Search

Owing to the increasing worldwide population explosion, managing waste generated from the food sector has become a cross-cutting issue globally, leading to environmental, economic, and social issues. Circular economy-inspired waste valorization approaches have been increasing steadily, generating new business opportunities developing valuable bioproducts using food waste, especially fruit wastes, that may have several applications in energy–food–pharma sectors. Dragon fruit waste is one such waste resource, which is rich in several value-added chemicals and oils, and can be a renewable resource to produce several value-added compounds of potential applications in different industries. Pretreatment and extraction processes in biorefineries are important strategies for recovering value-added biomolecules. There are different methods of valorization, including green extractions and biological conversion approaches. However, microbe-based conversion is one of the advanced technologies for valorizing dragon fruit waste into bioethanol, bioactive products, pharmaceuticals, and other valued products by reusing or recycling them. This state-of-the-art review briefly overviews the dragon fruit waste management strategies and advanced eco-friendly and cost-effective valorization technologies. Furthermore, various applications of different valuable bioactive components obtained from dragon fruit waste have been critically discussed concerning various industrial sectors. Several industrial sectors, such as food, pharmaceuticals, and biofuels, have been critically reviewed in detail. [ABSTRACT FROM AUTHOR]

This document is a special issue of the Environmental Science and Pollution Research Journal that focuses on three international conferences: the 6th International Congress on Water, Waste and Energy Management (WWEM-22), the 5th International Conference on Green Chemistry and Sustainable Engineering (GreenChem-22), and the 22nd International Conference on Green Energy and Environmental Technology (GEET-22). These conferences brought together researchers and scientists from around the world to discuss topics related to water, waste, green chemistry, green energy, and environmental technologies. The special issue specifically explores post-Covid trends and new insights for treating wastewaters and soils, including technologies for removing chemical and biological contamination. It includes selected papers from the conferences and acknowledges the organizers, authors, reviewers, and sponsors. The next edition of these conferences is scheduled for July 2024 in Lisbon, Portugal. Additionally, the document provides brief biographical information about several researchers in the field of chemical engineering and environmental science. It highlights their educational background, research interests, publications, and professional achievements. These researchers specialize in areas such as wastewater treatment, bioprocess technology, waste management, and catalysis. They have been involved in numerous research projects, published extensively, and received recognition for their work. The purpose of this document is to offer library patrons an overview of these researchers' qualifications and areas of expertise for potential research purposes. [Extracted from the article]

Food matrices contain bioactive compounds that have health benefits beyond nutritional value. The bulk of bioactive chemicals are still present in agro-industrial by-products as food matrices. Throughout the food production chain, there is a lot of agro-industrial waste that, if not managed effectively, could harm the environment, company, and how nutritiously and adequately people eat. It's important to establish processes that maximise the use of agro-industrial by-products, such as biological technologies that improve the extraction and acquisition of bioactive compounds for the food and pharmaceutical industries. As opposed to nonbiological processes, biological procedures provide high-quality, bioactive extracts with minimum toxicity and environmental impact. Fermentation and enzymatic treatment are biological processes for obtaining bioactive compounds from agro-industrial waste. In this context, this article summarises the principal bioactive components in agro-industrial byproducts and the biological methods employed to extract them. In this review efficient utilization of bioactive compounds from agro-industrial waste more effectively in food and pharmaceutical industries has been described. [ABSTRACT FROM AUTHOR]

The current world energy crisis and increasing greenhouse gas emissions demand a shift from fossil-based fuels to alternative and sustainable biofuels. The innate potential of microalgae over traditional terrestrial feedstocks to provide a high-quality and sustainable fuel portfolio has been recognized. Microalgae are known to mitigate atmospheric CO2 and convert it to valuable metabolites and bioactive compounds. The high growth rate of microalgal biomass with no additional requirements of feed and arable land makes microalgae as realistic alternative to existing biofuels sources. Micro-algae can store more primary metabolites under abiotic stress, which can be used as a possible source of energy. These metabolite storing abilities of microalgae have become a point of interest for the scientific community as the accumulated lipids serve as potential feedstock for biodiesel production by transesterification, whereas the carbohydrates can be used as the feedstock for bioethanol production by fermentation. Although microalgae-based biofuels are viable sources of energy, their commercialization and deployment in the fuel market remain a challenge. As a result, efforts are being undertaken to make it more cost-effective. This review describes the microalgae biorefinery method for producing biofuel along with its commercial potential, latest research updates in biofuel research, strategies to improve the algal metabolite content along with the limitations of using algal biomass for biofuels with possible solutions to overcome those limitations. [ABSTRACT FROM AUTHOR]

