Antibiotic resistance has reached universal proportions, and the discovery of effective alternatives to the common antibiotics currently used, could aid in solving this problem. The aim of this study was to characterise a bioflocculant produced from Pseudomonas aeruginosa strain F29, accession number OQ734844, that exhibited effective antibacterial activity against two antibiotic resistant bacteria, viz, Staphylococcus aureus SO183, and an identified strain of Pseudomonas aeruginosa , in another study. FTIR detected saturated nitro compounds, sulfones, polysulfides, phosphorus-chlorine bonds, magnesium oxide bonds and metal-chloride bonds. FTIR also detected the following functional groups: carboxyl, amide/peptide, aromatic alcohol, alkene, and halo. SEM showed a clumped and flaky bioflocculant surface, while EDX detected chlorine (56.00%), carbon (20.50%), sodium (12.50%), oxygen (4.00%), phosphorus (3.00%), sulfur (2.43%) magnesium (1.06%), potassium (0.32%) and nitrogen (0.30%). HPLC and MS detected varied peaks of glucose, galactose, inositol and mannose, D-ribose, arabinose, rhamnose and xylose. The phenol sulfuric acid method calculated the concentration of these sugars as 0.0059 g/L. The bioflocculant is a polymeric compound composed mainly of carbohydrates, proteins/polypeptides and organochlorines, possibly a novel “metalloglyco-protein/polypeptide organochlorine” bioflocculant. The presence of the metals: sodium, potassium and magnesium; the non-metals: phosphorus, sulfur and nitrogen; and multiple moieties, likely contributed to the antibacterial activity of the bioflocculant produced from Pseudomonas aeruginosa strain F29. From available documentation, this is the first report of a polyfunctional “metalloglyco-protein/polypeptide organochlorine” bioflocculant, that naturally contains saturated nitro compounds, sulfones, polysulfides, phosphorus chlorine compounds, magnesium oxide and metal chlorides; and of a bioflocculant produced from porcine faeces in Africa.

The worldwide occurrence of antibiotic resistance, has triggered the quest for viable alternatives, to the failing antibiotics in common usage. Biosurfactants have been studied for their potential in this regard. The aim of this study, was to characterise a biosurfactant, produced from Pseudomonas aeruginosa strain S16 (accession number OQ734845), shown to possess effective biocontrol activity, against Staphylococcus aureus SO183 at 0.060 g/L. Pseudomonas aeruginosa strain S16 was isolated from soil in a mixed farm, at Ajibode area, Ibadan, Oyo State, Nigeria, with the use of the pour plate method, identified through biochemical tests, and confirmed through molecular studies. Scanning electron microscopy revealed that the biosurfactant possessed a surface composed of, globular and spindle-shaped projections, while energy dispersive x-ray spectroscopy revealed that its elemental composition was mainly oxygen (3.00%), carbon (36.10%), nitrogen (43.00%), phosphorus (3.00%) and sodium (6.60%); the least abundant was manganese (0.48%). High performance liquid chromatography and mass spectrometry, revealed that the monosaccharides, were mainly rhamnose, glucose, xylose and mannose, while the phenol-sulfuric acid method measured their concentration as 0.0047 g/L. Fourier transform infrared spectroscopy, revealed the presence of carboxyl, alcohol, amine and halo functional groups, amongst others. The biosurfactant produced from Pseudomonas aeruginosa strain S16 was a positively charged, manganese-containing, polymeric biosurfactant made up of carbohydrates, lipid and peptide molecules. It was likely a positively-charged, manganese-containing glycolipopeptide/glycolipoprotein, polysaccharide-protein-fatty acid composite, or lipopolysaccharide-protein composite. The manganese probably conferred to it, the potential for antibacterial and diverse bioactivities. From available records, this is the first report of a manganese-containing biosurfactant.

