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 carbon sources 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 sole carbon 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

Agro-waste: a potential fermentation substrate for Penicillium chrysogenum

Common agro-wastes found in Lagos, Nigeria (cassava shavings, corncob, sawdust, and sugarcane pulp) were compared with glucose and lactose as fermentation substrates for Penicillium chrysogenum PCL501. Cassava shavings significantly (P<0.001) produced the highest amount of mycelia weight (0.43 ± 0.02 mg/ml) than all the other substrates. This was followed by corncob with peak mycelia weight of 0.33 ± 0.02 mg/ml. Peak mycelia weight of 0.27 ± 0.01 mg/ml was equally obtained with glucose and sugarcane pulp whereas lactose gave a slightly lower peak of 0.25 ± 0.01 mg/ml. Sawdust gave the least mycelia weight of 0.13 ± 0.01 mg/ml. Total sugar content of all the culture media steadily decreased as fungal growth progressed indicating that the organism utilized carbohydrates for growth and mycelia formation. Cultures containing cassava shavings and sawdust gave high protein peaks of 0.84 ± 0.05 and 0.65 ± 0.03 mg/ml respectively. Cultures containing corncob, glucose, lactose and sugarcane pulp yielded lower protein peaks of 0.37 ± 0.02, 0.30 ± 0.02, 0.24 ± 0.02 and 0.18 ± 0.01 mg/ml respectively. The results suggest that cassava shavings, corncob and sugarcane pulp could serve as cheap fermentation substrates for the growth of the fungus. Of all the substrates investigated, cassava shavings have the best potential to serve as substrate for fermentation by Penicillium chrysogenum PCL501. © 2009 International Formulae Group. All rights reserved

Xylanase production by Penicillium chrysogenum (PCL501) fermented on cellulosic wastes

Xylanase production by Penicillium chrysogenum PCL501, newly isolated from wood-wastes, was monitored at 24 h intervals for a period 168 h in media containing four different carbon sources (oatspelt xylan, wheat bran, sawdust, and sugarcane pulp). The highest xylanase activity of 6.47 Units mL-1 was obtained at 96 h in media containing wheat bran whereas media containing sugarcane pulp gave a peak value of 1.39 Units mL-1 at 144 h. Sawdust and xylan gave a peak xylanase activity of 1.35 and 0.79 Units mL-1 respectively at 120 h. Maximum protein released in xylan-containing media was 0.38 mg mL-1. Higher protein yield was obtained in media containing the agro-wastes, with wheat bran giving the highest value of 1.14 mg mL-1. The maximum specific xylanase activities were 2.59, 8.52, 16.06, and 9.36 Units mg Protein -1 for sawdust, sugarcane pulp, wheat bran and xylan respectively. Out of the three agro-wastes used in this study, wheat bran holds the greatest promise for cost-effective production of the xylanase enzyme. The carbon source is the highest inducer of the enzyme in the fungus

Information Sources Used by Postgraduate Students in Library and Information Science: A Citation Analysis of Dissertations

This paper is a citation analyses that assesses references of theses submitted to the Department of Library and Information Science at the University of Nigeria, Nsukka from 1997 to 2007 The results revealed that journals are cited more than other information resources, and online resources cited were very rarely from 1997-2005, but increased from 2006 and 2007. College and Research Libraries is the most cited journal. The major subject area covered in their research is library management/administration; user studies, information communication technology, and collection development while bibliometrics, preservation, special and public libraries were less commonly researched

Effect of carbon sources on cellulase (EC 3. 2. 1. 4) production by Penicillium chrysogenum PCL501

The effects of glucose, crystalline cellulose and sawdust of Mitragyna cilata on the growth and cellulase production, inferred from cellulase (EC 3. 2. 1. 4) activity, of Penicillium chrysogenum PCL501 was determined. Glucose-containing media gave the highest mycelia weight of 1.78 mg mL-1 in 120 h of incubation. This is about 3.5 – 4.5 times the maximum weights of 0.51 and 0.40 mg mL-1 respectively obtained from the cultures containing cellulose and sawdust. The cultures containing crystalline cellulose and sawdust produced extracellular protein with cellulase (EC 3. 2. 1. 4) activity whereas glucose-containing cultures yielded very low protein and no significant cellulase activity. Maximum protein content of 0.02, 0.13 and 0.46 mg mL-1 respectively were obtained from the cultures containing glucose, cellulose and sawdust. Peak cellulase activity values of 100.0 and 92.2 Units L-1 respectively were obtained for the cultures containing cellulose and sawdust. There is a correlation between the protein released and cellulase activity of the culture filtrates. P. chrysogenum PCL501 produces extracellular proteins with significant cellulase activity in media containing cellulose and sawdust but not in glucose-containing medium. Sawdust is indicated as a good inducer of cellulase activity in the organism. The waste cellulosic material can be used as low-cost carbon source for commercial cellulase production

Plant Waste Hydrolysis by Extracellular Enzymes of Aspergillus niger and Penicillium chrysogenum: Effect of Ammonia Pretreatment

Aspergillus niger (ANL301) and Penicillium chrysogenum (PCL 501) cultured in basal media with cellulose as sole carbon source yielded extracellular enzymes which partially hydrolyzed sawdust and sugarcane pulp into simple sugars. Pre-treatment of sawdust by ammonium hydroxide steeping increased the yield of simple sugars. The reducing sugars released from the pretreated sawdust by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were 3.58% and 7.02% of the total hydrolysable sugars respectively. This is in contrast to the 0.92% and 1.02% of the total hydrolysable sugars released respectively by the enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) from the non-pretreated sawdust. Enzymatic hydrolysis of sugarcane pulp by the crude enzymes was not significantly affected by ammonia pre-treatment. Reducing sugars released from non-pretreated sugarcane pulp by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were respectively 4.17% and 5.08% of the total hydrolysable sugars

