Natural Degradation Processes Research Articles

Citronella Oil as Additives in Active Carrageenan -based Food Packaging Films: A Review

The natural degradation process of plastics is slow and harmful to the environment, making biodegradable films a more advantageous option. These films not only reduce environmental pollution but also have the potential to preserve food products and extend their shelf life. This study explores the potential of utilizing iota carrageenan-based films in combination with essential oils for food packaging applications. Iota carrageenan, known for its high elasticity and thixothrophic properties, serves as an ideal base material for film formation. Essential oils, with antioxidant and antimicrobial properties, are incorporated into the packaging material to enhance shelf life and prevent food spoilage. Citronella oil demonstrates effective antimicrobial and antioxidant activities for food preservation. The presence of essential oils acts as plasticizers in the film, improving flexibility but requiring careful consideration of concentration to maintain network strength.

Integrated Application of Innovative Technologies for Oil Spill Remediation in Gran Tarajal Harbor: A Scientific Approach

This study examines recovery efforts at Gran Tarajal Harbor following a significant oil spill, employing a combination of innovative technologies tailored to enhance oil spill remediation. Cleanup operations incorporated advanced absorbent sponges with high reusability, absorbent granulates for targeted hydrocarbon capture, bioremediation techniques using allochthonous microorganisms to accelerate natural degradation processes, and the integration of newly designed oil containment barriers coupled with sponges. These technologies were instrumental in effectively mitigating environmental damage, as evidenced by a reduction in hydrocarbon concentrations in sediments from nearly 60,000 mg/kg to under 1600 mg/kg within seven months. Notably, advanced absorbent sponges demonstrated superior capacity for repeated use, optimizing the cleanup process and contributing to the sustainability of the response efforts. The most important finding of this research is the demonstrated efficacy of integrated approach in not only reducing hydrocarbon contamination but also in promoting ecological recovery. Heavy metal analyses revealed that lead and copper concentrations were primarily associated with routine port activities, while mercury levels, attributed to the spill, decreased significantly over time. Tissue analysis of local organisms showed minimal contamination, and assessments of biological communities indicated signs of ecological recovery. This work highlights the necessity of introduce new disruptive technologies in contingency plans.

Bioconversion of agriculture by-products with functionally enhanced Streptomyces sp. SCUT-3: Fish skin as a model

With the global population continuously rising, efficient bioconversion of inedible agricultural by-products is crucial for human food and energy sustainability. We here propose solid-state fermentation approaches to efficiently convert biopolymers into oligomers/monomers by accelerating the natural degradation process of the versatile Streptomyces sp. strain SCUT-3. Using fish skin as a representative by-product, 54.3 g amino acids and 14.7 g peptides (91 % < 2500 Da) were recovered from 89.0 g protein in 100 g tilapia skin sample by collagenase-overexpressed SCUT-3 for seven days at a 1:4 substrate:liquid ratio. Fish skin collagen hydrolysates exhibited excellent anti-oxidation, anti-hypertension, scratch-repairing, anti-aging, anti-ultraviolet radiation, and anti-inflammation effects on human skin fibroblasts In vitro and zebrafish larvae in vivo, indicating their potential applications in healthcare/skincare and anti-atopic dermatitis. As Laozi said, the divine law follows nature. This study underscores the efficacy of genetically engineered SCUT-3 according to its natural biomass utilization laws in large-scale biopolymer conversion.

Microbiological and decomposition analysis of mass mink burial sites during the COVID-19 pandemic

In 2020, Denmark buried approximately four million culled, farmed mink in mass graves treated with slaked lime due to widespread SARS-CoV-2 infections. After six months, environmental concerns prompted the exhumation of these cadavers. Our analysis encompassed visual inspections, soil pH measurements, and gas emission assessments of the grave environment. Additionally, we evaluated carcasses for decay status, cadaverine content, and the presence of various pathogens, including SARS-CoV-2 and mink coronavirus. Our findings revealed minimal microbial activity and limited carcass decomposition. Although viral RNA from SARS-CoV-2 and mink coronavirus, along with DNA from Aleutian mink disease virus, were detected, the absence of infectious SARS-CoV-2 in cell culture assays suggests slow natural degradation processes. This study provides critical insights for future considerations in managing mass burial scenarios during outbreaks of livestock-associated zoonotic pathogens.

