Roseoflavin-resistant strains

It was shown that Lact. plantarum CRL 725 was able to increase 2-fold the initial concentration of riboflavin in soymilk (Juarez del Valle et al. 2014). Roseoflavin-resistant variants of this strain were also obtained and evaluated in soymilk. One of the variants obtained was able to increase 6 times (1860 20 ng Bj/ml) the basal riboflavin levels of so3nnitk. Roseoflavin-resistant strains capable of synthesizing riboflavin in soymilk constitute an interesting and economically feasible biotechnology strategy that could be adapted by the food industry to develop novel vitamin-bioenriched functional foods with enhanced consumer appeal. 

Most of riboflavin-producing LAB were obtained by selecting roseoflavin-resistant mutants. Burgess et al. [98, 99] obtained by this means riboflavin-producing strains of Lc. lactis, Lb. plantarum, and Leuc. mesenteroides. Capozzi et al. [173] screened roseoflavin-resistant LAB strains from durum wheat flour and isolated two strains of Lb. plantarum that overproduced riboflavin. These strains were used to bioemich bread and pasta, achieving a two- and threefold more riboflavin content in these foods, respectively. Juarez del Valle et al. 

LAB were obtained from durum wheat flour samples and screened for roseoflavin-resistant variants to isolate natural riboflavin-overproducing strains (Capozzi et al. 2011). Two riboflavin-overproducing strains of Lact. plantarum were used for the preparation of bread (by means of sourdough fermentation) and pasta (using a prefermentation step) to enhance their vitamin B content. The applied approach resulted in a considerable increase of vitamin B content (about 2- and... 

On the other hand, it has been shown that mutants isolated on the basis of their resistance to the toxic riboflavin analog roseoflavin also exhibit a riboflavin-overproduction phenotype (Kukanova et al. 1982). Moreover, roseoflavin has been used to obtain constitutive riboflavin overproducing strains of B. subtilis (Perkins and Pcto 2002), L. lactis (Burgess et al. 2004), Lact. plantarum, Leuc. mesenteroides, and Propionibacteriumfreudenreichii (Burgess et al. 2006). Some of these have been shown to provide beneficial effects in vitamin depleted animals and could be inserted as novel starter cultures (LeBlanc et al. 2005a,b, 2006)... 

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