ghanaopendata/ghanaian-research-english huggingface dataset:
Characterization of Glucoamylase Produced by Aspergillus niger and Rhizopus sp.

Amylase enzymes are important enzymes employed in starch processing industries for hydrolysis of polysaccharides into simple sugars. Microorganisms including a number of fungal species have been used to produce amylases more economically than from other sources. Glucoamylase (C3009H4570N782O1012S13) is an exoenzyme that removes glucose units consecutively from the nonreducing ends of starch and oligosaccharides. The enzyme also cleaves α-1, 6- and α-1, 3-bonds but at a slower action. Glucoamylase is used in processed-food industry, fermentation technology, textile and paper industries. In this study, four native fungal isolates, Aspergillus niger, Aspergillus flavus, Rhizopus species and Fusarium oxysporum and the potential of five solid substrates, wheat bran, rice bran, groundnut pod, maize bran and cocoa pod for glucoamylase production were investigated using Solid-State Fermentation process. Isolates of Aspergillus niger and Rhizopus species on wheat bran as substrate at spore concentrations of 1 x 107 per ml produced the highest enzyme activities under optimum growth conditions. Glucoamylase production was found to be affected by temperature, pH, incubation period, nature of substrate and the kind of microorganism used. Glucoamylase production by Aspergillus niger was found to be affected by nitrogen. Glucoamylase produced by Aspergillus niger yielded maximum enzyme activity of 6.66 U/ml in 18 hours of incubation period at a temperature of 40ºC, nitrogen concentration of 0.2 g/l and at pH 5.0. Similarly, glucoamylase produced by Rhizopus species gave maximum enzyme activity of 4.44 U/ml in 18 hours of incubation period at a temperature of 40ºC and pH 4.5. Molecular weights of proteins in culture filtrates were determined by SDS-PAGE. Proteins with molecular weights 61.48, 29.68, 21.06 and 12.33 KDa were identified from culture filtrates of Aspergillus niger and proteins with molecular weights 96.40, 65.56, 51.80, 29.05 and vii 19.75 KDa were found from culture filtrates of Rhizopus species. Kinetic studies using Hanes-Woolf’s plot and starch as substrate gave Kmax = 0.0009548 g/l and Vmax = 2.387 g/l.min for enzyme produced by Aspergillus niger and Kmax = 0.0007443 g/l and Vmax = 2.481 g/l.min for enzyme produced by Rhizopus species

Source: KNUST
Characterization of latex from trees in the Bobiri forest of Ghana

In this study, ten latex samples collected from different trees in the Bobiri forest in the Ashanti region of Ghana, were characterized based on FT-IR, viscosity, protein content, ash content, crosslink density, surface tension and rubber content. The results were compared to that of Hevea brasiliensis, which was used as reference. FT-IR analyses showed peaks at 1637.06 and 2963.61 cm‐1 (C-H bond) and 1450.06 and 1470.00 cm‐1 (C=C bond). These peaks are common with isoprene units (C5H8). Of all the samples, Hevea brasiliensis had the highest rubber contents of 56.18%, and lowest total solids and crosslink density of 14.98 and 0.08 respectively. Pycnanthus angolensis was the most viscous. With respect to total solids and coagulum content, Landolphia hirsuta had the highest percentages of 88.4 and 13% respectively. Based on their properties, these latexes could be used as alternatives to Hevea brasiliensis.

Source: KNUST
Characterization of microorganisms involved in the second stage of soy sauce fermentation (moromi) and studies on the shelf life of soy sauce.

Microorganisms play an important role in the fermentation of soy sauce. The aim of this study was to identify and characterize the microorganisms that are involved in the second stage of soy sauce fermentation and the shelf life studied. The microorganisms were identified using biochemical and Analytical Profile Identification (API) system. The pattern of distribution of total microbial numbers, lactic acid bacteria, yeast and fungi were similar as their numbers generally decreased with time. During the fermentation, lactic acid bacteria (numbers) were the most dominant followed by yeasts (numbers) and fungi (numbers). Twenty strains of lactic acid bacteria were isolated from the soy sauce mash during moromi fermentation and these were observed mostly in the first three weeks of fermentation. Tetragenococcus halophilus (also known as Pediococcus halophilus) had the highest number, followed by Lactococcus lactis, Lactobacillus delbrueckii, Lactobacillus plantarum and Lactobacillus acidophilus respectively. Two of the lactics could not be identified. Twenty-five strains of yeasts and molds were also isolated during moromi fermentation. The predominant yeast strain was Zygosaccharomyces rouxii (Z. rouxii), which was followed by Trichosporon mucoides, Cryptococcus humicolus, Cryptococcus laurentii, Candida ciferrii, Pichia ohmeri and Candida famata respectively. No significant changes were observed in microbial load, colour, moisture content, pH, and all the sensory attributes (colour, saltiness, pungency, umami and overall acceptability) of the locally produced soy sauce over the six months storage under room temperature. These results indicate that soy sauce can locally be produced by using starter culture to shorten the moromi stage fermentation and can stay on the shelf for more than six months.

