Renewable Research Articles

The Convergence of Renewable Energy and Aquacultural Engineering for a Sustainable Food System

Renewable energy and aquacultural engineering combine to provide a disruptive approach to developing a sustainable and resilient food supply. This area of aquacultural engineering would automate feeding systems, oxygenation, recirculating aquaculture systems, and water quality monitoring by integrating renewable energy sources such as sun, wind, hydropower, and bioenergy. In order to improve the efficiency of freshwater and marine aquaculture systems, energy from renewable sources will reduce waste and maximize the usage of IoT and AI toward resource efficiency. For the agricultural sector, implementing renewable energy will diminish greenhouse gas emissions, reduce operations cost, and create energy independence for farms especially off-grid and remote ones. Diversification promotes eco-friendly practices such as IMTA and biofloc systems, increasing the organization's resilience to energy volatility and climate change. Although there are obstacles in the form of high upfront costs and integration complexity, renewable technology and hybrid systems do offer a viable solution. Through the preservation of ecological balance and the provision of a sustainable food supply for future generations, this combination of renewable energy and aquacultural innovation has the potential to completely transform aquaculture.

QUANTUM-INSPIRED CRYPTO SOLUTIONS:PIONEERING SUSTAINABLE FREQUENCIES

This project aims to develop a secure application that leverages quantum, computing and Google Quantum AI with a strong focus on sustainability .The application will employ advanced cryptographic techniques, including XOR gate signal processing and control engineering binomial z-transform methods, to ensure robust security and effectively prevent cybercrime. The application will be powered by renewable energy sources, specifically solar power, hydroelectric energy, and wind turbines. These renewable sources will be integrated with the quantum processor, utilizing AI predictive optimization control to efficiently manage energy consumption and maximize performance.This integration ensures that the application operates at peak efficiency while minimizing its carbon footprint. For example, the quantum processors operation can be optimized to align with the availability of renewable energy. During peak sunlight hours, solar panels can supply abundant power to the quantum processor, while the AI system predicts and adjusts the processors workload accordingly. Similarly, hydroelectric and wind turbine-generated power can be monitored and managed to provide consis- tent energy, ensuring that the quantum processor maintains high efficiency even when renewable energy availability fluctuates. Overall, this project represents a pioneering effort in the integration of quantum computing with sustainable practices, aiming to provide a secure and eco-friendly solution for modern cryptographic challenges.

Advanced methanotrophic bioreactor design for efficient bioremediation of hydrogen sulfide (H₂S) And Volatile Organic Compounds (Vocs): Integrating genetic engineering and industrial scalability

The convergence of advanced microbial biotechnology and metabolic engineering has facilitated groundbreaking advancements in bioremediation. This study presents the engineered Methylomicrobium buryatense strain 5GB1C-RO1, optimized for the simultaneous removal of hydrogen sulfide (H₂S) and volatile organic compounds (VOCs) within a two-stage methanotrophic bioreactor system. Through precise CRISPR/Cas9-mediated genome editing, critical metabolic pathways for sulfide oxidation (SQR, FCCAB, SOXABXYZ) and VOC degradation (alkB, adhP, todC1C2BA) were integrated, achieving catalytic efficiencies exceeding 3.2 × 10⁷ M⁻¹s⁻¹ and substrate conversion rates above 450 nmol min⁻¹ mg⁻¹ protein. The strain demonstrates exceptional robustness under industrial conditions, maintaining 95% pollutant removal efficiency at H₂S concentrations up to 1000 ppm and VOC concentrations exceeding 500 ppm. The innovative bioreactor system incorporates enhanced gas-liquid mass transfer mechanisms, achieving mass transfer coefficients (kLa) exceeding 300 h⁻¹ and enabling stable operation for over 1000 continuous hours. Experimental results confirm the system's capacity for pollutant mineralization, generating methane-rich biogas (>95% CH₄) and high-protein microbial biomass (>85%), which are valuable for energy and agricultural applications. This integrated bioremediation approach not only reduces reliance on chemical scrubbing and flaring but also supports circular economy principles by transforming waste gases into renewable resources. The technology provides a scalable, sustainable, and cost-effective solution to mitigate industrial emissions while addressing environmental and regulatory challenges. The findings highlight the potential of combining advanced genetic engineering with innovative bioreactor design to redefine industrial pollutant management and resource recovery.

