Biogenic synthesis of novel nanomaterials and their applications.

Despite the many benefits derived from the unique features and practicality of nanoparticles, the release of their toxic by-products or products from the synthesis stage into the environment could negatively impact natural resources and organisms. The physical and chemical methods for nanoparticle synthesis involve high energy consumption and the use of hazardous chemicals, respectively, going against the principles of green chemistry. Biological methods of synthesis that rely on extracts from a broad range of natural plants, and microorganisms, such as fungi, bacteria, algae, and yeast, have emerged as viable alternatives to the physical and chemical methods. Nanoparticles synthesized through biogenic pathways are particularly useful for biological applications that have high concerns about contamination. Herein, we review the physical and chemical methods of nanoparticle synthesis and present a detailed overview of the biogenic methods used for the synthesis of different nanoparticles. The major points discussed in this study are the following: (1) the fundamentals of the physical and chemical methods of nanoparticle syntheses, (2) the use of different biological precursors (microorganisms and plant extracts) to synthesize gold, silver, selenium, iron, and other metal nanoparticles, and (3) the applications of biogenic nanoparticles in diverse fields of study, including the environment, health, material science, and analytical chemistry.

Endophytic bacteria isolated from Urtica dioica L.- preliminary screening for enzyme and polyphenols production.

Endophytes, especially those isolated from herbal plants, may act as a reservoir of a variety of secondary metabolites exhibiting biological activity. Some endophytes express the ability to produce the same bioactive compounds as their plant hosts, making them a more sustainable industrial supply of these substances. Urtica dioica L. (common stinging nettle) is a synanthropic plant that is widely used in herbal medicine due to the diversity of bioactive chemicals it contains, e.g., polyphenols, which demonstrate anti-inflammatory, antioxidant, and anti-cancerous capabilities. This study aimed at isolating endophytic bacteria from stinging nettles for their bioactive compounds. The endophytic isolates were identified by both biochemical and molecular methods (16S rRNA) and investigated for enzymes, biosurfactants, and polyphenols production. Each of the isolated bacterial strains was capable of producing biosurfactants and polyphenols. However, three of the isolated endophytes, identified as two strains of Bacillus cereus and one strain of Bacillus mycoides, possessed the greatest capacity to produce biosurfactants and polyphenols. The derivatized extracts from culture liquid showed the 1.633 mol l-1 (9.691 mg l-1) concentration of polyphenol compounds. Therefore, the present study signifies that endophytic B. cereus and B. mycoides isolated from Urtica dioica L. could be a potential source of biosurfactants and polyphenols. However, further study is required to understand the mechanism of the process and achieve efficient polyphenol production by endophytic bacteria.

Identification of natural CTXM-15 inhibitors from aqueous extract of endophytic bacteria Cronobactersakazaki.

Nyctanthes arbor-tristis is one of India's valuable and populous medicinal plants which belongs to the family Oleaceae, and widely recognize as night jasmine. Over the years till date, different parts of the plant are used to treat or cure different ailments via various means of traditional medicine. Endophytes are organisms that live in the cell or body of other organisms with no apparent negative impact on the host which they inhabit and are of great source of novel bioactive compounds possessing important economic value. Secondary metabolites were identified in the aqueous extract of Cronobactersakazakii through quantitative phytochemical and GC-MS analysis. Antibacterial activity of the extract against clinical and ATCC strains of E. coli was assessed. Biological activity spectra of these compounds were predicted and categorized either as probably active (Pa) or probably inactive (Pi). Drug-likeness of bioactive compounds was determined as well as their ability to target protein (CTXM-15) responsible for antibiotic resistance in Gram-negative bacteria. Results revealed the presence of active compounds with pharmacological activities and considerable pharmacokinetics parameters. In addition, ligand-protein interactions of compounds with CTXM-15 proteins were identified. These results suggest that bioactive compounds of endophytic Cronobactersakazakii could contain novel chemical entities for the development of antibiotics against pathogenic microbes and other drugs for the amelioration of several infections.