Source: KNUST
Characterization of non-typhoidal salmonella isolated from patients attending Agona Swedru Municipal hospital

Introduction: There is increasing occurance of salmonellosis with observed emergence of high level resistance to antimicrobial agents leading to the difficulty in treating infected patients with invasive infections worldwide. The study aims at determining the Salmonella species causing diarrhoea in Agona Swedru Municipal Hospital, as diarrhoea ranked the third common complaints in the hospital. Methods: Clinical samples comprising stool (n=380), blood (n=378) and urine (n=375) were cultured for Salmonella and other bacteria. The Salmonella isolates were serotyped based on Kauffmann and White scheme. Antimicrobial susceptibility testing was performed on all the isolates using the disc diffusion Kirby-Bauer method. Double-disk synergy test was used to test the isolates for Extended Spectrum -Lactamase production. The Salmonella isolates were fingerprinted by Pulsed-Field Gel Electrophoresis (PFGE) to determine their genetic relatedness. Results: Thirteen (13) Salmonellae were isolated from the diarrhoeal patients stool samples (n=380). Among the Salmonella serovars identified, Salmonella Enterica (69.2%; n=9/13) predominated, followed by Salmonella Choleraesuis (23.1%; n=3/13) and Salmonella Paratyphi B (7.7%; n=1/13). The most common pathogen isolated other than Salmonella was Escherichia coli (63.6%; n=21/33), followed by Staphylococcus aureus (18.2%; n=6/33), Citrobacter species (9.1%; n=3/33), Proteus mirabilis (6.1%; n=2/33) and Pseudomonas aeruginosa (3.0%; n=1/33). Salmonella isolates showed varied resistance to antimicrobials tested, with resistance proportions being Cotrimoxazole (9/13 (69.2%), Tetracycline (3/13, 23.1%), Amoxicillin (2/13, 15.4%), Ampicillin (2/13, 15.4). All the isolates were sensitive to Ceftriaxone, Ciprofloxacin, Amikacin, Gentamicin, Amoxicillin- Clavulanic acid, Chloramphenicol and Meropenem. None of the Salmonella isolates were iv multidrug resistant (MDR) and none produced Extended Spectrum -Lactamase. Extended Spectrum -Lactamase production was varied among other isolates. The Salmonella Choleraesuis isolates though were same species, were of different PFGE types. Conclusion: Prevalence of Salmonellae among patients attending Agona Swedru Municipal Hospital was 3.4%. Most of the Salmonellae were non-Typhoidal Salmonellae. Proportion of isolates resistant to antibiotics was low. There are possibly different S. Choleraesuis isolates circulating in Agona Swedru and its environs.

Source: KNUST
Characterization of municipal solid waste in three selected communities in the Tarkwa Township of Tarkwa Nsuaem Municipality in Ghana

Most municipal and metropolitan assemblies have identified disposal of solid waste as a major problem that has gotten to a stage which needs urgent workable solutions. Increase in volume of waste generated by municipal residents, change in the quality of waste composition and the treatment and disposal method of waste collected are of major concern. Change in generation rate and quality of solid waste composition in municipalities coupled with ineffective management has led to serious environmental problems. Success of solid waste management plans stems on accurate and up to date data on quality and quantity of generated solid waste. This thesis presents the characterization of municipal solid waste (MSW) in the Tarkwa Nsuaem municipality, whose population is growing by an average of 3% per annum. Extensive field investigation was used for quantification and analysis of composition of MSW in selected residential areas. Field observations, secondary data and key informant interviews were also used. Simple random sampling and analysis of solid waste from specific sources were used for waste characterization whereas house-to-house weight analysis method was used for waste quantification. It was estimated that the average per capita daily generation rate was 0.92 kg per capita per day and average daily generation rate per household of average size 4.27 persons was 3.93 kg per household per day. The dominant solid waste of the municipality was organic waste and accounts for 68.56%, followed by plastics/rubber at 16.02%, paper and cardboard at 4.87%, ash/sand at 4.15%, textiles at 3.23%, non-ferrous metal at 1.65%, glass/ceramics at 0.92%, ferrous metals at 0.31% and potentially hazardous 0.29%. Recommendations were made on how to improve effectiveness, efficiency, integration and accountability and optimize municipal solid waste management.

