University of Nigeria, Nsukka

About: University of Nigeria, Nsukka is a education organization based out in Nsukka, Nigeria. It is known for research contribution in the topics: Population & Health care. The organization has 10211 authors who have published 13685 publications receiving 138922 citations.

Production of raw starch digesting amylase by Aspergillus niger grown on native starch sources

Abstract: Aspergillus niger isolated from rotting cassava produced raw starch degrading amylase on cassava, maize, sorghum and soluble potato-derived starch as the sole carbon source without prior gelatinisation. Maximum activity of the amylase was attaired using cassava starch as substrate. The crude enzyme solution which comprised a mixture of raw and non raw starch digesting amylase degraded both cereal and tuber or root starches significantly. Source of assay starch significantly influenced raw starch digesting activity. Optimum pH for the raw starch degrading and the extracellular amylase were 6.0 and 3.5-4.0, respectively. However, both enzyme activities appeared to be uninfluenced across a relatively broad pH range 3.0-7.0. No correlation was found between the capacity of starch to induce expression of the enzyme and its susceptibility to enzyme digestion. The adsorbability of the various starches to raw starch digesting amylase was directly related to their digestibility.

Preliminary assessment of trace metals and polycyclic aromatic hydrocarbons in the sediments

Abstract: Total concentrations of Cd, Cr, Co, Fe, Pb, Ni, Mn and Zn were determined by atomic absorption spectrophotometry in the surface sediments of Taylor Creek, Southern Nigeria. The most concentrated trace metals, ranging from 113.2 to 5160.7 mg/g-dry weights were Fe, Pb, Mn, Ni and Zn. There was no significant variation in sediment-associated metal levels (P>0.05). The Metal Pollution Index (MPI) was highest at Agbia/Nedugo and is attributed to local contamination of the Creek. The concentrations of low molecular weight polycyclic aromatic hydrocarbons (PAHs) were also detected and quantified in the sediments by capillary gas chromatography equipped with a flame ionization detector. The concentration levels of 178.1-1266.3 mg/g-wet weights were high for the PAHs. The results indicate that the pollutants, which are bio-accumulatable, could contribute to inferior biodiversity, and shifts in community composition from sensitive to tolerant taxa.

Banana peel as a biosorbent for the decontamination of water pollutants. A review

Abstract: Pollution of environmental waters and ecosystems is increasing. Adsorption is an effective technique for water decontamination, but is limited by the cost of commercial adsorbents such as activated carbon. Research has thus focused on the recycling and transformation of biowaste as low-cost, biodegradable adsorbents. In particular, banana peel is promising for commercial use due to its wide availability and efficiency. Here, we review the use of natural banana peel for the biosorption of pollutants from water. We discuss the factors controlling pollutants removal, and the regeneration and reuse of the biosorbent. pH of 5.0 to 7.0 is favorable for the removal of cationic pollutants, while pH of 2.0 to 4.0 is suitable for anionic pollutants. Generally, higher pollutant concentration induces lower removal, whereas higher banana peel dosage induces higher removal. Banana peel exhibits efficient removal of pollutants at various temperatures, with adsorption capacities mostly within 1–100 mg/g. Nitric acid is the most efficient eluent for heavy metal desorption from banana peel. Most studies showed efficient biosorbent reuse up to five cycles and above. We also discuss the thermodynamics, kinetics and isotherms of the adsorption process.