Synthesis Of Biomolecules Research Articles

Role of Bioactive Compounds in the Regulation of Mitochondrial Dysfunctions in Brain and Age-Related Neurodegenerative Diseases.

Mitochondria are multifunctional organelles that participate in a wide range of metabolic processes, including energy production and biomolecule synthesis. The morphology and distribution of intracellular mitochondria change dynamically, reflecting a cell’s metabolic activity. Oxidative stress is defined as a mismatch between the body’s ability to neutralise and eliminate reactive oxygen and nitrogen species (ROS and RNS). A determination of mitochondria failure in increasing oxidative stress, as well as its implications in neurodegenerative illnesses and apoptosis, is a significant developmental process of focus in this review. The neuroprotective effects of bioactive compounds linked to neuronal regulation, as well as related neuronal development abnormalities, will be investigated. In conclusion, the study of secondary components and the use of mitochondrial features in the analysis of various neurodevelopmental diseases has enabled the development of a new class of mitochondrial-targeted pharmaceuticals capable of alleviating neurodegenerative disease states and enabling longevity and healthy ageing for the vast majority of people.

Metal Ions, Metal Chelators and Metal Chelating Assay as Antioxidant Method

Heavy metals are essential for a wide range of biological processes, including the growth and reproduction of cells, synthesis of biomolecules, many enzymatic reactions, and the body’s immunity, but their excessive intake is harmful. Specifically, they cause oxidative stress (OS) and generate free radicals and reactive oxygen species (ROS) in metabolism. In addition, the accumulation of heavy metals in humans can cause serious damage to different organs, especially respiratory, nervous and reproductive and digestive systems. Biologically, metal chelation therapy is often used to treat metal toxicity. This process occurs through the interaction between the ligand and a central metal atom, forming a complex ring-like structure. After metals are chelated with appropriate chelating agents, their damage in metabolism can be prevented and efficiently removed from the body. On the other hand, heavy metals, including Zn, Fe and Cu, are necessary for the suitable functioning of different proteins including enzymes in metabolism. However, when the same metals accumulate at levels higher than the optimum level, they can easily become toxic and have harmful effects toward biomolecules. In this case, it induces the formation of ROS and nitrogen species (RNS) resulting in peroxidation of biological molecules such as lipids in the plasma membrane. Antioxidants have an increasing interest in many fields due to their protective effects, especially in food and pharmaceutical products. Screening of antioxidant properties of compounds needs appropriate methods including metal chelating assay. In this study, a general approach to the bonding and chelating properties of metals is described. For this purpose, the basic principles and chemical principles of metal chelation methods, both in vivo and in vitro, are outlined and discussed. Hence, in the main sections of this review, the descriptions related to metal ions, metal chelating, antioxidants, importance of metal chelating in biological system and definitions of metal chelating assays as widely used methods to determine antioxidant ability of compounds are provided. In addition, some chemical properties, technical and critical details of the used chelation methods are given.

Laser capture of tomato pericarp tissues for microscale carotenoid analysis by supercritical fluid chromatography.

Plant organs and tissues are comprised of an array of cell types often superimposed on a gradient of developmental stages. As a result, the ability to analyze and understand the synthesis, metabolism, and accumulation of plant biomolecules requires improved methods for cell- and tissue-specific analysis. Tomato (Solanum lycopersicum) is the world's most valuable fruit crop and is an important source of health-promoting dietary compounds, including carotenoids. Furthermore, tomato possesses unique genetic activities at the cell and tissue levels, making it an ideal system for tissue- and cell-type analysis of important biochemicals. A sample preparation workflow was developed for cell-type-specific carotenoid analysis in tomato fruit samples. Protocols for hyperspectral imaging of tomato fruit samples, cryoembedding and sectioning of pericarp tissue, laser microdissection of specific cell types, metabolite extraction using cell wall digestion enzymes and pressure cycling, and carotenoid quantification by supercritical fluid chromatography were optimized and integrated into a working protocol. The workflow was applied to quantify carotenoids in the cuticle and noncuticle component of the tomato pericarp during fruit development from the initial ripening to full ripe stages. Carotenoids were extracted and quantified from cell volumes less than 10nL. This workflow for cell-type-specific metabolite extraction and quantification can be adapted for the analysis of diverse metabolites, cell types, and organisms.