Management of disposable face mask (FM) used as personal protective equipment against transmission of COVID-19 has emerged as one of the key issues of COVID-19 pandemic. Disposable FM is a potential source of microplastic fibers in the environment. In this study, FM as carbon source for the cultivation of Pleurotus ostreatus mushroom was investigated in the attempt to reduce plastic build up in the environment due to its disposal. Growth substrate was prepared using FM as sole and/or partial carbon source varied with mahogany wood shavings (MWS) at 25, 50, 75, and 100% composition (wt/wt). Visual sorting under stereo microscope to detect presence or absence of microplastics in the mushrooms produced was conducted. Shortest spawn run (26 days) was recorded in MWS:FM 100:0 and optimum number of fruiting bodies (28) was achieved at MWS:FM 75:25; while, optimal fruiting body (fresh weight) (71 g), biological efficiency (88.8%), and proximate outputs (except carbohydrate) were achieved at MWS:FM of 25:75. The features of mushroom produced from MWS:FM 0:100 through visual sorting were suggestive of microplastics pollution. This study demonstrated the ability of P. ostreatus to utilize disposable FM as growth substrate for its production.

Abstract Antibiotic resistance has reached global proportions, and the discovery of effective alternatives to the common antibiotics currently in use, could aid in solving this problem. The aim of this study was to characterise a bioflocculant produced from Pseudomonas aeruginosa strain F29, accession number OQ734844, with 69% flocculating activity and which had been observed to possess biocontrol activity against Staphylococcus aureus SO183 at concentrations of 0.090 g/L and 0.150 g/L and against identified Pseudomonas aeruginosa at a concentration of 0.150 g/L. Pseudomonas aeruginosa strain F29, was isolated from pig fecal matter collected from a mixed animal farm in Ibadan, Nigeria via the pour plate method, identified through biochemical tests and confirmed through molecular studies. Fourier transform infrared (FTIR) spectroscopy of the bioflocculant revealed the presence of carboxyl, aromatic alcohol, alkene, halo and polysulfide functional groups. Scanning electron microscopy (SEM) revealed a clumped and flaky bioflocculant surface while energy dispersive X-ray spectroscopy (EDX) revealed the main chemical elements were chlorine (56.00%), carbon (20.50%), sodium (12.50%), oxygen (4.00%), and phosphorus (3.00%). High performance liquid chromatography (HPLC) and mass spectrometry (MS) revealed that the bioflocculant consisted of carbohydrate sugar moieties of glucose, galactose, inositol and mannose, D-ribose, arabinose, rhamnose and xylose; each with varied peaks. The phenolic sulfuric acid method showed that the concentration of these sugars was 0.0059 g/L. The bioflocculant was a polymeric compound composed mainly of carbohydrates and organochlorines, possibly known as a “glyco-organochlorine.” From available documentation, this is the first report of a “glyco-organochlorine” bioflocculant.

Antibiotic resistance has reached global proportions, and the discovery of effective alternatives to the common antibiotics in current use, could aid in solving this problem. The aim of this study was to characterise a bioflocculant produced from Pseudomonas aeruginosa strain F29, accession number OQ734844, that possessed 69% flocculating activity, and that had been observed to demonstrate biocontrol activity against Staphylococcus aureus SO183 at concentrations of 0.090 g/L and 0.150 g/L, and against identified Pseudomonas aeruginosa, at a concentration of 0.150 g/L. Pseudomonas aeruginosa strain F29, was isolated from pig fecal matter collected from a mixed animal farm in Ibadan, Nigeria via the pour plate method, identified through biochemical tests and confirmed through molecular studies. Fourier transform infrared spectroscopy (FTIR) of the bioflocculant, revealed the presence of carboxyl, amide/peptide, aromatic alcohol, alkene, halo and polysulfide functional groups. Scanning electron microscopy (SEM) revealed a clumped and flaky bioflocculant surface, while energy dispersive X-ray spectroscopy (EDX) revealed the presence of chlorine (56.00%), carbon (20.50%), sodium (12.50%), oxygen (4.00%), phosphorus (3.00%), sulphur (2.43%) magnesium (1.06%), potassium (0.32%) and nitrogen (0.30%). High performance liquid chromatography (HPLC) and mass spectrometry (MS) revealed that the bioflocculant possessed varied peaks of glucose, galactose, inositol and mannose, D-ribose, arabinose, rhamnose and xylose. The phenol sulfuric acid method revealed that the concentration of these sugars was 0.0059 g/L. The bioflocculant was a metal-containing polymeric compound composed mainly of carbohydrates, proteins/polypeptides and organochlorines, possibly a metal-containing “glyco-protein/polypeptide organochlorine.” From available documentation, this is the first report of this type of bioflocculant.

