Cellulase Production by Wild-type Aspergillus niger, Penicillium chrysogenum and Trichoderma harzianum Using Waste Cellulosic Materials

Waste cellulosic materials (corncob, sawdust and sugarcane pulp) and crystalline cellulose induced cellulase production in wild strains of Aspergillus niger, Penicillium chrysogenum and Trichoderma harzianum isolated from a wood-waste dump in Lagos, Nigeria. Cellulose-supplemented media gave the maximum cellulase activity of 0.54, 0.67 and 0.39 units mg Protein-1 for A. niger, P. chrysogenum and T. harzianum respectively. The maximum enzyme activity for A. niger was obtained at 36 h of cultivation, while P. chrysogenum and T. harzianum gave their maximum enzyme activities at 12 and 60 h respectively. For the cellulosic wastes, highest enzyme activity was obtained with sawdust where A. niger, P. chrysogenum and T. harzianum gave the maximum enzyme activity of 0.30, 0.24 and 0.20 units mg Protein-1 respectively after 144 h of cultivation. A. niger recorded the highest enzyme activity with any of the three cellulosic materials followed by P. chrysogenum. It thus appears that the use of sawdust presents the best option for low-cost commercial production of cellulase using A. niger and P. chrysogenum as discussed herewith

Assessment of bacteriological quality of ready to eat food (Meat pie) in Benin City metropolis, Nigeria

Eight triplicate samples of meat pie were randomly sampled from standard eatery and local kiosk in Benin City and analyzed microbiologically for the rates of Staphylococcus aureus and Escherichia coli. The mean microbial load on the fresh meat pie from the standard eatery ranged from 3x103 – 5x103cfu/g while the air preserved and refrigerated meat pie for (2 days) ranged between 2.3 x104 -3.8 x104 cfu/g and 8x 103-1.5 x104 cfu/g respectively. The mean microbial load of the fresh meat pie from the local kiosk ranged between 7x103-2.8x104 cfu/g while the air preserved and refrigerated meat pie for 2days ranged between 3x10-4 to too numerous to count (TNTC) and 1.3 x104 -2.8x104 cfu/g respectively. Six genera of the isolated bacteria include Staphylococcus, E. coli, klebsiella, Pseudomonas, Bacillus and Enterococcus. Statistical analysis of the mean microbial load showed a significant difference (P<0.05) between control and air preserved meat pie and no significant difference in the mean microbial load between control and refrigerated meat pie were (P>0.05)

Bioconversion of Cellulosic Wastes into a Valuable Resource: Cellulosic wastes - A Valuable Resource for Industrial Organisms, Enzymes, Media and Fermentation Substrates

Cellulosic wastes could be turned into several value-added products through bioconversion. This work examined four practical ways of transforming the vast amount of cellulosic wastes in our environment into a valuable resource. Being a natural habitat of cell-wall hydrolyzing organisms, cellulosic wastes are good sources of viable cellulolytic organisms. These are organisms that produce enzymes that degrade plant cell-wall polymers. The wastes can therefore serve as a source of low-cost fermentation substrates for producing industrial enzymes needed for the saccharification of cellulosic materials. It could also be used as cheap carbon and energy source for selective media used in cultivating cellulolytic organisms. Such uses will undoubtedly reduce the cost microbial media and also the production cost of cellulolytic enzymes. The waste cellulosic materials can also be enzymatically hydrolyzed into simple sugars using cellulolytic enzymes such as cellulases and xylanases. Hydrolysis of plant cell wall polysaccharides into simple sugars is the primary step needed for the conversion of cellulosic materials into bulk chemicals such as ethanol and biogas

Properties of Endoglucanase of Penicillium chrysogemum PCL501

Crude extracellular enzyme from a 3-day culture of Penicillium chrysogenum (PCL 501), in basal medium containing cellulose as the sole carbon source, yielded 0.67 ± 0.03, 19.94 ± 1.30 and 8.50 ± 0.50 units mg protein-1 of 1, 4- â-endoglucanase, â-glucosidase and xylanase activity respectively. The crude enzyme was subjected to ammonium sulphate precipitation (80% saturation) and gel filtration. A purification-fold of 7.5 was achieved. Two active fractions of 1, 4 âendoglucanase (EC 3. 2. 1. 4), which exhibited about the same activity towards carboxymethylcellulose (CMC), were obtained and pooled for the subsequent analyses. The endoglucanase gave a Vmax of 10.0 ± 0.4 μmol min-1 mg protein-1 and Km of 11.8 ± 0.4 gL-1 with CMC. The enzyme was most active at pH of 4.5 – 5.0 and temperature range of 40 – 50 OC. The optimum pH was 4.9 while the Optimum temperature was 48 OC. Divalent metal ions and EDTA affected the enzyme activity at 2.0 mM concentrations. Mn2+ and Fe2+ had stimulatory effects on the enzyme whereas Mg2+, Cu2+, Zn2+, Hg2+ and EDTA inhibited the enzyme activity. The effect of Ca2+ was not significant. Over 3- fold increase in the enzyme activity was recorded with Mn2+. Percentage inhibition of 65.9 and 79.7 respectively was obtained with Hg2+ and EDTA. The organism appears to produce two types of endoglucanase which differed in their molecular weight but not significantly in their activity. The enzyme activity was highly stimulated by manganese ion and inhibited by the metal-chelating agent, EDTA

Antibacterial effects of extracts of Ocimum gratissimum and piper guineense on Escherichia coli and Staphylococcus aureus