Antibacterial Effect of Some Eukaryotic Sterol Biosynthesis Inhibitors.

Isoprenoids and their derivatives are building blocks for the synthesis of biomolecules with important biological functions such as cholesterol in eukaryotes and lipid carrier undecaprenol, which is involved in cell wall biosynthesis in bacteria. With the global threat of multidrug-resistant bacteria, there is a need for finding new metabolic targets for killing bacteria. In the present study, we examined the impact of eukaryotic sterol biosynthesis inhibitors on the growth of four pathogenic bacteria. Antibacterial effect of HMG CoA reductase inhibitor (simvastatin), farnesyl pyrophosphate synthase inhibitor (alendronate), squalene epoxidase inhibitor (terbinafine), and lanosterol demethylase inhibitor (ketoconazole) were studied against four pathogenic bacteria: two gram-positive bacteria, Staphylococcus aureus and Enterococcus faecalis and two gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa. Broth microdilution method was used for assessing the antibacterial susceptibility of the components using 96 well plats. MIC and MBC were determined visibly. MIC of Ketoconazole for Staphylococcus aureus and Enterococcus faecalis were 0.166 and 1 mg/mL, respectively. Terbinafine had a weak inhibitory effect on Staphylococcus aureus (MIC: 8 mg/mL). Ketoconazole and terbinafine had no inhibitory effect on gram-negative bacteria. MBC of Simvastatin for both Staphylococcus aureus and Enterococcus faecalis was 0.5 mg/mL and of Alendronate for Pseudomonas aeruginosa was 6.6 mg/mL. Our results show that farnesyl pyrophosphate synthase and class II HMG-CoA reductases inhibitors (ketoconazole and simvastatin) have reasonable antibacterial activity against gram-positive bacteria. These two enzymes provide suitable targets for designing new antibiotics based on modifying the chemical structure of currently used drugs to obtain maximum activity.

Generation of Stable, Light-Driven Co-cultures of Cyanobacteria with Heterotrophic Microbes.

Co-cultivation of an autotrophic species with one or more heterotrophic microbes is a strategy for photobiological production of high-value compounds and is relatively underexplored in comparison to cyanobacterial or microalgal monocultures. Long-term stability of such consortia is required for useful collaboration between the partners, and this property can be increased by encapsulation of phototrophic partners within a hydrogel. Encapsulated cyanobacteria have advantages relative to planktonic cultures that may be useful to explore the potential for artificial microbial communities for targeted biomolecule synthesis, such as increased control over population sizes and reduced liquid handling requirements. In this chapter, we describe a method for encapsulation of genetically modified cyanobacterial strain (Synechococcus elongatus PCC 7942, CscB+) into a sodium alginate matrix, and the utilization of these encapsulated cells to construct stable, artificial autotroph/heterotroph co-cultures. This method has applications for the study of phototroph-based synthetic microbial consortia, and multi-species photobiological production.

Molecular Mechanisms and Regulation of Mammalian Mitophagy.

Mitochondria in the cell are the center for energy production, essential biomolecule synthesis, and cell fate determination. Moreover, the mitochondrial functional versatility enables cells to adapt to the changes in cellular environment and various stresses. In the process of discharging its cellular duties, mitochondria face multiple types of challenges, such as oxidative stress, protein-related challenges (import, folding, and degradation) and mitochondrial DNA damage. They mitigate all these challenges with robust quality control mechanisms which include antioxidant defenses, proteostasis systems (chaperones and proteases) and mitochondrial biogenesis. Failure of these quality control mechanisms leaves mitochondria as terminally damaged, which then have to be promptly cleared from the cells before they become a threat to cell survival. Such damaged mitochondria are degraded by a selective form of autophagy called mitophagy. Rigorous research in the field has identified multiple types of mitophagy processes based on targeting signals on damaged or superfluous mitochondria. In this review, we provide an in-depth overview of mammalian mitophagy and its importance in human health and diseases. We also attempted to highlight the future area of investigation in the field of mitophagy.