Microbial Bioherbicides Based on Cell-Free Phytotoxic Metabolites: Analysis and Perspectives on Their Application in Weed Control as an Innovative Sustainable Solution.

Weeds cause significant agricultural losses worldwide, and herbicides have traditionally been the main solution to this problem. However, the extensive use of herbicides has led to multiple cases of weed resistance, which could generate an increase in the application concentration and consequently a higher persistence in the environment, hindering natural degradation processes. Consequently, more environmentally friendly alternatives, such as microbial bioherbicides, have been sought. Although these bioherbicides are promising, their efficacy remains a challenge, as evidenced by their limited commercial and industrial production. This article reviews the current status of microbial-based bioherbicides and highlights the potential of cell-free metabolites to improve their efficacy and commercial attractiveness. Stirred tank bioreactors are identified as the most widely used for production-scale submerged fermentation. In addition, the use of alternative carbon and nitrogen sources, such as industrial waste, supports the circular economy. Furthermore, this article discusses the optimization of downstream processes using bioprospecting and in silico technologies to identify target metabolites, which leads to more precise and efficient production strategies. Bacterial bioherbicides, particularly those derived from Pseudomonas and Xanthomonas, and fungal bioherbicides from genera such as Alternaria, Colletotrichum, Trichoderma and Phoma, show significant potential. Nevertheless, limitations such as their restricted range of action, their persistence in the environment, and regulatory issues restrict their commercial availability. The utilization of cell-free microbial metabolites is proposed as a promising solution due to their simpler handling and application. In addition, modern technologies, including encapsulation and integrated management with chemical herbicides, are investigated to enhance the efficacy and sustainability of bioherbicides.

First evidence of metformin detected in Jakarta waters

Pharmaceutically active compounds have been considered contaminants of emerging concern, in response to evidence that these substances may adversely affect non-target organisms. The pharmaceutical metformin is the most commonly prescribed anti-diabetes medicine throughout the world. Metformin has been detected in numerous freshwater systems as well as in seawater at a number of sites around the world over the last few years, but has never been reported in the Indonesian capital city Jakarta. Several recent studies have highlighted various ecotoxicological effects of this medicine on aquatic organisms. Here we report the first evidence of metformin’s presence in Jakarta waters. Samples from the Angke river, one of the main rivers in Jakarta, were collected from six sites. Metformin was detected at three sites in concentrations ranging from 27 ng/L to 414 ng/L. Metformin is one of the most detected APIs (active pharmaceutical ingredients) in aquatic environments worldwide, and there is increasing concern regarding its impact on the health of wildlife and humans. However, this is the first report of metformin contamination in Jakarta waters, adding to the evidence of potentially increased pollution with pharmaceuticals, as noted in our previous studies. With no natural degradation processes, these chemical compounds can be easily reintroduced to the food chain and impact human health.

UVB-Aged Microplastics and Cellular Damage: An in Vitro Study

Plastics are synthetic organic compounds whose widespread use generates enormous waste. Different processes, such as mechanical abrasion, microbiological activity, and UVB irradiation, can fragment the plastic material and generate microplastics (MPs). MPs are ubiquitous, and various organisms, including humans, can ingest or inhale them, with potential adverse health effects. The differences between UV-aged and virgin particles were studied to evaluate the genotoxic damage and oxidative stress induced by polystyrene MPs with 1 and 5 µm sizes on the monocyte-like cell line (THP-1). Fourier transform infrared spectroscopy and Ζ-potential measurements were used to characterise MP particles after UVB exposure. Cells exposed to MPs show a widespread change in the cellular environment with the generation of reactive oxidative species (ROS), as indicated by the increased malondialdehyde level. The occurrence of genotoxic damage is correlated to the smaller size and ageing state of the MPs. The biochemical and genomic alterations observed in this in vitro study suggest that MPs, ubiquitous pollutants, following natural degradation and oxidation processes can cause various adverse effects on the health of the exposed population, making it necessary to carry out further studies to better define the real risk.

