Bioenergy and Biochemical Processing Technologies

The thermal transformation of lignocelluloses is important because energy is required. The drying process is unique during this transformation. In this study, gravimetric analysis was applied in determining the effective moisture diffusivity and the kinetic parameters for the drying process of cassava stalk lignocellulosic biomass. The drying process was evaluated on the biomass at temperatures 80, 100, and 120 °C from 0 to 8 h using time interval of 0.5 h. The effective moisture diffusivities, Deff, varied from 1.63 × 10−11 m2/s (80 °C) to 2.56 × 10−11 m2/s (120 °C). The activation energy (Ea) during the drying process estimated at the three chosen temperatures was calculated to be 12.93 kJ/mole with a pre-exponential factor, Do, of 1.30 × 10−9 m2/s. Based on statistical analysis (coefficient of determination and average absolute error), the experimental data best fit was provided by the Midilli-Kucuk mathematical model when compared with the other two drying models (Page and Newton).

Municipal waste management has been a major challenge in developing countries and Nigeria in particular. Agricultural wastes such as corn husk and plastic wastes like low-density polyethylene waste are some of the major municipal wastes constituting nuisance in the environment. The study was focused on the production of biochar and hybrid from carbonization of corn husk and co-carbonization of mixed corn husk and low-density polyethylene waste using a biomass gasifier with retort heating (BGRH). Product qualities were determined using scanning electron microscope (SEM), Branueur–Emmett–Teller (BET), and Fourier transform infrared spectroscopy (FTIR). Biochar and hybrid yields of 50% and 59.91%, respectively, were obtained from both processes respectively. Characterization results showed the biochar and hybrid surfaces to be rough, heterogeneous with no visible pores which were more apparent with the hybrid from the co-carbonization process. Low specific surface areas were determined for both the biochar and hybrid (31.5587 m2/g and of 27.1052 m2/g respectively) which was attributed to the short residence period at the peak temperatures (351.9 ° C and 332.8 ° C, respectively) of the BGRH employed, a consequence of combustion fuel type. FTIR results showed both the biochar and hybrid contain more C=O and C-H functional groups making the biochar sources of nutrient exchange sites.

Cu2ZnSnS4 (CZTS) has been a promising material in optoelectronic applications due to its low cost, non-toxicity, and availability of its constituent elements in the earth’s crust. CZTS has excellent thermal, chemical, electrical, and optical characteristics. The structural and optical characterizations of CZTS solar absorber layer thin films were explored in this study, which used the SILAR process to create thin films. The peak pattern from X-ray diffractometer shows the preferred orientation of (112), confirming the tetragonal structure of the deposited films. The crystallite size of deposited CZTS thin films are 223.69 nm and 251. 61 nm for CZTS-40 and CZTS-50respectively, whereas the microstrain decreases from 51.723 to 51.596 as the number of deposition cycles increases. The plane (112) Tc(hkl) values for CZTS-40 and CZTS-50 are greater than unity, indicating an excess of grain formed along the plane. The value of Tc also suggests a higher degree of intended plane alignment. Also, the surface morphology was examined under the scanning electron microscopy, and the grain sizes were analyzed to be 7 nm and 11 nm for CZTS-40 and CZTS-50, respectively, using the imageJ software. The energy band gap also reduces from 1.60 eV to 1.45 eV as the number of cycles increases from 40 to 50. The electrical resistance of the films ranges from 10−2 to 10−3. The decrease in resistivity was because of the rise in CZTS thin-film grain size. The sheet resistance increases as the crystallite size decreases. These materials are suitable for use in thin-film photovoltaic cells as absorber layers.

In this study, the production of biogas from three common animal waste namely cow dung, poultry droppings and swine dung was evaluated. This was done by assessing the daily and cumulative biogas yields from the three selected feedstocks. Plastic 12-l capacity batch-fed digesters were employed in this study. 4.8 kg of waste was used for all substrates digested. The waste was mixed with water to form slurry in a ratio of one part of waste to one part of water by volume to arrive at a substrate input of 0.0096m3/digester. Each reactor was connected via its gas outlet to a tyre tube used as the gas collecting apparatus. The volume of biogas yield was measured and recorded on a daily basis using a digital weighing scale. Poultry droppings had the highest cumulative volume of biogas production of 0.1741 m3 (0.0363 m3/kg), while cow dung and swine dung, respectively, produced 0.1020 m3 (0.0213 m3/kg) and 0.0670 m3 (0.0028 m3/kg) of biogas. The respective digestion of cow dung and poultry droppings and swine dung recorded average daily gas production of 0.0058 m3, 0.0034 m3 and 0.0022 m3, respectively. The anaerobic digestion process shows that poultry dung is one of the best feedstock for biogas production with its production profiles exceeding the production from the other two conventional feedstocks (cow dung and swine dung).