Modelling, Design & Analysis of Bidirectional Interleaved DC to DC Converter

In today’s scenario, global warming is a major issue for the environment. To fight this issue, the shift from nonrenewable sources to renewable sources and the use of electric vehicles are increasing day by day. The bidirectional converters are the crucial device to run such renewable plants and electrical cars, where bidirectional power exchange is needed. To make a more efficient and reliable system, advanced or interleaved multiphasing technologies are required. A new interleaving bidirectional DC-to-DC converter is proposed in this paper to minimize the input current ripples and increase power handling capacity. This paper mainly describes the analysis of interleaved bidirectional converters in steady-state and two- and three-phase interleaved converter closed-loop simulations in both modes. The results show the interleaving of inductor-currents and stiff output voltage along with the bidirectional power flow capability, and the waveforms of interleaved inductor current, input current ripples, and output voltage are presented.

A Serum- and Feeder-Free System to Generate CD4 and Regulatory T Cells from Human iPSCs.

iPSCs can serve as a renewable source of a consistent edited cell product, overcoming limitations of primary cells. While feeder-free generation of clinical grade iPSC-derived CD8 T cells has been achieved, differentiation of iPSC-derived CD4sp and regulatory T cells requires mouse stromal cells in an artificial thymic organoid. Here we report a serum- and feeder-free differentiation process suitable for large-scale production. Using an optimized concentration of PMA/Ionomycin, we generated iPSC-CD4sp T cells at high efficiency and converted them to Tregs using TGFβ and ATRA. Using genetic engineering, we demonstrated high, non-viral, targeted integration of an HLA-A2 CAR in iPSCs. iPSC-Tregs +/- HLA-A2-targeted CAR phenotypically, transcriptionally and functionally resemble primary Tregs and suppress T cell proliferation in vitro. Our work is the first to demonstrate an iPSC-based platform amenable to manufacturing CD4 T cells to complement iPSC-CD8 oncology products and functional iPSC-Tregs to deliver Treg cell therapies at scale.

Land sharing, land sparing, and Triad forestry: modeling forest composition, diversity, and carbon storage under climate change and natural disturbances

ContextForests are vital renewable resources for timber, while also serving as carbon reservoirs and habitats for many terrestrial species. However, there are tradeoffs between timber production and other ecosystem services, such as carbon storage and biodiversity, highlighting the need for new management strategies that more effectively balance these tradeoffs. This case study models the effectiveness of four such strategies, based on a newly proposed management plan for a state forest in coastal Oregon.ObjectivesWe tested the effectiveness of four landscape-scale forest management strategies designed to minimize tradeoffs between timber production, carbon storage, and biodiversity. These strategies include land sparing (spatially separating timber production from conservation), land sharing (integrating timber production with conservation), and two variants of Triad management (dividing forests into intensive, extensive, and reserve areas). This study assesses the long-term impacts of these strategies on timber production, tree and shrub diversity, and carbon storage, while also evaluating how natural disturbances (i.e. wind and fire) and climate change could affect their relative benefits.MethodsWe used the spatially interactive, raster-based forest landscape model, LANDIS-II, to simulate forest succession, management, windthrow, and wildfire under a range of potential climate futures from 2016 until 2100.ResultsOur results demonstrate that while all management strategies ensured sustainable timber production, land sharing promoted the highest occupancy, Shannon diversity index, and biomass of key early and mid-successional tree and shrub species identified by managers for their conservation value. In contrast, Triad management and land sparing tended to maximize carbon storage. Under extreme climate projections, carbon storage was equally compromised across all management strategies and there was a further shift towards Douglas-fir dominance.ConclusionTo our knowledge, this study represents the first modelled comparison of land sharing, land sparing, and Triad management under climate change and natural disturbance regimes. Management strategies differed in their provisioning of carbon, diversity, and plant biomass, and while the relative differences between these benefits remained consistent, all outcomes were negatively affected by climate change. We demonstrate the use of LANDIS-II in strategic forest planning and highlight the necessity of using spatial models for informed decision-making to simultaneously achieve multiple forest management objectives under climate change and disturbances.