Dynamic 3D model for decoding archaeological complexity of funerary contexts. Phenomena of collapse and fragmentation in an Iron Age burial of Padua (Italy)

Archaeological settings are intrinsically dynamic, undergoing transformations over time that significantly impact the archaeological record. These changes result from both deliberate human interventions and natural degradation processes. Post-depositional phenomena often distort our understanding of ancient contexts, complicating the identification of the original arrangement and hindering the interpretation of archaeological findings. This issue is particularly pronounced in funerary contexts, such as burials, which are susceptible to various natural and human-induced alterations. This study shows the potential of analysing funerary contexts within a processual framework and reconstructing them in a dynamic 3D environment. By employing metrically and morphologically accurate 3D reconstructions, it becomes possible to simulate, isolate, and analyze post-depositional phenomena. The precision of 3D simulation increases significantly when considering factors such as gravity. The goal of this study is to assess changes resulting from transformative phenomena, with a specific focus on creating a sequential representation that elucidates the burial's transformation processes, spanning from deposition to excavation phases.

Modeling coupling impacts of self-healing mechanisms and dynamic environments on systems subject to dependent failure processes

Modern smart products are endowed with the capability to autonomously repair damage from random shocks, thereby highlighting the critical necessity to incorporate this self-healing attribute in reliability assessments. This paper investigates periodically inspected self-healing systems that are exposed to dependent competing failure processes within dynamically evolving environments. The impact of environmental changes is manifested in that both the natural degradation process and the self-healing behavior are governed by distinct laws in varying environments. Explicit formulas for the system reliability and availability are analytically derived using the stochastic process theory, and their correctness is verified by proposed simulation algorithms respectively. Meanwhile, the inspection period is optimized by minimizing the long-run average cost rate. Lastly, a practical example of semiconductor lasers is applied to showcase the application of the presented methods. The sensitivity analysis reveals that increasing the self-healing time threshold or the shock arrival rate can improve the system performance while lowering the long-run average cost rate.

Artificial cellulosic leaf with adjustable enzymatic CO2 sequestration capability

Developing artificial leaves to address the environmental burden of CO2 is pivotal for advancing our Net Zero Future. In this study, we introduce EcoLeaf, an artificial leaf that closely mimics the characteristics of natural leaves. It harnesses visible light as its sole energy source and orchestrates the controlled expansion and contraction of stomata and the exchange of petiole materials to govern the rate of CO2 sequestration from the atmosphere. Furthermore, EcoLeaf has a cellulose composition and mechanical strength similar to those of natural leaves, allowing it to seamlessly integrate into the ecosystem during use and participate in natural degradation and nutrient cycling processes at the end of its life. We propose that the carbon sequestration pathway within EcoLeaf is adaptable and can serve as a versatile biomimetic platform for diverse biogenic carbon sequestration pathways in the future.

SEM/EDX and FTIR/ATR Behavior of Ammonium Perchlorate Under Accelerated Aging in a New Solid Rocket Motor Fuel Composition with Superior Explosive and Mechanical Performance

Abstract The oxidation potential of perchlorates is high, which makes this material suitable for fuels with high specific impulse. Perchlorates are characterized by a ClO4- moiety/anion in their molecular structure and are crystalline materials used in the formation of solid fuels. Ammonium perchlorate (AP) particle size and shape influence the manufacturing process of fuels and their burning rate. The physical and chemical processes that can occur in the natural degradation process of composite fuels are related to molecular reactions and diffusion phenomena governed by kinetic processes and can be accelerated by increasing the temperature. The paper presents studies carried out by scanning electron microscopy and infrared spectrometry on the behavior of ammonium perchlorate in the new composite material of solid rocket motor fuel under the effect of high temperature, in the range of 65-85οC, at regular time intervals. The self-initiation temperature was also determined, with a temperature rise rate controlled at 5ºC/minute. It is very likely that these accelerated aging studies will show the changes that occur in the stability, sensitivity, mechanical and functional properties of fuels during their lifetime.

