Publications by authors named "Amechi S Nwankwegu"

Fruiting body development is a principal mechanism in fungal morphogenesis, which often involves complex interplays of hormonal regulation, gene expression, and metabolic immobilisation influenced by environmental interactions, ultimately leading to the differentiation of multicellular structures. In fungal communities, including ascomycetes and basidiomycetes, fruiting body development ensures protection and facilitates the dispersal of ascospores. Constrained by environmental factors that vary across morphogenetic stages, a thorough synthesis of the critical ecological optima, which primarily regulate the multi-omics footprint encompassing diverse molecular perspectives characterising fruiting body formations, is key.

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Understanding the causes of environmental phenomena is crucial for promoting positive outcomes and mitigating negative ones. Partial least squares structural equation modelling (PLS-SEM) is becoming a valuable tool for evaluating causal relationships in ecological environment studies (EES). However, many studies using PLS-SEM often overlook nonlinear relationships and interactions between environmental factors, and have not fully utilized the powerful capabilities of machine learning.

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Effective management of Harmful Algal Blooms (HABs) requires understanding factors influencing their occurrence. This study explores these dynamics in the Pengxi River, a tributary of the Three Gorges Reservoir, focusing on nutrient stratification and algal blooms. We hypothesized that nutrient levels in eutrophic waters with stable stratification correlate with HAB magnitude and that disruption of stratification triggers blooms due to nutrient shifts.

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Taxa-specific responses to the increasing anthropogenic eutrophication offer promising insights for mitigating harmful algal blooms (HABs) in freshwaters. The present study evaluated the HABs species dynamics in response to the ecosystem anthropogenic enrichment during cyanobacterial-dominated spring HABs in the Pengxi River, Three Gorges Reservoir, China. Results show significant cyanobacterial dominance with a relative abundance (RA = 76.

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Secondary metabolites (toxins) production during harmful algal blooms (HABs) further increases the public health risks associated with water quality deterioration from anthropogenic eutrophication. In the present study, the dynamic pattern in the production of metabolites under different nutrient conditions in Ceratium-dominated spring HABs was investigated in Pengxi River, China. Results revealed five (5) important toxins all attributable to the Dinophyceae including azaspiracid 2&4, okadaic acid, tetrodotoxin, brevetoxin, and saxitoxin, each exhibiting certain levels of specificity to the ecosystem enrichments.

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The mechanisms of phylogenetic turnover of microbial communities to environmental perturbations in sediments remain unclear. In this study, the molecular mechanisms of phylogenetic turnover, and impact of antibiotics and antibiotic resistance genes (ARGs) on the modification of microbial assemblages were unravelled. We investigated 306 ARGs, 8 transposases, and 4 integron integrases, bacteria, and eukaryotic diversity through high-throughput quantitative PCR and illumina sequencing, 21 antibiotics and 3 tetracycline byproducts.

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Aquaculture contributes remarkably to the global economy and food security through seafood production, an important part of the global food supply chain. The success of this industry depends heavily on aquafeeds, and the nutritional composition of the feed is an important factor for the quality, productivity, and profitability of aquaculture species. The sustainability of the aquaculture industry depends on the accessibility of quality feed ingredients, such as fishmeal and fish oil.

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The ecological impacts of antibiotics and antibiotic resistance genes (ARGs) on water ecology remain elusive in natural environments. We investigated the influence of antibiotics, ARGs and salinity gradient on the surface water ecosystem. Cefquinome (104.

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The microbial food-loop is critical to energy flow in aquatic food webs. We tested the hypothesis that species composition and relative abundance in a microbial community would be modified by the development of toxic algal blooms either by enhanced carbon production or toxicity. This study tracked the response of the microbial community with respect to composition and relative abundance during a 7-day algal bloom event in the Three Gorges Reservoir in May 2018.

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Nutrient availability, is a crucial anthropogenic stressor promoting freshwater eutrophication and rapid expansion of harmful algal blooms (HABs), deteriorating water quality and threatening public health worldwide. The estimation of the HABs community responses to diel changes in the nutrients while characterizing the ecosystem growth limiting factors, is key to prudent watershed management. The present study investigated the short-term variabilities in autumn cyanobacterial responses to the external nutrient inputs into the Pengxi River using the nutrient addition bioassay approach.

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Environmental pollution mitigation measure involving bioremediation technology is a sustainable intervention for a greener ecosystem biorecovery, especially the obnoxious hydrocarbons, xenobiotics, and other environmental pollutants induced by anthropogenic stressors. Several successful case studies have provided evidence to this paradigm including the putative adoption that the technology is eco-friendly, cost-effective, and shows a high tendency for total contaminants mineralization into innocuous bye-products. The present review reports advances in bioremediation, types, and strategies conventionally adopted in contaminant clean-up.

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In this study, a radial basis function neural network (RBFNN) model was developed and implemented in a multi-objective optimization procedure to determine the optimal hydraulic loading rate (HLR), hydraulic retention time (HRT), and mass loading rates (MLR) for enhanced removal of nitrogen and phosphorus by an integrated surface flow treatment wetland-pond system treating drinking source water in Yancheng, China. Prior to modelling, the system's 6-year nitrogen and phosphorus removal efficiencies were found to trend downwards as effluent concentrations trended positively. Meanwhile, operating parameter interaction effects impacted final effluent quality.

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Recently, reservoirs in southern China are witnessing incidents involving black water, which are harmful to the aquatic ecosystem. This study unravels the cause of the black water events by studying the occurrence and the ecological risks of contaminants (Pb, Cu, Cd, Zn, Ni, TFe, Mn, S, P, and DOC) in sediments of Tianbao reservoir. Due to the significantly high concentration of TFe, Mn, and P in the sediments, the study further used the thin film diffusion gradient (DGT) technology and high-resolution dialysis method to investigate the movement of Fe, Mn, S, and reactive P within the sediments.

