Due to the increased demand of animal protein in developing countries, intensive farming is instigated, which results in antibiotic residues in animal-derived products, and eventually, antibiotic resistance. Antibiotic resistance is of great public health concern because the antibiotic-resistant bacteria associated with the animals may be pathogenic to humans, easily transmitted to humans via food chains, and widely disseminated in the environment via animal wastes. These may cause complicated, untreatable, and prolonged infections in humans, leading to higher healthcare cost and sometimes death. In the said countries, antibiotic resistance is so complex and difficult, due to irrational use of antibiotics both in the clinical and agriculture settings, low socioeconomic status, poor sanitation and hygienic status, as well as that zoonotic bacterial pathogens are not regularly cultured, and their resistance to commonly used antibiotics are scarcely investigated (poor surveillance systems). The challenges that follow are of local, national, regional, and international dimensions, as there are no geographic boundaries to impede the spread of antibiotic resistance. In addition, the information assembled in this study through a thorough review of published findings, emphasized the presence of antibiotics in animal-derived products and the phenomenon of multidrug resistance in environmental samples. This therefore calls for strengthening of regulations that direct antibiotic manufacture, distribution, dispensing, and prescription, hence fostering antibiotic stewardship. Joint collaboration across the world with international bodies is needed to assist the developing countries to implement good surveillance of antibiotic use and antibiotic resistance.

Antibiotic Use in Agriculture and Its Consequential Resistance in Environmental Sources: Potential Public Health Implications

Bacterial biofilms are complex surface attached communities of bacteria held together by self-produced polymer matrixs mainly composed of polysaccharides, secreted proteins, and extracellular DNAs. Bacterial biofilm formation is a complex process and can be described in five main phases: (i) reversible attachment phase, where bacteria non-specifically attach to surfaces; (ii) irreversible attachment phase, which involves interaction between bacterial cells and a surface using bacterial adhesins such as fimbriae and lipopolysaccharide (LPS); (iii) production of extracellular polymeric substances (EPS) by the resident bacterial cells; (iv) biofilm maturation phase, in which bacterial cells synthesize and release signaling molecules to sense the presence of each other, conducing to the formation of microcolony and maturation of biofilms; and (v) dispersal/detachment phase, where the bacterial cells depart biofilms and comeback to independent planktonic lifestyle. Biofilm formation is detrimental in healthcare, drinking water distribution systems, food, and marine industries, etc. As a result, current studies have been focused toward control and prevention of biofilms. In an effort to get rid of harmful biofilms, various techniques and approaches have been employed that interfere with bacterial attachment, bacterial communication systems (quorum sensing, QS), and biofilm matrixs. Biofilms, however, also offer beneficial roles in a variety of fields including applications in plant protection, bioremediation, wastewater treatment, and corrosion inhibition amongst others. Development of beneficial biofilms can be promoted through manipulation of adhesion surfaces, QS and environmental conditions. This review describes the events involved in bacterial biofilm formation, lists the negative and positive aspects associated with bacterial biofilms, elaborates the main strategies currently used to regulate establishment of harmful bacterial biofilms as well as certain strategies employed to encourage formation of beneficial bacterial biofilms, and highlights the future perspectives of bacterial biofilms.

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Beyond Risk: Bacterial Biofilms and Their Regulating Approaches.

Cultivating microalgae in wastewater for biomass production, pollutant removal, and atmospheric carbon mitigation; a review.

An assessment of groundwater quality for irrigation and drinking purposes around brick kilns in three districts of Balochistan province, Pakistan, through water quality index and multivariate statistical approaches

Water makes up about 70% of the earth’s surface and is one of the most important sources vital to sustaining life. Rapid urbanization and industrialization have led to a deterioration of water quality at an alarming rate, resulting in harrowing diseases. Water quality has been conventionally estimated through expensive and time-consuming lab and statistical analyses, which render the contemporary notion of real-time monitoring moot. The alarming consequences of poor water quality necessitate an alternative method, which is quicker and inexpensive. With this motivation, this research explores a series of supervised machine learning algorithms to estimate the water quality index (WQI), which is a singular index to describe the general quality of water, and the water quality class (WQC), which is a distinctive class defined on the basis of the WQI. The proposed methodology employs four input parameters, namely, temperature, turbidity, pH and total dissolved solids. Of all the employed algorithms, gradient boosting, with a learning rate of 0.1 and polynomial regression, with a degree of 2, predict the WQI most efficiently, having a mean absolute error (MAE) of 1.9642 and 2.7273, respectively. Whereas multi-layer perceptron (MLP), with a configuration of (3, 7), classifies the WQC most efficiently, with an accuracy of 0.8507. The proposed methodology achieves reasonable accuracy using a minimal number of parameters to validate the possibility of its use in real time water quality detection systems.

https://www.mdpi.com/2073-4441/11/11/2210/pdf

Efficient Water Quality Prediction Using Supervised Machine Learning

Due to alarming increase in population and rapid industrialization, drinking water quality is being deteriorated day by day in Pakistan. This review sums up the outcomes of various research studies conducted for drinking water quality status of different areas of Pakistan by taking into account the physicochemical properties of drinking water as well as the presence of various pathogenic microorganisms. About 20% of the whole population of Pakistan has access to safe drinking water. The remaining 80% of population is forced to use unsafe drinking water due to the scarcity of safe and healthy drinking water sources. The primary source of contamination is sewerage (fecal) which is extensively discharged into drinking water system supplies. Secondary source of pollution is the disposal of toxic chemicals from industrial effluents, pesticides, and fertilizers from agriculture sources into the water bodies. Anthropogenic activities cause waterborne diseases that constitute about 80% of all diseases and are responsible for 33% of deaths. This review highlights the drinking water quality, contamination sources, sanitation situation, and effects of unsafe drinking water on humans. There is immediate need to take protective measures and treatment technologies to overcome unhygienic condition of drinking water supplies in different areas of Pakistan.