A comprehensive study was conducted to determine the effect of fuel mixtures on the structural properties of core-shell 0.5Li2MnO3·0.5LiNi0.5Mn0.3Co0.2O2 cathode material (CS-SG-7525). The core (LiNi0.5Mn0.3Co0.08O2) was synthesized using the citric acid monohydrate and ammonium acetate fuel-rich solution combustion method in ratio 3:1. The shell (Li2MnO3) was coated on the core using sol gel method. A high (003)/(104) peak and a clearly distinctive splitting of (006)/(102) and (108)/(110) doublet peaks suggesting a good layered structure material were observed in all the XRD pattern. Two strong peaks are observed at 500 cm−1 and 600 cm−1 for Eg and A1g Raman modes, respectively, for the material. These peaks were attributed to rhombohedral phase (R3m space group) of a layered structure of core segment (LiNi0.5Co0.2Mn0.3O2). Some narrow and weak peaks were observed around 300–440 cm−1. These peaks were attributed to monoclinic symmetry (C2/m space group) of the layered structure of the shell segment (Li2MnO3). The surface morphological revealed that the material is made up of irregular particle shape with rough surfaces. The particle size of the materials ranges from 0.28 to 1.49 μm with average particle size of 0.67 μm. The ICP-OES revealed the elemental composition of the materials was close to its nominal values. The synthesized material could be used as Li-ion batteries cathode materials.

This paper presents the energy demand and carbon footprints analysis in the University of Lagos, Nigeria, a subset of the service sector with additional unique features such as facilities for teaching, research, sport, etc. An energy-environment scenarios-based software, Long-range Energy Alternatives Planning (LEAP) is employed to analyse and project for energy consumption (excluding transportation) and the associated global warming potential (GWP) resulting from emitted air pollutants and greenhouse gases (GHGs) between 2009 and 2033. The energy mix comprises firewood, charcoal, LPG, kerosene, diesel, and electrical energy in the University. Results show that 70% of the total consumption occurs in the residential area, followed by the faculty and service area at 21.9% and the commercial centres at 8.1%. GWP has significant contributions from residential areas and commercial centres with biogenic CO2 having 1100%, SO2 740%, and CO 330% at the target year.

Biodiesel has comparable properties to diesel fuel; hence, it becomes a promising substitute to diesel fuel. The development of exceedingly effective biocatalyst is a key prerequisite for the production of biofuels, most especially biodiesel. Heterogeneous catalysts are regarded to be very prospective for transesterification process in biodiesel production owing to their numerous advantages, which include separation of catalyst from reaction mixture with ease, separation from reaction mixture with ease, regeneration, decreased corrosion, decreased cost and environmental friendliness. Heterogeneous catalysts can substitute homogeneous catalysts in situations that limit their efficiency. Hence, synthesized sustainable catalysts are required for increasing process performance, reduction in energy cost and production of cleaner products like ultralow sulphur biodiesel. Here, we gave a brief review on the advancement in sustainable heterogeneous catalysts for biodiesel production.

Despite the shift towards renewable energy, crude oil has continued to account for a large part of the global energy consumption, leading to the rapid depletion of crude oil volumes from mature fields. Hence, it is necessary to maximize the production of this essential commodity. Marginal fields are estimated to currently represent between 30% and 40% of world oil production and are gaining importance due to the natural decline in production from large mature fields. In general, most fields with low-abundant reserves, poor economic performance, high cost and technical difficulty in development are called marginal fields or small fields. However, with regards to the Nigerian petroleum industry, abandoned fields previously operated by international oil companies are alluded to as marginal. In this study, an extensive review of previously reported marginal oil field practices is provided. In addition, following the recent passage of the Petroleum Industry Act (PIA) and the successful completion of the 2020 marginal field bid round, this work examines the current legal framework for the development of marginal oilfields in Nigeria. It also reviews other pertinent issues in the industry affecting the marginal field initiative.