Cell disruption is very important for the value-added biocompounds (VAB) to come out from microalgae. Among the most demanding microalgae at industrial level, diatoms and Haematococcus pluvialis have hooked the race. However, they at the same time face difficulty in their cell wall disruption for the VAB to come out as it is very rigid and thick. This is among the major barrier in construction of diatom solar panels for biofuel production. Different diatom walls experience different shear forces for harvesting its biomass. This results in raising the overall cost of photobioreactors controlling their growth and recovery of biomass and VAB. In order to lower the cost, the cell wall of microalgae needs to milk the metabolites without itself getting sacrificed. The current review in depth discusses the techniques to break the cell wall of microalgae especially diatoms and Haematococcus using nanotechnological approaches without lysing the cell. The research gaps, commercial applications, and future research directions have been identified and discussed to strengthen the environmental and economical sustainability. [ABSTRACT FROM AUTHOR]

Sespite the fact that composting is taken into consideration to have a low environmental effect, it is unavoidable that the composting of manure will emit anthropogenic greenhouse gases and different gases together with ammonia and other gases such as VOCs. Amongst the numerous waste management routines, composting is regarded as the sustainable treatment technique for recycling agro-industrial waste into valuable by-products Employment of cheap and abundant biomass resources is an advantage of this approach making it an extensively studied approach to manage biodegradable waste for a sustainable environment. In this regard, composting represents an effectual substitute for organic waste management, since it reduces the dumping of wastes in landfills and the usage of improper disposal techniques. [Extracted from the article]

Live microorganisms in the fermented foods termed probiotics and their secondary metabolites with bioactive potential were considered as potential anti-viral capabilities through various mechanisms. Given the importance of functional and fermented foods in disease prevention, there is a need to discuss the contextualization and deep understanding of the mechanism of action of these foods, particularly considering the appearance of coronavirus (COVID-19) pandemic, which is causing health concerns and increased social services globally. The mechanism of probiotic strains or their bioactive metabolites is due to stimulation of immune response through boosting T-lymphocytes, cytokines, and cell toxicity of natural killer cells. Proper consumption of these functional and fermented foods may provide additional antiviral approaches for public benefit by modulating the immune functions in the hosts. [ABSTRACT FROM AUTHOR]

The demand for fossil fuels has resulted in their rapid depletion and rise in the fuel costs. Moreover, fossil fuels have serious negative impacts on the environment due to their harmful emissions leading to global warming. This has paved the way for research into finding a renewable alternative to fossil fuels and exploring potential biofuel feedstocks. Biofuels are non-toxic, renewable, and have properties that are similar to conventional fuels. Among the studied feed-stocks, microalgae serve as a viable biofuel feedstock due to a number of advantages over another plant-based feed-stocks. Algal biofuels can help to restore the former green environment by completely replacing fossil fuels. However, only large-scale production and commercialization can meet these requirements. Numerous studies have been conducted to screen algal species with higher lipid yield. Despite decades of intensive research, biofuels have not reached the target of replacing conventional fuels. This is due to the challenges at every stage of its production process, starting from large-scale cultivation to commercial release of product. Novel lipid recovery strategies can be employed to tackle these limitations. For example, hybrid liquid biphasic system can be used to decrease the production costs (Yong et al. in J Water Process Eng 38: 101665, 2020). The aim of the review is to summarize the up to date research in the field of algae biofuels and to bring the focus on characterization and commercialization of algal lipids as a source of alternate energy. Furthermore, strategies to improve lipid accumulation and challenges associated with existing technologies are also discussed. [ABSTRACT FROM AUTHOR]

Natural astaxanthin has shown its potential value in food, pharmaceuticals and nutraceutical industries. It is found in yeasts, algae, salmons, shrimps etc. but its substantial amounts are biosynthesized in Haematococcus pluvialis. The Haematococcus cells can biosynthesize large amounts of astaxanthin under stress conditions during their red stage to enhance the astaxanthin accumulation and elevation of its productivity. The stress related conditions are best suited in wastewater and can be an economical way of cultivating microalgae for astaxanthin production compared to the artificial media simulated growth in indoor or outdoor photobioreactors. It is well known fact that industrial effluents are rich in various macro and micronutrients which promote algal growth but, in some condition, due to absence of some nutrients the microalgal cells of Haematococcus come in conditions of stress leading to high astaxanthin accumulation. The present review discusses microalgae responsible for producing astaxanthin under stress conditions and valorising the effluents from industrial wastewater. This is further associated with optimizing techniques for culturing microalgae with high biomass and its biocompounds. It also highlights the challenges and knowledge gaps in using wastewater as medium for large scale production of valuable biocompounds like astaxanthin, which paves way towards sustainable environment. [ABSTRACT FROM AUTHOR]

