Phytochemical analysis, antioxidant, antibacterial potentials and chemical composition of methanol extract of Oscillatoria sp.

Background: Algae contains some useful phytochemicals and Oscillatoria sp. is a green microalga which has various applicationsObjectives: Phytochemicals, antioxidant, antibacterial potential and chemical composition of methanol extract of Oscillatoria sp. were evaluated.Materials and Methods: Extraction of bioactive compound from Oscillatoria sp., determination of phytochemicals, antioxidant, antibacterial potential and chemical composition of the methanol extract.Results: Saponin, alkaloids and flavonoids were detected in the methanol extract while glycosides and phenols were absent. The scavenging assay for the antioxidant increased in a dose dependent (100 -1000 μg/mL) manner. The DPPH scavenging activity, Total phenolic content, Ferric Reducing Antioxidant Power Assay (FRAP) and hydrogen peroxide scavenging activity ranged from 21.8 - 44.9%, 9.09 -21.46%, 0.43 - 42.49% and 19.4 - 74.4% respectively. The methanol extract had inhibitory activity against the test pathogens in which Pseudomonas aeruginosa ATCC 27853 (24.0 mm) had the highest susceptibility. GCMS chromatogram of the methanol extract of Oscillatoria sp. shows fifteen major peaks which indicated the presence of Oleic acid, stearic acid, aracidic acid, methyl laurate, methyl myristate, oxirane and palmitic acid.Conclusion: Oscillatoria sp. methanol extract contain some phytochemicals and some heterocyclic compounds. The extract had good antioxidant capability and appreciable antibacterial activity against the test pathogens.Keywords: Oscillatoria sp.; methanol extract; Phytochemical; Antioxidant; GC-MS; Antibacteria

Phytochemical Screening and Microbial Inhibitory Activities of Ficus Capensis

Ficus plant components have application in traditional medicine because of the myriad uses they have been subjected to. The ease of application is based on the secondary metabolites this plant contains. The challenges faced by modern medicine especially in the complete cure of microbially-associated diseases through abrupt and unpredictable genetic mutations in the presence of conventional drugs informed the investigation of the microbial inhibitory activities of the stem, root and leaf parts of F. capensis against test disease causing microorganisms. The phenolic, alkaloid and tannin phytochemical fractions were highest in F. capensis bark extract (180, 165 and 155 μg/ml respectively) followed by that contained in the stem extract (100, 90 and 85 μg/ml respectively). While Streptococcus faecalis and Pseudomonas mirabilis were resistant to many different antibiotics (87.5%), they were effectively inhibited by all concentrations of ethanolic F. capensis extracts. The minimum inhibitory concentration of ethanolic extracts ranged from 25% leaf and stem extract concentration respectively (4mm) against S. faecalis and (2mm) against P.mirabilis. All test isolates were 100% susceptible to ethanol extract growth inhibition.

Production, Characterization and Purification of Laccase by Yeasts Isolated from Ligninolytic Soil

Laccases are multi copper oxidases having wide substrate specificity for phenolic compounds, amines, inorganic compounds like iodine, using oxygen and producing water as by product. The aim of this study is to produce, characterize and purify laccase from yeast isolated from different samples. Yeast isolates were screened for laccase production using tannic acid, catechol, hydroquinone and acetaminophen. Two isolates from soil were selected for further study based on their positive response to screening compounds. Maximum laccase production was achieved with glucose as the best carbon source (10g/l) for Kluyveromyces sp.Dw1 and maltose for Pichia sp.Dw2; Sodium nitrate (3g/l) as the best nitrogen source, optimum pH of 6.0, optimum temperature of 30°C and 350C for Kluyveromyces sp.Dw1and Pichia sp.Dw2 respectively. Rice bran supported the highest laccase production of 88.625U/L in Kluyveromyces sp.Dw1and cane bagasse (79.107U/L) in Pichia sp.Dw2. The addition of inducers like copper sulphate and acetaminophen stimulated maximum laccase production. Maximum activity recorded at pH 9.0, 300C and 500C temperature for Kluyveromyces sp.Dw1and Pichia sp.Dw2 respectively. Laccase activity was retained in the presence of Ca2+, K+, Hg+, EDTA and Benzoic acid. Kluyveromyces sp.Dw1 had Km value of 0.08mM and 0.13mM for Pichia sp.Dw2 using ABTS as substrate. From this study, Kluyveromyces dobzhanskii Dw1 and Pichia manshurica Dw2 produced laccase that oxidized ABTS with higher laccase production using agro wastes and inducers