Higher doses of ascorbic acid may have the potential to promote nutrient delivery via intestinal paracellular absorption.

The significance of plasma ascorbic acid (AA) is underscored by its enzymatic and antioxidant properties as well as involvement in many aspects of health including the synthesis of biomolecules during acute illness, trauma and chronic health conditions. Dietary intake supports maintenance of optimal levels with supplementation at higher doses more likely pursued. Transient increased intestinal paracellular permeability following high dose AA may be utilised to enhance delivery of other micronutrients across the intestinal lumen. The potential mechanism following dietary intake however needs further study but may provide an avenue to increase small intestinal nutrient co transport and absorption, including in acute and chronic illness.

Warburg and pasteur phenotypes modulate cancer behavior and therapy.

Energetic pathways combine in the heart of metabolism. These essential routes supply energy for biochemical processes through glycolysis and oxidative phosphorylation. Moreover, they support the synthesis of various biomolecules employed in growth and survival over branching pathways. Yet, cellular energetics are often misguided in cancers as a result of the mutations and altered signaling. As nontransformed and Pasteur-like cells metabolize glucose through oxidative respiration when only oxygen is sufficient, some cancer cells bypass this metabolic switch and run glycolysis at higher rates even in the presence of oxygen. The phenomenon is called aerobic glycolysis or the Warburg effect. An increasing number of studies indicate that both Warburg and Pasteur phenotypes are recognized in the cancer microenvironment and take vital roles in the regulation of drug resistance mechanisms such as redox homeostasis, apoptosis and autophagy. Therefore, the different phenotypes call for different therapeutic approaches. Combined therapies targeting energy metabolism grant new opportunities to overcome the challenges. Nevertheless, new biomarkers emerge to classify the energetic subtypes, thereby the cancer therapy, as our knowledge in coupling energy metabolism with cancer behavior grows.

Nano-Zoo Interfacial Interaction as a Design Principle for Hybrid Soil Remediation Technology.

Using nanotechnology to remediate contaminated agricultural soil is promising but faces notable technical and economic challenges. Importantly, widely distributed soil invertebrates can potentially act as natural mobile facilitators for in situ nanoscale remediation of contaminated soil. Herein, we have drawn inspiration from nano-bio interaction and established a hybrid remediation framework using nanoscale zerovalent iron (nZVI) and nematodes for organochlorine-contaminated soil. Approximately 80% pentachlorophenol (PCP, initially 50 mg/kg) was synergistically degraded by nZVI and nematodes within 3 days. Mechanistically, exposure to nZVI stimulated the synthesis of reductive biomolecules (including collagen, glutathione, and l-cysteine) which acted as a bioreductive barrier and significantly mitigated the toxicity of PCP. At the microinterface, collagen distributed in the epidermis chelated nZVI; subsequently, l-cysteine and glutathione strongly accelerated nZVI-induced PCP dechlorination by facilitating the reductive dissolution of nZVI oxide shell and electron transfer from Fe0 core to PCP. On the basis of the interfacial interaction, an optimized soil remediation approach composed of nZVI, nematodes, and l-cysteine was established, demonstrating a 2.1-fold increase in removal efficiency with only 48.5% nZVI consumption compared with the nZVI treatment alone. This work provides a heuristic model for developing cost-efficient remediation technologies with the synergistic force of functional materials and indigenous biota, which may be widely applicable to a range of environmental contamination scenarios.