The upsurge in the prevalence of side effects of many synthetic antimicrobial agents and incidence of multidrug resistant bacteria has spurred scientists on the research for plant based antimicrobial of therapeutic potentials. Ocimum gratissimum and Piper guineense present such potential of high medicinal value. These plants are used in Nigeria traditionally as condiments and for treatment of various ailments such as pyorrhea, dysentery and bronchitis. Aqueous and ethanol extracts of O. gratissimum and P. guineense leaves were screened for antibacterial activity against Escherichia coli and Staphylococcus aureus. Both extracts were found to exhibit selective inhibition against the isolates. The diameter zones of inhibition exhibited by the extracts were between 2 + 0.01 – 10 + 0.10 mm. The minimum inhibitory concentration (MIC) determined by the agar diffusion method was between 10.00 and 2.50 mg/ml-1. Ethanol extracts showed more inhibitory effect compared to the aqueous extracts. Results obtained show that the extracts of O. gratissimum and P. guineense possess some level of antibacterial activities against E. coli and S. aureus

GROWTH AND CELLULASE ACTIVITY OF WILD-TYPE ASPERGILLUS NIGER ANL301 IN DIFFERENT CARBON SOURCES

A wild-type Aspergillus niger (ANL301) isolated from wood-waste in Lagos, Nigeria, produces extracellular proteins with cellulase (EC 3. 2. 1. 4) activity. Three different carbon sources (Glucose, Cellulose and Sawdust) influenced the organism’s growth and the production of extracellular cellulase enzymes. Best growth was obtained with glucose at 72 hours of incubation. The peak mycelia weight of 1.56 mg/ mL obtained with glucose was about 3 times the maximum weight of 0.58 and 0.49 mg/ mL respectively obtained with cellulose and sawdust at 96 hours. The peak protein contents of the culture filtrates were 0.02, 0.15 and 0.69 mg/ mL respectively in the media containing glucose, cellulose and sawdust. There was no significant cellulase activity in the filtrates from glucose-containing media. The culture filtrates of the organism from cellulose- and sawdust-containing media yielded significant cellulase activities with maximum values of 105.6 Units /L (at 72 hours for cellulose) and 101.9 Units /L (at 144 hours for sawdust). There is a correlation between the protein content and cellulase activity of the culture filtrates. Sawdust can serve as a low-cost substrate for cellulase production by the organism

Assessment of water quality in Canaanland, Ota, Southwest Nigeria

In this study, water points in Canaanland, Ota, and nearby Iju River were analyzed for biological and physicochemical properties including heavy metal content. Water quality parameters examined were pH, alkalinity, salinity, conductivity, turbidity, total hardness, total solids (TS), total dissolved solids (TDS), total suspended solids (TSS), dissolved oxygen (Do), biochemical oxygen demand (BOD), iron (Fe), lead (Pb), zinc (Zn) and chromium (Cr). All the water samples were slightly acidic (5.96 – 6.54) except the bottled/ sachet Hebron water and Iju River water. The results were compared against drinking water quality standards laid by World Health Organization (WHO) and Nigerian Standard for Drinking Water (NSDW). The potable water samples were within the standards for consumable water and so are considered safe for human consumption. The surface waters, on the other hand, have high levels of total dissolved solids, conductivity and salinity. The BOD of the effluent water showed that the water was contaminated and the use of the water for domestic purposes by the inhabitants could lead to hazardous side effects

Evaluation of antibacterial activity of Pisidium guajava and Gongronema Latifolium

Pisidium guajava and Gongronema latifolium are local plants used traditionally in south-eastern Nigeria to treat ailments such as cough, loss of appetite, malaria and stomach disorders. In this study, aqueous and ethanolic leaf extracts of P. guajava and G. latifolium were screened for antibacterial activity against two clinically isolated organisms of the gastrointestinal tract, Escherichia coli and Staphylococcus aureus. Results obtained show that leaf extracts of both plants possess significant antibacterial activities against the two isolates. Ethanolic extracts showed more inhibitory effect compared to the aqueous extracts. Extracts of P. guajava exhibited higher inhibitory effect than that of G. latifolium. The diameter of zones of inhibition by the leaf extracts of P. guajava was 8 - 16 mm and 14 - 21 mm respectively for the aqueous and ethanolic extracts. The minimum inhibitory concentrations (MICs) were 5.0 and 0.625 mg ml-1 respectively for the aqueous and ethanolic extracts of P. guajava. For the extracts of G. latifolium, the diameter of zones of inhibition was between 6 and 10 mm while MICs were 10.0 and 2.5 mg ml-1 respectively for the aqueous and ethanolic extract

Proximate analysis of Sphenostylis stenocarpa and Voadzeia subterranean consumed in South –Eastern Nigeria

Proximate analyses of two traditional grain legumes consumed in Eastern Nigeria- Bambara groundnut (Voadzeia subterranean) and African yam beans (Sphenostylis stenocarpa) were carried out. Bambara groundnut was found to contain 2.86±0.02% moisture, 32.40±0.02% protein, 7.35± 0.02% fat, 5.78±0.02% ash, 2.68±0.02% crude fiber and 51.78±0.02% total carbohydrates. African yam beans contained the following: 1.96± 0.02% moistuire, 37.21±0.02% proteins, 9.49±0.02% fat, 5.35±0.02 Ash, 3.55±0.02 crude fiber and 44.4±0.02% total carbohydrates. The result indicates that the two underutilized food legumes have high protein content with African yam beans having slightly higher value of the protein nutrient. They also contain varying levels of ash content, crude fiber and carbohydrates. This reveals that bambara groundnut and African yam beans are important food sources that can be exploited particularly in the developing countries were there is shortage in animal protein and under nutrition facing many families in developing countries