Analysis of The Energy Impact of Electric Vehicle Integration in Uruguay

Objective: The objective of this study is to investigate the integration of EVs in Uruguay between 2025 and 2040, based on data from the National Energy Balance (BEN) and the 2005–2030 Energy Policies (PE0530) document, aiming to analyze the impacts of the increasing adoption of EVs on the country's electrical system.. Theoretical Framework: The methodology of this research is based on the development of scenarios derived from indicators of the electric sector, transport sector, population, and vehicle fleet. It is structured around new indicators that allow the comparison of energy demand increases under three EV adoption rates in Uruguay: natural (1%), moderate (3%), and accelerated (10%). Python programming was used to evaluate the extrapolations of these indicators through Simple Linear Regression (RLS) and Simple Exponential Smoothing (SES), determining the most appropriate methodology using Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) metrics. Data were collected from governmental websites in Uruguay and other publicly accessible domains. Method: The methodology adopted for this research comprises [concisely describe the study design, including approach, participants, instruments, procedures, etc.]. Data collection was carried out through [explain the specific methods used, such as interviews, questionnaires, observations, among others]. Results and Discussion: The results revealed that EV adoption generates increasing impacts on electrical demand, with 1% and 3% scenarios showing controlled impacts, while the 10% scenario demonstrates a significant increase, requiring strategic adaptations to avoid overloading the electrical system. Despite the usefulness of RLS and SES projection methodologies, their limitations lie in their sensitivity to extreme variations and reliance on historical data, which may hinder accuracy in contexts of rapid changes or unforeseen factors, such as future policies or technological advancements. Research Implications: This study presents practical and theoretical implications, highlighting Uruguay's need to invest in the expansion of the SIN and renewable sources to meet potential future EV demand, as well as to implement integrated policies for electric mobility. Theoretically, it reinforces the use of methodologies like RLS and SES for robust projections, influencing sectors such as the automotive industry, adapting to electrification, and the environmental sector, through emissions reductions, showcasing the impact of interdisciplinary approaches. Originality/Value: This study adds value by highlighting how different scenarios affect the SIN infrastructure of a country, especially one powered by 97% renewable energy sources. The approach can guide the formulation of future energy policies, assisting in infrastructure planning, setting renewable generation targets, and promoting electric mobility. By quantifying demands and benefits, this study provides input for strategic decisions, supporting sustainable energy transition and aligning public policies.

Bridging the gap between defossilization and decarbonization to achieve net-zero industry

Abstract This paper examines the compatibility of broad decarbonization efforts, as embodied in the Circular Carbon Economy (CCE) framework, with a narrower concept of defossilization in achieving net-zero industry. Through case studies of the United States, Norway, and the United Arab Emirates (UAE), we analyze national industrial decarbonization strategies and present findings from extensive fieldwork, including 139 expert interviews and 124 site visits supplemented with document analysis.
Our results reveal that CCE and defossilization, or decarbonization through the elimination of fossil fuel extraction and use, are potentially compatible concepts in the long-term pursuit of net-zero industry. The CCE approach, which incorporates energy efficiency, renewable energy, electrification, low-carbon fuels, and carbon capture, utilization and storage, particularly offers a practical pathway for oil and gas producing countries to transition towards net-zero industrial emissions. CCE allows these and similar countries balance environmental goals with technical, economic, social and political challenges associated with defossilization.
The case studies demonstrate that all three countries are adopting CCE strategies tailored to their unique contexts. The US emphasizes a portfolio approach integrating multiple technologies, the UAE focuses on leveraging existing fossil fuel infrastructure for CCE efforts, and Norway capitalizes on its abundant renewable resources while investing in CCS and hydrogen projects utilizing its extensive oil and gas sector expertise and resources.
Key policy recommendations include technology and policy leadership from countries pursuing a CCE framework, encouragement of public-private partnerships in the deployment of CCE technologies and ensuring social equity as net-zero industry is pursued in the near and long term. We also summarize existing approaches, pathways, and frameworks for industrial decarbonization, as well as barriers and challenges. We lastly call for further research on integration of CCE and defossilization visions, strategies and roadmaps and a strong focus on international cooperation in achieving net-zero industry.

Drivers and challenges for wood-based construction in urban areas

Abstract Wood-based construction (WBC) has gained prominence as a sustainable alternative to traditional construction, offering significant environmental benefits such as carbon storage and reduced greenhouse gas emissions. Its importance lies in its potential to contribute to climate change mitigation while supporting economic growth and innovation in the construction industry. Therefore, understanding the drivers and challenges of WBC is essential for its future development. This study, at the first stage, conducted a literature review to identify the key drivers and challenges associated with WBC, categorizing them into environmental, technical, economic, and perception and policy aspects. Then, based on these findings, we conducted 20 semi-structured interviews with WBC experts from Finland in the construction industry, public administration and academia to compare theoretical perspectives with practical insights. Results revealed that literature often focuses on matters such as life-cycle assessments, policy development, and renewable resource management. On the other hand, interviewees emphasize practical concerns like technical feasibility, economic viability, and client perceptions. Climate considerations are acknowledged by interview participants as important but are often viewed as external expectations rather than core business drivers. This study highlights the gap between academic research and industry practice.