Isolation and screening of microplastics from Nodularia spumigena and Phaeodactylum tricornutum and determining the efficacy of biodegradation of microplastics obtained using the synergistic consortium

Microplastics are a form of plastics which are less than 5mm in size. They are the major threat for the environment and mankind, as they critically influence the food chain. The best way to extinct them from the environment is to degrade them in eco-friendly manner where biodegradation is the optimal therapy. Phytoplanktons play a vital role in phytoremediation. They are capable of in taking certain water pollutants such as micro plastics. Nodularia spumigena and Phaeodactylum tricornutum were screened and the microplastics were extracted using optimized enzymatic or alklanized digestion process and then dried. The micro plastics obtained were weighed and the concentration of microplastic present per gram of the sample was calculated. UV- VIS spectroscopy and FTIR instrumental analysis were used to analyse the digestion process. In order to formulate a synergistic consortium to degrade the thus obtained microplastic, plastic undergoing the natural degradation process from the dump yard was collected and crowded plate technique was performed and the strains involved in the degradation were thus isolated and identified and sequenced. Synergistic consortium was formulated and then incubated with the microplastics screened. The incubation period was of about 60 days. UV- Spectroscopic analysis was done on 0th day, 30th day and 60th day. The graph evidently illustrates the difference as the incubation time progresses. The peak depicts the microplastic degradation based on the turbidity. As the microplastic gets degraded, the growth of the organism in the consortium also gets limited because the microplastics are the only source of carbon.

Spatial distribution characteristics of carbazole and polyhalogenated carbazoles in water column and sediments in the open Western Pacific Ocean

Polyhalogenated carbazoles (PHCZs), an emerging persistent halogenated organic pollutant, have been detected in the environment. However, our understanding of PHCZs in the ocean remains limited. In this study, 47 seawater samples (covering 50 – 4000 m) and sediment samples (49 surface and 3 cores) were collected to investigate the occurrence and spatial distribution patterns of carbazole and its halogenated derivants (CZDs) in the Western Pacific Ocean. In seawater, the detection frequencies of CZ (97.87%) and 3-CCZ (57.45%) were relatively high. In addition, the average concentration of ΣPHCZs in the upper water (< 150 m, 0.23 ± 0.21 ng/L) was significantly lower than that in the deep ocean (1000 – 4000 m, 0.65 ± 0.56 ng/L, P < 0.05), which may indicate the vertical transport of PHCZs in the marine environment. The concentration of ΣCZDs in surface sediment ranges from 0.46 to 6.48 ng/g (mean 1.54 ng/g), among which CZ and 36-CCZ were the predominant components. Results from sediment cores demonstrate a noteworthy negative correlation between the concentration of CZDs and depth, indicating the ongoing natural degradation process occurring in sediment cores over a long period. This study offers distinctive insights into the occurrence, composition, and vertical features of CZDs in oceanic environments.

Accelerated Weathering Testing (AWT) and Bacterial Biodegradation Effects on Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/Rapeseed Microfiber Biocomposites Properties.

In the context of sustainable materials, this study explores the effects of accelerated weathering testing and bacterial biodegradation on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/rapeseed microfiber biocomposites. Accelerated weathering, simulating outdoor environmental conditions, and bacterial biodegradation, representing natural degradation processes in soil, were employed to investigate the changes in the mechanical, thermal and morphological properties of these materials during its post-production life cycle. Attention was paid to the assessment of the change of structural, mechanical and calorimetric properties of alkali and N-methylmorpholine N-oxide (NMMO)-treated rapeseed microfiber (RS)-reinforced plasticized PHBV composites before and after accelerated weathering. Results revealed that accelerated weathering led to an increase in stiffness, but a reduction in tensile strength and elongation at break, of the investigated PHBV biocomposites. Additionally, during accelerated weathering, the crystallinity of PHBV biocomposites increased, especially in the presence of RS, due to both the hydrolytic degradation of the polymer matrix and the nucleating effect of the filler. It has been observed that an increase in PHBV crystallinity, determined by DSC measurements, correlates with the intensity ratio I1225/1180 obtained from FTIR-ATR data. The treatment of RS microfibers increased the biodegradation capability of the developed PHBV composites, especially in the case of chemically untreated RS. All the developed PHBV composites demonstrated faster biodegradation in comparison to neat PHBV matrix.