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The management of black water depends primarily on the knowledge of the dynamics of organic matter (OM), iron (Fe), sulfide (S), and manganese (Mn), at the water-sediment boundary (WSB). However, the mechanistic path of these substances leading to black water remains unsettled. In this study, a 35-day field study was conducted using the thin-film diffusion gradient technology (DGT) and the planar optrode to address the unknown combined effects of Fe, Mn, OM, S, and tannins from Eucalyptus species on Tianbao reservoir.

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The rational eutrophication management largely depends on the knowledge of the dynamics in the dissolved inorganic nutrients especially nitrogen forms which trigger exponential primary productivity in eutrophic systems. The present study investigated the phytoplankton interactions with the dissolved N forms, nitrate (NO) and ammonium (NH) in a sub-tropical Yangtze River tributary, China vulnerable to multiple anthropogenic stressors following the impoundment of the largest hydraulic structure, the Three Gorges Dam. Results indicated strong NO inhibition by the low NH pool exerting toxic effects on the major phytoplankton groups, particularly the Bacilliariophyta (relative abundance < 1%) while significant Cyanophyta proliferation prevailed (relative abundance ≥ 90%).

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Tianbao reservoir in southern China (surrounded by Eucalyptus plantation) serves as a source of drinking water for the inhabitants. However, the reservoir water experiences black water (BW) of which the cause remains unclear. In this study, field observation and simulated laboratory experiment were conducted to understand the cause of the BW.

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Algal blooms have thrived on the third-largest shallow lake in China, Taihu over the past decade. Due to the recycling of nutrients such as nitrate and ammonium, this problem has been difficult to eradicate. Sediment flux, a product of diagenesis, explains the recycling of nutrients.

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The deterioration of reservoirs in southern China due to the kinetics of Iron (Fe), Phosphorus (P) and sulphide (S) at the sediment-water interface (SWI) is a major problem that needs urgent attention. Studies on the biogeochemistry of Fe, P, and S using high-resolution profile techniques in reservoirs in this region are limited. The diffusive gradient in thin films (DGT) technique, high-resolution dialysis, DGT-computer imaging densitometry (CID), DGT-induced fluxes in sediments (DIFS) and planar optode (PO) device were used to describe the dynamics Fe-P-S in SWI during hypoxia.

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Most aquatic systems show characteristic seasonal fluctuations in the total nutrient pool supporting primary productivity. The nutrient dynamics essentially exacerbate critical demand for the counterpart micronutrients towards achieving ecosystem equilibrium. Herein, the phytoplankton demand for iron (Fe) uptake under high concentration of nitrate-nitrogen during spring in Xiangxi Bay, China, was studied.

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After the impoundment of the Three Gorges Reservoir (TGR), algal blooms in the sidearm tributaries have resulted from increasing nutrient loads along the major tributaries. Field sampling and in situ nutrient addition bioassay were implemented to examine the nutrient limitation of phytoplankton growth and bloom initiation during autumn in Xiangxi Bay of the TGR. Result shows that P is the primary limiting nutrient for algal growth and bloom in Xiangxi Bay during autumn.

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The increasing freshwater ecosystem nutrient budget is a critical anthropogenic factor promoting freshwater eutrophication and episodic bloom of harmful algae which threaten water quality and public health. To understand how the eutrophic freshwater ecosystem responds in term of phytoplankton community structure dynamics to a sudden rise in nutrient concentrations, a microcosm study by nutrient addition bioassay was implemented in Xiangxi Bay (XXB) of Three Gorges Reservoir, China. Our results showed that dissolved trace elements supply adequately altered the phytoplankton community structure creating a regime shift from cyanobacteria-dominated to essentially Chlorophytes-dominated system, relative abundance (>70%).

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The present review reports all management approaches (physical, chemical, and biological) traditionally adopted in mitigating the global impact of harmful cyanobacterial blooms (cyanoHABs). It recognizes that each mitigation strategy shows characteristic associated limitations and notes that no remedial step has provided a sustainable solution to HABs on a global scale. It emphasizes that the putative anthropogenic N&P inputs reduction through improved wastewater treatment and regulation of point and non-point sources-agricultural fertilizers only offer a short term solution.

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Surface sediment samples were collected from four areas (the Jingdezhen Industrialized Area (JDZ), Upstream (UP), the Dexing Mining Area (DX), and Downstream (DM)) to investigate the concentration and chemical composition of heavy metals. The sediments were analysed for Cu, Zn, Pb, Cd, Cr, As, and Ni using a sequential extraction scheme according to the improved BCR (European Community Bureau of Reference) method. The obtained results show that the maximum values of Cu (793.

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The integration of first and second order kinetic model in parameter estimation for the degradation pattern of total petroleum hydrocarbon (TPH) in spent lubricating petroleum oil (SLPO) over a four-month period was the subject of the present investigation. Study design considered four treatment microcosms notably; sewage sludge (SB), monitored natural recovery (MNR), surfactant (SA) and control (SO). The rate of TPH degradation using sewage sludge as amendment material depicted effective TPH removal within ten weeks.

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Due to increasing reports on poor-quality palm oil in the market, there has been a continual decrease in demand and revenue cum product rejection of palm oil sold in Jos, Nigeria. Hence, the significance of this work aims to moderate the microbial and physical qualities of crude palm oil sold in different major markets in order to increase revenue through quality control and quality assurance protocols. The intent is to create awareness among government monitoring agencies, buyers (exporters and importers), and to promote standard processing procedures among manufacturers.

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