Strongly phosphorescent and water-soluble gold(I)-silver(I)-cysteine nanoplatelets via versatile small biomolecule cysteine-assisted synthesis for intracellular hypochlorite detection

In biological systems, abnormal levels of hypochlorite (ClO−) could result in cell dysfunctions. Herein, we report a facile, one-step and green approach based on the versatile small biomolecule cysteine both serving as reducing agent and ligand for synthesizing the strongly photoluminencent and water-soluble Au(I)–Ag(I)-cysteine complexes nanoplatelets (Au(I)–Ag(I)-Cys nanoplatelets) for intracellular hypochlorite detection. Multiple spectroscopic and microscopical tools have been used to characterize the resultant Au(I)–Ag(I)-Cys nanoplatelets. It was found that with the cysteine-assisted synthesis approach, the Ag(I) doping to the Au(I) complexes could form the supramolecular organometallic nanoplatelets. Inside, the Au(I)–Ag(I) metallophilic interactions showing an Au to Ag charge transfer property were formed, thereby enhancing the photoluminescence (PL) intensity via the charge transfer from the bioligand's S to the metal-metal center. The quantum yield (QY) was measured to show a maximum 16-fold enhancement (i.e., from 0.85 to 13.8%). Interestingly, in the presence of ClO−, the metal-thiolate ligand structure of the as-synthesized Au(I)–Ag(I)-Cys nanoplatelets could be oxidatively damaged, causing the PL quenching, thereby producing the effect of biorecognition towards ClO− anions. The ClO−-induced PL quenching produced two linear regions at ClO− concentrations of 0.01–5.0 μM and 5.0–1000 μM with a limit of detection (LOD) of 8.0 nM (S/N = 3). The ClO−-induced PL quenching was specific over the other typical reactive oxygen species (ROS) and the potential interfering substances in biological samples. In addition, the Au(I)–Ag(I)-Cys nanoplatelets had good biocompatibility. Thus, they could be further developed as a biosensor for detecting endogenous ClO− anions in living cells.

Controlling Surface Wettability for Automated In Situ Array Synthesis and Direct Bioscreening.

The in situ synthesis of biomolecules on glass surfaces for direct bioscreening can be a powerful tool in the fields of pharmaceutical sciences, biomaterials, and chemical biology. However, it is still challenging to 1) achieve this conventional multistep combinatorial synthesis on glass surfaces with small feature sizes and high yields and 2) develop a surface which is compatible with solid-phase syntheses, as well as the subsequent bioscreening. This work reports an amphiphilic coating of a glass surface on which small droplets of polar aprotic organic solvents can be deposited with an enhanced contact angle and inhibited motion to permit fully automated multiple rounds of the combinatorial synthesis of small-molecule compounds and peptides. This amphiphilic coating can be switched into a hydrophilic network for protein- and cell-based screening. Employing this in situ synthesis method, chemical space can be probed via array technology with unprecedented speed for various applications, such as lead discovery/optimization in medicinal chemistry and biomaterial development.

Effect of different illumination patterns on the growth and biomolecular synthesis of isolated Chlorella Thermophila in a 50 L pilot-scale photobioreactor

Optimum light exposure for the cultivation of microalgae to obtain high biomass density varies between different species. In the current work, isolated microalgae strain Chlorella thermophila was used to investigate the growth and biomolecular content under exposure of various light regimes in a pilot-scale flat plate photobioreactor (50 L). Here, three different lighting patterns namely fixed (4500 lx intensity with 14:10 light/dark ratio), variable (0−4500 lux variable intensity with 14:10 light/dark ratio) and continuous mode (4500 lx intensity with 24:0 light/dark ratio) were studied for the evaluation of the importance of light/dark period and sinusoidal illumination. Results demonstrated that the light/dark period had a significant influence on the growth and synthesis of biomolecules. The biomass concentration at fixed mode was found to be 5.6 and 1.9 fold higher compared to continuous mode and variable mode, respectively. Chlorophyll content was found to be the highest (4.8 %, w/w) in fixed mode while protein content was highest (68 %, w/w) in variable mode. The highest content of carotenoids (0.69 %, w/w) and carbohydrates (38 %, w/w) were noticed in continuous lighting mode. The highest average productivity of 16.4, 10.5, 4.03, 0.76, 0.6 (mg/L.day) were achieved for biomass, proteins, carbohydrate, chlorophylls and carotenoids, respectively in fixed mode.