Potentiality of Diethylamine as Agent of Deproteination and Deacetylation in the Extraction of Chitosan from Scylla serrata Shell

The potentiality of diethylamine as deproteination and deacetylation agent in the extraction of chitosan from Scylla serrata (giant mud crab) shell was investigated. The aim was to find an alternative agent to inorganic alkalis as possible replacement for use in the production of high quality chitosan with the right stability. Pretreatment of the shell was carried out and followed by demineralization using hydrochloric acid. Diethylamine was used for deproteination and deacetylation by modifying some published protocols. Moisture, ash, fat and protein contents of the extracts were determined using their respective standard methods. Fourier Transform Infrared (FTIR) technique was used for spectroscopic analysis. Scylla serrata shell was composed of 14.25% protein, 32.84% mineral (CaCO3), 31.52% chitin and 21.39% chitosan. Moisture, ash, fat and protein contents of chitin extracted from Scylla serrata shell were 2.35%, 3.03%, 1.79% and 3.85% respectively while those of chitosan were 1.65%, 3.84%, 0.53% and 2.80% respectively. Degree of deacetylation (DDA) and carbon to nitrogen ratio were 69.24% and 5.67 respectively. FTIR spectra of the extracted chitin and chitosan from Scylla serrata showed the presence of some active compounds of carbonyl, amide, amine and hydroxyl groups. However, CH3 waging along chain (952 cm-1), CO stretching at 1026 cm-1 and 1073 cm-1, and amide II band (1563 cm-1) were not found in the extracted chitin while HPO42- and amide III were also not found in the extracted chitosan. These moieties were present in the standard chitin and chitosan respectively. This study has shown that diethylamine (organic base) has great potential as agent of deproteination and deacetylation in the extraction of chitosan from Scylla serrata. Consequently, academic activity in the area of investigation of the stability of the extracted chitosan from Scylla serrata using diethylamine as deproteination and deacetylation agent is strongly recommended. Keywords: Diethylamine, deproteination, deacetylation, chitin and chitosan, Scylla serrata shell. DOI: 10.7176/CMR/12-7-07 Publication date:October 31st  2020

Pectinolytic activity of wild-type filamentous fungi fermented on agro-wastes

Five filamentous fungi (Aspergillus clavatus, Aspergillus niger, Fusarium sp., Penicillum chrysogenum and Trichoderma sp.) isolated from agrowaste samples in Lagos metropolis, Nigeria, depolymerized citrus pectin. Best pectolytic activity, as indicated by the diameter of clear, hydrolyzed zones on the medium plates containing commercial citrus pectin as sole carbon source, was obtained with A. niger, closely followed by P. chrysogenum. The two fungi also produced pectinases with different agrowastes (pineapple peel, orange peels, sawdust, sugarcane pulps and wheat bran) as the sole carbon source. The highest pectinase activity by both fungi was produce with wheat bran as the sole carbon source. Peak pectinase activity of 350.28 ± 2.82 and 478.25 ± 3.04 IU mg-1 protein was respectively obtained by submerged fermentation (SmF) at 48 h for A. niger and P.chrysogenum in media containing wheat bran as the sole carbon source. Solid-state fermentation (SSF) yielded higher levels of pectinase activity than the SmF. The strains of A. niger and P. chrysogenum have good prospect for pectinase production. Wheat bran is a good low-cost fermentation substrate for pectinase production by the investigated fungi

The effectiveness of locally-prepared peritoneal dialysate in the management of children with acute kidney injury in a south-east Nigerian tertiary hospital

Background: Peritoneal dialysis (PD) is the preferred mode of renal replacement therapy (RRT) in children with acute kidney injury (AKI). The gold standard remains the use of commercially-prepared PD fluid. In resource-poor nations, its availability and affordability remain a challenge.Aim: This study aims to report the effectiveness of locally-prepared PD fluid in the management of AKI in a south-east Nigerian tertiary hospital.Subjects and Methods: This was a retrospective study conducted at the paediatric ward of the University of Nigeria Teaching hospital, Enugu. The case records of 36 children seen over three years, diagnosed with AKI and requiring PD were reviewed. The retrieved information comprised biodata, aetiology of AKI, indications for PD, pre-and post-dialysis estimated glomerular filtration rate (eGFR) and patient outcomes.Results: The children (20 males and 16 females) were aged 3 to 36 months with a mean age of 9.92 ± 6.29 months. The common aetiologies of AKI were septicemia (30.6%), hemolytic uremic syndrome (19.4%), and toxic nephropathy (16.7%). The frequent indications for PD were uremic encephalopathy (58.3%) and severe metabolic acidosis (38.8%). The pre-and post-dialysis mean urine flow rate was 0.16 + 0.13 and 2.77 + 0.56 ml/kg/hour respectively. The eGFR before PD, at discontinuation, and a week later was 6.06 + 2.87, 24.44 + 15.71 and 59.07 + 22.22 mls/min/1.73m2 respectively.Conclusion: PD with locally-prepared dialysate is safe, effective and a life-saving alternative in the management of AKI in childrenKeywords: Peritoneal dialysis; renal replacement therapy; acute kidney injury; children; dialysate; developing country