The essential properties of polyethylene terephthalate (PET), such as chemical inertness and durability that make it a suitable material for the packaging of mineral and soft drinks, have led to it becoming a major environmental pollutant and a threat to the planet. Ecologically friendly solutions such as bioremediation are now being advocated for by scientists. This paper, therefore, seeks to explore the potential capacity of Pleurotus ostreatus and Pleurotus pulmonarius in biodegrading PET plastic on two different substrates (soil and rice straw). The substrates were combined with 5% and 10% plastic before inoculation with Pleurotus ostreatus and Pleurotus pulmonarius and then left to incubate for 2 months. Biodegradation, monitored by FT-IR pointed to the formation of new peaks in the incubated plastics after 30 and 60 days unlike in the control. Changes in band intensity and shifts in the wavenumbers caused by stretching of functional groups, C-H, O-H and N-H in the band region of 2898 cm(-1) to 3756 cm(-1) are confirmed indicators of successful breakdown caused by contact with P. ostreatus and P. pulmonarius. The FT-IR analysis also gave an indication of N-H stretching at 3338.04 cm(-1) and 3228.62 cm(-1) for PET flakes incubated with Pleurotus sp. Furthermore, degradation products like hydrocarbons, carboxylic acids, alcohols, esters, and ketones were also detected in the GC-MS analysis of the decomposed PET plastic after 30 and 60 days. These compounds are formed due to chain scission caused by the fungal species. There was a discoloration of the PET flakes caused by an increase in carboxyl-terminated species as a result of enzymes secreted by the fungi in the process of biodegradation.

Introduction. A workable strategy is bioaugmentation, which involves introducing certain bacteria in sufficient quantities to promote biodegradation. This study focuses on isolating and utilizing malodor-reducing bacteria from fecal wastes obtained from a poultry farm in Ashi, Ibadan. Methods. Standard methods were employed to isolate and identify species of Pseudomonas and Bacillus. Quantitative detection of hydrogen sulfide gas and other relevant parameters was performed using MSA Orion and Multi Gas Detector. Hydrogen sulfide (H2S) release was quantitatively monitored during fermentation, considering varying loads of inocula. Results. The bacterial isolates comprised Pseudomonas aeruginosa, P. fluorescens, P. putida, Bacillus fastidiosus, B. licheniformis, B. megaterium, B. subtilis, B. sphaericus, and B. thuringiensis. Odor levels varied based on inocula load and fermentation duration. In batches with Pseudomonas, hydrogen sulfide was undetectable after two days, while Bacillus-inoculated batches required ten days. The formation of microbial mats and subsequent decrease in H2S content contributed to malodor reduction. Notably, fluorescent pseudomonas exhibited successful mineralization during the treatment of fecal waste. Conclusion. Pseudomonas isolates demonstrated superior effectiveness in odor reduction compared to Bacillus isolates.

This chapter describes survival of microorganisms in the atmosphere and their fate in relation to the climatic factors affecting their abundance and deposition. Microorganisms get to the atmosphere through the agents of wind, soil, animals, and human activities. Climatic conditions such as temperature, relative humidity, and radiation have major effects on the fate of bioaerosols suspension in the atmosphere and influence the deposition by gravitational settling on surfaces. This chapter highlights the possibility of long-distance travel of bioaerosol from one continent to the other such as the transatlantic dissemination of fungal spores. It equally highlights the effects of airborne microbial pathogens on plants and animals including human population. The public health significance of these airborne microorganisms is also given due consideration. This chapter elucidates the global effects of the distribution of the microorganisms on global health and safety of world population.

