Microbial ß-glucosidases: Recent advances and applications.

The global ß-glucosidase market is currently estimated at ∼400 million USD, and it is expected to double in the next six years; a trend that is mainly ascribed to the demand for the enzyme for biofuel processing. Microbial ß-glucosidase, particularly, has thus garnered significant attention due to its ease of production, catalytic efficiency, and versatility, which have all facilitated its biotechnological potential across different industries. Hence, there are continued efforts to screen, produce, purify, characterize and evaluate the industrial applicability of ß-glucosidase from actinomycetes, bacteria, fungi, and yeasts. With this rising demand for ß-glucosidase, various cost-effective and efficient approaches are being explored to discover, redesign, and enhance their production and functional properties. Thus, this present review provides an up-to-date overview of advancements in the utilization of microbial ß-glucosidases as "Emerging Green Tools" in 21st-century industries. In this regard, focus was placed on the use of recombinant technology, protein engineering, and immobilization techniques targeted at improving the industrial applicability of the enzyme. Furthermore, insights were given into the recent progress made in conventional ß-glucosidase production, their industrial applications, as well as the current commercial status-with a focus on the patents.

Biochemical and in silico structural properties of a thermo-acid stable ß-glucosidase from Beauveria bassiana.

ß-glucosidase hydrolyses the glycosidic bonds in cellobiose and cello-oligosaccharides, a critical step in the saccharification for biofuel production. Hence, the aim of this study was to gain insights into the biochemical and structural properties of a ß-glucosidase from Beauveria bassiana, an entomopathogenic fungus. The ß-glucosidase was purified to homogeneity using salt precipitation, ultrafiltration, and chromatographic techniques, attaining a specific activity of 496 U/mg. The molecular mass of the enzyme was then estimated via SDS-PAGE to be 116 kDa, while its activity pattern was confirmed by zymography using 4-methylumbelliferyl-ß-d-glucopyranoside. Furthermore, the pH optima and temperature of the enzyme were found to be pH 5.0 and 60 °C respectively; its activity was significantly enhanced by Mg2+ and Na+ and was found to be relatively moderate in the presence of ethanol and dichloromethane. Molecular docking of the modelled B. bassiana ß-glucosidase structure with the substrates, viz., 4-nitrophenyl ß-d-glucopyranoside and cellobiose, revealed the binding affinity energies of -7.2 and -6.2 (kcal mol-1), respectively. Furthermore, the computational study predicted Lys-657, Asp-658, and Arg-1000 as the core amino acid residues in the catalytic site of the enzyme. This is the first investigation into a purified ß-glucosidase from B. bassiana, providing valuable insights into the functional properties of carbohydrases from entomopathogenic fungal endophytes.

Diverse origins of fibrinolytic enzymes: A comprehensive review.

Fibrinolytic enzymes cleave fibrin which plays a crucial role in thrombus formation which otherwise leads to cardiovascular diseases. While different fibrinolytic enzymes have been purified, only a few have been utilized as clinical and therapeutic agents; hence, the search continues for a fibrinolytic enzyme with high specificity, fewer side effects, and one that can be mass-produced at a lower cost with a higher yield. In this context, this review discusses the physiological mechanism of thrombus formation and fibrinolysis, and current thrombolytic drugs in use. Additionally, an overview of the optimization, production, and purification of fibrinolytic enzymes and the role of Artificial Intelligence (AI) in optimization and the patents granted is provided. This review classifies microbial as well as non-microbial fibrinolytic enzymes isolated from food sources, including fermented foods and non-food sources, highlighting their advantages and disadvantages. Despite holding immense potential for the discovery of novel fibrinolytic enzymes, only a few fermented food sources limited to Asian countries have been studied, necessitating the research on fibrinolytic enzymes from fermented foods of other regions. This review will aid researchers in selecting optimal sources for screening fibrinolytic enzymes and is the first one to provide insights and draw a link between the implication of source selection and in vivo application.

Writing a Scientific Review Article: Comprehensive Insights for Beginners.