New insights into metabolomics profile generation in fermented tea: the relevance of bacteria and metabolites in Fuzhuan brick tea.

BACKGROUND: The contribution of bacteria to fermented tea is not clear and the associated research is relatively limited. To reveal the role of microorganisms in fermented tea processing, the microbial community and metabolites of Fuzhuan brick tea (FBT), a Chinese traditional fermented tea, were revealed via high-throughput sequencing and liquid chromatography-mass spectrometry (LC-MS). RESULTS: In FBT, bacterial communities had a higher abundance and diversity, Lactococcus and Bacillus were the main bacteria, and Eurotium was the predominant fungus. The predictive metabolic function indicated the pathways of cellular growth, environmental information, genetics and material metabolism of bacterial communities were abundant, whereas the fungal community predictive metabolic function was almost saprotroph. Using LC-MS, 1143 and 536 metabolites were defined in positive and negative ion mode, respectively. There were essential correlations between bacterial populations and metabolites, such that Bacillus was correlated significantly with 44 metabolites (P < 0.05) and Enterococcus was significantly associated with 15 metabolites (P < 0.05). Some of the main active components were significantly correlated with the bacteria, such as Enterococcus, Lactococcus and Carnobacterium. CONCLUSION: Not only Eurotium, but also the bacteria were involved in the changes of metabolomics profile in fermented FBT. The present study assists in providing new insights into metabolomics profile generation in fermented tea. The present research lays a foundation for controlling the FBT fermentation by artificial inoculation to improve quality. © 2021 Society of Chemical Industry.

PVA based nanofiber containing cellulose modified with graphitic carbon nitride/nettles/trachyspermum accelerates wound healing.

Today, bacterial cellulose has received a great deal of attention for its medical applications due to its unique structural properties such as high porosity, good fluid uptake, good strength, and biocompatibility. This study aimed to fabricate and study bacterial cellulose/graphitic carbon nitride/nettles/trachyspermum nanocomposite by immersion and PVA/BC/g-C3 N4 /nettles/trachyspermum nanofiber by electrospinning method as a wound dressing. The g-C3 N4 and g-C3 N4 solution were synthesized and then were characterized using Fourier transform infrared, X-ray diffraction, Zeta Potential, and scanning electronic microscope analyzes. Also, the antibacterial properties of the synthesized materials were proved by gram-positive and gram-negative bacteria using the minimum inhibitory concentration method. Besides, the toxicity, migration, and cell proliferation results of the synthesized materials on NIH 3T3 fibroblasts were evaluated using MTT and scratch assays and showed that the BC/PVA/g-C3 N4 /nettles/trachyspermum composite not only had no toxic effect on cells but also contributed to cell survival, cell migration, and proliferation has done. To evaluate the mechanical properties, a tensile strength test was performed on PVA/BC/g-C3 N4 /nettles/trachyspermum nanofibers, and the results showed good strength of the nanocomposite. In addition, in vivo assay, the produced nanofibers were used to evaluate wound healing, and the results showed that these nanofibers were able to accelerate the wound healing process so that after 14 days, the wound healing percentage showed 95%. Therefore, this study shows that PVA/BC/g-C3 N4 /nettles/trachyspermum nanofibers effectively inhibit bacterial growth and accelerate wound healing.

Bacterial Cellulose Membrane Containing Epilobium angustifolium L. Extract as a Promising Material for the Topical Delivery of Antioxidants to the Skin.