Pullulan is a commercially available exopolymer biosynthesized by Aureobasidium pullulans supplemented with nitrogen, carbon and other vital components through submerged and solid-state fermentation. These nutrients are very expensive and it raises the cost for the production of pullulan. Hence, the need of alternative cost-effective raw materials for its production is a prerequisite. Owing to its unique physicochemical features, pullulan has various applications in the food, pharmacological, and biomedical domains. Food industrial wastes generate a considerable number of by-products which accumulates and has a negative influence on the environment. These by-products are made up of proteins, carbohydrates, and other components, can be employed as substrates for the production of pullulan. The present review briefs on the pullulan production using food processing waste and by-products and the elements that impact it. It provides an insight into versatile applications of pullulan in food industries. Various challenges and future prospects in the field of research on pullulan production have been uncovered. [ABSTRACT FROM AUTHOR]

Nutraceuticals have attained substantial attention due to their health-boosting or disease-prevention characteristics. Growing awareness about the potential of nutraceuticals for the prevention and management of diseases affecting human has led to an increase in the market value of nutraceuticals in several billion dollars. Nevertheless, limitations in supply and isolation complications from plants, animals or fungi, limit the large-scale production of nutraceuticals. Microbial engineering at metabolic level has been proved as an environment friendly substitute for the chemical synthesis of nutraceuticals. Extensively used microbial systems such as E. coli and S. cerevisiae have been modified as versatile cell factories for the synthesis of diverse nutraceuticals. This review describes current interventions in metabolic engineering for synthesising some of the therapeutically important nutraceuticals (phenolic compounds, polyunsaturated fatty acids and carotenoids). We focus on the interventions in enhancing product yield through engineering at gene level or pathway level. [ABSTRACT FROM AUTHOR]

Large-scale food waste (FW) disposal has resulted in severe environmental degradation and financial losses around the world. Although FW has a high biomass energy contents and a growing large number of national projects to recover energy from FW by anaerobic digestion (AD) are being developed. AD is a promising solution for FW management and energy generation when compared to typical disposal options including landfill disposal, incineration, and composting. AD of FW can be combined with an existing AD operation or linked to the manufacture of value-added products to reduce costs and increase income. AD is a metabolic process that requires four different types of microbes: hydrolyzers, acidogens, acetogens, and methanogens. Microbes use a variety of strategies to avoid difficult situations in the AD, such as competition for the same substrate between sulfate-reducing bacteria and methane-forming bacteria. An improved comprehension of the microbiology involved in the anaerobic digestion of FW will provide new insight into the circumstances needed to maximize this procedure, including its possibilities for use in co-digestion mechanisms. This paper reviewed the present scientific knowledge of microbial community during the AD and the connection between microbial diversity during the AD of FW. [ABSTRACT FROM AUTHOR]

Machine learning techniques were employed to evaluate the effect of process parameters viz. microwave power (100 W, 300 W, 600 W); pH (1, 1.5, 2); and microwave time (the 60 s, 120 s, 180 s) on the pectin yield from Citrus limetta peel. A fourth-order polynomial function of 66.60 scales was used by the Support Vector Regression (SVR) model at an epsilon (ε) value of 0.003. The co-efficient of determination (R2) and root mean square error-values for training data and test data were 0.984; 0.77 and 0.993; 0.66 respectively. At optimized conditions, microwave power 600 W, pH 1, and time 180 s the best yield of 32.75% was obtained. The integrity of pectin skeletal was confirmed with FTIR and 1H NMR spectrums. The physicochemical analysis revealed that CLP is a high-methoxyl pectin (HMP) with a 63.20 ± 0.88% degree of esterification, 798.45 ± 26.15 equivalent weight, 8.06 ± 0.62% methoxyl content, 67.93 ± 3.36 AUA content, 6.27 ± 0.27 g water/g pectin WHC, 2.68 ± 0.20 g oil/g pectin OHC, low moisture, ash and protein content of 6.85 ± 0.10%, 3.87 ± 0.10% and 2.61 ± 0.06% respectively, which can be utilized as a food additive. Therefore, pectin extraction from Citrus limetta peel using a greener technique like MAE is an eco-friendly, time-saving approach to transform waste into a versatile food additive. [ABSTRACT FROM AUTHOR]