Review articles present comprehensive overview of relevant literature on specific themes and synthesise the studies related to these themes, with the aim of strengthening the foundation of knowledge and facilitating theory development. The significance of review articles in science is immeasurable as both students and researchers rely on these articles as the starting point for their research. Interestingly, many postgraduate students are expected to write review articles for journal publications as a way of demonstrating their ability to contribute to new knowledge in their respective fields. However, there is no comprehensive instructional framework to guide them on how to analyse and synthesise the literature in their niches into publishable review articles. The dearth of ample guidance or explicit training results in students having to learn all by themselves, usually by trial and error, which often leads to high rejection rates from publishing houses. Therefore, this article seeks to identify these challenges from a beginner's perspective and strives to plug the identified gaps and discrepancies. Thus, the purpose of this paper is to serve as a systematic guide for emerging scientists and to summarise the most important information on how to write and structure a publishable review article.

Biochemical engineering for elemental sulfur from flue gases through multi-enzymatic based approaches - A review.

Flue gases are the gases which are produced from industries related to chemical manufacturing, petrol refineries, power plants and ore processing plants. Along with other pollutants, sulfur present in the flue gas is detrimental to the environment. Therefore, environmentalists are concerned about its removal and recovery of resources from flue gases due to its activation ability in the atmosphere to transform into toxic substances. This review is aimed at a critical assessment of the techniques developed for resource recovery from flue gases. The manuscript discusses various bioreactors used in resource recovery such as hollow fibre membrane reactor, rotating biological contractor, sequential batch reactor, fluidized bed reactor, entrapped cell bioreactor and hybrid reactors. In conclusion, this manuscript provides a comprehensive analysis of the potential of thermotolerant and thermophilic microbes in sulfur removal. Additionally, it evaluates the efficacy of a multi-enzyme engineered bioreactor in this process. Furthermore, the study introduces a groundbreaking sustainable model for elemental sulfur recovery, offering promising prospects for environmentally-friendly and economically viable sulfur removal techniques in various industrial applications.

Current research trends on cosmetic microplastic pollution and its impacts on the ecosystem: A review.

Since the advent of microplastics, it has become a vital component, directly or indirectly, in our daily lives. With advancements in their use, microplastics have become an integral part of personal care, cosmetics, and cleaning products (PCCPs) and emerged as a domestic source of environmental pollution. Over the years, researchers have ascertained the harmful effects of microplastics on the environment. In this context, the assessment and monitoring of microplastics in PCCPs require considerable attention. In addition, it raises concern regarding the need to develop innovative, sustainable, and environmentally safe technologies to combat microplastic pollution. Therefore, this review is an endeavor to uncover the fate, route and degradation mechanism of cosmetic microplastics. In addition, the major technological advancement in cosmetic microplastic removal and the steps directed toward mitigating cosmetic microplastic pollution are also discussed.

Cellulosic Ethanol Production Using Waste Wheat Stillage after Microwave-Assisted Hydrotropic Pretreatment.

One of the key elements influencing the efficiency of cellulosic ethanol production is the effective pretreatment of lignocellulosic biomass. The aim of the study was to evaluate the effect of microwave-assisted pretreatment of wheat stillage in the presence of sodium cumene sulphonate (NaCS) hydrotrope used for the production of second-generation bioethanol. As a result of microwave pretreatment, the composition of the wheat stillage biomass changed significantly when compared with the raw material used, before treatment. Microwave-assisted pretreatment with NaCS effectively reduced the lignin content and hemicellulose, making cellulose the dominant component of biomass, which accounted for 42.91 ± 0.10%. In post pretreatment, changes in biomass composition were also visible on FTIR spectra. The peaks of functional groups and bonds characteristic of lignins (C-O vibration in the syringyl ring, asymmetric bending in CH3, and aromatic skeleton C-C stretching) decreased. The pretreatment of the analyzed lignocellulosic raw material with NaCS resulted in the complete conversion of glucose to ethanol after 48 h of the process, with yield (in relation to the theoretical one) of above 91%. The highest observed concentration of ethanol, 23.57 ± 0.10 g/L, indicated the high effectiveness of the method used for the pretreatment of wheat stillage that did not require additional nutrient supplementation.