Detection of naphthenic acid uptake into root and shoot tissues indicates a direct role for plants in the remediation of oil sands process-affected water

Bitumen extraction from surface-mined oil sands deposits results in the accumulation of large volumes of oil sands process-affected water (OSPW). Naphthenic acids (NAs) are primary contributors to OSPW toxicity and have been a focal point for the development of OSPW remediation strategies. Phytoremediation is an approach that utilizes plants and their associated microbes to remediate contaminants from soil and groundwater. While previous evidence has indicated a role for phytoremediation in OSPW treatment through the transformation and degradation of NAs, there are no reports that demonstrate the direct uptake of NAs into plant tissue. Using NAs labelled with 14C radioisotopes (14C-NAs) paired with whole-plant autoradiography, we show that NAs representing aliphatic (linear), single-ring, and diamondoid compounds were effectively removed from hydroponic solution and OSPW-treated soil by sandbar willow (Salix interior) and slender wheatgrass (Elymus trachycaulus) and their associated microbiomes. The NA-derived 14C label accumulated in root and shoot tissues of both plant species and was concentrated in vascular tissue and rapidly growing sink tissues, indicating that 14C-NAs or their metabolic derivatives were incorporated into physiological processes within the plants. Slender wheatgrass seedlings grown under axenic (sterile) hydroponic and soil conditions also effectively removed all 14C-NAs, including a highly stable diamondoid NA, demonstrating that plants can directly take up simple and complex NAs without the assistance of microbes. Furthermore, root and shoot tissue fractionation into major biomolecule groups suggests that NA-derived carbon is allocated toward biomolecule synthesis rapidly after NA treatment. These findings provide evidence of plant-mediated uptake of NAs and support a direct role for plants and their associated microbes in the development of future large-scale OSPW phytoremediation strategies.

Catalytic Kinetics Considerations and Molecular Tools for the Design of Multienzymatic Cascade Nanoreactors

AbstractWithin the cellular microenvironment of organisms, the surface‐ and volume‐ enclosed multiple enzymes perform highly complex series of chemical reactions for very selective and efficient synthesis of biomolecules. Several efforts have been carried out to mimic these timely and spatially defined natural enzyme cascade reactions onto the artificial multienzyme nano‐assemblies via immobilization of two or more enzymes on nanosupport, while maintaining the catalytic activity. These biocatalytic systems undergo cascade reactions for the efficient production of chemicals and materials of interest. Their increasing interest is based on their numerous potential applications in the area of environmental, biomedical and applied chemistry. A variety of nanosupports and multienzyme immobilization techniques have been optimized and reported. Nanoreactors usually show molecular crowding and anomalous diffusion of substances that modify the mass action kinetic laws. Thus, the kinetics is different than those shown by free diluted enzymes. Consequently, the catalytic activity considerations in cascade reactions on nanoassemblies are of great importance. Thus, in this work, important parameters of enzyme kinetics in cascade reaction and the molecular tools for the design and optimization of bi‐ and multi‐enzymatic nanobioreactors reactions are discussed.