The need for exogenous phytase in animal feed processing is increasing due to its ability to breakdown anti-nutrients in grains which constitute a large proportion of animal feeds. This study investigated the production of phytase using indigenously isolated Aspergillus sp. and the characterization of the purified phytase. The Aspergillus sp. was isolated from a poultry site using phytate screening medium (PSM). Quantitative estimation of phytase production was carried out using 2 × 108 spores/100 mL basal medium containing 0.5% sodium phytate as substrate at 30 °C and 150 rpm for 5 days under submerged fermentation condition. The extracted crude enzyme was purified using ammonium sulphate and gel filtration chromatography using Sephadex G-75 gel. The enzyme was characterized by investigating the effect of temperature, pH, and nutrient sources on the purified enzyme. Molecular identification confirmed the isolate as Aspergillus flavus (accession number of MT899184). The total activity observed in crude faction (609 U/mL) reduced to 187.5 U/mL in the ammonium sulphate fraction and then to 77.6 U/mL in the Sephadex G-75 fraction. Optimum temperature and pH were 40 °C and 6, respectively. The enzyme remained active for 5 min at both 70 °C and 80 °C. However, at 100 °C, all activity was lost. Glucose was the preferred carbon source and had higher activity (0.185 U/mL) but was unable to utilize sucrose. This study concludes that this isolate may be exploited for industrial production of phytase which has great application in animal feed industries.

One important source of nutrients is fruit juices, and they may also possess therapeutic properties that help to alleviate the risk of many diseases. Soursop fruits are large and may be consumed fresh (raw), fermented or cooked. The aim of this work was to optimise soursop juice recovery after clarification with partially purified alpha amylase. This was done using the response surface methodology. The independent variables were temperature, volume of enzyme used and time of clarification. The results showed that the highest volume of juice recovery which was the dependent variable would be obtained at 27.5 °C for 30 min with a desirability of 95.6%.

This study sought to detect the Class A extended-spectrum beta-lactamases (ESBLs) present in Pseudomonas aeruginosa from clinical samples using molecular methods. Twenty-seven P. aeruginosa isolates were characterized among one hundred and fifty clinical samples obtained from three major hospitals in Ogun State. Twenty-five isolates were found to be ESBL producers upon phenotypic screening. DNA was extracted using Zymo DNA extraction kit. Polymerase chain reaction was used to amplify the ESBL genes using specific primers for the CTX-M, SHV, and TEM genes. Agarose gel electrophoresis was used to resolve the amplicons, and they were visualized with a UV transilluminator, 64% (16 isolates) were found positive for TEM, 52 and (13 isolates) for SHV, and 44% (11 isolates) for CTX-M. Some isolates were found positive for two or more of the screened genes. This research identifies the need for surveillance of ESBL producers within Ogun state.

The production and application of pectinases have been studied in the last decade due to their importance in the degradation of pectin in plant cell walls. The importance of this enzyme is shown in its industrial applications in the fruit juice and textile industries, oil extraction, bleaching of plywood, improvement in diet degradation of dairy animals, and drug delivery, to mention a few. The studies in literature obtained on the SCOPUS database for use in the study were selected based on the methodology of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The systematic review of literature was limited to open access, agriculture and biological sciences, and biochemistry, genetics, and molecular biology, subsections on the database. The study was designed to include the microorganisms, the substrates, the research design employed for the enzyme production, and the fermentation method for pectinase production. Other criteria include, the “state” of the pectinase applied, application areas of the enzyme (produced), key findings, and suggestions for further studies (gaps). Despite the 1554 documents accessed on the 4th of May, 2021, on the SCOPUS database involving pectinase, studies concerning both production and application in the last decade resulted in 12 documents relative to 137 documents reported on the production of pectinases from 2011 to 2020. The results from the study showed fungi as the preferred microorganism compared to bacteria for pectinase production and application studies. The one-factor-at-a-time (OFAT) design of the experiment was significantly (approximately 75%) employed compared to using response surface methodology (RSM) for pectinase production and application studies. Nevertheless, the findings from the study demonstrate pectinases as an important class of enzymes worth investigating due to its importance in industrial processes.