Bacterial cellulose membranes (BCs) are becoming useful as a drug delivery system to the skin. However, there are very few reports on their application of plant substances to the skin. Komagataeibacter xylinus was used for the production of bacterial cellulose (BC). The BC containing 5% and 10% ethanolic extract of Epilobium angustifolium (FEE) (BC-5%FEE and BC-10%FEE, respectively) were prepared. Their mechanical, structural, and antioxidant properties, as well as phenolic acid content, were evaluated. The bioavailability of BC-FESs using mouse L929 fibroblasts as model cells was tested. Moreover, In Vitro penetration through the pigskin of the selected phenolic acids contained in FEE and their accumulation in the skin after topical application of BC-FEEs was examined. The BC-FEEs were characterized by antioxidant activity. The BC-5% FEE showed relatively low toxicity to healthy mouse fibroblasts. Gallic acid (GA), chlorogenic acid (ChA), 3,4-dihydroxybenzoic acid (3,4-DHB), 4-hydroxybenzoic acid (4-HB), 3-hydroxybenzoic acid (3-HB), and caffeic acid (CA) found in FEE were also identified in the membranes. After topical application of the membranes to the pigskin penetration of some phenolic acid and other antioxidants through the skin as well as their accumulation in the skin was observed. The bacterial cellulose membrane loaded by plant extract may be an interesting solution for topical antioxidant delivery to the skin.

Structural Phylogeny of Different Allergens May Reveal Common Epitopic Footprint.

BACKGROUND: The incidence of allergy has been increasing at an alarming rate over the last few decades. OBJECTIVE: Our present study aims to find out the structurally homologous motifs present in different proteinaceous allergens. METHODS: Significant number of protein sequences and their corresponding structures of various pollen, fungal, bacterial, and food allergens were retrieved and the sequence and structural identity were analyzed. RESULTS: Intra- and inter-sequence along with their structural analysis of the proteinaceous allergens revealed that no significant relationships exist among them. A few, but not the negligible number of high structural similarities, were observed within different groups of allergens from fungus, angiosperms, and animals (Aves and Mammalia). CONCLUSION: Our in silico study on thirty-six different allergens showed a significant level of structural similarities among themselves, regardless of their sequences.

Emulsifier peptides derived from seaweed, methanotrophic bacteria, and potato proteins identified by quantitative proteomics and bioinformatics.

Global focus on sustainability has accelerated research into alternative non-animal sources of food protein and functional food ingredients. Amphiphilic peptides represent a class of promising biomolecules to replace chemical emulsifiers in food emulsions. In contrast to traditional trial-and-error enzymatic hydrolysis, this study utilizes a bottom-up approach combining quantitative proteomics, bioinformatics prediction, and functional validation to identify novel emulsifier peptides from seaweed, methanotrophic bacteria, and potatoes. In vitro functional validation reveal that all protein sources contained embedded novel emulsifier peptides comparable to or better than sodium caseinate (CAS). Thus, peptides efficiently reduced oil-water interfacial tension and generated physically stable emulsions with higher net zeta potential and smaller droplet sizes than CAS. In silico structure modelling provided further insight on peptide structure and the link to emulsifying potential. This study clearly demonstrates the potential and broad applicability of the bottom-up approach for identification of abundant and potent emulsifier peptides.

Natural products as drugs and tools for influencing core processes of eukaryotic mRNA translation.

Eukaryotic protein synthesis is the highly conserved, complex mechanism of translating genetic information into proteins. Although this process is essential for cellular homoeostasis, dysregulations are associated with cellular malfunctions and diseases including cancer and diabetes. In the challenging and ongoing search for adequate treatment possibilities, natural products represent excellent research tools and drug leads for new interactions with the translational machinery and for influencing mRNA translation. In this review, bacterial-, marine- and plant-derived natural compounds that interact with different steps of mRNA translation, comprising ribosomal assembly, translation initiation and elongation, are highlighted. Thereby, the exact binding and interacting partners are unveiled in order to accurately understand the mode of action of each natural product. The pharmacological relevance of these compounds is furthermore assessed by evaluating the observed biological activities in the light of translational inhibition and by enlightening potential obstacles and undesired side-effects, e.g. in clinical trials. As many of the natural products presented here possess the potential to serve as drug leads for synthetic derivatives, structural motifs, which are indispensable for both mode of action and biological activities, are discussed. Evaluating the natural products emphasises the strong diversity of their points of attack. Especially the fact that selected binding partners can be set in direct relation to different diseases emphasises the indispensability of natural products in the field of drug development. Discovery of new, unique and unusual interacting partners again renders them promising tools for future research in the field of eukaryotic mRNA translation.