An investigation into the stability and degradation of plastics in aquatic environments using a large-scale field-deployment study

The fragmentation of plastic debris is a key pathway to the formation of microplastic pollution. These disintegration processes depend on the materials' physical and chemical characteristics, but insight into these interrelationships is still limited, especially under natural conditions. Five plastics of known polymer/additive compositions and processing histories were deployed in aquatic environments and recovered after six and twelve months. The polymer types used were linear low density polyethylene (LLDPE), oxo-degradable LLDPE (oxoLLDPE), poly(ethylene terephthalate) (PET), polyamide-6 (PA6), and poly(lactic acid) (PLA). Four geographically distinct locations across Aotearoa/New Zealand were chosen: three marine sites and a wastewater treatment plant (WWTP). Accelerated UV-weathering under controlled laboratory conditions was also carried out to evaluate artificial ageing as a model for plastic degradation in the natural environment. The samples' physical characteristics and surface microstructures were studied for each deployment location and exposure time. The strongest effects were found for oxoLLDPE upon artificial ageing, with increased crystallinity, intense surface cracking, and substantial deterioration of its mechanical properties. However, no changes to the same extent were found after recovery of the deployed material. In the deployment environments, the chemical nature of the plastics was the most relevant factor determining their behaviours. Few significant differences between the four aquatic locations were identified, except for PA6, where indications for biological surface degradation were found only in seawater, not the WWTP. In some cases, artificial ageing reasonably mimicked the changes which some plastic properties underwent in aquatic environments, but generally, it was no reliable model for natural degradation processes. The findings from this study have implications for the understanding of the initial phases of plastic degradation in aquatic environments, eventually leading to microplastics formation. They can also guide the interpretation of accelerated laboratory ageing for the fate of aquatic plastic pollution, and for the testing of aged plastic samples.

Advances in recycling of waste vulcanized rubber products via different sustainable approaches

The recycling of waste vulcanized rubber (WVR) products is highly challenging due to the presence of a three-dimensional (3D) sulfur crosslinked network hindering the natural degradation process.

Dynamics of desertification of arid ecosystems of Kizlyar pastures

The authors conducted research to identify the sources of formation of sand massifs, which then become the main cause of desertification of the territories of Kizlyar pastures, in order to carry out protective measures. In the article, the authors present materials confirming desertification and its ecological aspects. The ecological state of arid territories of Russia is one of the most acute problems that requires constant monitoring. Global changes in climatic conditions have a significant impact on the functioning of terrestrial ecosystems, including the soil cover. With the warming of the climate, the development of the processes of wind erosion and soil salinization increases. As a result, the pastures of Kizlyar were driven into extreme conditions. Pastures have come to an extremely critical state, and the degree of degradation of damage caused by these processes is much higher than other regions of the European South of Russia. The ecological situation of the territory is deteriorating rapidly. According to various estimates, large areas of them are occupied by open sands – 60.0 - 71.3 thousand hectares. As the analysis of the experience of the work carried out on the Kizlyar pastures shows, their effectiveness was extremely low, and in some places they contributed to the strengthening of the development of natural degradation processes. As a result, destabilizing factors have emerged that ensure the production of established phytocenoses, worsening conditions and progressing every year. At present, there are practically no improved pasture lands with natural vegetation in the Tersk-Kum lowland. In the current situation, the priority is to stop the activity of moving sands, as well as to improve the state of the species diversity of vegetation, otherwise, if these processes continue at the same pace, it may endanger the very existence of pastures and the basis of life in this territory.

Oxidation 1-methyl naphthalene based on the synergy of environmentally persistent free radicals (EPFRs) and PAHs in particulate matter (PM) surface