Environmental and clinical bacteria have developed resistance to the commonly available antibiotics, erstwhile produced to treat diseases caused by them. Indeed, antibiotic resistance has morphed into an issue of worldwide proportions in urgent need of effective remedies. The aim of this study was to assess the antibacterial activity of exopolysaccharide produced from stock culture of Pseudomonas aeruginosa strain S16 (accession number OQ734845), which had previously been isolated from soil in the environment, on selected identified environmental and clinical bacteria, which were both antibiotic-resistant and antibiotic-susceptible. Bacterial isolates were initially isolated from both soil and pig faecal matter using serial dilution and pour plate methods, before they were identified through biochemical tests. Screening tests for exopolysaccharide production in these isolates, had shown up S16 and F22 as the best producers of exopolysaccharide; identified as Pseudomonas aeruginosa strain S16 (accession number OQ734845) and Providencia vermicola strain F22 (accession number OQ734846), respectively. The latter was not a pseudomonad and was therefore excluded from the study. The antibacterial properties of the exopolysaccharide were then assessed using agar well diffusion assay and it was observed to be effective only against Staphylococcus aureus SO183 at 0.260 g/L and against identified Klebsiella pneumoniae only at 0.156 g/L.The positive controls used in the study were antibiotic discs containing the class of antibiotics susceptible to each selected identified bacterium. The exopolysaccharide from Pseudomonas aeruginosa strain S16, therefore, proved promising as an alternative antibiotic to the present failing antibiotics in common usage.

Utilization of disposable face mask (FM) as carbon source for the cultivation of Pleurotus ostreatus mushroom was investigated in the attempt to reduce plastic build up in the environment due to its disposal. Growth substrate was prepared using FM as sole and/or partial carbon source varied with mahogany wood shavings (MWS) at 25, 50, 75 and 100% composition (wt/wt). Visual sorting under stereo microscope to detect presence or absence of microplastics in the mushrooms produced was conducted. Shortest spawn run (25.5 days) and optimum number of fruiting bodies (28) were achieved at MWS:FM 75:25 while optimal fruiting body (fresh weight) (71g), biological efficiency (88.8%) and proximate outputs (except carbohydrate) were achieved at MWS:FM of 25:75. No form of microplastic fibre, fragments, microbeads, foams and nurdles was detected in the produced mushroom. This study demonstrated the ability of Pleurotus ostreatus to utilize disposable FM as growth substrate for its production.

The chemical properties of the soil and heavy metals (6) in transformer oil polluted soil inoculated with two lower fungi Aspergillus niger (U3) and Aspergillus sp (I5) for the period of 0-10 weeks was investigated in this study. Soil was collected from three sites from a depth of 0-15 cm and heavy metals analysis was conducted using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The heavy metal concentrations in the soil collected from Ibadan inoculated with the two fungi vary ranging from 306.82-383.31 mg -kg(-1) (Fe), 7.53-11.02 mg -kg(-1) (Mn), 7.71-19.01 mg -kg(-1) (Cu), 9.84-11.49 mg -kg-1 (Zn), 7.77-10.56 mg -kg-1 (Mg) and 8.3211.78 mg -kg-1 (Pb) while soil from Warri had Fe concentration of 76.06-153.10 mg -kg-1, Zn 0.16-0.78 mg -kg(-1), Mg 0.32-3.91 mg -kg-1, Pb 0.09-0.35 mg -kg-1 and soil collected from Ughelli had Fe concentration of 91.71-145.98 mg -kg(-1) and 0.30-2.85 mg -kg-1. The soil from the study sites were observed to be rich in Fe and Cu but had low level of lead which is vital as the presence of high level of lead in the soil could be harmful to living organisms.