Lignocellulosic wastes have capacity to substitute fossil fuels as sustainable sources of renewable energy, with added advantage over environmental and health challenges. This research was aimed at producing biogas from anaerobic co-digestion of thermo-alkaline pretreated corn stover with cattle rumen content. The thermal and alkaline pretreatment approaches were intended to render the substrates amenable to microbial biodegradation in the biodigester. Assessment of the microbial succession over the 20-day biodigestion period was done using standard microbiological methods. Results reveal that the pretreated and untreated corn stover showed 45.69% and 14.42% decrease in lignin and hemicelluloses contents, respectively, with a 37.60% increase in cellulose component. Species of Bacillus, Proteus, Staphylococcus, Enterococcus, Bacteroides, Clostridium, Pseudomonas, Fusobacterium, Aspergillus, Penicillium, Mucor, and Rhizopus were isolated. A cumulative biogas volume of 54.97 m3 at a temperature range of 29.8–31.1 °C and alkaline pH of 7.05–7.84 were recorded. This study highlights the possibility of producing biogas from anaerobic co-digestion of thermo-alkaline pretreated corn stover and cattle rumen content. The ready availability of the waste substrates and the high biogas yield recorded show promise as an alternative solution to the global energy need while presenting a waste management strategy with capacity for improved bioeconomy.

Aflatoxins produced by Aspergillus flavus and Aspergillus parasiticus are secondary metabolites that pose a major threat to global food security resulting in detrimental impacts on human and animal health. This study screened for the presence of aflatoxigenic fungi and their metabolites – aflatoxins in tiger nut (Cyperus esculentus L.) seeds and the produced tiger nut drinks. Samples were obtained from three major dealers in Ota, Ogun state, using the snowball sampling technique. The seeds were cleaned and processed into milk drinks thereafter stored at 4 °C for 15 hours prior to analysis. The milk drink was serial diluted and plated on Rose Bengal chloramphenicol media at 28 °C for 7 days for initial fungi isolation. The pure isolates were obtained on potato dextrose agar. Total fungal count ranged from 1.0 × 104 cfu/ml (in tiger nut drinks) to 3.0 × 106 cfu/g (in tiger nut). Qualitative assessment of the toxigenic potential of the fungi was assessed on ammonium hydroxide on yeast extract sucrose agar where positive isolates showed pink or red coloration. Preliminary findings from this study reveal that the seeds used to prepare the tiger nut drinks were contaminated with aflatoxins produced by the fungal contaminants. It is imperative that proper storage of grains is important for the overall health benefits of humans, thus reducing disease burden in the society.

Laccases represent a family of copper-containing oxidases involved in the biocatalysis of the one electron enzymatic oxidation of phenolic and aromatic compounds with a resultant reduction of oxygen to water. Their wide substrate variability on both phenolic and non-phenolic compounds arising from the activities of mediator systems lends a potential for their varying applications in the environmental, pharmaceutical, and food industries, especially the bioremediation of poly-aromatic hydrocarbon-contaminated soils. Thus, playing essential roles in the realization of United Nations Sustainable Development Goal (SDG) number eleven, which is aimed at the achievement of safe, reliable, and sustainable cities and communities. However, product recovery and purification remain critical concerns in laccase production, with reports showing that downstream processing accounts for approximately eighty percent of the total costs of industrial enzymes production. In light of this and considering the emerging and increasing biotechnological applications of laccases, an effective purification procedure would be key in the post-production processing. This review, therefore, explores the current affordable, quick, and efficient approaches that offer minimal processing steps at reduced production costs as well as laccase immobilization and mediator systems. A highlight of the various biotechnological applications of laccases alongside the current challenges and future prospects of laccase use in industries and environmental remediation of recalcitrant contaminants is presented.

In this review, insight is given on the effect of wall shear stress (WSS) on the initiation and progression of plaque growth in micro-circulation by using mathematical models. The understanding of the trigger for the initiation and progression of the disease has improved over the years and has led to better models for describing the process. Models have been developed and tested in order to describe haemodynamic properties in blood vessels to accurately simulate the process. The Navier-Stokes equation is the backbone model for all computational fluid dynamic simulation and applications, which has found foundational importance in simulations related to atherosclerosis studies. The risk factors associated with the disease are discussed. The rheological models associated with blood are analyzed and compared with studies that have been carried out in the past. A systematic review of the major findings of the simulation results has been brought afore, with a focus on wall shear stress (WSS), degrees of stenosis and plaque growth. It was concluded that the current studies are not holistic enough to give insight into the pathophysiology of the disease. Recommendations on how further studies should be done to improve the knowledge gap in this subject matter were proposed.

