The aim of this work is to select filamentous fungal strains isolated from saw dust, soil, and decaying wood with the potential to produce xylanase and cellulase enzymes. A total of 110 fungi were isolated. Fifty-seven (57) of these fungi were isolated from soil samples, 32 from sawdust, and 19 from decaying wood. Trichoderma and Aspergillus had the highest relative occurrence of 42.6% and 40.8%, respectively. Trichoderma viride Fd18 showed the highest specific activity of 1.30 U mg−1 protein for xylanase, while the highest cellulase activity of 1.23 U mg−1 was shown by Trichoderma sp. F4. The isolated fungi demonstrated potential for synthesizing the hydrolytic enzymes.

No abstract

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.

No abstract

Five xylanolytic fungi were isolated from saw dust samples collected from a saw mill dump in Ibadan, Nigeria. The effect of lignocellulosic substrates on the production of xylanases was studied in shake flasks. Trichoderma sp. Fd4 produced high yield of the enzyme when grown in 2% wheat bran. Similarly, xylan, lactose and maltose, used as carbon sources induced the production of high levels of xylanase. Trichoderma viride Fd18 produced 10.4 U/ml of xylanase using NH 4 Cl as nitrogen source, while NH 4 NO 3 repressed enzyme production by Aspergillus ustus Fb2. The fungal isolates produced good amount of xylanase at 30-40 o C, pH 4.5-6.0, 7 days of incubation, initial spore size of 10 6 and in presence of NaCl and KCl in the basal medium.

This study was carried out to evaluate the effect of effluent produced from Yola abattoir on the heavy metals, the physicochemical parameters and the bacteriological quality of the contaminated soil. Stratified sampling technique was used to collect soil samples from the abattoir environment. Isolation of bacteria, cultural and biochemical characteristics were assessed using pour-plate and conventional techniques. Heavy metals presence was determined using atomic absorption spectrophotometer (AAS). Heavy metal tolerance by bacteria was done by agar plate method. The molecular identification was carried out using 16S rRNA gene of the bacteria. All data obtained were subjected to statistical analyses using analysis of variance (ANOVA) and t-test. Total bacterial count ranged from 6.19 x 105 and 8.50 x 105 CFU/mL. Bacterial species of Pseudomonas, Klebsiella, Staphylococcus, Bacillus, Streptococcus, Staphylococcus and Escherichia coli were isolated and identified. The highest mean value of the physicochemical parameters for pH, organic carbon, total nitrogen content, water holding capacity, total solid and total suspended solid of the effluent contaminated soil were 7.03, 7.97 %, 13.76 %, 2.48 %, 3346 g/cm, 1263 mg/L and 872 mg/L respectively. The minimum tolerance concentration of 50 ppm for copper, iron, zinc and cobalt was observed with a bacterium identified to be a strain of Pseudomonas aeruginosa. The isolated and identified Pseudomonas aeruginosa HBS2 strain has the potential to be used in bioremediation.

Background: Bacteria are capable of developing resistance against the effect of antibacterial agents used in eliminating them from their typical environment. This should be monitored to ensure an economic practice while eliminating or preventing bacteria in an environment. Objectives: The aim of this study was to isolate and identify environmental bacteria and investigate their ability to resist antibacterial effects of biocides and antibiotics. Methods: Environmental samples were collected and different bacterial isolates were obtained and characterized. Antimicrobial susceptibility testing was carried out on 6 of the obtained isolates. Results: Six different bacterial species were isolated and characterized from the environmental samples, including Staphylococcus aureus