Production and partial purification of glucoamylase from Aspergillus niger isolated from cassava peel soil in Nigeria

Glucoamylase is an enzyme that hydrolyses 1,4α and 1,6β-glucosidic linkages in polysaccharides yielding glucose. Aspergillus niger strains 1, 2 and 3 were locally isolated from cassava peel dumpsite for the production of glucoamylase enzyme. A. niger strains 1, 2 and 3 were screened for their hyper producing ability on potato dextrose agar using plate assay method fortified with starch agar, and showed zone of clearance of 17.0, 23.0 and 8.0 mm, respectively. The glucoamylase activity for A. niger strains 1 and 2 were 13 000.0 and 11 740.0, respectively. These values were however higher than the activity as obtained from the commercial enzyme with 2 500.0. Investigations on the protein (mg/ml), and specific activity (units/mg) on glucoamylase produced by A. niger strains 1 and 2 was 24.20, 537.19, 23.13 and 507.57, respectively. Fractionation of the enzyme ammonium sulphate (% w/v) using 60, 80 and 100% showed that the enzyme activities were 33 179.86, 47 985.86 and 19 167.65 units/ml, respectively. Protein concentrations were 16.29, 16.29 and 21.55 units/mg, respectively, while specific activities were 2 036.82, 2 945.725 and 889.45 units/mg, respectively. The production, packaging, and commercialization of glucoamylase in Nigeria will save a lot of foreign exchange earnings, and boost the economy of Nigeria.Keywords: Glucoamylase, specific activity, Aspergillus niger, fractionation, cassava peel.African Journal of Biotechnology, Vol 13(21) 2154-215

The Association between Malaria and Iron Status or Supplementation in Pregnancy: A Systematic Review and Meta-Analysis

Introduction Malaria prevention and iron supplementation are associated with improved maternal and infant outcomes. However, evidence from studies in children suggests iron may adversely modify the risk of malaria. We reviewed the evidence in pregnancy of the association between malaria and markers of iron status, iron supplementation or parenteral treatment. Methods and Findings We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Global Health Library, and the Malaria in Pregnancy library to identify studies that investigated the association between iron status, iron treatment or supplementation during pregnancy and malaria. Thirty one studies contributed to the analysis; 3 experimental and 28 observational studies. Iron supplementation was not associated with an increased risk of P. falciparum malaria during pregnancy or delivery in Africa (summary Relative Risk = 0.89, 95% Confidence Interval (CI) 0.66–1.20, I2 = 78.8%, 5 studies). One study in Asia reported an increased risk of P. vivax within 30 days of iron supplementation (e.g. adjusted Hazard Ratio = 1.75, 95% CI 1.14–2.70 for 1–15 days), but not after 60 days. Iron deficiency (based on ferritin and C-reactive protein) was associated with lower odds for malaria infection (summary Odds Ratio = 0.35, 0.24–0.51, I2 = 59.2%, 5 studies). With the exception of the acute phase protein ferritin, biomarkers of iron deficiency were generally not associated with malaria infection. Conclusions Iron supplementation was associated with a temporal increase in P vivax, but not with an increased risk of P. falciparum; however, data are insufficient to rule out the potential for an increased risk of P. falciparum. Iron deficiency was associated with a decreased malaria risk in pregnancy only when measured with ferritin. Until there is more evidence, it is prudent to provide iron in combination with malaria prevention during pregnancy