This study evaluated the pectin content and pectinase activity in both the flavedo and albedo of Citrus sinensis and the comparison of pectinase activities from the albedos of Citrus sinensis (sweet orange), Citrus aurantifolia (lemon), and Thaumatococcus danielli (sweet prayer plant). The pectinase was produced from Aspergillus niger in solid-state fermentation with the substrates. The pectin content and pectinase activity were assessed using standard methods. Both the pectin content and pectinase activity of Citrus sinensis albedo were notably higher (p < 0.05) than those of the flavedo. In comparison with the other plants (Citrus aurantifolia and Thaumatococcus danielli), Citrus sinensis albedo exhibited the highest pectinase activity, followed by Citrus aurantifolia and Thaumatococcus daniellii. The implication of the findings showed the albedos of fruit wastes as superior substrates for pectinase production than flavedos. Thus, albedos from Citrus aurantifolia and Thaumatococcus daniellii could be exploited as supplement substrates for the local production of pectinases.

Surfactants are surface-active chemicals with a world production of more than 15 million tons per annum. The majority of surfactants in the market are produced from petrochemical sources, and thus they are termed synthetic surfactants. With the increased environmental consideration from consumers and producers, increased interest is moving toward biologically derived surfactants (biosurfactants). In this study, waste cooking oil was utilized as a carbon source in rhamnolipid production in a batch reactor using Pseudomonas putida, a nonpathogenic microorganism, as a way of improving the uneconomical production of rhamnolipid, a biosurfactant using waste materials. Two nitrogen sources, ammonium nitrate and urea, were used and varied to investigate their effects on rhamnolipid production. The waste cooking oil consumption by the microbe was quantified with the use of a carbon oxygen demand (COD) kit. The activity of the biosurfactant was verified by determining surface tension using the capillary tube method. Results showed that P. putida was capable of using waste cooking oil and both nitrogen sources to produce rhamnolipid with higher cell growth obtained for ammonium nitrate. It was also shown that the utilization of ammonium nitrate as a nitrogen source improved the growth of Pseudomonas putida at an initial waste cooking oil concentration of 6%, while the use of urea as a nitrogen source yielded a higher production of rhamnolipid of 8.8 g/L after 96 h. Therefore, waste cooking oil was successfully utilized in this study as a waste substrate for rhamnolipid production using Pseudomonas putida.

The best mix of water hyacinth (WH) to be co-digested with cow dung (CD) in order to maximize gas yield from a batch-fed anaerobic digester was assessed in this study. Eleven mix ratios were evaluated over a 40-day retention period. A rotameter flow meter was used to measure the gas flow rate, while the volume of gas produced was determined using a non-linear parameter estimation model. The results showed that WH single-substrate digestion produced a cumulative gas volume of 32.18 L, which corresponds to 5.14 L/kg of WH, while single-substrate digestion of CD produced an ultimate gas volume of 126.95 L, corresponding to 20.3 L/kg of CD. The results showed a range of 53.18–141.72 L with 2 WH:8 CD recording the highest value corresponding to 22.68 L/kg. The biogas production rate curve had a striking R2 value of 0.9828, and the standard deviation of the rate constant is 0.007422. This mix produced maximum biogas of 9.895529 L/day, and this was produced on day 17 of the digestion process. A significant R2 value of 0.9834 was observed from the third-order polynomial curve. The 2 WH:8 CD digestion mix was remarkably the best CD-aided WH digestion mix because it has recorded the highest ultimate biogas yield of 141.72 L.

The neem tree is popularly known in Nigeria as ‘Dogonyaro’ and has been known across the world for its various answers facing some major health concerns to human race. This paper aims at evaluating the oil extract of neem seeds for it anti-microbial properties, phytochemical screening as well as the GC-MS analysis. Soxhlet extraction method was used with hexane as solvent. Phytochemical analysis on the oil showed the presence of triterpenes within which the main ingredient azadirachtin was found while the anti-microbial analysis carried out on the oil indicated a high inhibition zone on fungal microbes – Candida albicans and Rhizopus which cause Candidiasis and ketoacidosis in man which can be fatal. Hence drugs can be formulated in treating such diseases from the neem oil.

