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Background Actinomycetes are prolific producers of bioactive compounds which can be used to combat microbial infections. Microbial infections have resulted to increase in mortality and morbidity rates world-wide, especially in developing nations. This study was carried out to isolate and identify actinomycetes with potentials of synthesizing bioactive compounds, to produce and partially purify antimicrobial extracts, to characterize bioactive compounds in the extracts, to assess their antibacterial activity and to profile other biological properties of the bioactive compounds synthesized by the actinomycetes. Results Streptomyces sp. SUI (MT584797), Streptomyces sp. SW72IV (MT584818) and Streptomyces sp. SW72VII (MT584816) were isolated and identified. Ultraviolet–visible spectra absorption ranged between 241 and 251 nm wavelengths showing the polyene or chromone and unsaturation nature of the natural compounds. Infrared (IR) spectra indicated functional groups such as hydroxyl, aliphatic bromo, carbonyls, esters, carboxylic acids and silicon oxy compounds in the compounds produced by the three strains. Gas Chromatography-Mass Spectrum (GC–MS) identified elaidic acid isopropyl ester (32.11%), Octadec-9-enoic acid (17.44%) and 2, 3-dihydroxyl elaidate (10%) to be mostly produced by Streptomyces sp. SUI, Streptomyces sp. SW72IV and Streptomyces sp. SW72VII respectively. The three strains exhibited antimicrobial activity against Bacillus sp. Pseudomonas aeruginosa ATCC 9077, Staphylococcus aureus ATCC 700699, Candida albicans and Aspergilus flavus. Conclusion The results showed that the three strains of Streptomyces could be sources of antimicrobial bioactive compounds and other secondary metabolites that can be used in the production of pharmaceutical bioactive agents that are effective against pathogens, and production of biological materials that can be used in cosmetics and food industries.

Due to increase in demand for energy as a result of human population explosion, industrialization and environmental hazards posed by fossil fuels, there is a need to source for alternative energy sources that are cheaper and environmental friendly. Three different lignocellulosic biomasses were studied for their suitability for bioethanol production. Fungi and yeasts were isolated using serial dilution and spread plate methods. Identification of both fungi and yeasts was done using their cultural and microscopy characteristics. Saccharification of the pre-treated biomass was done with both crude cellulase and mycelia inoculant. Bioethanol was produced using batch culture fermentation. Ethanol produced was detected using spectrometric method and quantified using High Performance Liquid Chromatography (HPLC). The effects of substrate concentration, pH and temperature on ethanol yield were optimized. Fifty fungal isolates were obtained from soil collected. Six yeasts, all Kluyveromyces species fermented three sugars to ethanol with isolate Kluyveromyces sp.Y2 having the shortest time. It was selected for fermentation. Aspergillus niger S48 had highest cellulase activity measured in a zone of hydrolysis of 26.0 mm. It had the highest glucanase activity, endoglucanase (0.462 U/mL) and exoglucanase (0.431 U/mL). The outcome of this study indicated that crude cellulase produced by Aspergillus niger S48 hydrolyzed the pre-treated rice chaff with 1.07 mg/mL of fermentable sugars higher than 0.87 mg/mL when the mycelia of the fungus was inoculated to pretreated rice chaff for hydrolysis. Ethanol was optimally produced at 12 % substrate concentration using rice chaff, at a temperature of 35 °C and pH 5.0.

Aim: The aim of this work was to screen for important broad-spectrum antimicrobial metabolitesproducing species of Actinomycetes from the uncultivated soil of Ekiti State, Southwestern, Nigeria. Methodology: Ten uncultivated or barren soil samples each of 20 g were collected across Ekiti state between April and June 2014 for the isolation of Actinomycetes. The isolate was identified culturally as well as molecularly using 16S rDNA analysis. The influence of production parameters on antimicrobial activity was performed using standard method. The antimicrobial metabolites were produced by submerged fermentation. Partial purification was carried out by column chromatography. Chemical characteristics of the metabolites were determined by Fourier transformed infra-red spectrometer (FTIR) and gas chromatography coupled with mass spectrometer. The antimicrobial activity was carried out by agar well diffusion and macro broth dilution. Results: Out of ten actinomycetes isolated, Isolate EK18 possessed broad-spectrum antimicrobial activity and it was identified to be a strain of Crossiella based on its 16S rDNA gene sequence

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