Liquid Metals for Advanced Batteries: Recent Progress and Future Perspective

ABSTRACTThe shift toward sustainable energy has increased the demand for efficient energy storage systems to complement renewable sources like solar and wind. While lithium‐ion batteries dominate the market, challenges such as safety concerns and limited energy density drive the search for new solutions. Liquid metals (LMs) have emerged as promising materials for advanced batteries due to their unique properties, including low melting points, high electrical conductivity, tunable surface tension, and strong alloying tendency. Enabled by the unique properties of LMs, four key scientific functions of LMs in batteries are highlighted: active materials, self‐healing, interface stabilization, and conductivity enhancement. These applications can improve battery performance, safety, and lifespan. This review also discusses current challenges and future opportunities for using LMs in next‐generation energy storage systems. image

Engineering yeast to produce fraxetin from ferulic acid and lignin

Lignin, the most abundant renewable source of aromatic compounds on earth, remains underexploited in traditional biorefining. Fraxetin, a naturally occurring flavonoid, has garnered considerable attention in the scientific community due to its diverse and potent biological activities such as antimicrobial, anticancer, antioxidant, anti-inflammatory, and neurological protective actions. To enhance the green and value-added utilization of lignin, Saccharomyces cerevisiae was engineered as a cell factory to transform lignin derivatives to produce fraxetin. The expression of scopoletin 8-hydroxylase (S8H) and coumarin synthase (COSY) enabled S. cerevisiae to produce fraxetin from ferulic acid, one of the three principal monomers. The optimized fermentation strategies produced 19.1 mg/L fraxetin from ferulic acid by engineered S. cerevisiae. Additionally, the engineered cell factory achieved a fraxetin titer of 7.7 mg/L in lignin hydrolysate. This study successfully demonstrates the biotransformation of lignin monomers and lignin hydrolysate into fraxetin using a S. cerevisiae cell factory, thereby providing a viable strategy for the valorization of lignin.Key points• AtS8H showed substance specificity in the hydroxylation of scopoletin.• AtCOSY and AtS8H were key enzymes for converting ferulic acid into fraxetin.• Yeast was engineered to produce fraxetin from lignin hydrolysate.

Innovation Strategies for Ecological Sustainability: Effects of Natural Resources and Energy Consumption

ABSTRACTTo attain global ecological sustainability within the framework of ecological modernization, this study scrutinizes the multifaceted interaction among environmental‐related patent technologies (ERPT), natural resources, energy consumption (both renewable and nonrenewable energy usage) and globalization on the ecological footprint. To assess the novel aspects of the ongoing objective, this study employs Disc/Kraay, fully modified ordinary least square (FMOLS), and dynamic ordinary least square (DOLS) regression to generate comparative results across a panel of technologically advanced countries and resource‐rich least‐developed countries from 1990 to 2022. The empirical outcomes indicate that economies leading in eco‐friendly technologies and renewable sources of energy enhance environmental sustainability by minimizing their ecological footprint over time. In contrast, countries that rely heavily on natural resource extraction to meet energy demands tend to exacerbate ecological degradation. The process of globalization demonstrates the same trend for both developed and developing countries over the long term significantly elevating the level of ecological footprint. The Dumitrescu and Hurlin causality test discloses a reverse causal connection among concerning variables such as natural resources, ERPT, and energy reliance excluding globalization over the extended duration. The recommendations derived from the results suggest that governments in developing countries should strategically promote the adoption and dissemination of innovative, eco‐friendly resource extraction technologies. Meanwhile, governments in developed countries should focus on overhauling their ecological policies to play a crucial role in supporting and advancing ecological sustainability efforts in developing nations.