Depleting fossil fuel resources such as crude oil and coal are responsible for greenhouse gas emissions and global warming. Hence, converting biogenic waste such as animal waste and agricultural and industrial residues to biogas (CH4 and CO2) using anaerobic digestion (AD) is a sustainable, renewable, and environmentally friendly way of producing fuel. This nature-derived bioconversion process provides energy security and additional environmental services such as waste management. Furthermore, the liquid and solid waste generated through the AD process could be used as soil amendments to increase fertility. However, natural recalcitrance of biomass pertaining to the intricate network of polysaccharides and lignin, high crystallinity of cellulose, and reduced accessible surface area are some of the major bottlenecks to utilizing these resources as received. Pretreatment helps open up the plant cell wall by disrupting the lignin carbohydrate complex, de-lignifying the biomass, aiding the enzymes to access the polysaccharides due to higher surface area efficiently, and hydrolyze them into simple sugars with the help of bacterial consortium during AD process. This review gives an overview of physical, chemical, biological, and combinatorial pretreatment methods of lignocellulosic substrates and their effect on AD process. Biological pretreatment has emerged as a more desirable pretreatment method in terms of environment safety and efficiency for lignin degradation. Though the higher pretreatment duration has been observed as the most significant challenge that need to be addressed for its adoption on commercial scale. Therefore, research is required to either explore the naturally occurring or prepare the genetically engineered microbes for selective degradation of lignin at faster rates and high tolerance for variation in environment factors. [ABSTRACT FROM AUTHOR]

With the rise in global population, industrialization, and economic expansion, the persistent overconsumption of conventional fossil fuels has resulted in the depletion of fossil fuel reserves. This has fuelled the need to investigate and boost scientific research efforts on sustainable and renewable bioenergy feedstock. A substitute that can minimize reliance on nonrenewable energy resources while also lowering greenhouse gas emissions. In this context, biofuels have received a great deal of interest in recent years as a prospective substitute for conventional fossil fuels. The prime reason behind this is the feedstock utilized in their synthesis. The feedstocks employed here are environmentally safe, nontoxic, and emit little to no pollution. These feedstocks are classified into four generations: first, second, third, and fourth. Food crops and lignocellulosic biomass and waste constitute first- and second-generation feedstocks. The third- and fourth-generation feedstock is microalgae. This paper provides a comprehensive overview of feedstocks utilized to produce biofuels, including the various pre-treatment methods, strategies, and techno-economic analysis in order to pave the way for next-generation biofuels. It also covers the advantages, drawbacks, challenges, and current developments. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction (HTL) is an evolving technology that can convert waste with high moisture and low energy content to electricity, heat, hydrogen and other synthetic fuels more efficiently. The lee side is that the HTL process produces enormous amounts of wastewaters (HTWW), having high organic and nutrient load. The discharge of the HTWW would contaminate the environment and result in the loss of valuable bioenergy sources. The valorisation of HTWW has drawn considerable interest. Therefore, this review highlights the valorisation of wastewater during the HTL of biomass. The review paper begins with the discussion of the role of microalgae in valorizing the HTWW. The survey illustrates that the selection of appropriate technology is dependent on biomass characteristics of the microalgae. Finally, potential research opportunities are recommended to improve the viability of the HTL wastewater valorisation for bioenergy production. Overall, this review concludes that combining various processes, such as microalgae-anaerobic digestion, and bio-electrochemical system - microalgae-anaerobic digestion would be beneficial in maximizing HTWW valorisation. [ABSTRACT FROM AUTHOR]

Lignin is an aromatic compound found as a major component of plant cell wall and therefore, present abundantly in nature as a renewable resource. Due to its organic nature, it has the potential to serve as feedstock for value addition to sustainable bioproducts. Under biorefinery concept, each of the plant biomass components viz. cellulose, hemicellulose, and lignin must be converted to some or the other products. Thus, development of different strategies to valorize lignin for chemicals other value-added products can remove the economic constraint on bioethanol-based biorefineries. However, lignin is highly heterogenous than its counterparts and therefore, very recalcitrant to bioconversion making its biovalorization very difficult. To fully utilize the potential of lignin, it is necessary to understand its degradation process and develop efficient biochemical/microbial strategies to achieve cost-effective lignin bioconversion. In recent times, many innovations have taken place in sustainable microbial utilization and bioconversion of lignin. Therefore, this paper focuses on the progress made in lignin biotransformation's for production of bio-based products, chemicals, and bioenergy in the context of biorefinery concept, with a critical perspective on biotechnological advancements, challenges, and future needs. [ABSTRACT FROM AUTHOR]

The use of agricultural residue as a substrate and implementation of nanomaterials for cellulase immobilization can improve the efficiency at higher temperature and will lead to reduce the cost of cellulose-assisted biofuel production. The immobilization utilizing cellulase with amino, chitosan, or polymeric functionalities enhanced stability, activity, reusability, inhibition reduction, purification, and selectivity during enzymatic hydrolysis. Covalent interaction between the substrate and the cellulose marks in greater enzymatic immobilization, which pilots to higher biofuel production. Among the various techniques available for immobilization of cellulase on activated and functionalized magnetic nanoparticles, glutaraldehyde-based covalent binding are the most efficient process for cellulase immobilization. This review provides an overview of different cellulase immobilization strategies, factors, and its kinetics for enhanced biofuel production. The expanding need for low-cost immobilized cellulase, as well as its diverse applications in a variety of industries, is propelling research in this field. [ABSTRACT FROM AUTHOR]