Effective approaches to discover new microbial metabolites in a large strain library.

Natural products have provided many molecules to treat and prevent illnesses in humans, animals and plants. While only a small fraction of the existing microbial diversity has been explored for bioactive metabolites, tens of thousands of molecules have been reported in the literature over the past 80 years. Thus, the main challenge in microbial metabolite screening is to avoid the re-discovery of known metabolites in a cost-effective manner. In this perspective, we report and discuss different approaches used in our laboratory over the past few years, ranging from bioactivity-based screening to looking for metabolic rarity in different datasets to deeply investigating a single Streptomyces strain. Our results show that it is possible to find novel chemistry through a limited screening effort, provided that appropriate selection criteria are in place.

Biological Nanofactories: Using Living Forms for Metal Nanoparticle Synthesis.

Metal nanoparticles are nanosized entities with dimensions of 1-100 nm that are increasingly in demand due to applications in diverse fields like electronics, sensing, environmental remediation, oil recovery and drug delivery. Metal nanoparticles possess large surface energy and properties different from bulk materials due to their small size, large surface area with free dangling bonds and higher reactivity. High cost and pernicious effects associated with the chemical and physical methods of nanoparticle synthesis are gradually paving the way for biological methods due to their eco-friendly nature. Considering the vast potentiality of microbes and plants as sources, biological synthesis can serve as a green technique for the synthesis of nanoparticles as an alternative to conventional methods. A number of reviews are available on green synthesis of nanoparticles but few have focused on covering the entire biological agents in this process. Therefore present paper describes the use of various living organisms like bacteria, fungi, algae, bryophytes and tracheophytes in the biological synthesis of metal nanoparticles, the mechanisms involved and the advantages associated therein.

The Detection of Elemental Signatures of Microbes in Martian Mudstone Analogs Using High Spatial Resolution Laser Ablation Ionization Mass Spectrometry.

The detection and identification of biosignatures on planetary bodies such as Mars in situ is extremely challenging. Current knowledge from space exploration missions suggests that a suite of complementary instruments is required in situ for a successful identification of past or present life. For future exploration missions, new and innovative instrumentation capable of high spatial resolution chemical (elemental and isotope) analysis of solids with improved measurement capabilities is of considerable interest because a multitude of potential signatures of extinct or extant life have dimensions on the micrometer scale. The aim of this study is to extend the current measurement capabilities of a miniature laser ablation ionization mass spectrometer (LIMS) designed for space exploration missions to detect signatures of microbial life. In total, 14 martian mudstone analogue samples were investigated regarding their elemental composition. Half the samples were artificially inoculated with a low number density of microbes, and half were used as abiotic controls. The samples were treated in a number of ways. Some were cultured anaerobically and some aerobically; some abiotic samples were incubated with water, and some remained dry. Some of the samples were exposed to a large dose of γ radiation, and some were left un-irradiated. While no significant elemental differences were observed between the applied sample treatments, the instrument showed the capability to detect biogenic element signatures of the inoculated microbes by monitoring biologically relevant elements, such as hydrogen, carbon, sulfur, iron, and so on. When an enrichment in carbon was measured in the samples but no simultaneous increase in other biologically relevant elements was detected, it suggests, for example, a carbon-containing inclusion; when the enrichment was in carbon and in bio-relevant elements, it suggests the presences of microbes. This study presents first results on the detection of biogenic element patterns of microbial life using a miniature LIMS system designed for space exploration missions.

The strategies and techniques of drug discovery from natural products.

Natural products have been the main sources of new drugs. The different strategies have been developed to find the new drugs based on natural products. The traditional and ethic medicines have provided information on the therapeutic effects and resulted in some notable drug discovery of natural products. The special activities of the medicine plants such as the side effects have inspired scientists to develop the novel small molecular. The microorganisms and the endogenous active substances from human or animal also become the important approaches to the drug discovery. The tremendous progress in technology led to the new strategies in drug discovery from natural products. The bioinformation and artificial intelligence have facilitated the research and development of natural products. We will provide a scene of strategies and technologies for drug discovery from natural products in this review.