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Drinking Water Quality Status and Contamination in Pakistan.

The upflow anaerobic sludge blanket (UASB) reactor has been recognized as an important wastewater treatment technology among anaerobic treatment methods. The objective of this study was to perform literature review on the treatment of domestic sewage using the UASB reactor as the core component and identifying future areas of research. The merits of anaerobic and aerobic bioreactors are highlighted and other sewage treatment technologies are compared with UASB on the basis of performance, resource recovery potential, and cost. The comparison supports UASB as a suitable option on the basis of performance, green energy generation, minimal space requirement, and low capital, operation, and maintenance costs. The main process parameters such as temperature, hydraulic retention time (HRT), organic loading rate (OLR), pH, granulation, and mixing and their effects on the performance of UASB reactor and hydrogen production are presented for achieving optimal results. Feasible posttreatment steps are also identified for effective discharge and/or reuse of treated water.

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Review of Upflow Anaerobic Sludge Blanket Reactor Technology: Effect of Different Parameters and Developments for Domestic Wastewater Treatment

Heavy metals are environmental contaminants globally They have polluted agricultural soils and caused detrimental effects on our ecosystem Toxic effects of heavy metals have been reported in plants, animals, humans, and microorganisms Heavy metal remediation is essential to preserve the health of agricultural soils and would lead to enhanced crop growth and yield Various techniques and strategies have been used in recent years to remediate contaminated soils, but most of them were costly, environmentally unfriendly, and negatively affect soil properties However, use of microbes to remediate heavy metals has been found to be cost effective and environmentally clean Microbes enhance stability in agricultural soil health, which leads to sustained plant growth and development under stressful conditions Particular agents used for bioremediation are bacteria, fungi, and algae Bacterially-mediated processes have been used to alleviate heavy metal toxicity Endophytic bacteria have greater potential to tolerate and remediate heavy metals stress Bacterial strains showed potential to alleviate heavy metals from the rhizosphere of target plant species and improve their growth Arbuscular mycorrhizal fungi alleviate heavy metal toxicity by inhibiting their uptake and translocation in plant parts In addition, many morphological and physiological changes are induced by fungi Macro- and micro-algae have been reported to alleviate heavy metal toxicity mostly in marine systems Reports suggested that applications of the above bioremediation agents alleviate heavy metal stress, enhance phytoremediation capacity in combination with plant growth–promoting bacteria, and ultimately improve plant growth attributes

Role of Bioremediation Agents (Bacteria, Fungi, and Algae) in Alleviating Heavy Metal Toxicity

Contamination of soil is a major problem globally with colligated danger for ecosystem and human health. Chromium (Cr) is a toxic heavy metal and caused harmful effect on growth and development of plants. Phytostabilization reduced the mobility of heavy metals with addition of amendments which can significantly decrease metal solubility in soil. Phytostabilization can be achieved by application of biogas slurry (BGS) and endophytic bacteria as amendments in the contaminated soils. The present study revealed that the Burkholderia phytofirmans PsJN and BGS improved the growth, physiology, and antioxidant activity and reduced Cr uptake under a pot experiment spiked with Cr (20 mg kg−1 soil). The experiment was designed under completely randomized design, four treatments with three replications in normal and Cr-contaminated soil. The inoculation of endophytic bacteria improved the growth and physiology of Brassica. This study showed that the inoculation of endophytic bacteria stabilized the Cr levels in soil and minimized the uptake by the plant shoots and roots in BGS-amended soil. Similarly, activity of antioxidants such as catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), and glutathione s-transferase (GST) was decreased to normal with combined treatment of BGS and endophytic bacteria in Cr-stressed soil. Overall, the best results were analyzed by combined treatment of BGS and endophytic bacteria to improve growth, physiology, and antioxidant activity of Brassica and immobilize Cr in soil. Moreover, results emphasized the need to use BGS alone or in combination with endophytic bacteria to optimize crop performance, stabilize Cr concentration, and improve environmental efficiency.

Efficiency of biogas slurry and Burkholderia phytofirmans PsJN to improve growth, physiology, and antioxidant activity of Brassica napus L. in chromium-contaminated soil

Muhammad Nafees

Papers

Drinking Water Quality Status and Contamination in Pakistan.

Review of Upflow Anaerobic Sludge Blanket Reactor Technology: Effect of Different Parameters and Developments for Domestic Wastewater Treatment

Role of Bioremediation Agents (Bacteria, Fungi, and Algae) in Alleviating Heavy Metal Toxicity

Efficiency of biogas slurry and Burkholderia phytofirmans PsJN to improve growth, physiology, and antioxidant activity of Brassica napus L. in chromium-contaminated soil