Among many existing microalgae, Haematococcus pluvialis has been known as the potential source of natural astaxanthin which have remarkable antioxidant properties and wide applications in pharmaceutical, aquaculture, therapeutic, and nutraceutical sectors. However, the high cost of extracting this pigment makes the cost of astaxanthin very high. Latest research has shown that pulsed electric field (PEF) is simple yet sensitive technique to permeabilize the thick cell wall of H. pluvialis and extract the pigment. Although there exists plenty of conventional techniques for large scale extraction of value-added compounds from microalgae, none of them can be applied successfully. In PEF controlling and optimizing the parameters makes this technique facile to get the desired products accounting to little loss in cell viability. The review provides a close view on the astaxanthin accumulation under stress conditions in microalgae. It also documents biocompatible electric treatment for cell permeabilization, the capacity of microalgae to survive and regenerate the pool of extracted compounds. This communication attempts to review the challenges and perspectives of research in this field of work. [ABSTRACT FROM AUTHOR]

Bio-based fuels and chemicals through the biorefinery approach has gained significant interest as an alternative platform for the petroleum-derived processes as these biobased processes are noticed to have positive environmental and societal impacts. Decades of research was involved in understanding the diversity of microorganisms in different habitats that could synthesize various secondary metabolites that have functional potential as fuels, chemicals, nutraceuticals, food ingredients, and many more. Later, due to the substrate-related process economics, the diverse low-value, high-carbon feedstocks like lignocellulosic biomass, industrial byproducts, and waste streams were investigated to have greater potential. Among them, municipal solid wastes can be used as the source of substrates for the production of commercially viable gaseous and liquid fuels, as well as short-chain fattyacids and carboxylic acids. In this work, technologies and processes demanding the production of value-added products were explained in detail to understand and inculcate the value of municipal solid wastes and the economy, and it can provide to the biorefinery aspect. [ABSTRACT FROM AUTHOR]

Astaxanthin (3,3-dihydroxy-β, β-carotene-4,4-dione) is a ketocarotenoid synthesized by Haematococcus pluvialis/lacustris, Chromochloris zofingiensis, Chlorococcum, Bracteacoccus aggregatus, Coelastrella rubescence, Phaffia rhodozyma, some bacteria (Paracoccus carotinifaciens), yeasts, and lobsters, among others However, it is majorly synthesized by Haematococcus lacustris alone (about 4%). The richness of natural astaxanthin over synthetic astaxanthin has drawn the attention of industrialists to cultivate and extract it via two stage cultivation process. However, the cultivation in photobioreactors is expensive, and converting it in soluble form so that it can be easily assimilated by our digestive system requires downstream processing techniques which are not cost-effective. This has made the cost of astaxanthin expensive, prompting pharmaceutical and nutraceutical companies to switch over to synthetic astaxanthin. This review discusses the chemical character of astaxanthin, more inexpensive cultivating techniques, and its bioavailability. Additionally, the antioxidant character of this microalgal product against many diseases is discussed, which can make this natural compound an excellent drug to minimize inflammation and its consequences. [ABSTRACT FROM AUTHOR]

In this study, a five-factorial central composite design was employed to optimize pectin extraction from novel source, through ultrasound-assisted extraction. A 35.58% yield was obtained under optimized conditions of pH 1.0, solid (g): liquid (mL) ratio 1:24, amplitude 84.2 Hz, duty cycle 23 s/30 s, and time 30 min. The equivalent weight, methoxyl content, anhydrouronic acid content, degree of esterification, water-holding capacity, and oil-holding capacity of the extracted pectin were 796.40 ± 2.07, 8.29 ± 0.38%, 71.32 ± 0.54%, 64.66 ± 2.08%, 8.04 ± 0.10 g water/g pectin, and 2.24 ± 030 g oil/g pectin, respectively. The chemical profile of the extracted pectin was assessed with FTIR and NMR analyses. The extracted pectin was utilized as a butter substitute in cookies. Up to 30% butter in cookies could be replaced with the extracted pectin without altering the sensory and physicochemical properties. Overall, results of presented work suggest that using waste-derived pectin as a fat substitute in cookies offers a sustainable and health-promoting approach for converting waste into wealth. [ABSTRACT FROM AUTHOR]

