The Composition and Antimicrobial Activities of Cyperus conglomeratus, Desmos chinensis var. lawii and Cyathocalyx zeylanicus Essential Oils
The essential oil compositions of the rhizomes of Cyperus conglomeratus (Cyperaceae) collected from Oman and the leaves of two Annonaceae plants, Desmos chinensis var. lawii and Cyathocalyx zeylanicus collected from India were studied by GC, GC-MS and 13C NMR spectroscopy. Twenty-six compounds, representing 84.4% of the oil were identified in C. conglomeratus, where eugenol (31.3%), α-cyperone (10.5%) and cyperotundone (8.4%) were the major compounds. Twelve compounds, constituting 100%, were identified in D. lawii oil, of which benzyl benzoate (58.7%), β-caryophyllene (23.2%), limonene (4.9%) and α-humulene (4.0%) were the major constituents. Thirty-two compounds, comprising 98.0%, were identified in C. zeylanicus oil, of which β-caryophyllene (21.6%), α-pinene (20.4%) and E-β-ocimene (11.8%) were the major components. The antibacterial and antifungal activities of the oils were tested against a panel of five bacterial and two fungal strains. The oils showed moderate activity against all the tested microbial strains. The minimum inhibitory concentrations of the oils were also determined.
Évaluation de l’activité antibactérienne du Cyperus conglomeratus (Cyperaceae)
Cette étude consiste à évaluer l’activité antibactérienne de la plante médicinale Cyperus conglomeratus, très répandue dans la vallée d’Oued Righ (sud-est de l’Algérie). Les résultats de l’enquête ethnobotanique montrent que cette plante est utilisée dans plusieurs applications phytothérapiques et possède des propriétés thérapeutiques diversifiées. L’évaluation de l’effet antimicrobien des extraits phénoliques de la plante sur des souches bactériennes à Gram positif et à Gram négatif, telles que Staphylococcus aureus, Enterococcus aureus, Bacillus subtilis, Escherichia coli et Pseudomonas aeruginosa, montre que les extraits butanoliques et acétate d’éthyle se sont manifestés par une activité modérée contre les cinq souches susmentionnées. En revanche, l’extrait chloroformique montre que les activités antibactériennes sont assez appréciables. Le criblage phytochimique confirme que les familles responsables de la bonne activité antibactérienne décelée sont principalement les phénols, flavonoïdes, tanins, stérols et glycosides mis en évidence en quantités variables dans les parties aériennes de la plante.
Microbial flora of frozen tail meat from captive Nile crocodiles (Crocodylus niloticus).
Frozen tail meat samples from nine Nile crocodiles (Crocodylus niloticus) were evaluated for microbial numbers and types. Microbial analyses yielded a mean aerobic plate count (APC, 30 degrees C) of 4.86 log cfu/g, a mean coliform count (TC, 37 degrees C) of 3.77 log cfu/g and a mean faecal coliform count (FC, 44 degrees C) of 3.40 log cfu/g. Salmonella was isolated from three samples, and beta-haemolytic streptococci from two samples. Yersinia, Aeromonas, Staphylococcus aureus and Bacillus cereus were not isolated. Typical bacterial genera recovered included Flavobacterium, Pseudomonas, Acinetobacter, Enterobacter, Moraxella, Micrococcus, Staphylococcus and Streptococcus.