The conversion of fruit wastes into single-cell protein is an alternative solution to the worldwide protein deficiency and environmental pollution concerns. In this study, we assessed the proximate analyses of pineapple and watermelon peels as potential substrates for single-cell protein production. Using the Association of Official Agricultural Chemists (AOAC) methods, fruit wastes were collected, dried, and pulverized before analyses for their proximate composition. The components assessed include moisture, crude protein, crude fat, crude fibre, total ash, and carbohydrate. The results obtained revealed that pineapple and watermelon peels respectively had 2.27 ± 0.00% and 5.15 ± 0.01% of crude protein, 1.05 ± 0.04% and 0.78 ± 0.05% of fibre, 8.32 ± 0.06% and 5.42 ± 0.03% of fat, 27.80 ± 0.05% and 30.24 ± 0.02% of ash, and 56.38 ± 0.01% and 54.75% ± 0.05% of carbohydrate. This result shows that fruit wastes can serve as a good substrate for the cultivation of single-cell protein.

Turbidity, the measurement for impurity and the opposite phenomenon of clarity, is described as the reduced transparency of a liquid caused by the existence of undissolved matter in the form of suspended particles. The permissible volume of light through the liquid, or light that is not dispersed or absorbed but emitted through the liquid and propagated toward the observer, provides a foundation for the analysis of various subject matters, such as liquid mass concentration and impurity identification. The turbidity of urine is increased by the presence of cellular debris, cast, and, in some cases, crystal and other debris in the urine. Blood (both red and white blood cells), hemoglobin, cholesterol, albumin, leukocyte esterase, nitrites, ketones, bilirubin, and urobilinogen are all substances that are not expected to be found in urine, the presence of which can increase urine turbidity. Owing to the principle of turbidimetry, it is not the detection of turbidity that is the cause of the turbid state of urine but the presence of suspended particles and a rough estimate of the number of suspended particles in urine. This research exposes the different methods of obtaining the turbidity of a liquid sample and the working principles of turbidimetry and nephelometry.

Pathogenic Gram-negative bacteria mostly produce extended-spectrum beta-lactamases (ESBLs), a feature that confers resistance to some newer generations of antibiotics. The study was aimed at evaluating the antibiotic resistance status of Pseudomonas aeruginosa isolates collected from September to November 2020 from tertiary care hospitals in Ogun State, Nigeria. One hundred fifty isolates from clinical samples (high vaginal swab, wound, urine, ear, blood) were obtained, and their susceptibility pattern was determined against eight antibiotics. Out of the 150 samples, 27 P. aeruginosa were identified. Anti-microbial susceptibility testing was carried out on the isolates using the modified Kirby-Bauer disc diffusion method, and ESBL production was detected phenotypically. The mean age group of the patients was 29.56 years. Gentamicin from the aminoglycoside class showed best activity (74.1%), and ampicillin and penicillin showed little to no activity (100% and 96.3%, respectively). Cephalosporins, ceftazidime and cefuroxime were 100% resistant, while the fluoroquinolones Ciprofloxacin and Ofloxacin had a mean resistance of 40.7%. The moderate active antibiotic was streptomycin (44.4% susceptible). The poor monitoring of antibiotic usage, the abuse of their availability and the acquisition of resistance elements by organisms in hospitals and the community may be the causes of high antibiotic resistance.

Fruits are packed with a wide selection of compounds that provide innumerable benefits to the body. Watermelons contain citrulline, have high concentration of water, and consist of many phytochemicals that promote health. Unfortunately, they can be contaminated by bacteria. Pathogens previously isolated from watermelons include Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, and Escherichia coli. Hence, this research was conducted to identify some bacterial pathogens found in cut watermelons sold in Ota. These bacteria indicate that the watermelons commonly sold on the streets can pose health risks to consumers. Watermelons were purchased from roadside vendors, and bacterial contaminants were recovered using microbiological methods. The mean bacterial load ranged from 1.6 × 107 to 2.7 × 108 CFU/mL. The bacteria recovered were Escherichia coli, Klebsiella, Staphylococcus, Proteus, and Micrococcus. The microbial composition of cut watermelon poses a likely health risk to consumers. The improvement of cut fruit safety and quality is needed, and educating handlers with regard to hygiene will also help reduce the bacterial load found on fruits. Knowledge of the bacterial pathogens present in cut watermelon fruits will provide health practitioners with relevant information for disease treatment.