Microalgae and cyanobacteria are photosynthetic microorganisms' sources of renewable biomass that can be used for bioplastic production. These microorganisms have high growth rates, and contrary to other feedstocks, such as land crops, they do not require arable land. In addition, they can be used as feedstock for bioplastic production while not competing with food sources (e.g., corn, wheat, and soy protein). In this study, we review the macromolecules from microalgae and cyanobacteria that can serve for the production of bioplastics, including starch and glycogen, polyhydroxyalkanoates (PHAs), cellulose, polylactic acid (PLA), and triacylglycerols (TAGs). In addition, we focus on the cultivation of microalgae and cyanobacteria for wastewater treatment. This approach would allow reducing nutrient supply for biomass production while treating wastewater. Thus, the combination of wastewater treatment and the production of biomass that can serve as feedstock for bioplastic production is discussed. The comprehensive information provided in this communication would expand the scope of interdisciplinary and translational research. [ABSTRACT FROM AUTHOR]

The coronavirus pandemic of 2019 has already exerted an enormous impact. For over a year, the worldwide pandemic has ravaged the whole globe, with approximately 250 million verified human infection cases and a mortality rate surpassing 4 million. While the genetic makeup of the related pathogen (SARS-CoV-2) was identified, many unknown facets remain a mystery, comprising the virus's origin and evolutionary trend. There were many rumors that SARS-CoV-2 was human-borne and its evolution was predicted many years ago, but scientific investigation proved them wrong and concluded that bats might be the origin of SARS-CoV-2 and pangolins act as intermediary species to transmit the virus from bats to humans. Airborne droplets were found to be the leading cause of human-to-human transmission of this virus, but later studies showed that contaminated surfaces and other environmental factors are also involved in its transmission. The evolution of different SARS-CoV-2 variants worsens the condition and has become a challenge to overcome this pandemic. The emergence of COVID-19 is still a mystery, and scientists are unable to explain the exact origin of SARS-CoV-2. This review sheds light on the possible origin of SARS-CoV-2, its transmission, and the key factors that worsen the situation. [ABSTRACT FROM AUTHOR]

Contamination of the environment with heavy metals (HMs) has led to huge global environmental issues. Industrialization activities such as mining, manufacturing, and construction generate massive amounts of toxic waste, posing environmental risks. HMs soil pollution causes a variety of environmental issues and has a detrimental effect on both animals and plants. To remove HMs from the soil, traditional physico-chemical techniques such as immobilization, electro-remediation, stabilization, and chemical reduction are used. Moreover, the high energy, trained manpower, and hazardous chemicals required by these methods make them expensive and non-environmentally friendly. Bioremediation process, which involves microorganism-based and microorganism-associated-plant-based approaches, is an ecologically sound and cost-effective strategy for restoring HMs polluted soil. Microbes adjust their physiology to these conditions to live, which can involve significant variations in the expression of the genes. A set of genes are activated in response to toxic metals in microbes. They can also adapt by modifying their shape, fruiting bodies creating biofilms, filaments, or chemotactically migrating away from stress chemicals. Microbes including Bacillus sp., Pseudomonas sp., and Aspergillus sp. has been found to have high metals remediation and tolerance capacity of up to 98% whether isolated or in combination with plants like Helianthus annuus, Trifolium repens, and Vallisneria denseserrulata. Several of the regulatory systems that have been discovered are unique, but there is also a lot of "cross-talk" among networks. This review discusses the current state of knowledge regarding the microbial signaling responses, and the function of microbes in HMs stress resistance. [ABSTRACT FROM AUTHOR]

Continuous urbanization and modernization have increased the burning of fossil fuels to meet energy needs across the globe, emanating environmental pollution and depleting fossil fuels. Therefore, a shift towards sustainable and renewable energy is necessary. Several techniques to exploit biomass to yield energy are trending, with pyrolysis one of them. Usually, a single feedstock is employed in pyrolysis for anoxygenic generation of biochar together with bio-oil at elevated temperatures (350–600 °C). Bio-oil produced through pyrolysis can be upgraded to crude oil after some modification. However, these modifications of bio-oil are one of the major drawbacks for its large-scale adoption, as upgradation increases the overall cost. Therefore, in recent years the scientific community has been researching co-pyrolysis technology that involves the pyrolysis of lignocellulosic biomass waste with non-biodegradable waste. Co-pyrolysis reduces the need for post-modification of bio-oil, unlike pyrolysis of a single feedstock. This review article discusses the recent advancements and technological challenges in waste biomass co-pyrolysis, the mechanism of co-pyrolysis, and factors that affect co-pyrolysis. The current study critically analyzes different recent research articles presented in databases such as PubMed, MDPI, ScienceDirect, Springer, etc. Hence, this review is one-of-a-kind in that it attempts to explain each and every aspect of the co-pyrolysis process and its current progress in the scientific field. Consequently, this review also compiles the remarkable achievements in co-pyrolysis and recommendations for the future. [ABSTRACT FROM AUTHOR]

