RESUMO
Flavonoids are a large group of plant secondary metabolites with a variety of biological properties and are therefore of interest to many scientists, as they can lead to industrially interesting intermediates. The anaerobic gut bacterium Eubacterium ramulus can catabolize flavonoids, but until now, the pathway has not been experimentally confirmed. In the present work, a chalcone isomerase (CHI) and an enoate reductase (ERED) could be identified through whole genome sequencing and gene motif search. These two enzymes were successfully cloned and expressed in Escherichiaâ coli in their active form, even under aerobic conditions. The catabolic pathway of E.â ramulus was confirmed by biotransformations of flavanones into dihydrochalcones. The engineered E.â coli strain that expresses both enzymes was used for the conversion of several flavanones, underlining the applicability of this biocatalytic cascade reaction.
Assuntos
Proteínas de Bactérias/metabolismo , Eubacterium/enzimologia , Flavonoides/metabolismo , Liases Intramoleculares/metabolismo , Oxirredutases/metabolismo , Proteínas de Bactérias/genética , Biocatálise , Cristalografia por Raios X , Escherichia coli/metabolismo , Eubacterium/genética , Flavanonas/química , Flavanonas/metabolismo , Flavonoides/química , Liases Intramoleculares/genética , Oxirredutases/genética , Estrutura Quaternária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Análise de Sequência de DNARESUMO
A number of methyl-branched aldehydes impart interesting flavor impressions, and especially 12-methyltridecanal is a highly sought after flavoring compound for savory foods. Its smell is reminiscent of cooked meat and tallow. For the biotechnological production of 12-methyltridecanal, the literature was screened for fungi forming iso-fatty acids. Suitable organisms were identified and successfully grown in submerged cultures. The culture medium was optimized to increase the yields of branched fatty acids. A recombinant carboxylic acid reductase was used to reduce 12-methyltridecanoic acid to 12-methyltridecanal. The efficiency of whole-cell catalysis was compared to that of the purified enzyme preparation. After lipase-catalyzed hydrolysis of the fungal lipid extracts, the released fatty acids were converted to the corresponding aldehydes, including 12-methyltridecanal and 12-methyltetradecanal.
Assuntos
Aldeídos/metabolismo , Conidiobolus/enzimologia , Proteínas Fúngicas/metabolismo , Oxirredutases/metabolismo , Aldeídos/química , Biotecnologia , Biotransformação , Conidiobolus/crescimento & desenvolvimento , Conidiobolus/metabolismo , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Aromatizantes/química , Aromatizantes/metabolismo , Proteínas Fúngicas/química , Oxirredutases/químicaRESUMO
In the past flavor research and the development of new flavorings were constantly driven by the interaction of flavor analysis, structure elucidation, and chemical synthesis accompanied by sensory. Highly potent flavor compounds were identified in numerous food products and helped to establish a powerful toolbox for flavorists. Nowadays we experience the merging of various scientific disciplines, for example medicine, biology, chemistry, and various technologies in the field of flavor research, which shows direct impact on our understanding of flavors. At the same time modern life has profoundly changed our eating habits. This situation generates new challenges for product development teams, which represent all facets of technologies. This paper will illustrate different examples for the evolution of product-oriented flavor research and future trends.