Nanocellulose in tissue engineering and bioremediation: mechanism of action.

Nanocellulose are nano-sized components which are biodegradable, biocompatible and renewable. It offers mechanical strength and chemical stability in plants and bacteria. The environmental contamination is reduced by employing various bioremediation techniques which usesmicroorganisms like algae, bacteria and fungi as bio-adsorbents. The bio adsorbent property of nanocellulose contribute more for the bioremediation methods and the detailed study of its mechanism and application is essential which is discussed here. The mechanism happening between the contaminant and nanocellulose adsorbent should be explored in detail in order to develop effective new bioremediation strategies. Nanocellulose structural functionalization helps to modify the nanocellulose structure based on which it can be utilized for specific functions. Exploring the mechanisms that contribute to the implementation of nanocellulose in tissue engineering helps for further developments and advancement in the biomedical application of nanocellulose. Not much studies are available that elucidate and study the basic steps involved in the biomedical and environmental usage of nanocellulose. This review has focussed on the basic mechanisms involved in the use of nanocellulose in tissue engineering and bioremediation processes.

Isolation, biochemical characterization, and development of a biodegradable antimicrobial film from Cirrhinus mrigala scale collagen.

Collagen is a promising candidate for food and pharmaceutical applications due to its excellent biocompatibility, low antigenicity, and controlled biodegradability; however, its heavy price restricts its utilization. Fish scales generated during the processing are generally regarded as waste material and an environmental pollutant, though they are a promising source of collagen. In the present study, Cirrhinus mrigala scales were demineralized and extracted for acid-soluble collagen (ASC) using acetic acid, with a collagen yield of 2.7%. UV-Vis spectra, SDS-PAGE, FTIR analyses, and amino acid composition confirmed the type I nature of the collagen extracted. The denaturation temperature of the collagen was found to be 30.09 °C using differential scanning calorimetry (DSC). The collagen was highly soluble at acidic pH and lower NaCl concentrations while its solubility was lowered in alkaline conditions and NaCl concentrations above 0.5 M. The collagen exhibited good emulsifying potential with an emulsion activity index (EAI) and emulsion stability index (ESI) of 21.49 ± 0.22 m2 g-1 and 15.67 ± 0.13 min, respectively. Owing to the good physicochemical characteristics of the extracted collagen, collagen-chitosan-neem extract (CCN) films were prepared subsequently which showed good antimicrobial activity against Bacillus subtilis NCIM 2635, Staphylococcus aureus NCIM 2654, Escherichia coli NCIM 2832, and Pseudomonas aeruginosa NCIM 5032, suggesting the potential of collagen in the development of antimicrobial films. These results demonstrate that the collagen from fish waste could be valorized and used effectively along with chitosan and neem extract for the synthesis of novel biodegradable films with antimicrobial efficacy.

Beauveria bassiana Xylanase: Characterization and Wastepaper Deinking Potential of a Novel Glycosyl Hydrolase from an Endophytic Fungal Entomopathogen.

Beauveria bassiana is an entomopathogenic fungus widely used as a biopesticide for insect control; it has also been shown to exist as an endophyte, promoting plant growth in many instances. This study highlights an alternative potential of the fungus; in the production of an industrially important biocatalyst, xylanase. In this regard, Beauveria bassiana SAN01 xylanase was purified to homogeneity and subsequently characterized. The purified xylanase was found to have a specific activity of 324.2 U·mg-1 and an estimated molecular mass of ~37 kDa. In addition, it demonstrated optimal activity at pH 6.0 and 45 °C while obeying Michaelis-Menton kinetics towards beechwood xylan with apparent Km, Vmax and kcat of 1.98 mg·mL-1, 6.65 µM·min-1 and 0.62 s-1 respectively. The enzyme activity was strongly inhibited by Ag2+ and Fe3+ while it was significantly enhanced by Co2+ and Mg2+. Furthermore, the xylanase was shown to effectively deink wastepaper at an optimal rate of 106.72% through its enzymatic disassociation of the fiber-ink bonds as demonstrated by scanning electron microscopy and infrared spectroscopy. This is the first study to demonstrate the biotechnological application of a homogeneously purified glycosyl hydrolase from B. bassiana.