A poultry-fish farming system provides an opportunity for farmers to feed fishes on a low monetary cost level by utilising poultry droppings. Wastes from poultry, majorly bird excreta, which may contain pathogenic or antibiotic-resistant bacteria, are usually released into ponds to feed fishes. This study focused on the physicochemical analysis of pond water samples and determination of antibiotic resistance pattern of multidrug-resistant (MDR) Gram-negative bacteria isolated from poultry droppings, pond water, and fishes collected from two integrated poultry-fish farms in Osun State, Nigeria. Physicochemical analysis of the pond water samples from the farms revealed higher levels of turbidity (farm A = 580.78 +/- 297.7 NTU and farm B = 1162.25 +/- 19.23 NTU), total dissolved solids (farm A = 391.9 +/- 36.47 mg/L and farm B = 803.65 +/- 61.26 mg/L), biochemical oxygen demand (farm A = 23.73 +/- 1.24 mg/L and farm B = 28.86 +/- 0.94 mg/L), chemical oxygen demand (farm A = 35.59 +/- 1.86 mg/L and farm B = 43.29 +/- 1.46 mg/L), phosphate (farm A = 3.638 +/- 0.25 mg/L and farm B = 3.54 +/- 0.26 mg/L), iron (farm A = 2.64 +/- 0.42 mg/L and farm B = 9.11 +/- 3.48 mg/L), and manganese (farm A = 0.43 +/- 0.04 and farm B = 0.66 +/- 0.21 mg/L) compared to the permissible limits. Out of eighty Gram-negative bacteria isolated, 55 (68.75%) exhibited MDR phenotypes. These include 32 (58.2%) and 15 (27.3%) bacteria isolated on both farms from poultry dropping and fish samples, respectively. Meanwhile, 8 (14.5%) bacteria were isolated from water samples collected from farm B only. The multiple antibiotic resistance (MAR) index on both farms ranged from 0.37 to 1.00. MicrobactTM 24E identified the MDR bacteria as members of the genera Aeromonas (21.82%), Burkholderia (16.36%), Pseudomonas (14.55%), Enterobacter (10.91%), Acinetobacter (9.09%), Moraxella (5.45%), Serratia (5.45%), Escherichia (5.45%), Proteus (3.64%), Citrobacter (1.82%), Stenotrophomonas (1.82%), Hafnia (1.82%) and Cronobacter (1.82%). Five of all the MDR bacterial isolates, which include Enterobacter agglomerans (n = 2), Burkholderia pseudomallei (n = 2), and Aeromonas hydrophilia (n = 1), were resistant to all the antibiotics tested. Meanwhile, four bacterial isolates, which include Pseudomonas aeruginosa (n = 2), Serratia marcescens (n = 1), and Citrobacter youngae (n = 1), were resistant to all classes of antibiotics tested. Strains of E. agglomerans, B. pseudomallei, and Aeromonas hydrophilia isolated from poultry droppings and fishes have the same antibiotype patterns. This shows the interaction between poultry and pond environments relating to the spread of antibiotic-resistant bacterial strains from poultry droppings to fish. The outcome of the study provides baseline information for future studies to understand the possible impact of integrated poultryfish farming in matters of public health concerns such as food safety, dissemination of pathogens, and antibiotic resistance.