Nutrition of conilon coffee under fertilization of nitrogen and molybdenum

Nitrogen (N) is the most applied nutrient in Coffea canephora crop. However, the absorption of N, especially in the form of nitrate, does not guarantee its effective use in the synthesis of biomolecules. The reduction of nitrate in the cytosol is often limited by the deficiency of molybdenum (Mo). This study, conducted during two coffee production cycles under field conditions, aimed to evaluate the effects of applying Mo on the nutrition of Conilon coffee subjected to doses of N. The experimental design used was in randomized blocks, in a 2 x 5 factorial scheme, the first factor being the absence and presence of molybdic fertilization and the second factor, N doses (300, 500, 700, 900 and 1,100 kg ha−1 year−1). Increasing doses of N promoted a linear increase in S, and within certain limits, increased the concentrations of N-NH4 +, P, K and Ca in coffee leaves; while there was a decrease in the levels of Mg and Mo. The sodium molybdate fertilizer applied to the soil was efficient in supplying Mo to the coffee. Although the Conilon maintains basal levels of nitrate in the leaves, molybdic fertilization prevented the excessive accumulation of NO3 - in plants submitted to N doses above 515 kg ha−1. In the second year, the highest concentrations of N-NH4 +, P, K and Ca were achieved with doses of N between 698 and 967 kg ha−1, which provided yield greater than 145 bags ha−1.

Quercetin Improves the Endocrine Function of Rat Testicular Tissue Under in Vitro Conditions

Summary Compounds of natural origin are often used for their beneficial effects on the male endocrine system and the synthesis of steroid biomolecules in testicular tissue. One of such compounds is quercetin (QUE), which belongs to the flavonoid family and is found in a wide range of vegetables, fruits and plant products. The purpose of this study is to evaluate the impact of QUE on the endocrine function of rat testicular fragments under in vitro conditions. Testicular fragments from adult Wistar rats (n=9), cultured in the D-MEM medium with different concentrations of QUE (namely 1, 10 and 100 µmol/L) for 24 h at 37°C (5% CO2), were used in the experiment conducted. Following culture, the medium was separated and the levels of cholesterol (CHOL) and male hormones were measured. CHOL values were quantified spectrophotometrically, whereas the concentrations of androstenedione (ANDRO), dehydropeiandrosterone (DHEA) and testosterone (TEST) were quantified using the enzyme-linked immunosorbent assay (ELISA) commercial kit. The results obtained indicate that 10 µmol/L QUE significantly increased (P<0.001; P<0.05) the concentrations of all the steroid biomolecules considered (CHOL, ANDRO, DHEA and TEST) when compared to the control samples. Accordingly, our findings confirm the positive impact of QUE on the endocrine function and steroidogenesis of rat testicular tissue under in vitro conditions.

Monitoring Deuterium Uptake in Single Bacterial Cells via Two-Dimensional Raman Correlation Spectroscopy

Raman-stable isotope labeling using heavy water (Raman-D2O) is attracting great interest as a fast technique with various applications ranging from the identification of pathogens in medical samples to the determination of microbial activity in the environment. Despite its widespread applications, little is known about the fundamental processes of hydrogen-deuterium (H/D) exchange, which are crucial for understanding molecular interactions in microorganisms. By combining two-dimensional (2D) correlation spectroscopy and Raman deuterium labeling, we have investigated H/D exchange in bacterial cells under time dependence. Most C-H stretching signals decreased in intensity over time, prior to the formation of the C-D stretching vibration signals. The intensity of the C-D signal gradually increased over time, and the shape of the C-D signal was more uniform after longer incubation times. Deuterium uptake showed high variability between the bacterial genera and mainly led to an observable labeling of methylene and methyl groups. Thus, the C-D signal encompassed a combination of symmetric and antisymmetric CD2 and CD3 stretching vibrations, depending on the bacterial genera. The present study allowed for the determination of the sequential order of deuterium incorporation into the functional groups of proteins, lipids, and nucleic acids and hence understanding the process of biomolecule synthesis and the growth strategies of different bacterial taxa. We present the combination of Raman-D2O labeling and 2D correlation spectroscopy as a promising approach to gain a fundamental understanding of molecular interactions in biological systems.

Long Noncoding RNA CTD-2245E15.3 Promotes Anabolic Enzymes ACC1 and PC to Support Non-Small Cell Lung Cancer Growth.

