ABSTRACT
Abstract We evaluated the antimicrobial activity of Aspilia latissima - an abundant plant from the Brazilian Pantanal region - against Candida albicans, Candida parapsilosis, Candida krusei, Candida tropicalis, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli and Staphylococcus aureus. The crude extracts and fractions showed activity in all tested microorganisms. The chloroform fraction of the leaves and roots showed the most antimicrobial activity against S. aureus, with an MIC of 500 μg/mL. This fraction was submitted to bioautographic assays to characterize the activity of the compounds. Two bands from the leaves (L-A and L-B) and three bands from the roots (R-C, R-D and R-E) were bioactive. Within the root-derived bands, the terpene derivatives stigmasterol, kaurenoic acid and kaura-9(11), 16-dien-18-oic acid were identified. Antibiotic activity of A. latissima is reported for the first time.
Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/drug effects , Anti-Bacterial Agents/pharmacology , Antifungal Agents/chemistry , Antifungal Agents/drug effects , Antifungal Agents/pharmacology , Asteraceae/chemistry , Asteraceae/drug effects , Asteraceae/pharmacology , Bacteria/chemistry , Bacteria/drug effects , Bacteria/pharmacology , Brazil/chemistry , Brazil/drug effects , Brazil/pharmacology , Fungi/chemistry , Fungi/drug effects , Fungi/pharmacology , Gas Chromatography-Mass Spectrometry/chemistry , Gas Chromatography-Mass Spectrometry/drug effects , Gas Chromatography-Mass Spectrometry/pharmacology , Microbial Sensitivity Tests/chemistry , Microbial Sensitivity Tests/drug effects , Microbial Sensitivity Tests/pharmacology , Plant Extracts/chemistry , Plant Extracts/drug effects , Plant Extracts/pharmacology , Plant Leaves/chemistry , Plant Leaves/drug effects , Plant Leaves/pharmacology , Plant Roots/chemistry , Plant Roots/drug effects , Plant Roots/pharmacologyABSTRACT
Devido às concentraçöes de inulina em H. tuberosus, leveduras com boa produçäo de inulinase e alto potencial fermentativo säo imprescindíveis na viabilizaçäo industrial deste vegetal. Selecionando-se leveduras com estas propriedades, dentre 21 espécies avaliadas, encontram-se 11 linhagens com boa capacidade fermentativa. As leveduras com maior rendimento de produçäo de álcool foram Kluyveromyces marxianus, K. fragilis, Candida pseudotropicalis e Torulopsis coelliculosa. Em fermentaçöes sucessivas conduzidas a 30-C, com 15,6% de ART e por 48 horas, chegou-se a obter o rendimento médio de 85% em relaçäo ao teórico. Nestas condiçöes, após 10 horas de fermentaçäo encontraram-se rendimentos de 74,4% e uma taxa de fermentaçäo de 5,9g/1/h**-1. A atividade máxima da inulinase foi de 3,6micronM (equivalente frutose)/ml/min e verificou-se ocorrer repressäo catabólica da inulinase por frutose em K. marxianus e K. fragilis. Com estes resultados conclui-se ser viável a fermentaçäo de extratos sem prévia hidrólise, o que facilitará o processamento industrial de extratos de H. tuberosus
