RESUMO
El objetivo del presente trabajo fue establecer parámetros que permitan en forma rápida y sencilla, predecir la habilidad de distintas cepas de Aspergillus niger, para producir ácido cítrico. Se logró establecer una relación entre morfología y productividad. Así mismo se diseñó un medio sólido de facil manejo, que evidencia rápidamente la producción de un buen nivel de ácido cítrico, por la cepa en estudios. La efectividad de la selección fue luego confirmada mediante la productividad en un cultivo sumergido
Assuntos
Aspergillus niger/metabolismo , Meios de Cultura , Esporos Fúngicos/metabolismo , Maleatos/biossínteseRESUMO
The pathway whereby certain bacterial strains of the genus Bacillus degrade m-hydroxybenzoate is delineated. Of 12 strains examined, nine were tentatively classified as representatives of the species Bacillus brevis, two of Bacillus sphaericus and one of Bacillus megaterium. All strains degraded m-hydroxybenzoate via the same pathway. m-Hydroxybenzoate was hydroxylated to 2,5-dihydroxybenzoate (gentisate), which was oxidized by a gentisate 1,2-deoxygenase yielding maleylpyruvate. Maleylpyruvate was hydrolyzed without prior cis, cis to cis, trans isomerization yielding pyruvate and maleic acid. Numerous soils were examined by plate-count procedures and found to contain 10(4) to 10(6) aerobic sporeformers able to grow on m-hydroxybenzoate per g of dry soil.
Assuntos
Bacillus/metabolismo , Hidroxibenzoatos/metabolismo , Microbiologia do Solo , Bacillus/enzimologia , Bacillus megaterium/enzimologia , Bacillus megaterium/metabolismo , Biodegradação Ambiental , Sistema Livre de Células , Fumarato Hidratase/metabolismo , Gentisatos/metabolismo , Hidrolases/metabolismo , Isomerases/metabolismo , Maleatos/biossíntese , Oxigenases/metabolismo , Piruvatos/biossínteseAssuntos
Alcanos/metabolismo , Candida/metabolismo , Adipatos/biossíntese , Candida/crescimento & desenvolvimento , Carbono/metabolismo , Cromatografia Gasosa , Citratos/biossíntese , Fermentação , Glucose/metabolismo , Ácidos Cetoglutáricos/biossíntese , Maleatos/biossíntese , Manometria , Nitrogênio/metabolismo , Consumo de Oxigênio , Petróleo/metabolismo , Piruvatos/biossíntese , Succinatos/biossínteseAssuntos
Leucina/biossíntese , Malatos/metabolismo , Neurospora/metabolismo , Acetatos/metabolismo , Anidridos/biossíntese , Isótopos de Carbono , Fenômenos Químicos , Química , Citratos , Isocitratos , Isomerismo , Malatos/biossíntese , Maleatos/biossíntese , Modelos Estruturais , Mutação , Neurospora crassa/metabolismo , Propano/biossíntese , Relação Estrutura-Atividade , Trítio , Valina/metabolismo , Difração de Raios XRESUMO
A new B(12)-coenzyme-dependent isomerization, catalyzed by extracts of a nicotinate-fermenting clostridium, results in the conversion of alpha-methyleneglutaric acid to dimethylmaleic acid. These two acids are intermediates in the multistep anaerobic process wherein nicotinate is converted, ultimately, to one mole each of propionate, acetate, carbon dioxide, and ammonia. Dimethylmaleic acid reacts in its anhydride form with 2,4-dinitrophenylhydrazine to form N-2',4'-dinitrophenyl-anilino-3,4-dimethylmaleimide. The characteristic reddish color exhibited by the latter derivative in alkaline solution serves as a convenient quantitative assay for dimethylmaleic acid. Comparison of the 2,4-dinitrophenylhydrazine derivatives of the product of the enzymic reaction and of synthetic dimethylmaleic anhydride showed them to be identical in every respect.