Recently, the use of antibiotics for the treatment of numerous infections and diseases increased significantly, and led to noticeable reduction in the rate of mortality and morbidity. The increased development of multidrug resistant bacterial strains that is attributable to the indiscriminate use of antibiotics has led to the search for new antimicrobials of plants origin. This study aimed to assess the potentials of the multidrug resistant bacterial strains to develop resistance to the aqueous fruit extract of Xylopia aethiopica. The tested bacterial strains were; Staphylococcus epidermidis, Staphylococcus saprophyticus, Bacillus cereus, Pseudomonas aeruginosa and Escherichia coli. In this study, on using the in vitro agar well diffusion assay; the bacterial strains exhibited different diameters of zones of inhibition; ranging from 1.75± 1.06 mm to 12.75± 1.06 mm, on treatment with various concentrations of the aqueous fruit extract. The recorded MIC value for E. coli was 250 mg/ ml, while the other bacterial strains recorded 125 mg/ ml. On the other hand, the obtained MBC value for Staphylococcus saprophyticus and Staphylococcus epidermidis was 2000 mg/ ml, whereas E. coli and P. aeruginosa recorded 1000 mg/ ml. However, the MBC of B. cereus was not detected. The bacterial strains were subjected to a sub-optimal concentration of the extract after exposure for 5, 10, 15 and 20 d. After exposure for 20 d, P. aeruginosa expressed sensitivity only at 2000 mg /ml of the extract with a diameter of inhibition of 4.25± 0.35 mm. E. coli exhibited sensitivity at 2000 and 1000 mg/ ml, recording diameters of inhibition of 4.5± 0.71 mm and 2.50± 0.71 mm, respectively. The other strains exhibited resistance on treatment with 250 mg/ ml of the extract, except for B. cereus, which recorded inhibition diameter of 3.50 ±0.71 mm. This study demonstrated that exposure of the MDR resistant bacterial strains to a sub-optimal concentration of the aqueous fruit extract of Xylopia aethiopica could initiate resistance development.

Antibiotics for many years were known to be effective against different strains of bacteria and other microbes. The discovery of antibiotics has led to a severe reduction in death and disease. However, the indiscriminate use of antibiotics resulted in the development of resistance and multiple resistances by bacteria hence, the search for alternative therapy for the treatment of infectious diseases making researchers shift their attention to plant antimicrobials. Nevertheless, the possibility of bacteria developing resistance to plant antimicrobials is not well studied. This study aims to evaluate the development of resistance in multi-drug resistant bacteria to antimicrobials from the methanol extract of the stem bark of Artocarpus altilis. The susceptibility of multi-drug resistant Staphylococcus epidermis, Escherichia coli, Bacillus cereus, Staphylococcus saprophyticus, Proteus mirabilis and Pseudomonas aeruginosa to methanol extract of Artocarpus altilis at different concentrations (160mg/l, 80mg/l, 40mg/l and 20mg/ml) was tested after which the bacteria were exposed to a sub-lethal concentration over some time. The result displayed that Proteus mirabilis showed no sensitivity at all concentrations after eighteen days of exposure. In comparison, the other bacterial test isolates only showed activity at 160mg/ml and 80mg/ml after 24 days of exposure except for Bacillus cereus, which showed activity at the lowest concentration (20mg/ml). This study demonstrated that exposure of bacteria to antimicrobial plant extract at a sub-lethal concentration could induce the development of resistance.

Pharmaceutical wastewaters are recognized as reservoirs of antibiotic resistance genes (ARGs) and antibiotic resistant bacteria (ARB), and also as hotspots for their horizontal gene transfer (HGT) using mobile genetic elements. Our study employed the use of PCR analysis of metagenomic DNA samples obtained from four pharmaceutical wastewaters using known primers to study the prevalence of thirty-six ARGs and four MGEs active against the commonly used antibiotics in Nigeria. The ARGs most frequently detected from the metagenomic DNA samples in each of the antibiotic classes under study include tetracycline [tet(G)], aminoglycoside [aadA, strA and strB], chloramphenicol [catA1], sulphonamides [sulI and sulII], and β-lactams and penicillins [blaOXA]. The ARGs showed a 100% prevalence in their various environmental sources. The pharmaceutical facility PFIV showed the highest concentration of ARGs in this study. The highest concentration for MGEs was shown by pharmaceutical facility PFIII, positive for intl1, intl2, and IFS genes. This study highlights the wide distribution of ARGs to the antibiotics tested in the wastewater, making pharmaceutical wastewater reservoirs of ARGs which could potentially be transferred from commensal microorganisms to human pathogens.