Experimental Study of Compression Behavior on Monolayer FFF Samples

Additive manufacturing (AM) processes, such as Fused Filament Fabrication (FFF), enable the production of lightweight parts with high stiffness-to-weight ratios, making them highly suitable for a wide range of engineering applications. However, ensuring the mechanical reliability of these components, particularly for load-bearing purposes, requires systematic mechanical testing of well-designed specimens to asses their suitability. While the tensile properties of additively manufactured materials have been extensively studied, the compressive behavior of components produced via AM, particularly those made from thermoplastic materials, remains comparatively underexplored and insufficiently characterized in the existing body of research. Among these materials, polylactic acid (PLA)—a biodegradable thermoplastic derived from renewable resources—has gained prominence in AM applications. Recent studies have investigated the compression properties of PLA in reinforced materials; however, the focus has primarily been on solid, semi-solid, or porous specimens. These investigations largely overlook thin-walled structures, which are integral to weight-saving designs and commonly feature in topology-optimized structures. Understanding the mechanical behavior of monolayers, the fundamental building blocks of most AM components, is essential for accurately predicting the overall performance of multilayer structures. Monolayers represent the smallest, most basic structural elements of AM parts, and their properties directly influence the behavior of the final, more complex assemblies. Establishing a methodology that correlates monolayer properties with those of multilayer components could significantly streamline testing procedures. By performing mechanical tests on monolayers, instead of on more intricate multilayer specimens, manufacturers could reduce testing complexity and cost while accelerating the development process. The current literature reveals a gap in the design and analysis of thin-walled AM specimens, especially monolayers, under compressive loads. Specifically, the design of monolayer or thin-walled AM compression specimens without infill has not been thoroughly explored. This article addresses this gap by investigating the design and testing of AM monolayer compression specimens produced using FFF of PLA. Three distinct specimen geometries are considered—circular, helicoidal, and S-shaped—to evaluate their potential for understanding and predicting the compressive behavior of AM monolayer structures.

Coptis Root-Derived Hierarchical Carbon-Supported Ag Nanoparticles for Efficient and Recyclable Alkyne Halogenation

The advancement of green chemistry and sustainable chemical processes has been significantly facilitated by catalytic systems derived from plant roots, which also present substantial application prospects in the realm of chemical synthesis. This study utilized the roots of Rhizoma Coptidis as a support to successfully fabricate a silver-based nanocatalyst. By depositing silver nanoparticles onto the root material of Coptis chinensis and subjecting it to carbonization, a silver/carbon composite was synthesized, featuring monodisperse silver nanoparticles and a hierarchical mesoporous carbon framework. This composite exhibits robust surface activity, a well-defined pore structure, and superior mechanical properties. The catalyst achieves a catalytic yield nearing 90%, showcasing remarkable activity in terminal alkyne halogenation reactions. Its stability and recyclability are markedly enhanced; it retains 95% of its mass and remains unaltered in the reaction solvent for over 160 h after five cycles. This method simplifies the synthesis of terminal alkynes and their derivatives, rendering the process more environmentally benign and efficacious. Furthermore, it broadens the potential applications of Rhizoma Coptidis in synthetic chemistry and pioneers a novel approach for the synthesis of precious metal catalysts from renewable resources.

Double Cross-linked Methacrylated Carboxymethyl Pea Starch Cryogels with Highly Compressive Elasticity and Hemostatic Function.

As an abundant renewable natural material, starch has attracted unprecedented interest in the biomedical field. Carboxylated starch particles have been investigated for topical hemostasis, but the powder may not provide physical protection or support for wounds. Here, we prepared macroporous cryogel sponges of methacrylated carboxymethyl starch (CM-ST-MA) containing a covalent and a calcium ionic double network. The second ionic cross-linking network enhanced the compressive strength and toughness dramatically but reduced the swelling ratios. Cryogels and sponges exhibited excellent compressive elasticity at low Ca2+ concentrations (0.01 M). Cryogels became more plastic and dry sponges became rigid and brittle at high Ca2+ concentrations. The cryogels have outstanding wet-thermal stability but are still degradable via enzymatic hydrolysis. All CM-ST-MA sponges showed excellent biocompatibility, hemocompatibility, and outstanding hemostasis in in vitro assays. In the in vivo mouse tail amputation model, both CM-ST-MA cryogels without or with Ca2+ (0.01 M) reduced the blood loss and bleeding time significantly.

Modeling and Prediction of Demand Response Based on Deep Quantum Neural Networks

Demand Response (DR) plays a crucial role in modern power networks, addressing the challenges posed by increasing renewable energy integration, grid modernization, and sustainability goals. By modifying electricity consumption patterns in response to signals such as price fluctuations or grid conditions, DR helps balance supply and demand on the grid, reduce peak demand, alleviate grid congestion, and integrate renewable energy resources more effectively. However, effective DR strategies require accurate modeling and prediction of DR behavior. In this research, a novel modeling and prediction strategy for DR that integrates deep learning and quantum computing principles is proposed. The approach involves two main phases: preprocessing and prediction. During preprocessing, input data undergo normalization using an improved Z-score technique. Subsequently, the normalized data are processed by the Modified Deep Quantum Neural Network (MDQNN) model during the prediction phase. MDQNN, an enhanced version of Deep Quantum Neural Networks (DQNN), employs angle encoding to enhance prediction accuracy by effectively identifying patterns. The efficacy of this strategy is demonstrated through comprehensive analyzes, highlighting its potential to enhance DR prediction accuracy and contribute to the advancement of power network optimization and sustainability objectives.

