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

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

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 Activity of Culture Extracts of Penicillium chrysogenum PCL501: Effects of Carbon Sources

Penicillium chrysogenum PCL501 produced β-lactam antibiotics when fermented with different agro-wastes: cassava shavings, corncob, sawdust and sugarcane pulp. In vitro antibacterial activity of the culture extracts was tested against four clinical bacterial isolates, namely, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. All the culture extracts and standard drug (commercial Benzyl Penicillin) inhibited the growth B. subtilis and E. coli; the potency varied with carbon source. Antibacterial activity of extracts from cultures containing cassava shavings and sugarcane pulp was comparable with that of the standard drug. The MIC against the susceptible organisms was 0.20mg/ml for the standard drug and ranged from 0.40 to 1.50mg/ml for the culture extracts. Neither the culture extracts nor the standard drug inhibited K. pneumoniae and P. aeruginosa; the bacterial strains produced β-lactamase enzymes. Cassava shavings and sugarcane pulp are indicated as suitable cheap carbon sources for the production of antibiotics by Penicillium chrysogenum PCL501

Isolation of Cellulolytic Microfungi Involved in Wood-Waste Decomposition: Prospects for Enzymatic Hydrolysis of Cellulosic Wastes

Wood-wastes from dump-sites at Okobaba Saw-mills on the western part of the Lagos lagoon were examined for cellulolytic microorganisms. Cellulolytic microfungi were isolated from the wastes using minimal salt agar medium containing 0.2% (w/v) crystalline cellulose, sugarcane pulp, corn cob or saw-dust as sole carbon/energy source. The colonies of cellulolytic microfungi which appeared on the plates increased in size and number as the incubation period (days) increased. Among the fungal isolates were two pathogenic Aspergilli (A flavus and A fumigatus), three different black Aspergilli (herein designated as A.niger I, A.niger II and A.niger III), Botrytis cinerea, Fusarium species and Penicillium species. Cell-free filtrates of 7 – day cultures of A.flavus, A.niger I, A.niger II, B. cinerea and P.species grown on the minimal salt broth supplemented with crystalline cellulose as sole carbon/energy source showed very significant CM–cellulase activity. P. species gave a very high value that was over 4 times the value for the closest organism, A.niger II. There is a good propect for cellulase production using the virgin strain of P. species isolated from the wood-wastes

Kinetic Study and Characterization of 1,4-β-Endoglucanase of Aspergillus niger ANL301

Submerged fermentation of Aspergillus niger ANL 301 in basal medium containing cellulose as sole carbon source, yielded crude extracellular proteins with 0.54 ± 0.02 units mg protein-1 of 1,4-β-endoglucanase activity. Partial purification by ammonium sulphate precipitation (80% saturation) and gel filtration on Sephadex 25-300 gave two active fractions of 1,4-β-endoglucanase, which exhibited close activity towards carboxymethyl-cellulose (CMC). The pH profile of the pooled enzyme fractions showed three activity peaks at pH 3.5, 5.5 and 7.0. The enzyme was most active at pH 5.5 and showed optimal activity at 50°C. Vmax of 4.4 ± 0.4 µmol min-1 mg protein-1 and Km of 12.5 ± 0.4 gL-1 was obtained with CMC for the enzyme. Different divalent metal ions and EDTA affected the enzyme activity at 2.0 mM concentrations in different ways. Mn2+ and Fe2+ exhibited 253.4 and 24.0% stimulatory effects, respectively on the enzyme activity. Mg2+, Ca2+, Cu2+, and Zn2+ inhibited the enzyme by between 22.3 and 29.4%, whereas 75.0 and 71.3% inhibition were obtained with Hg2+ and EDTA, respectively. Manganese ion showed an exceptional activation of the 1,4-β-endoglucanase. The organism produced two types of 1,4-β-endoglucanase with different molecular weights

The Rhetoric of Collaborative Ministry: A Perspective on Ministry Based on Augustine\u27s Rhetorical Theory with Particular Reference to Abakaliki Diocese

The concern of the Catholic Church in this century and the immediate past centuries has been how the faithful will effectively internalize and role-play the Gospel in their life. The implication of this concern for the Catholic Church is rooted in the inter-cultural and counter-cultural encounter between Christianity and any of the cultures in question, and at this point the African Culture in Abakaliki diocese. To negotiate a complexity of this magnitude, one cannot ignore its rhetorical ripples around the individual, culture, Church family and the society at large. The Christian culture must be translated to the language the people being evangelized must understand. The Gospel will have to take an incarnate nature among the people in order for them to role-play it in their life. Therefore, the significance of Augustine\u27s rhetorical theory in addressing a complexity of this kind is invaluable as a theoretical basis to launch a process of action. Augustine strongly upholds the role of caritas (love) which demands communication and eventually becomes the source whereby we can overcome ambiguities in situations that are rhetorical in nature. Within the African context such ambiguities are resonate in the development of Catholic Christian ministry in a way that will more aggressively assimilate and adapt to the African (Abakaliki diocesan) society. It must be acknowledged that the African society is already family and community oriented, where the role of the individual is paramount. These existing roles are forms of service to the community and may qualify for a ministry if interpreted in religious terms. Therefore how can collaborative ministry allow the birth of new ministries while addressing the needs of the Catholic Christian communities in Africa? The significance of collaborative ministry as recommended by the fathers during African Synod for the African Catholic Church, derives from the biblical sense of ministry indicative of Christ\u27s mandate to his followers, to go out to the whole world and proclaim the gospel (Holy Bible, Mk 16: 15); while assuring them I am with you always, until the close of the age (Holy Bible, Mt 28: 20). There is no exclusion in ministry