The Effect of Temperature on Nutrient Removal from Wastewater by Selected Fungal Species

The main goal of wastewater treatment is to safeguard the environment by preventing the pollution of receiving water bodies. This study was aimed at investigating the effect of temperature in nutrient removal by four test fungal species (Fusarium sp, Absidia sp, Aspergillus niger and Aspergillus flavus) in synthetic wastewater at different incubation temperatures of 25oC, 30oC, 35oC and 40°C. After inoculation with each test isolate, aliquot samples were taken prior inoculation and every 24 h, for 96 h for the estimation of phosphate, nitrate and pH in the wastewater, using standard procedures. After 96 h incubation, the percentage phosphate concentration removal ranged between 29.17 %-36.17 %, 26.17 %-35.75 %, 8.01 %-37.94 % and 11.19 %-42.65 %, in the presence of the Fusarium sp, Absidia sp, Aspergillus niger and Aspergillus flavus, respectively. Optimum temperature for phosphate removal was observed at 30°C -40°C. After 96 h incubation at 25oC, the phosphate concentration was very high with most of the isolates. In the case of nitrate, highest removals of 42.89 % and 82.07 % were obtained at 35°C in the presence of the Fusarium sp and Aspergillus flavus. In the presence of the Absidia sp and the Aspergillus niger, maximum removals of 21.21 % and 30.59 %, respectively were observed at 25°C, after 96 h incubation. The study was revealed the effect of temperature in the removal of phosphate and nitrate from wastewater by the test fungal species

Antibacterial activity of watermelon (Citrullus lanatus) seed against selected microorganisms

This study was aimed at evaluating the effect of extraction methods on the antibacterial activity of Citrullus lanatus seed extract. C. lanatus (watermelon) is a popular fruit consumed all over the world. Three solvents were used for the extraction process: chloroform, methanol and distilled water while two extraction conditions- cold extraction and Soxhlet extraction (coded as hot in this study) were employed. Antibacterial activity of the seed extracts was determined by agar well diffusion method. The seed extracts were tested against clinical isolates including Staphylococcus sp., Escherichia coli, Proteus sp., Klebsiella sp. and a type Pseudomonas aeruginosa (ATCC 27853). It was observed that the cold methanol extracts had the highest antibacterial effect on Staphylococcus sp. followed by hot methanol extract while cold chloroform extract showed no antibacterial activity. In the presence of P. aeruginosa only the hot methanol and chloroform extracts showed significant antibacterial potentials (p≤0.05). Also, saponins which have been implicated in antimicrobial activity were found to be present in moderate and high concentrations in the hot and cold methanol extracts respectively. Results of this study reveal that the kind of solvent employed as well as the conditions for extraction (cold maceration and Soxhlet extraction) influenced the efficacy of the extract against specific test organisms. Furthermore, the presence of saponins may have influence the relatively high zone of inhibition recorded with cold and hot methanol extracts against some of the test organisms

Antimicrobial activity of Chrysophyllum albidum seed extract and its effect on the physicochemical properties of cherry tomato fruits during postharvest storage

The high water content of Lycopersicon esculentum usually favors microbial growth, thus resulting in shelf- life reduction and economic loss. In an effort to develop an ecofriendly preservative for cherry tomatoes, a comprehensive study establishing the antimicrobial activity of the seeds of Chrysophyllum albidum and Persea americana was carried out. Folin Ciocalteu, AlCl 3 colorimetric, and agar well diffusion assays were, respectively, used to determine the total phenolic content (TPC), total flavonoid con-tent, and the antimicrobial potential of the extracts. Although the ethanolic extract of C. albidum displayed the highest TPC (90.71  ± 2.17 mg/g GAE), the antimicrobial studies indicated that aqueous extract of C. albidum seed (CAA), which showed the presence of saponins (total saponin content: 7.82%) had the highest zone of inhibition against Samonella typhi (24.5  ± 0.05 mm) and Pseudomonas aeruginosa (22.5  ± 0.05 mm). Treatments with 50 and 100 mg/ml of CAA retained firmness in tomatoes and signifi -cantly (p < .05) preserved the postharvest qualities (total soluble solids, total acidity, and ascorbic acid content) of cherry tomatoes. Novelty impact statement: Seeds of Chrysophymum albidum and Persea americana , which are usually discarded, possess antioxidant and antimicrobial phytochemicals with the aqueous extract of C. albidum (CAA) exhibiting more impressive antimicrobial properties. CAA treatment significantly preserved the postharvest qualities of cherry tomatoes. Hence, CAA is a cheap and easily affordable natural product treatment can be used to prolong the shelf- life of cherry tomatoes, thus minimizing economic loss due postharvest wastage of tomatoes