Reshmy et al. [[4]] reviewed cellulase immobilization strategies for biofuel production, discussing different cellulase immobilization strategies, factors, and its kinetics for enhanced biofuel production. A paper by Yadva et al. [[1]] on multidisciplinary pretreatment approaches to improve the bio-methane production from lignocellulosic biomass presents an overview of physical, chemical, biological, and combinatorial pretreatment methods of lignocellulosic substrates and their effect on AD process. There has been an increasing role and significance of industrial bioprocessing and sustainable developments in different walks of life - be it human life or animal life, plant life, or overall on the environment, which has attained global relevance related to sustainable development goals. [Extracted from the article]

In a biorefinery process, 5‐Hydroxymethylfurfural (HMF) is a promising biomass‐derived chemical with diverse industrial applications. The biotransformation of HMF to different high‐valued furanic derivatives, such as 2,5‐furandicarboxylic acid, 2,5‐diformylfuran, 5‐hydroxymethyl‐2‐furancarboxylic acid, and 5‐formyl‐2‐furancarboxylic acid, has led to the transition from fossil‐derived products to bio‐based chemicals through sustainable routes. Although, chemocatalytic conversion of HMF has been extensively studied in the recent years, the higher selectivity, environment friendliness, and mild reaction conditions of HMF bioconversion has established these processes as a promising alternative to harsh chemical conditions. To understand the present status and challenges of HMF bioconversion, this review retrospects and describes the recent advancements in the biotransformation of HMF and systematically assesses the recent findings and developments in the HMF biotransformation through various reaction schemes. Further, this review illustrates, in comprehensive detail, the merits and challenges of various biological processes and it proposes a few research trends for economical and facile HMF bioconversion for commercialization. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Soil contaminated with hydrophobic organic hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), pose a serious threat to the ecosystem and human health. Moreover, the sorption and desorption of the PAHs, due to the interaction with the soil organic matter (SOM) and other contaminants, greatly affect the fate and mycoremediation efficiency of the contaminated soil. On the other hand, the application of surfactants with or without additives for the mobilization of PAHs from contaminated soil has garnered increasing attention for soil remediation. In this context, several commercial surfactants and biosurfactants were reported either as soil flushing agents or soil additives, followed by either in situ or ex situ mycoremediation of the PAHs from contaminated soil. Hence, for a successful implementation of surfactants for mycoremediation of contaminated soil, a comprehensive introspection on its chemistry and mechanism is necessary. Thus, this review focuses primarily on understanding the effect of surfactants and the mechanism of desorption of PAHs from the soil. This work also emphasizes the effect of surfactants on the efficiency of mycoremediation of contaminated soil. Further, the review summarizes various surfactant‐assisted mycoremediation strategies of contaminated soil. Finally, the limitations of surfactant‐assisted mycoremediation, precipitative, and partitioning loss, along with toxicity of the surfactants, were reviewed. Thus, this review will aid in understanding the underlying mechanism and efficiency of surfactant‐assisted mycoremediation and it also proposes current research trends to improve the efficiency and enhance the bioremediation of PAHs‐contaminated soil. © 2021 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Among the prevalent methods already in existence for the plastic waste management, catalytic pyrolysis has been proved to be an efficient one. The research work involved the synthesis of the catalyst from eucalyptus seeds, a commercially available agricultural waste product aided in pyrolysis. The raw eucalyptus seeds were cleaned, powdered, and surface-modified using sulphuric acid. Analysis of the surface-reformed eucalyptus seeds showed that they possess the characteristics equivalent to the activated carbon and micropores similar to that of zeolite which is used as a catalyst for pyrolysis. Hence, the prepared catalyst was used in the pyrolysis process and its performance was compared with that of the commercial activated carbon and zeolite. Zeolite Y generally lowers the temperature of the pyrolysis reaction to 180–190 °C, while the produced catalyst made the pyrolysis reaction possible between 120 and 130 °C. The output of the pyrolysis reaction was a hydrocarbon oil, which was analysed using gas chromatography-flame ionization detector (GC-FID). The oil was found to have a composition between C6 and C20, which includes petroleum, kerosene, and diesel. Hence, the oil obtained was proven to be more useful, as a fuel for locomotive and reheating purposes. [ABSTRACT FROM AUTHOR]

Environmental contamination with persistent organic pollutants has emerged as a serious threat of pollution. Bioremediation is a key to eliminate these harmful pollutants from the environment and has gained the interest of researchers during the past few decades. Scientific knowledge upon microbial interactions with individual pollutants over the past decades has helped to abate environmental pollution. Traditional bioremediation approaches have limitations for their applications; hence, it is essential to discover new bioremediation approaches with biotechnological interventions for best results. The developments in various methodologies are expected to increase the efficiency of bioremediation techniques and provide environmentally sound strategies. This paper deals with the profiling of microorganisms present in polluted sites using various techniques such as culture-based approaches and omics-based approaches. Besides this, it also provides up-to-date scientific literature on the microbial electrochemical technologies which are nowadays considered as the best approach for remediation of pollutants. Detailed information about future outlook and challenges to evaluate the effect of various treatment technologies for remediation of pollutants has been discussed. [ABSTRACT FROM AUTHOR]