Cold plasma for the preservation of aquatic food products: An overview.

Cold plasma (CP) is an upcoming technology implemented for the preservation of highly perishable foods, especially aquatic food products (AFPs). The high moisture content, high-quality protein with all essential amino acids and unsaturated fatty acids makes AFP more susceptible to microbial spoilage and oxidation of lipids and proteins. Spoilage lowers the nutritive value and could generate toxic components, making it unsafe for consumption. In recent times, the rising demand for food products of aquatic origin with preserved quality and extended shelf-life has been recorded. In addition, minimally or nonthermally processed and preserved foods are gaining great attention. CP technology has demonstrated an excellent ability to inactivate microorganisms without promoting their resistance and triggering some deteriorative enzymes, which are typical factors responsible for the spoilage of AFP. Consequently, CP could be recommended as a minimal processing intervention for preserving the quality of AFP. This review focuses on different mechanisms of fish spoilage, that is, by microorganisms and oxidation, their inhibition via the application of CP, and the retention of quality and shelf-life extension of AFP.

Enzymatic approaches in the bioprocessing of shellfish wastes.

Several tonnes of shellfish wastes are generated globally due to the mass consumption of shellfish meat from crustaceans like prawn, shrimp, lobster, crab, Antarctic krill, etc. These shellfish wastes are a reservoir of valuable by-products like chitin, protein, calcium carbonate, and pigments. In the present scenario, these wastes are treated chemically to recover chitin by the chitin and chitosan industries, using hazardous chemicals like HCl and NaOH. Although this process is efficient in removing proteins and minerals, the unscientific dumping of harmful effluents is hazardous to the ecosystem. Stringent environmental laws and regulations on waste disposal have encouraged researchers to look for alternate strategies to produce near-zero wastes on shellfish degradation. The role of enzymes in degrading shellfish wastes is advantageous yet has not been explored much, although it produces bioactive rich protein hydrolysates with good quality chitin. The main objective of the review is to discuss the potential of various enzymes involved in shellfish degradation and their opportunities and challenges over chemical processes in chitin recovery.

Characterisation, pathogenicity and hydrolytic enzyme profiling of selected Fusarium species and their inhibition by novel coumarins.

Three Fusarium species isolated locally were characterised by the amplification of their rDNA ITS region, host specificity, and hydrolytic enzyme production. The strains were identified as Fusarium pseudoanthophilum, which is being reported for the first time in South Africa, as well as F. foetens and F. fujikuroi. All the three strains were capable of infecting vegetables such as tomatoes, bell and cayenne peppers, belonging to the Solanaceae family. The Fusarium strains also showed significant production of cell wall degrading enzymes in vitro, such as amylase, cellulase, xylanase, and polygalacturonase, thus highlighting the possibilities of these enzymes as pathogenic factors. Subsequently, the strains were discovered to be susceptible to three halogenated coumarins. The most effective of the tested coumarins, 6-bromo3-2,2-dibromoacetyl-2H-chromen-2-one, showed MIC values of 0.125, 0.0625 and 0.125 mg/ml against F. foetens, F. pseudoanthophilum and F. fujikuroi, respectively. The antifungal potentials of the halogenated coumarins were confirmed in silico through PASS analysis, toxicity prediction and docking studies. Findings from this study demonstrate the use of these coumarins as potential control agents against the Fusarium species and other pathogenic fungi in general.

Crystal structure of a thermophilic fungal cyanase and its implications on the catalytic mechanism for bioremediation.