Aim: Di-(2-ethylhexyl) phthalate (DEHP) has been identified as an endocrine-disrupting chemical, commonly found in the environment. The aim of this study was to isolate bacteria from municipal solid waste (MSW) leachates in Nigeria and its ability to degrade DEHP. Methodology and results: The DEHP degrading bacterium was isolated and identified. The degradation process was monitored aerobically at varying temperature and pH and the metabolites were determined using High PerformanceLiquid Chromatography and Gas Chromatography-Mass Spectrometry, respectively. Based on the morphology and the 16S rDNA sequence, the bacterial isolate was identified as Bacillus aquimaris. B aquimaris was able to degrade 99% of 200 mg/L DEHP within 12 days. The optimum pH and temperature for its biodegradation were 8 and 25 °C, respectively and the intermediate metabolites were identified as butyl octyl phthalate and phthalic acid. Conclusion, significance and impact of study: This study showed that B. aquimaris could be a useful tool for the biodegradation of DEHP in the environment.

The burden of heavy metals in the environment can be reduced using organic amendment stimulated bacterial remediation. This study employed cattle manure slurry stimulated bacterial inoculum to treat heavy metals-contaminated soil. Samples of contaminated soil and cattle manure were collected from the area surrounding a steel rolling mill and a commercial animal pen respectively. Bacteria were isolated using pour plate technique; identified using various biochemical tests and screened for resistance to heavy metal salts by incorporating heavy metal salts into agar plates. The contaminated soil and manure slurry were analysed for heavy metals and then sterilised separately. Five kilogram of the sterilised contaminated soil was weighed and mixed with 100g of sterilized cow dung slurry and aseptically packed into plastic nursery bags. Bacterial samples showing high tolerance to heavy metal salts were introduced into the bags singly and as a consortium for bioremediation exercise. Thirty-six bacterial isolates were obtained from the contaminated soil. Chemical analysis revealed that the soil was heavily contaminated especially with lead and chromium with concentrations of 1505.1-2333.6 and 1526.0-1678.7 mg/kg, respectively. Alcaligenes faecalis, Pseudomonas azotoformans and Bacillus mycoides exhibited high tolerance to heavy metals salt and were selected for bioremediation. Post bioremediation analysis of the soil samples revealed a reduction in the concentration of heavy metals concentration with major reduction in the concentration of chromium in groups treated with P. azotoformans. Biostimulation of microorganisms with organic amendment effectively remediated heavy metals contaminated soil and can be employed in the treatment of such contaminated environments.

Background:Multi-drug Resistant (MDR) bacteria could lead to treatment failure of infectious diseases and could be transferred by non-potable water. Few studies have investigated occurrence of Antibiotic Resistance Genes (ARGs) among bacteria including Aminoglycoside Modifying Genes (AMGs) from Drinking Water Distribution Systems (DWDS) in Nigeria. Here, we aimed at characterization of AMGs from DWDS from selected states in southwestern Nigeria.Methods:One hundred and eighty one (181) MDR bacteria that had been previously characterized using 16S rDNA and showed resistance to at least one aminoglycoside antibiotic were selected from treated and untreated six water distribution systems in southwestern Nigeria. MDR bacteria were PCR genotyped for three AMGs:aph (3″)c, ant (3″)b and aph(6)-1dd.Results:Out of 181 MDR bacteria genotyped, 69(38.12%) tested positive for at least one of the genotyped AMGs. Highest (50, 27.62%) detected gene was ant (3″)c followed by aph (3″)c(33, 18.23%). Combination of aph(3″)c and ant (3″)b in a single bacteria was observed as the highest (14, 7.73%) among the detected gene combination. Alcaligenes sp showed the highest (10/20) occurrence of ant (3″)b while aph(3″)c was the highest detected among Proteus sp (11/22). Other bacteria that showed the presence of AMGs include: Acinetobacter, Aeromonas, Bordetella, Brevundimonas, Chromobacterium, Klebsiella, Leucobacter, Morganella, Pantoae, Proteus, Providencia, Psychrobacter and Serratia.Conclusions:High occurrence of ant (3″)c and aph (3″)c among these bacteria call for urgent attention among public health workers, because these genes can be easily disseminated to consumers of these water samples if present on mobile genetic elements like plasmids, integrons and transposons.