Mucormycosis (MM) is an invasive fungal infection that causes severe systemic infections and poses health risks and threat to life. Despite its impact on human health, MM infection is neglected and underrepresented compared to other infections. Invasiveness of MM severely compromises systemic and metabolic functions of the hepatic system, degeneration of lungs, trachea, and alveoli epithelial cell with increased fatality rate, and associated risk with therapeutic use of glucocorticoids in COVID-19. In Africa, the prevalence rate remains unknown due to late prognosis and non-reportability of the disease. Hence, there is a need to include MM diagnosis in patients with COVID-19, increase surveillance of emerging clonal strains, and regulate the routine glucocorticoids use in COVID-19 infection therapy.

Locally produced plant-based fermented condiments serving as daily dietary protein in Nigeria tend to have poor safety and shelf-life quality. This study evaluates the fermentation, preservation, and shelf-life quality of probiotic lactobacilli fermented Nigerian condiments. Three fermented condiments [Locust beans “Iru” or “Dawadawa” (Parkia biglobosa); Oil beans “Ugba” (Pentaclethra macrophylla); Castor oil “Ogiri” (Ricinus communis)] were produced after 72-hr spontaneous fermentation fortified with a consortium of probiotic Lactobacillus starter. The pH and growth kinetics of the probiotic Lactobacillus were monitored during the fermentation. The resulting fermented condiments were analyzed for shelf-life quality analyses including color, aroma, pH, aerobic bacteria, and fungal; and lactobacilli were monitored on weekly basis during the period of storage. The pLAB_GAC fermented condiments exhibited improved color and odor, and pH tends towards acidity (pH = 5.2). The control and pLAB fermented condiments showed higher aerobic bacteria and visible fungal growth from week 1 storage with lower Lactobacilli presence and increased spoilage when compared with the pLAB_GAC fermented condiments. After 3 weeks of storage, comparative shelf-life studies evaluated revealed the pLAB-GAC fermented condiments with improved quality and shelf-life period. Probiotic lactobacilli starter strains expressed improved preservative potential for Nigerian condiment, and this could be harnessed for biotechnological production of safe fermented condiments with improved shelf-life.

Salmonella serovars distribution in Benue State was evaluated using standard microbiological techniques. Eighteen isolates of varying Salmonella species were obtained from four hundred and twenty stool samples collected from Patients in the three senatorial districts sampled. Four distinct serovars of S. enterica and one S. bongori, were identified. S. enterica Typhimurium was 6 (33.33%) and prevalence of 1.43%. S. enterica Typhi and S. enterica Heidelberg had 2 cases each, whereas S. enterica Agona, S. enterica Paratyphi B, S. enterica Huaian and S. bongori had a lone case each. Significant association was established between occurrence of Salmonella infection and causative serovars (χ2 = 57.93, P < 0.05). Molecular characterization results showed that the dendrogram formed 2 main clusters with two divergent Salmonella strains. The first sub cluster had four strains isolated from different locations: S. enterica Heidelberg-MG663473.1 from Gboko; S. enterica Typhimurium-JQ228518.1 from Katsina-Ala; S. enterica Typhimurium-CP014981 from Makurdi and S. enterica Typhimurium-CP023166.1 from Kwande. Seventy-five percent (75%) of strains in this group were Typhimurium serovars. S. enterica Typhimurium-CP023166.1 isolated from Kwande was a unique strain that showed wider genetic variability but related to the check strain (S. bongori - KU060291.1). The second sub cluster consisted of S. enterica Paratyphi B-JQ694526.1; S. enterica Heidelberg-CP019176.1; S. enterica Typhimurium-CP024619.1 and S. bongori-FR877557.1. The second main cluster had 8 strains consisting of 4 enteritidis, 2 Typhi, 1 Huaian and 1 Typhimurium from all locations except Gboko. S. enterica Typhimurium-MH196335.1 was divergent from the main clusters of the check strain. S. enterica serovar Agona strain 392869-2 was unique and is related with enteritidis strain. It is established that diverse salmonella serovars exist and cause infections in Benue State.

