Xylanase production by Aspergillus niger ANL 301 using agro - wastes

Xylanase production by wild-type Aspergillus niger ANL301, newly isolated from wood-waste, was monitored at 24 h intervals for a period 168 h in media containing different carbon sources. The carbonsources were oat-spelt xylan (Fluka) and three agro-wastes (sawdust, sugarcane pulp and wheat bran). Highest xylanase activity of 6.47 units/mL was obtained at 96 h in media containing wheat bran as solecarbon source. Maximum activity value for the media containing sugarcane pulp was 0.95 units/mL obtained also at 96 h. Sawdust and oat spelt xylan gave the peak enzyme activities of 0.65 and 0.80 units/mL respectively at 120 h. High protein yield was obtained in media containing the agro-wastes, with wheat bran giving the highest value of 1.14 mg/mL at 96 h. The maximum specific xylanase activities were 3.86, 3.37, 5.69, and 9.36 units/ mg protein for sawdust, sugarcane pulp, wheat bran and oat spelt xylan, respectively. Out of the three agro-wastes used in this study, wheat bran holds greatest promise for low cost production of the xylanase enzyme

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

ABSTRACT 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

Potentials of cellulosic wastes in media formulation

Potential use of cellulosic wastes as carbon and energy sources in selective media formulations was investigated. Two agar media, Czapek-Dox and Sabouraud’s agar, were modified by substituting theircarbon sources with cellulose, sawdust and sugarcane pulps. Then, two fungi; Aspergillus niger ANL301 and Penicillium chrysogenum PCL501, newly isolated from wood-wastes, were transferred to the unmodified and modified media and their growth was monitored for 120 h. Growth of the organisms on modified media containing sawdust and sugarcane pulp compared favorably with that obtained for the unmodified equivalents. Modified Czapek-Dox agar containing 2% (w/v) sawdust (Wood agar) and sugarcane pulps (Cane agar) gave 78.9 – 93.3% of the maximum growth obtained on Sabouraud’s agar. The modified Sabouraud’s agar containing sawdust (Wood-Pep agar) and sugarcane pulps (Cane-Pep agar) yielded 84.4 – 100% of the maximum growth on Sabouraud’s agar. Cellulose-containing media gave a lower level of growth (60.0 – 66.7%) of that obtained for the unmodified media

Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.

Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates

Okochi, “Properties of endoglucanase of Penicillium chrysogemumPCL501,”Australian

Abstract: 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 of 1, 4-â-endoglucanase, â-glucosidase and xylanase activity -1 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 â-endoglucanase (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 mg protein and Km of 11.8 ± 0.4 gL with CMC. The enzyme was Zn , Hg and EDTA inhibited the enzyme activity. The effect of Ca was not significant. Over 3- fold increase in the enzyme activity was recorded with Mn . Percentage inhibition of 65.9 and 79.7 2+ respectively was obtained with Hg and EDTA. The organism appears to produce two types of 2+ 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

Okochi, “Properties of endoglucanase of Penicillium chrysogemumPCL501,”Australian

Abstract: 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 of 1, 4-â-endoglucanase, â-glucosidase and xylanase activity -1 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 â-endoglucanase (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 mg protein and Km of 11.8 ± 0.4 gL with CMC. The enzyme was Zn , Hg and EDTA inhibited the enzyme activity. The effect of Ca was not significant. Over 3- fold increase in the enzyme activity was recorded with Mn . Percentage inhibition of 65.9 and 79.7 2+ respectively was obtained with Hg and EDTA. The organism appears to produce two types of 2+ 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

Biodegradation Potential of Two Rhodococcus Strains Capable of Utilizing Aniline as Carbon Source in a Tropical Ecosystem.

Two closely related strains of Rhodococcus species, isolated from aniline polluted tropical ecosystem, were able to utilize aniline as carbon source in 3.0 and 4.0 mM concentrations at 30°C and pH of about 6.4. Rapid increase in turbidity and a sharp decline in pH were observed in the cultures of both organisms within 24 h of incubation. Shortly after the period, growth became slower. Turbidity values obtained at 4.0 mM concentrations of aniline was about twice the values obtained at 3.0 mM concentrations. Aniline concentrations of 10 mM and above were found to be toxic for the organisms. Rhodococcus species because of its significant prevalence in agricultural soils can be used as an effective means of recovering tropical agricultural land polluted with aniline, aniline-based herbicides or its derivatives