Cyanase catalyzes the bicarbonate-dependent degradation of cyanate to produce ammonia and carbon dioxide, and ammonia is a considerable alternative nitrogen source. Strikingly, the cyanase from the thermophilic fungus Thermomyces lanuginosus (Tl-Cyn) has the highest catalytic efficiency reported among these enzymes. However, its molecular mechanism of action is not clearly understood, because currently there is no structural information available on fungal cyanases. Here we report the crystal structure of Tl-Cyn in complex with inhibitors malonate and formate at 2.2 Å resolution. The structure reveals extensive interactions at the subunit interfaces in a dimer, and a decamer is formed by a pentamer of these dimers. Our biochemical, kinetic and mutagenesis studies confirm the structural observations on the complex and provide further insights into its catalytic mechanism and inhibition. The structure has also aided the creation of a mutant enzyme with enhanced catalytic activity, and such enzymes may have the potential for biotechnological applications, including biotransformation and bioremediation. Moreover, other fungal cyanases with potentially high catalytic activity could also be predicted based on the Tl-Cyn structure, as the active site region among fungal cyanases are highly conserved.

Environmental Impacts of Microplastics and Nanoplastics: A Current Overview.

The increasing distribution of miniaturized plastic particles, viz. microplastics (100 nm-5 mm) and nanoplastics (less than 100 nm), across the various ecosystems is currently a subject of major environmental concern. Exacerbating these concerns is the fact that microplastics and nanoplastics (MNPs) display different properties from their corresponding bulk materials; thus, not much is understood about their full biological and ecological implications. Currently, there is evidence to prove that these miniaturized plastic particles release toxic plastic additives and can adsorb various chemicals, thereby serving as sinks for various poisonous compounds, enhancing their bioavailability, toxicity, and transportation. Furthermore, there is a potential danger for the trophic transfer of MNPs to humans and other higher animals, after being ingested by lower organisms. Thus, this paper critically analyzes our current knowledge with regard to the environmental impacts of MNPs. In this regard, the properties, sources, and damaging effects of MNPs on different habitats, particularly on the biotic components, were elucidated. Similarly, the consequent detrimental effects of these particles on humans as well as the current and future efforts at mitigating these detrimental effects were discussed. Finally, the self-cleaning efforts of the planet via a range of saprophytic organisms on these synthetic particles were also highlighted.

Plastic biodegradation: Frontline microbes and their enzymes.

Plastic polymers with different properties have been developed in the last 150 years to replace materials such as wood, glass and metals across various applications. Nevertheless, the distinct properties which make plastic desirable for our daily use also threaten our planet's sustainability. Plastics are resilient, non-reactive and most importantly, non-biodegradable. Hence, there has been an exponential increase in plastic waste generation, which has since been recognised as a global environmental threat. Plastic wastes have adversely affected life on earth, primarily through their undesirable accumulation in landfills, leaching into the soil, increased greenhouse gas emission, etc. Even more damaging is their impact on the aquatic ecosystems as they cause entanglement, ingestion and intestinal blockage in aquatic animals. Furthermore, plastics, especially in the microplastic form, have also been found to interfere with chemical interaction between marine organisms, to cause intrinsic toxicity by leaching, and by absorbing persistent organic contaminants as well as pathogens. The current methods for eliminating these wastes (incineration, landfilling, and recycling) come at massive costs, are unsustainable, and put more burden on our environment. Thus, recent focus has been placed more on the potential of biological systems to degrade synthetic plastics. In this regard, some insects, bacteria and fungi have been shown to ingest these polymers and convert them into environmentally friendly carbon compounds. Hence, in the light of recent literature, this review emphasises the multifaceted roles played by microorganisms in this process. The current understanding of the roles played by actinomycetes, algae, bacteria, fungi and their enzymes in enhancing the degradation of synthetic plastics are reviewed, with special focus on their modes of action and probable enzymatic mechanisms. Besides, key areas for further exploration, such as the manipulation of microorganisms through molecular cloning, modification of enzymatic characteristics and metabolic pathway design, are also highlighted.

Enhanced xylanase and endoglucanase production from Beauveria bassiana SAN01, an entomopathogenic fungal endophyte.