Source: KNUST
Characterization of pectin extracted from muskmelon (Cucumis melo L.)

Muskmelon (Cucumis melo L.) fruits are cultivated for their seeds, but the peels are potential sources of pectin for food and pharmaceutical applications. The objective of this study was to extract and characterize pectin from muskmelon peels subjected to two different drying techniques. The pectin was extracted using acid treatment and the structure, chemical composition and functional properties determined. Oven and solar dried muskmelon pectin extracts gave comparable yields (6.48% and 5.27%), high degree of methylation (60.53 and 64.97%) and anhydrouronic acid content of 46.99% and 56.60%, respectively. Intrinsic viscosity was 0.3 gdL-1 irrespective of drying technique used. The pectin extracts from the oven and solar dried muskmelon demonstrated good water absorption (208g/100g and 269g/100g), oil absorption (237g/100g and 152g/100g) and emulsion (50% and 46%) capacities, respectively. The different drying techniques used did not significantly influence physicochemical and functional properties. The findings show that muskmelon pectin are high methoxyl pectin with good functional properties which can be tailored for use in food and pharmaceutical formulations.

Source: KNUST
Characterization of Salmonella enterica from invasive bloodstream infections and water sources in rural Ghana

Background: Non-typhoidal Salmonella (NTS) cause the majority of bloodstream infections in Ghana, however the mode of transmission and source of invasive NTS in Africa are poorly understood. This study compares NTS from water sources and invasive bloodstream infections in rural Ghana. Methods: Blood from hospitalised, febrile children and samples from drinking water sources were analysed for Salmonella spp. Strains were serotyped to trace possible epidemiological links between human and water-derived isolates.. Antibiotic susceptibility testing was performed, Results: In 2720 blood culture samples, 165 (6%) NTS were isolated. S. Typhimurium (70%) was the most common serovar followed by S. Enteritidis (8%) and S. Dublin (8%). Multidrug resistance (MDR) was found in 95 (58%) NTS isolates, including five S. Enteritidis. One S. Typhimurium showed reduced fluroquinolone susceptibility. In 511 water samples, 19 (4%) tested positive for S. enterica with two isolates being resistant to ampicillin and one isolate being resistant to cotrimoxazole. Serovars from water samples were not encountered in any of the clinical specimens. Conclusion: Water analyses demonstrated that common drinking water sources were contaminated with S. enterica posing a potential risk for transmission. However, a link between S. enterica from water sources and patients could not be established, questioning the ability of water-derived serovars to cause invasive bloodstream infections.

Source: KNUST
Characterization of Salmonella and other gram negative bacterial pathogens obtained from stool and blood at Cape Coast Teaching Hospital

Salmonella infections are of serious public health concern since these bacteria have been reported as the most frequently cause of foodborne illness and a common cause of human gastroenteritis and bacteremia worldwide. In addition to the increasing rate and invasiveness of salmonellosis, these bacteria are constantly developing resistance to the commonly tested antibiotics. This study was conducted to characterize Salmonella among other isolates from stool and blood cultures at the Cape Coast Teaching Hospital. A total of 971 samples comprising of 463 blood and 508 stool were collected and cultured over a 13 month period (March, 2014 – April, 2015). 17 (3.3%) Salmonellae and 3 (0.6%) Shigella flexneri were recovered from the stool samples cultured and the blood samples yielded bacteria other than Salmonella. There was 69/463 (14.9%) prevalence of bacterial isolates from blood. The blood isolates included Staphylococcus aureus (24/69, 34.8%), Citrobacter freundii (10/69, 14.5%), Escherichia coli (6/69, 8.7%) and Pseudomonas aeruginosa (6/69, 8.7%). The Salmonella serovars encountered were Salmonella Typhi (13/17, 76.5%) and Salmonella Typhimurium (4/17, 23.5%). There was 82% (14/17) multidrug resistance among the Salmonellae with resistance to ampicillin, co-trimoxazole and tetracycline being 65% each. Among the Salmonellae, no drug resistance was observed against cefotaxime, ceftriaxone, gentamycin, amikacin, meropenem, levofloxacin and ciprofloxacin and none produced ESBL. Among the blood isolates, resistance to ampicillin, tetracycline and co-trimoxazole were 96%, 91%, 87% respectively. The PFGE analysis indicated different clones that were closely related among the Salmonella Typhi. A similar analysis was observed among the Salmonella Typhimurium gel pattern analyzed.