Incidence of entomopathogenic Bacillus spp. in some plantations in Ibadan, Nigeria

Soil samples from some agricultural research plantations (IITA, CRIN, IAR&T, NIHORT and FRIN) in Ibadan metropolis, Nigeria were screened for the presence of entomopathogenic strains of Bacillus species. The loamy-sand and sandy-loam soil types were typical soil texture of these locations with soil pH ranging between 4.9 and 6.1. The loamy-sand soil type recorded the highest number of Bacillus spp. and the history of pesticides applied on the sampling locations did not seem to affect the distribution of Bacillus thuringensis and other entomopathogenic Bacillus spp. in the different soils. Eighty-two strains of Bacillus spp. were isolated with only seven of these being entomopathogenic. The seven strains of Bacillus spp. were toxic to Anopheles mosquito larvae exhibiting between 5% and 15% mortality within 72h

Investigation of the Role of Selected Fungal Strains in the Removal of Phosphate and Nitrate in Synthetic Wastewater

Aims: This study investigate the role of four fungi species in the removal of phosphate and nitrate in a low nutrient synthetic wastewater. Also investigated was the effect of initial inoculum size on the nutrient removal ability of the strains. Materials and Methods: The fungal strains used for the study were Aspergillus niger, Aspergillus flavus, Absidia spp and Fusarium spp Four different initial inoculum sizes of each of the respective isolates were used for the nutrient removal studies. After inoculation with the test strains, aliquot samples were taken from the media at time zero and every 24h, for the estimation of total phosphate, nitrate and pH in the medium, using standard methods. Results: All the strains showed nitrate removal ability, irrespective of the initial inoculum size used for inoculation. After 96 h, the percent nitrate removed ranged from 25.25% to 77.52%, 26.12% to 39.80%, 8.88% to 44.23% and 29.50% to 87.34%, in the presence of Aspergillus niger, Aspergillus flavus, Absidia spp and Fusarium spp, respectively. None of the fungi exhibited phosphate removal ability, except Aspergillus niger which showed very slight potential for phosphate removal. Despite the observed differences in nitrate concentration removed by the different strains, these differences were not observed to differ significantly between the initial inoculum sizes used for investigation (p≤ 0.05). Similarly, the phosphate concentrations in the presence of the test strains did not differ significantly between the different initial inoculum sizes (p≤ 0.05). The pH values of the wastewater inoculated with the fungal strains increased with time of incubation. This trend was also observed irrespective of the initial inoculum size used. Conclusion: The study was able to provide an insight into the phosphate and nitrate removal efficiency of the test strains under the experimental conditions. Keywords: Phosphate; nitrate; fungi; nutrient removal; wastewater

SCREENING FOR HEPATITIS B SURFACE ANTIGEN (HBsAg) AMONG HEALTH CARE WORKERS (HCW) IN AN URBAN COMMUNITY SOUTH –SOUTH NIGERIA