Influence of bacterial organic selenium on blood parameters, immune response, selenium retention and intestinal morphology of broiler chickens.

BACKGROUND: Several studies indicated that dietary organic selenium (Se) usually absorbed better than an inorganic source, with high retention and bioavailability. Dietary Se as an antioxidant element affects the immune system and hematological status in animals. Therefore, the aim of this study was to evaluate the effect of dietary supplementation of bacterial selenium as an organic source on hematology, immunity response, selenium retention, and gut morphology in broiler chickens. RESULTS: The present results revealed that supplementation of inorganic Se was associated with the lowest level of RBC, HB, and PCV with significant difference than ADS18-Se. In the starter stage, both T2 and T5 were associated with the significantly highest IgG level compared to the basal diet, while all supplemented groups showed higher IgM levels compared to the control group. In the finisher phase, all Se supplemented groups showed significant (P ˂ 0.05) increases in IgG, IgA, and IgM levels compared to T1. Birds fed bacterial-Se showed high intestinal villus height and better Se retention more than sodium selenite. The organic selenium of ADS18 had a superior action in improving Se retention compared to ADS1 and ADS2 bacterial Se. CONCLUSIONS: Bacterial organic Se had a beneficial effect on the villus height of small intestine led to high Se absorption and retention. Thus, it caused a better effect of Se on hematological parameters and immunity response.

Mediterranean Sea bacteria as a potential source of long-chain polyunsaturated fatty acids.

Long-chain polyunsaturated fatty acids (LC-PUFAs), including EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are important nutritional ingredients in fish feed. So far, fish oil has been used as a main source of LC-PUFAs; however, the limited global supply of fish oil is not able to meet the demand of the growing aquaculture sector. Hence, sustainability of aquaculture industry could be supported by searching alternative sources of these compounds. Marine microorganisms represent a sustainable and stable supply source of LC-PUFAs. A collection of 209 bacterial isolates obtained from sediment samples recovered in the Mediterranean Sea was screened in order to select new LC-PUFAs producers. Among 95 putative producers selected based on colourimetric screening, 31 quickly growing were selected for further studies. The detection of LC-PUFAs was confirmed from 15 isolates belonging to the genera Marinobacter, Halomonas and Thalassospira by GC-FID analysis. Among them, the isolate Marinobacter sp. G16.20 was found to be a potentially high LC-PUFA producer exhibiting relatively high levels of DHA in particular (maximum productivity of 1.85 ± 0.371 mg/g, representing 45.89% of the total fatty acids detected and identified). Microorganisms belonging to the genera reported in this study showed biotechnological traits interesting for their potential future application in aquaculture.

Intersecting Xenobiology and Neometabolism To Bring Novel Chemistries to Life.

The diversity of life relies on a handful of chemical elements (carbon, oxygen, hydrogen, nitrogen, sulfur and phosphorus) as part of essential building blocks; some other atoms are needed to a lesser extent, but most of the remaining elements are excluded from biology. This circumstance limits the scope of biochemical reactions in extant metabolism - yet it offers a phenomenal playground for synthetic biology. Xenobiology aims to bring novel bricks to life that could be exploited for (xeno)metabolite synthesis. In particular, the assembly of novel pathways engineered to handle nonbiological elements (neometabolism) will broaden chemical space beyond the reach of natural evolution. In this review, xeno-elements that could be blended into nature's biosynthetic portfolio are discussed together with their physicochemical properties and tools and strategies to incorporate them into biochemistry. We argue that current bioproduction methods can be revolutionized by bridging xenobiology and neometabolism for the synthesis of new-to-nature molecules, such as organohalides.