This study was undertaken to explore alternative applications of the widely known entomopathogenic/endophytic fungus, Beauveria bassiana, besides its sole use as a biocontrol agent. B. bassiana SAN01, was investigated for the production of two glycoside hydrolases, xylanase and endoglucanase under submerged conditions. Among the different biomass tested, wheat bran provided the best results for both xylanase and endoglucanase, and their production levels were further enhanced using response surface methodology. Under optimised conditions, heightened yields of 1061 U/ml and 23.03 U/ml were observed for xylanase and endoglucanase, respectively, which were 3.44 and 1.35 folds higher than their initial yields. These are the highest ever production levels reported for xylanase and endoglucanase from any B. bassiana strain or any known entomopathogenic fungi. Furthermore, the efficacy of xylanase/endoglucanase cocktail in the saccharification of sugarcane bagasse was evaluated. The highest amount of reducing sugar released from the pretreated biomass by the action of the crude Beauveria enzyme cocktail was recorded at 30°C after 8 h incubation. The significant activities of the hydrolytic enzymes recorded with B. bassiana in this study thus present promising avenues for the use of the entomopathogen as a new source of industrial enzymes and by extension, other biotechnological applications.

Biotechnological potential of Beauveria bassiana as a source of novel biocatalysts and metabolites.

Beauveria bassiana though widely perceived as an entomopathogenic fungus has also been found in nature to be endophytic. As entomopathogens, the life cycle of different B. bassiana strains are organized and adapted as pathogens to their invertebrate hosts while as endophytes they maintain a symbiotic relationship with their plant hosts. To fulfill these aforementioned ecological roles, this fungus secretes an array of enzymes as well as secondary metabolites, which all have significant biological roles. Basically, chitinases, lipases and proteases are considered to be the most important of all the enzymes produced by B. bassiana. However, studies have also shown their ability to produce other vital enzymes which include amylase, asparaginase, cellulase, galactosidase etc. Previous reports on this filamentous fungus have laid more emphasis on its entomopathogenicity, its endophytism and its highly acclaimed application in the biological control of pests. This review, however, is the first to fully assess the enzyme-secreting potential of this entomopathogenic fungus and its use as a novel source of several industrial biocatalysts and other important biochemicals. This article highlights the inherent properties of the fungus to degrade various biopolymers as well as its relative safety for human use. Some of the important factors have raised the possibilities of exploitation for industrial production and as safe hosts for gene expression.

Recent advances in microbial glutaminase production and applications-a concise review.

This article focuses on significant advances in the production and applications of microbial glutaminases and provides insight into the structures of different glutaminases. Glutaminases catalyze the deamidation of glutamine to glutamic acid, and this unique ability forms the basis of their applications in various industries such as pharmaceutical and food organizations. Microbial glutaminases from bacteria, actinomycetes, yeast, and fungi are of greater significance than animal glutaminases because of their stability, affordability, and ease of production. Owing to these notable benefits, they are considered to possess considerable potential in anticancer and antiviral therapy, flavor enhancers in oriental foods, biosensors and in the production of a nutraceutical theanine. This review also aims to fully explore the potential of microbial glutaminases and to set the pace for future prospects.

Xylan from bambara and cowpea biomass and their structural elucidation.

This work is the first report on the isolation and structural elucidation of xylan from bambara and cowpea biomass. The xylans, isolated using acidic delignification followed by NaOH extraction method gave 12.3% and 13.6% yield, respectively. 1H NMR analyses revealed that both the xylans were glucuronoxylan. The presence of xylose and glucuronic acid was confirmed by monosaccharide analysis and uronic acid assay. Further, xylooligosaccharide production from bambara and cowpea xylans was carried out using xylanase from three different glycoside hydrolase families, and the products were analyzed by TLC and MALDI-ToF MS. The hydrolysis products of both xylans resembled hardwood glucuronoxylan fragments, generated under similar conditions. The most common oligosaccharides observed in the hydrolysates were Xyl2, Xyl3, MeGlcA3Xyl3, MeGlcAXyl4 and MeGlcAXyl5. A series of computational approaches were also used to study the interactions of the three different xylanases with xylan. Thus, untapped biomass such as bambara and cowpea could serve as a potential source for xylan which could further be converted to xylooligosaccharides and many other value-added chemicals.