bacillus subtilis can produce high levels of riboavin (Stahmann et al. 2000).
Ashbya gossypii was the rst organism used in industrial riboavin production. Itwas isolated as a plant pathogen and characterized as a natural riboavin producer. Riboavin is produced from fatty acids through the glyoxylate cycle, gluconeogenesis, the pentose phosphate pathway and the purine and riboavin synthetic pathways (Fig. 1). Moreover, genome sequencing of A. gossypii has been completed (Dietrich et al. 2004), and metabolic engineering by gene manipulation has become more readily available. Many efforts have been made to improve riboavin productivity in A. gossypii. Riboavin can be synthesized by
T. Kato E. Y. Park
Department of Applied Biological Chemistry,...