According to a report from Global Cancer Observatory (GLOBOCAN), cervical cancer is rated as one of the most dominant types of cancer in Nigeria. Traditionally, medicinal plants are known to be well utilized in treating cancerous diseases. The research reported herein therefore aimed at screening Citrullus colocynthis extracts for their potential cytotoxic effects against cervical cancer cells HeLa. Qualitative phytochemical screening was done according to standard procedures. The HeLa cell line, a model of cervical cancer, was then exposed for 48 h to a range of concentrations, up to 500 μg/ml of the ethyl acetate (CCE) and methanol extracts (CCM) of the whole fruit of C. colocynthis, followed by cell viability quantification with the 3-(4,5-dimethylthiazol-2-yl)-2,5-dipenyltetrazolium bromide (MTT) assay. The phytochemical screening confirmed phenols, tannins, flavonoids, cardiac glycosides, saponins, triterpenoids, steroids, and alkaloids in the sample vegetable. The preliminary cytotoxicity assay (to estimate potential anticancer activity) showed CCE was thrice more potently cytotoxic with an IC50 value of 33.95 ± 3.39 (μg/ml) than CCM with anIC50 value of 101.59 ± 24.37. These findings suggest that C. colocynthis extracts could serve as a source of leads for the development of drugs to treat cervical cancer.

Cholera is a deadly disease that has affected people globally with high rate of occurrence in Nigeria annually. The study examined the susceptibility of the infectious agent; Vibrio cholerae isolated from surface water sources in Makurdi Local Government to commonly used antibiotics. Sixteen (16) surface waters samples obtained from streams, ponds, and river were subjected to bacteriological analyses for identification of Vibrio cholerae and confirmed by biochemical analyses and Gram stain reactions. The result of the antibiotics susceptibility test showed that Vibrio cholerae was resistant to Nalidixic acid (0) followed by Augmentin (0–20 mm), Streptomycin (5–20 mm), Ceporex (0–18 mm), and Amplicin (0–20 mm). However, they were susceptible to Tarivid (12–28 mm), Reflacine (16–26 mm), Ciproflox (10–30 mm), Gentamycin (12–23 mm), and Septrin (8–20 mm). The result shows that pathogenic, toxigenic, and antibiotic resistant Vibrio cholerae are present and persist in aquatic environments. This is of serious public health implication and poses great challenges to Vibrio cholera control programs and health of the surface water consumers.

In recent times, dispersion of solid materials nanoparticles has become common phenomena to enhance thermal characteristics of working fluid in thermodynamics systems. Thermal conductivity of nanofluids (a mixture of nanoparticles and the working fluid) are mostly higher than the working fluid. In this paper, we examined a critical and systematic review of previous and current literatures on the history of refrigerants and the need for nanofluids in refrigeration systems. Also, we study the types of refrigeration system and refrigerants, application of nanofluids in refrigeration systems for performance enhancement.

The review compared the performance of steam to that of the alternative heat transfer fluids. Steam is a cheaper conventional heat transfer material produced from water that is readily available in nature. It can be operated at temperatures as high as 350 °C and are effective for high-temperature process operations. However, corrosivity, especially at high temperatures and its impacts on metals and plant equipment during operations, poses a significant problem to steam application. In addition, thermal stability becomes an issue at higher temperatures. This review covered alternative heat transfer fluids that operate at higher temperatures with high thermal stability over a long period. The study found that alternative transfer fluids such as synthetic aromatic heat transfer fluids are more suitable and effective in industrial plants at high temperatures. The suitability is because of its high thermal stability, anti-coking, anti-oxidation, and anti-corrosion properties. A commercial synthetic organic heat transfer fluid made up of a eutectic mixture of diphenyl oxide and biphenyl was an effective heat transfer source at temperatures up to 400 °C without undergoing thermal degradation. The review successfully identified the most efficient alternative to steam in operations that require heat transfer fluids in the chemical industry.

The use of energy has evolved significantly in the past 5 decades from coal to oil to being dominated using natural gas in the next 30 years. When the complete switch from crude oil to natural gas will occur, is still a debatable topic but some researchers suggest the age of natural gas has arrived. Natural gas presently provides about 25% of the global energy supply and its desire is increasing significantly. From an environmental point of view, natural gas has also become a more desirable energy source as it is the cleaner as compared to other fossil fuels, relatively cheaper and abundant and proving stability of supply. However, some natural gas resource turn to produce liquid hydrocarbons called condensates when their pressure drops below the dew point pressure forming liquids called condensates. Gas condensate fields are very valuable resources high gas prices due to expanding gas markets. Likewise, they are also very valuable when gas prices are low because of they can produce valuable liquids. Producing from these condensate systems is challenging as they tend to produce liquids upon pressure reduction below dew point. The development of gas condensate reservoirs is like the development of dry gas reservoirs. However, two significant differences are: condensates flow in the near the wellbore region of the reservoir and significant liquid production over the life of the reservoir. This review discusses condensate reservoir development options. The advantages and disadvantages of the various development options are discussed.