Studies of the environmental fate through the interactions of particle-associated polycyclic aromatic hydrocarbons (PAHs) with environmentally persistent free radicals (EPFRs) are presented. The formation of PAHs and EPFRs typically occurs side by side during combustion-processes. The laboratory simulation studies of the model PAH molecule 1-Methylnaphthalene (1-MN) interaction with model EPFRs indicate a transformational synergy between these two pollutants due to mutual and matrix interactions. EPFRs, thorough its redox cycle result in the oxidation of PAHs into oxy-/hydroxy-PAHs. EPFRs have been shown before to produce OH radical during its redox cycle in aqueous media and this study has shown that produced OH radical can transform other PM constituents resulting in alteration of PM chemistry.In model PM, EPFRs driven oxidation process of 1-MN produced 1,4-naphthoquinone, 1-naphthaldehyde, 4-hydroxy-4-methylnaphthalen-1-one, and various isomers of (hydroxymethyl) naphthalene. Differences were observed in oxidation product yields, depending on whether EPFRs and PAHs were cohabiting the same PM or present on separate PM. This effect is attributed to the OH radical concentration gradient as a factor in the oxidation process, further strengthening the hypothesis of EPFRs’ role in the PAH oxidation process.This finding is revealing new environmental role of EPFRs in a natural degradation process of PAHs. Additionally, it points to implications of such PM surface chemistry in the changing mobility of PAHs into an aqueous medium, thus increasing their bioavailability.

Update on Autophagy Inhibitors in Cancer: Opening up to a Therapeutic Combination with Immune Checkpoint Inhibitors.

Autophagy is a highly conserved and natural degradation process that helps maintain cell homeostasis through the elimination of old, worn, and defective cellular components, ensuring proper cell energy intake. The degradative pathway constitutes a protective barrier against diverse human diseases including cancer. Autophagy basal level has been reported to be completely dysregulated during the entire oncogenic process. Autophagy influences not only cancer initiation, development, and maintenance but also regulates cancer response to therapy. Currently, autophagy inhibitor candidates mainly target the early autophagy process without any successful preclinical/clinical development. Lessons learned from autophagy pharmaceutical manipulation as a curative option progressively help to improve drug design and to encounter new targets of interest. Combinatorial strategies with autophagy modulators are supported by abundant evidence, especially dealing with immune checkpoint inhibitors, for which encouraging preclinical results have been recently published. GNS561, a PPT1 inhibitor, is a promising autophagy modulator as it has started a phase 2 clinical trial in liver cancer indication, combined with atezolizumab and bevacizumab, an assessment without precedent in the field. This approach paves a new road, leading to the resurgence of anticancer autophagy inhibitors as an attractive therapeutic target in cancer.

Novel Simarouba glauca extract mediated biocompatible reduction of graphene oxide for robust scavenging of dyes and promising electrochemical applications

Dyes and pharmaceutical products are major environmental contaminants in the effluent of various industries such as cosmetics, textiles, pharmaceuticals, etc. Moreover, these non-biodegradable pollutants are frequently discharged into the water media without adequate precautions. Because of their intricate aromatic structures, dyes are resistant to natural degradation processes. As a result, various treatment techniques have been developed to remove dyes. Green synthesis is one such environmental technique regarding an alternative perception for the degradation of harmful materials like heavy metals, dyes etc. by exploiting biological samples. Therefore, in the present study dye adsorption and desorption studies of the green synthesised reduced graphene oxide (RGO) were investigated. The study presents an effective green reduction method for the facile synthesis of RGO using novel Simarouba/(Lakshmi Taru) extract through the reflux method at a temperature of 90 °C. As synthesised RGO has been analysed by SEM, XRD, Raman, UV–visible, Photoluminescence, TGA analysis, and FTIR studies. Cyclic voltammetry study exhibited a substantial improvement in current density for the RGO-3 hr sample. The maximum reduction efficiency of RGO accomplished using 100 ml of Simarouba extract was found to be 80% and it exhibits an outstanding capacity for the removal of dye with 94% efficiency. It was reported that Rhodamine B dyes were completely adsorbed within 10 min using 20 mg of RGO. It is investigated that adsorption follows langmuir isotherm model and pseudo-second-order kinetics. The thermodynamic studies specified that the whole adsorption is spontaneous, endothermic and physisorption in nature. The electrostatic interaction between the negatively charged surface of graphene oxide and reduced graphene oxide and positively charged surface of rhodamine B is responsible for the high affinity of adsorption of the graphene oxide and reduced graphene oxide. The proposed study reports the synthesis of highly stable and recyclable green-reduced GO by a cost-effective and eco-friendly technique.