In situ and ex situ bioremediation of heavy metals: the present scenario

Enhanced population growth, rapid industrialization, urbanization and hazardous industrial practices have resulted in the development of environmental pollution in the past few decades. Heavy metals are one of those pollutants that are related to environmental and public health concerns based on their toxicity. Effective bioremediation may be accomplished through “ex situ” and “in situ” processes, based on the type and concentration of pollutants, characteristics of the site but is not limited to cost. The recent developments in artificial neural network and microbial gene editing help to improve “in situ” bioremediation of heavy metals from the polluted sites. Multi-omics approaches are adopted for the effective removal of heavy metals by various indigenous microbes. This overview introspects two major bioremediation techniques, their principles, limitations and advantages, and the new aspects of nanobiotechnology, computational biology and DNA technology to improve the scenario

Evaluation of predictive machine learning models for drug repurposing against delta variant of SARS-CoV-2 spike protein

Drug repurposing is a major approach used by researchers to tackle the COVID-19 pandemic which has been worsened by the current surge of delta variant in many countries. Though drugs like Remdesivir and Hydroxychloroquine have been repurposed, studies prove these drugs have insignificant effect in treatment. So, in this study, we use the already FDA approved database of 1615 drugs to apply semi-flexible and flexible molecular docking methods to calculate the docking scores and identify the best 20 potential inhibitors for our modelled delta variant spike protein RBD. Then, we calculate 2325 1-D and 2-D molecular descriptors and use machine-learning algorithms like K-Nearest Neighbor, Random Forest, Support Vector Machine and ensemble stacking method to build regression-based prediction models. We identify 15 best descriptors for the dataset all of which were found to be inversely correlated with ligand binding. With only these few descriptors, the models performed excellently with an area under curve (AUC) value of 0.952 in Regression Error Characteristic curve for ensemble stacking. Therefore, we comment that these 15 descriptors are the most important features for the binding of inhibitors to the spike protein and hence these should be studied properly in terms of drug repurposing and drug discovery

Immobilized enzymes as potent antibiofilm agent

Biofilm has been a point of concern in hospitals and various industries. They not only cause various chronic infections but are also responsible for the degradation of various medical appliances. Since the last decade, various alternate strategies are being adopted to combat the biofilm formed on various biotic and abiotic surfaces. The use of enzymes as a potent anti-fouling agent is proved to be of utmost importance as the enzymes can inhibit biofilm formation in an eco-friendly and cost-effective way. The physical and chemical immobilization of the enzyme not only leads to the improvement of thermostability and reusability of the enzyme, but also gains better efficiency of biofilm removal. Immobilization of amylase, cellobiohydrolase, pectinase, subtilisin A and β-N-acetyl-glucosaminidase (DspB) are proved to be most effective in inhibition of biofilm formation and removal of matured biofilm than their free forms. Hence, these immobilized enzymes provide greater eradication of biofilm formed on various surfaces and are coming up to be the potent antibiofilm agent.Universidade de Vigo/CISU

Valorisation of CO 2 into Value-Added Products via Microbial Electrosynthesis (MES) and Electro-Fermentation Technology

Microbial electrocatalysis reckons on microbes as catalysts for reactions occurring at electrodes. Microbial fuel cells and microbial electrolysis cells are well-known in this context; both prefer the oxidation of organic and inorganic matter for producing electricity. Notably, the synthesis of high energy-density chemicals (fuels) or their precursors by microorganisms using bio-cathode to yield electrical energy is called Microbial Electrosynthesis (MES), giving an exceptionally appealing novel way for producing beneficial products from electricity and wastewater. This review accentuates the concept, importance and opportunities of MES, as an emerging discipline at the nexus of microbiology and electrochemistry. Production of organic compounds from MES is considered as an effective technique for the generation of various beneficial reduced end-products (like acetate and butyrate) as well as in reducing the load of CO2 from the atmosphere to mitigate the harmful effect of greenhouse gases in global warming. Although MES is still an emerging technology, this method is not thoroughly known. The authors have focused on MES, as it is the next transformative, viable alternative technology to decrease the repercussions of surplus carbon dioxide in the environment along with conserving energy

Microbiomics for enhancing electron transfer in an electrochemical system

In microbial electrochemical systems, microorganisms catalyze chemical reactions converting chemical energy present in organic and inorganic molecules into electrical energy. The concept of microbial electrochemistry has been gaining tremendous attention for the past two decades, mainly due to its numerous applications. This technology offers a wide range of applications in areas such as the environment, industries, and sensors. The biocatalysts governing the reactions could be cell secretion, cell component, or a whole cell. The electroactive bacteria can interact with insoluble materials such as electrodes for exchanging electrons through colonization and biofilm formation. Though biofilm formation is one of the major modes for extracellular electron transfer with the electrode, there are other few mechanisms through which the process can occur. Apart from biofilm formation electron exchange can take place through flavins, cytochromes, cell surface appendages, and other metabolites. The present article targets the various mechanisms of electron exchange for microbiome-induced electron transfer activity, proteins, and secretory molecules involved in the electron transfer. This review also focuses on various proteomics and genetics strategies implemented and developed to enhance the exo-electron transfer process in electroactive bacteria. Recent progress and reports on synthetic biology and genetic engineering in exploring the direct and indirect electron transfer phenomenon have also been emphasized

Nanodecoys: A Quintessential Candidate to Augment Theranostic Applications for a Plethora of Diseases