Microbial acetylcholinesterase inhibitors for Alzheimer's therapy: recent trends on extraction, detection, irradiation-assisted production improvement and nano-structured drug delivery.

Neurodegenerative disorders especially Alzheimer's disease (AD) are significantly threatening the public health. Acetylcholinesterase (AChE) inhibitors are compounds of great interest which can be used as effective agents for the symptomatic treatment of AD. Although plants are considered the largest source for these types of inhibitors, the microbial production of AChE inhibitors represents an efficient, easily manipulated, eco-friendly, cost-effective, and alternative approach. This review highlights the recent advances on the microbial production of AChE inhibitors and summarizes all the previously reported successful studies on isolation, screening, extraction, and detecting methodologies of AChE inhibitors from the microbial fermentation, from the earliest trials to the most promising anti-AD drug, huperzine A (HupA). In addition, improvement strategies for maximizing the industrial production of AChE inhibitors by microbes will be discussed. Finally, the promising applications of nano-material-based drug delivery systems for natural AChE inhibitor (HupA) will also be summarized. KEY POINTS: • AChE inhibitors are potential therapies for Alzheimer's disease. • Microorganisms as alternate sources for prospective production of such inhibitors. • Research advances on extraction, detection, and strategies for production improvement. • Nanotechnology-based approaches for an effective drug delivery for Alzheimer's disease.

Recent Developments in the Facile Bio-Synthesis of Gold Nanoparticles (AuNPs) and Their Biomedical Applications.

Gold nanoparticles (AuNPs) are extensively studied nanoparticles (NPs) and are known to have profound applications in medicine. There are various methods to synthesize AuNPs which are generally categorized into two main types: chemical and physical synthesis. Continuous efforts have been devoted to search for other more environmental-friendly and economical large-scale methods, such as environmentally friendly biological methods known as green synthesis. Green synthesis is especially important to minimize the harmful chemical and toxic by-products during the conventional synthesis of AuNPs. Green materials such as plants, fungi, microorganisms, enzymes and biopolymers are currently used to synthesize various NPs. Biosynthesized AuNPs are generally safer for use in biomedical applications since they come from natural materials themselves. Multiple surface functionalities of AuNPs allow them to be more robust and flexible when combined with different biological assemblies or modifications for enhanced applications. This review focuses on recent developments of green synthesized AuNPs and discusses their numerous biomedical applications. Sources of green materials with successful examples and other key parameters that determine the functionalities of AuNPs are also discussed in this review.

Microbial Degradation of Hydrocarbons-Basic Principles for Bioremediation: A Review.

Crude oil-derived hydrocarbons constitute the largest group of environmental pollutants worldwide. The number of reports concerning their toxicity and emphasizing the ultimate need to remove them from marine and soil environments confirms the unceasing interest of scientists in this field. Among the various techniques used for clean-up actions, bioremediation seems to be the most acceptable and economically justified. Analysis of recent reports regarding unsuccessful bioremediation attempts indicates that there is a need to highlight the fundamental aspects of hydrocarbon microbiology in a clear and concise manner. Therefore, in this review, we would like to elucidate some crucial, but often overlooked, factors. First, the formation of crude oil and abundance of naturally occurring hydrocarbons is presented and compared with bacterial ability to not only survive but also to utilize such compounds as an attractive energy source. Then, the significance of nutrient limitation on biomass growth is underlined on the example of a specially designed experiment and discussed in context of bioremediation efficiency. Next, the formation of aerobic and anaerobic conditions, as well as the role of surfactants for maintaining appropriate C:N:P ratio during initial stages of biodegradation is explained. Finally, a summary of recent scientific reports focused on the removal of hydrocarbon contaminants using bioaugmentation, biostimulation and introduction of surfactants, as well as biosurfactants, is presented. This review was designed to be a comprehensive source of knowledge regarding the unique aspects of hydrocarbon microbiology that may be useful for planning future biodegradation experiments. In addition, it is a starting point for wider debate regarding the limitations and possible improvements of currently employed bioremediation strategies.