Hepatitis B virus (HBV) infection is a major public health problem worldwide, while infection is highest in the developing world particularly Asia and sub-Saharan Africa. Healthcare workers (HCW) are at extra risk of acquiring blood-borne viral infections, particularly hepatitis B (HBV), this study is therefore aimed at estimating prevalence of Hepatitis B virus infection and its associated risk factors among health care workers in Uyo Metropolis. A total of 188 Health personnel, which constitutes Nurses, Doctors, Medical Laboratory Scientists, Technicians/Assistants, Pharmacists And Ward Assistance, were screened for HBV surface antigen (HBsAg) using ELISA HBsAg kits (Clinotech diagnostic 3rd generation). A wellstructured questionnaire was used to determine demographic and other relevant data. Out of the one hundred and Eighty-eight (188) respondents screened. Thirty two (32) representing 17.0% were found to be seropositive. Distribution of Hepatitis B Infection based on age showed a higher prevalence of (4.8%) among subjects aged 46-50years; X2Values = 0.708; P>0.05. Considering gender, female subjects recorded (17.3%) prevalence compared to (16.7%) recorded by the Male subjects;X2 Values= 0.538, df = 1, p>0.05.Considering the profession of the subjects screened, the highest prevalence of 6.9% was found among nurses while the least prevalence of 0.53% was recorded among pharmacists. From the result obtained, it is obvious that the prevalence of HBV tends to be high among personnel with high proximity to blood and body fluids, it is therefore important that health personnel be properly informed about their risk to HBV infection, so as to adopt measures to avoid infection, while routine vaccination of health workers against HBV is highly recommended. Keywords: Health Care Workers (HCW), (HBsAg), Screenin

Comparative study of the phytochemicals and in vitro antimicrobial potential of six medicinal plants

This study sought to investigate the antimicrobial activity of sixBackground: plants used in traditional medicine in Africa. The antimicrobial activity of the six medicinal plant extracts (aqueousMethods: and ethanol) were evaluated against  (ATCC 21784),  Proteus mirabilis (ATCC27856) were  using thePseudomonas aeruginosa Aspergillus fumigatus agar-well diffusion protocol. The activities of these extracts were compared with the positive controls chloramphenicol and griseofulvin. Similarly, the phytochemicals from the extracts were qualitatively assayed and their percentage yield calculated by standard methods.  The bacterial organisms used,   and  , wereResults: P. mirabilis P. aeruginosa slightly-to-highly susceptible to aqueous and ethanolic extracts from the various test plants, while   was insensitive to the treatments. The ethanolic A. fumigatus extracts of the sampled plants showed superior inhibitory performance on the target bacteria to the aqueous extracts. Aqueous and ethanolic extracts of  ,   and  showed inhibitoryAframomum melegueta Moringa oleifera Cola nitida consistency against the target bacteria. Superior inhibitory activity was observed for ethanol extracts of  seed and   pod against A. melegueta M. oleifera and  . Variations in phytochemicals were noticedP. mirabilis P. aeruginosa across solvents and plant parts for all plants. Phenols were detected in the aqueous and ethanolic extracts of   and , but relatively C. nitida Cola acuminate appeared denser in extracts of  seed and  A. melegueta Chrysophyllum albidium fruits. The extracts of  ,  and  tested positive C. nitida C. acuminate A. melegueta for the presence of flavonoids, which were undetected in  and  C. albidium M. seed and pod extracts. None of the extracts showed the presence ofoleifera every phytochemical assayed during the study.  Extracts of the medicinal plants assessed in this study showedConclusions: antibacterial potential. Developing new methodologies that preserve the bioactive potency of phyto-extracts for optimal microbicidal activity is promising for development of safe, non-reactive pharmaceutical

Effect of operational parameters,characterization and antibacterial studies of green synthesis of silver nanoparticles using Tithonia diversifolia