Nanoparticles (NPs) designed for various theranostic purposes have hugely impacted scientific research in the field of biomedicine, bringing forth hopes of a future revolutionized area called nanomedicine. A budding advancement in this area is the conjugation of various cell membranes onto nanoparticles to develop biomimetic cells called ‘Nanodecoys’ (NDs), which can imitate the functioning of natural cells. This technology of coating cell membranes on NPs has enhanced the working capabilities of nano-based techniques by initiating effective navigation within the bodily system. Due to the presence of multiple functional moieties, nanoparticles coated with cell membranes hold the ability to interact with complex biological microenvironments inside the body with ease. Although developed with the initial motive to increase the time of circulation in the bloodstream and stability by coating membranes of red blood cells, it has further outstretched a wide range of cell lines, such as mesenchymal stem cells, beta cells, thrombocytes, white blood cells, and cancer cells. Thus, these cells and the versatile properties they bring along with them open up a brand-new domain in the biomedical industry where different formulations of nanoparticles can be used in appropriate dosages to treat a plethora of diseases. This review comprises recent investigations of nanodecoys in biomedical applications

Strategies of Nanomaterial Application for Enhanced Wound Curing: An Overview

The biological process of healing of wounds deals with the regeneration of cells and is of utmost importance mainly because of the morphological and functional attributes of the tissue. One of the modern approaches is to use novel nanomaterial based wound dressings and other therapeutic treatments that have higher efficiency and specificity. Researchers all around the world have established the competence of various organic, inorganic or polymer-based and biogenically synthesized nanomaterials as a weapon for wound curing. Various matrices carrying nanoparticles like hydrogels, hydrocolloids are used in nano based drug delivery system. The biocompatibility, antimicrobial efficacy and sustained rate of drug delivery are the three main features that are considered for designing a nano drug for effective wound healing. The modification of the nanosized liposome using propylene glycol increases cell-permeation and retention in skin layer. Curcumin loaded liposomes show high anti-inflammatory effect, carbon nanodots (CNDs) and graphene oxide based nanosheets have also shown an immense importance in possessing high surface area. They also show potency in promoting fibroblast growth factors and collagen deposition for speedy recovery of wound. Moreover, the chronic wounds, that could not be cured by common antibiotics, can be addressed by nano based drugs not only for their easy penetration to deeper layer of tissues but also for their efficiency in killing some biofilm associated bacterial strains. Hence, nowadays nano based dressing materials are widely used for rapid recovery of wounds of various types

Exploiting microbes in the petroleum field : Analyzing the credibility of microbial enhanced oil recovery (MEOR)

Crude oil is a major energy source that is exploited globally to achieve economic growth. To meet the growing demands for oil, in an environment of stringent environmental regulations and economic and technical pressure, industries have been required to develop novel oil salvaging techniques. The remaining ~70% of the world’s conventional oil (one-third of the available total petroleum) is trapped in depleted and marginal reservoirs, and could thus be potentially recovered and used. The only means of extracting this oil is via microbial enhanced oil recovery (MEOR). This tertiary oil recovery method employs indigenous microorganisms and their metabolic products to enhance oil mobilization. Although a significant amount of research has been undertaken on MEOR, the absence of convincing evidence has contributed to the petroleum industry’s low interest, as evidenced by the issuance of 400+ patents on MEOR that have not been accepted by this sector. The majority of the world’s MEOR field trials are briefly described in this review. However, the presented research fails to provide valid verification that the microbial system has the potential to address the identified constraints. Rather than promising certainty, MEOR will persist as an unverified concept unless further research and investigations are carried out

Lactic Acid Bacteria (LAB): Autochthonous and Probiotic Microbes for Meat Preservation and Fortification

The enhanced concern of the consumers regarding the safety, quality of the food products, and avoidance of the use of chemical food preservatives has resulted in a breakthrough in biopreservation. This has resulted in the use of beneficial microbial species, including bacteria and their secondary metabolites, to enhance the shelf-life and quality of the food products. Meat preservation and fortification are among the biggest concerns, as they are relevant to the majority of food products. The chemical preservatives conventionally used in preserving meat and meat products possess several detrimental effects on the consumers. Thus, alternative strategies are needed to combat strategically in facilitating the shelf-life and quality. Lactic acid bacteria (LAB) are considered the safest organism and have a profound role in food and food-processing industries. The biofilm developed by the bacteria prevents the growth of various undesirable microorganisms on meat and meat products. Various studies depicted that LAB produces various antimicrobial metabolites that can act effectively on the food-degrading pathogens, rendering it safe and enhancing shelf-life. This review, thus, deals with the use of LAB as biopreservatives for enhancing the shelf-life of meat and meat products and helping its fortification

Recent advances and challenges in the utilization of nanomaterials in transesterification for biodiesel production

Due to diminishing fossil fuel supplies and rising energy needs, there has been an ever-increasing demand for renewable energy sources. The available renewable energy resources, such as solar, wind, hydropower, and biofuels, provide a new way of supplying the world's energy needs. Biofuels stand out among them because they are sustainable and have the potential to bring the idea of a global bioeconomy to life. As a result of their production of biofuels like biomethane, biohydrogen, and biodiesel, atmospheric CO2 is being fixed, eventually lowering the world's carbon footprint. Current developments in the production of bioenergy have concentrated on producing biodiesel among other biofuels. Biodiesel is being produced from a variety of feedstocks using a number of processes, including transesterification, micro-emulsion, direct mixing, and pyrolysis. The most popular method among these is transesterification, which makes use of a variety of catalysts. As a result of the development of nanotechnology, nanocatalysts with desirable properties, such as increased catalytic activity, increased surface area, and superior thermal stability, have been made and modified. In this review, various nanocatalyst types and manufacturing processes are examined in relation to transesterification. It explores how crucial nanocatalysts are in boosting biodiesel production, highlights potential barriers, and makes recommendations for their widespread use in the future