Source: KNUST
Characterization of Non-Typhoidal Salmonella Isolated from patients attending Agona Swedru Municipal Hospital

Introduction: There is increasing occurance of salmonellosis with observed emergence of high level resistance to antimicrobial agents leading to the difficulty in treating infected patients with invasive infections worldwide. The study aims at determining the Salmonella species causing diarrhoea in Agona Swedru Municipal Hospital, as diarrhoea ranked the third common complaints in the hospital. Methods: Clinical samples comprising stool (n=380), blood (n=378) and urine (n=375) were cultured for Salmonella and other bacteria. The Salmonella isolates were serotyped based on Kauffmann and White scheme. Antimicrobial susceptibility testing was performed on all the isolates using the disc diffusion Kirby-Bauer method. Double-disk synergy test was used to test the isolates for Extended Spectrum -Lactamase production. The Salmonella isolates were fingerprinted by Pulsed-Field Gel Electrophoresis (PFGE) to determine their genetic relatedness. Results: Thirteen (13) Salmonellae were isolated from the diarrhoeal patients stool samples (n=380). Among the Salmonella serovars identified, Salmonella Enterica (69.2%; n=9/13) predominated, followed by Salmonella Choleraesuis (23.1%; n=3/13) and Salmonella Paratyphi B (7.7%; n=1/13). The most common pathogen isolated other than Salmonella was Escherichia coli (63.6%; n=21/33), followed by Staphylococcus aureus (18.2%; n=6/33), Citrobacter species (9.1%; n=3/33), Proteus mirabilis (6.1%; n=2/33) and Pseudomonas aeruginosa (3.0%; n=1/33). Salmonella isolates showed varied resistance to antimicrobials tested, with resistance proportions being Cotrimoxazole (9/13 (69.2%), Tetracycline (3/13, 23.1%), Amoxicillin (2/13, 15.4%), Ampicillin (2/13, 15.4). All the isolates were sensitive to Ceftriaxone, Ciprofloxacin, Amikacin, Gentamicin, Amoxicillin-Clavulanic acid, Chloramphenicol and Meropenem. None of the Salmonella isolates were multidrug resistant (MDR) and none produced Extended Spectrum -Lactamase. Extended Spectrum -Lactamase production was varied among other isolates. The Salmonella Choleraesuis isolates though were same species, were of different PFGE types. Conclusion: Prevalence of Salmonellae among patients attending Agona Swedru Municipal Hospital was 3.4%. Most of the Salmonellae were non-Typhoidal Salmonellae. Proportion of isolates resistant to antibiotics was low. There are possibly different S.Choleraesuis isolates circulating in Agona Swedru and its environs.

Source: KNUST
Characterization of oil extracted from nine high-in-oil groundnut accessions

Groundnut is a rich source of oil in the diet based on its physicochemical properties. The objectives was to evaluate the physicochemical properties of oil from nine new high-in-oil accession produced by the Council for Scientific and Industrial Research (CSIR), Crop Research Institute, Fumesua. Free fatty acid, peroxide value, acid value, saponification value and iodine value were determined for all nine groundnut accessions using HPLC. The groundnut accession has the percentage of oil yield in a range of 37%- 51%. The results revealed that the variety G 203 had the highest saponification value of 230 mgKOH/g is an indication of higher number of fatty acid of lower molecular weight hence good for industrial purpose. Variety G 204 and G 210 both recorded the highest acid value of 0.49 mg KOH/g and indication of faster deterioration. G 204 and G 210 also recorded the highest free fatty acid of 0.23 and 0.20 content / g respectively. Peroxide value of 5.09 mEq/kg was the highest recorded for sample G/C 214 which is indicative of fast oxidation. The high iodine value is indicative of dehydrogenation and it was recorded in sample G/C 210. Analysis of the fatty acid profile revealed 24 different acyl glycerides among the various accession. The number of acyl glyceride present in each sample ranged between 16-18 carbon. These indicate that those samples were free from contamination and of high quality. The properties of all the groundnut accession were within the standard limits and this is an indicative of a quality oil for industrial purposes.