Background: There is a growing interest in the green synthesis of silver nanoparticles (AgNPs) using plant extract because the technique is cost effective,eco-friendly and environmentally benign. This is phasing out the use of toxic and hazardous chemical earlier reported. Tithonia diversifolia is a wild sun flower that grows widely in the western part of Nigeria with a proven medicinal benefit. However, several studies carried out have left doubts on the basic operational parameters needed for the green synthesis of AgNPs. The objective of this work was to carry out green synthesis of AgNPs using T. diversifolia extract via an eco-friendly route through optimization of various operational parameters,characterization, and antimicrobial studies. Method: Green synthesis of TD-AgNPs was done via bottom-up approach through wet chemistry technique using environmentally benign T. diversifolia plant extract as both reducing and stabilizing agent. Phytochemical Screening of the TD plant extract was carried out. Experimental optimization of various operational parameters—reaction time, concentration, volume ratio, and temperature was investigated. TD-AgNPs were characterized by UV – Vis spectroscopy, FTIR Spectroscopy, SEM/energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Antimicrobial studies against multi-drug resistant microorganisms (MDRM) were studied using the agar well diffusion method. Results: This study reveals the importance of various operational parameters in the synthesis of TD-AgNPs. Excellent surface plasmon resonance peaks(SPR)were obtained at optimum experimental factors of 90 min reaction time under room temperature at 0.001 M concentration with the volume ratio of 1:9(TD extract:Ag ion solution). The synthesis was monitored using UV– Vis and maximum wavelength obtained at 430 nm was due to SPR. The morphology and elemental constituents obtained by TEM, SEM, and EDX results revealed a spherical shape of AgNPs with prominent peak of Ag at 3.0 kV in EDX spectrum. The crystallinity nature was confi rmed by XRD studies. FTIR analysis proved presence of biomolecules functioning as reducing, stabilizing, and capping agents. These biomolecules were confi rmed to be flavonoid, triterpenes, and saponin from phytochemical screening. The antimicrobial studies of TD-AgNPs were tested against MDRM—Escherichia coli, Salmonella typhi, Salmonella enterica, and Bacillus subtilis. Discussion: The variation of reaction time, temperature, concentration, and volume ratio played substantive and fundamental roles in the synthesis of TD-AgNPs. A good dispersion of small spherical size between 10 and 26 nm was confirmed by TEM and SEM. A dual action mechanism of anti-microbial effects was provided by TD-AgNPs which are bactericidal and membrane-disruption. Based on the antimicrobial activity, the synthesized TD-AgNPs could fi nd good application in medicine, pharmaceutical, biotechnology, and food science

Silver nanoparticle synthesis by Acalypha wilkesiana extract: phytochemical screening, characterization, influence of operational parameters, and preliminary antibacterial testing

Single pot green synthesis of silver nanoparticles (AgNPs) was successfully carried out using medicinal plantextract ofAcalypha wilkesianavia bottom-up approach. Five imperative operational parameters (pH, contact time,concentration, volume ratio and temperature) pivotal to the synthesis of silver nanoparticles were investigated.The study showed pH 9, 90 min contact time, 0.001 M Agþconcentration, volume ratio 1:9 (extract: Agþsolu-tion), and temperature between 90–100�C were important for the synthesis ofAcalypha wilkesianasilvernanoparticles (AW-AgNPs). Phytochemical screening confirmed the presence of saponins,flavonoids, phenols andtriterpenes for A.wilkesiana. These phytomolecules served as both capping and stabilizing agent in the greensynthesis of silver nanoparticles. AW-AgNPs was characterized by UV-Vis Spectroscopy, Fourier TransformInfrared (FTIR) Spectroscopy and Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM)and Energy Dispersive X-ray (EDX). The surface Plasmon resonance (SPR) was observed at 450 nm which is acharacteristic absorbance region of AW-AgNPs formation as a result of the collective oscillation of free electron ofsilver nanoparticles. FTIR Spectroscopy confirmed the presence of functional groups responsible for bioreductionof Agþ. SEM and TEM results confirmed a well dispersed AW-AgNPs of spherical shape. EDX shows the elementaldistribution and confirmed AgNPs with a characteristic intense peak at 3.0 keV. AW-AgNPs showed significantinhibition against selected Gram negative and Gram positive prevailing bacteria. AW-AgNPs can therefore berecommended as potential antimicrobial and therapeutic agent against multidrug resistant pathogens