Long noncoding RNAs (lncRNA) have been shown to play critical regulatory roles in the onset and progression of human cancers. However, the functions of a large proportion of lncRNAs are still unexplored. Here we describe a novel lncRNA, CTD-2245E15.3, that promotes lung tumorigenesis by regulating the anabolic enzymes acetyl-CoA carboxylase 1 (ACC1, encoded by the ACACA gene) and pyruvate carboxylase (PC). Differentially expressed lncRNAs between non-small cell lung cancer (NSCLC) and paired adjacent nontumor tissues were identified by a microarray and validated using quantitative real-time polymerase chain reaction. CTD-2245E15.3 was significantly upregulated in NSCLC and was mainly located in the cytoplasm. Knockdown of CTD-2245E15.3 by specific antisense oligonucleotides suppressed cell growth in vitro and in vivo, largely due to cell-cycle arrest and induction of apoptosis. Overexpression of CTD-2245E15.3 in an orthotopic model of lung cancer led to a significant increase in total tumor burden. CTD-2245E15.3 exerted its oncogenic function by binding ACC1 and PC, which are key anabolic factors for biomolecule synthesis in rapidly proliferating tumor cells. Knockdown of CTD-2245E15.3 increased phosphorylation of ACC1 at an inhibitory site for enzymatic activity and promoted PC degradation via ubiquitination. Supplements of palmitate or oxaloacetate, products of ACC1 and PC, alleviated the suppression of cell growth caused by loss of CTD-2245E15.3. These findings reveal the important role of CTD-2245E15.3 as an oncogenic lncRNA in the anabolic process for tumor growth. SIGNIFICANCE: These findings demonstrate a novel lncRNA CTD-2245E15.3 that binds and positively regulates anabolic enzymes ACC1 and PC to promote tumor growth. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/13/3509/F1.large.jpg.

Illuminating Life's Origins: UV Photochemistry in Abiotic Synthesis of Biomolecules.

Solar radiation is the principal source of energy available to Earth and has unmatched potential for the synthesis of organic material from primordial molecular building blocks. As well as providing the energy for photochemical synthesis of (proto)biomolecules of interest in origins of life-related research, light has also been found to often provide remarkable selectivity in these processes, for molecules that function in extant biology and against those that do not. As such, light is heavily implicated as an environmental input on the nascent Earth that was important for the emergence of complex yet selective chemical systems underpinning life. Reactivity and selectivity in photochemical prebiotic synthesis are discussed, as are their implications for origins of life scenarios and their plausibility, and the future directions of this research.

Involvement of a Quorum Sensing Signal Molecule in the Extracellular Amylase Activity of the Thermophilic Anoxybacillus amylolyticus.

Anoxybacillus amylolyticus is a moderate thermophilic microorganism producing an exopolysaccharide and an extracellular α-amylase able to hydrolyze starch. The synthesis of several biomolecules is often regulated by a quorum sensing (QS) mechanism, a chemical cell-to-cell communication based on the production and diffusion of small molecules named “autoinducers”, most of which belonging to the N-acyl homoserine lactones’ (AHLs) family. There are few reports about this mechanism in extremophiles, in particular thermophiles. Here, we report the identification of a signal molecule, the N-butanoyl-homoserine lactone (C4-HSL), from the milieu of A. amylolyticus. Moreover, investigations performed by supplementing a known QS inhibitor, trans-cinnamaldehyde, or exogenous C4-HSL in the growth medium of A. amylolyticus suggested the involvement of QS signaling in the modulation of extracellular α-amylase activity. The data showed that the presence of the QS inhibitor trans-cinnamaldehyde in the medium decreased amylolytic activity, which, conversely, was increased by the effect of exogenous C4-HSL. Overall, these results represent the first evidence of the production of AHLs in thermophilic microorganisms, which could be responsible for a communication system regulating thermostable α-amylase activity.