Source: KNUST
Characterization of Starch from New Cassava Accessions at Different Maturity

Cassava (Manihot esculanta) is a root crop which serves as an important source of starch on a global scale. The objective of this work was to investigate the characteristics of starch from some new cassava accessions at different maturity. Six new cassava accessions (Abrabopa, Agra, Amansen, Ampong, Bankyehemma and Duadekpakpa) were harvested at four different months (from April – July 2017; i.e., 7-10th month) after planting. The starch was extracted using the conventional method of starch extraction and their yield calculated. The amylose was determined by means of spectrophotometry whereas pasting properties of the starches were analyzed using Rapid Visco Analyzer. Average starch yield ranged from 18-29% with the highest yield recorded in the 10th month for the various varieties studied. There were no significant differences (p > 0.05) in the peak viscosity, final viscosity, peak time and pasting temperature but significant differences were recorded for setback, trough and breakdown of the starch samples. The amylose (14-25%) and amylopectin (76-85%) content of the varieties differed significantly (p < 0.05). The present work shows that maturity affects the starch yield, composition and pasting properties of the new cassava accessions and this should be considered in deciding the time to harvest each accession for specific food and non-food industrial applications.

Source: KNUST
Characterization of Starch from Some New Cassava Accessions at Different Maturity

Cassava is a crop which has been used widely in the production of many products. This has activated interest in cassava-based products. It has been known as one most important sources of starch on a global scale. The aim of this research was to investigate the characteristics of starch from new cassava accessions at different maturity. Three cassava varieties (Agra, ampong and bankyehemma) were harvested at four different months (from April - July) after planting. Starch was extracted using the conventional method of starch extraction and the yield calculated. The amylose content was determined by means of spectrophotometry whereas pasting properties of the starches from the varieties were analyzed using Rapid Visco Analyzer. Bankyehemma, Agra and ampong had their highest starch yield in the 10th month after planting with bankyehemma the highest yield of 25.67±0.58 % and Agra having the lowest of 23.67±0.58 %. There were no significant differences in the peak viscosity, final viscosity, peak time and pasting temperature but significant differences were recorded for setback, trough and breakdown. The results showed that differences in varieties affect the starch yield and pasting properties of cassava. The amylose content of the varieties differed significantly (p=0.05). The highest amylose content was recorded by Agra (23.16 ± 0.03%) at the 7th month and the lowest recorded for bankyehemma (14.53 ± 0.12%) in that same month. Based on these results, bankyehemma can be selected and used for starch in the food industries

Source: KNUST
Characterization of Typhoid Intestinal Perforation in Africa: Results From the Severe Typhoid Fever Surveillance in Africa Program

Background. Typhoid intestinal perforation (TIP) remains the most serious complication of typhoid fever. In many countries, the diagnosis of TIP relies on intraoperative identification, as blood culture and pathology capacity remain limited. As a result, many cases of TIP may not be reported as typhoid. This study demonstrates the burden of TIP in sites in Burkina Faso, Democratic Republic of Congo (DRC), Ethiopia, Ghana, Madagascar, and Nigeria. Methods. Patients with clinical suspicion of nontraumatic intestinal perforation were enrolled and demographic details, clinical findings, surgical records, blood cultures, tissue biopsies, and peritoneal fluid were collected. Participants were then classified as having confirmed TIP, probable TIP, possible TIP, or clinical intestinal perforation based on surgical descriptions and cultures. Results. A total of 608 participants were investigated for nontraumatic intestinal perforation; 214 (35%) participants had surgically-confirmed TIP and 33 participants (5%) had culture-confirmed typhoid. The overall proportion of blood or surgical site Salmonella enterica subspecies enterica serovar Typhi positivity in surgically verified TIP cases was 10.3%. TIP was high in children aged 5–14 years in DRC, Ghana, and Nigeria. We provide evidence for correlation between monthly case counts of S. Typhi and the occurrence of intestinal perforation. Conclusions. Low S. Typhi culture positivity rates, as well as a lack of blood and tissue culture capability in many regions where typhoid remains endemic, significantly underestimate the true burden of typhoid fever. The occurrence of TIP may indicate underlying typhoid burden, particularly in countries with limited culture capability.

Source: KNUST