The interest in pullulan produced from industrial wastes has substantially increased due to its industrial applications. The major constraint in pullulan production is expensive and low yield. In this study, attempts were made on the evaluation of media components for maximum pullulan production from Aureobasidium pullulans MTCC 1991 using cassava waste in solid-state fermentation. A statistical approach was scrutinized to evaluate the effects of yeast extract, K2HPO4, (NH4)2SO4, MgSO4⋅7H2O, and NaCl on pullulan production. The optimal conditions eliciting the maximum pullulan yield (6.45 g pullulan/L of culture broth) were found to be 0.6 g/L yeast extract, 3 g/L K2HPO4, 0.2 g/L (NH4)2SO4, 0.3 g/L MgSO4⋅7H2O, and 1 g/L NaCl. The produced pullulan was extracted using the solvent precipitation method and characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy spectroscopic analysis that confirmed pullulan with linear α (1–6) linkage. The results revealed that cassava waste could be used as an effective carbon source for the production of pullulan. [ABSTRACT FROM AUTHOR]

Renewable energy accounts for 33 percent of the primary energy consumption across the world. Current world faces a major waste and climate change crisis. In many developing countries, over the past two and a half centuries, a variety of renewable power techniques have been actively pursued in distinct fields in the fields of research, growth, demonstration, manufacturing, and implementation. A replacement for fossil fuels using waste biomass is essential and considered as a promising strategy to meet our energy needs. At the same time, the emissions of greenhouse gas and managing municipal solid waste have to become crucial due to growing population demand. Biomass includes the energy stored in the sun and plants. It also serves as a primary energy source. Plants absorb the power of the sun during the process called photosynthesis. When biomass is combusted, chemical energy can be released into biomass as heat that can be used for domestic applications. The use of biomass results in management expenses contributes to climate changes, decrease the risk to lives and assets thereby ensure a safe and competitive energy source for the beneficial impact on the environment and the economy. This paper overviews about various applications of renewable energy sources produced from the municipal wastes and microbes. Prospects for the commercialization of bio-algal fuels, applications, and its challenges are discussed. The role of microbes (microalgae) in the energy production process and to use bioenergy as a future trend for economic development is discussed. [ABSTRACT FROM AUTHOR]

The era of rapid industrialization succeeded by a shift in organizational focus on research and technology development which has fueled many industries along with the dairy industry to grow at an exponential rate. The dairy industry has achieved remarkable growth in the last decade in India. Waste produced by dairy industry consists of a high organic load thus cannot be discharged untreated. Even though treatment and management of waste are well documented, but the main problem is concerned with sludge produced after treatment. There is a gap in the application of various methods for effective treatment of the waste, hence there is a need for technology-oriented research in this area because of a paradigm shift in perspectives towards sustainable management of waste to recover value added products including energy as energy demand is also rising. Sludge which is generally land spread can also be used for energy generation. This paper discusses the environmental effects of waste generated due to dairy industrial activities; various methods used for the advanced treatment of dairy waste. This review article aims to present and discuss the state-of-art information for recovery of value-added products (single cell protein, biofertilizers, biopolymers and biosurfactants) from dairy waste with emphasis on integration of technologies for environmental sustainability. This paper also includes challenges and future perspectives in this field. [ABSTRACT FROM AUTHOR]

The quest for a chemical surfactant substitute has been fuelled by increased environmental awareness. The benefits that biosurfactants present like biodegradability, and biocompatibility over their chemical and synthetic counterparts has contributed immensely to their popularity and use in various industries such as petrochemicals, mining, metallurgy, agrochemicals, fertilizers, beverages, cosmetics, etc. With the growing demand for biosurfactants, researchers are looking for low-cost waste materials to use them as substrates, which will lower the manufacturing costs while providing waste management services as an add-on benefit. The use of low-cost substrates will significantly reduce the cost of producing biosurfactants. This paper discusses the use of various feedstocks in the production of biosurfactants, which not only reduces the cost of waste treatment but also provides an opportunity to profit from the sale of the biosurfactant. Furthermore, it includes state-of-the-art information about employing municipal solid waste as a sustainable feedstock for biosurfactant production, which has not been simultaneously covered in many published literatures on biosurfactant production from different feedstocks. It also addresses the myriad of other issues associated with the processing of biosurfactants, as well as the methods used to address these issues and perspectives, which will move society towards cleaner production. [ABSTRACT FROM AUTHOR]