Multi-Criteria Optimal Operation Strategy for Photovoltaic Systems in Large-Scale Logistics Parks Concerning Climate Impact

Solar power is widely regarded as one of the most promising renewable resources for generating electricity and reducing building energy consumption. Logistics parks, with their low-rise buildings and extensive rooftop areas, offer significant advantages for solar energy utilization via rooftop photovoltaics (PVs). However, limited research has been conducted on the proper operational principles and optimized control strategies for the PV systems of logistics parks, particularly regarding the mismatch between power generation and the loads of various building types under varying climatic conditions. This study proposes four optimal PV operation strategies for large-scale logistics parks across diverse climatic regions, developed using a multi-criteria optimization approach. The strategies optimize the azimuth and tilt angles of PV panels under four adjustment frequencies: annual, semi-annual, seasonal, and monthly. The investigated strategies are validated in a 5500 m2 logistics park, comprising refrigerated storage, warehouses, sorting centers, and other facilities. The results indicate that the proposed strategies outperform conventional fixed-angle approaches, with the monthly adjustment strategy delivering the best performance. Economic costs are reduced by 9.26–17.02%, while self-sufficiency can be improved by 2.00–7.08%. Cold regions with high solar radiation show particularly significant benefits, with self-consumption increasing by 82.44–359.04%. This study provides valuable insights and practical guidelines for optimizing PV system operations in logistics parks, offering enhanced energy efficiency and cost-effectiveness.

Climate change response measures in South African road transport sector: lessons from BRICS countries

Climate change can be mainstreamed into road transport sector and its policies by integrating mitigation actions, focusing on Green-House Gas (GHG) emission reduction, and building adaptive capacity for a climate-resilient road transport sector. Although research frequently emphasizes the difficulties of adaptation, this article explores the influence of climate change on the road transport network and examines how road transport contributes to climate change. Factors such as experiencing the costs of climate change, valuing the local ecosystem, resources availability, and political will is key to successful adaptation efforts. This article used desk research to gather information on mitigation and adaptation actions adopted by BRICS countries from various sources like government documents, the internet, books, articles and scientific reviews. It is therefore, deduced that BRICS countries can promote climate-friendly transport by prioritizing green logistics, green innovation and renewable natural resources, while promoting sustainable development and supporting renewable energy. BRICS represents Brazil, Russia, India, China, and South Africa, a group of developing economies working together to strengthen their economic and political influence. This article draws lessons from BRICS countries and conclude that South Africa should decrease fossil fuel use in the road transport sector for climate-friendly options.

Recent advances in engineering non-native microorganisms for poly(3-hydroxybutyrate) production.

Poly(3-hydroxybutyrate) (PHB) is a biodegradable polymer that belongs to a group of polymers called polyhydroxyalkanoates (PHAs). PHB can be synthesized from renewable resources, making it a promising alternative to petroleum-derived plastics. It is also considered non-toxic, biodegradable, and biocompatible, which makes it suitable for various applications in the medicine and biomedicine. Many microorganisms biosynthesize and accumulate PHB naturally. However, recent advancements in metabolic engineering and synthetic biology have allowed scientists to engineer non-native microorganisms to produce PHB. This review comprehensively summarizes all non-native microbial hosts used for PHB biosynthesis and discusses different metabolic engineering approaches used to enhance PHB production. These strategies include optimizing the biosynthesis pathway through cofactor engineering, metabolic pathway reconstruction, and cell morphology engineering. Moreover, the CRISPR/Cas9 approach is also used for manipulating the genome of non-host microorganisms to enable them produce PHB. Among non-native microbial hosts, Escherichia coli has been successfully used for industrial-scale PHB production. However, further genetic engineering approaches are needed to make non-native microbial hosts more suitable for large-scale PHB production.

Comparative Study of Squalane Products as Sustainable Alternative to Polyalphaolefin: Oxidation Degradation Products and Impact on Physicochemical Properties

The growing demand for sustainable lubricant solutions is driving the exploration of bio-based materials that deliver comparable performance to conventional, primarily fossil-based lubricant chemistries. This study focuses on squalane as a sustainable base oil, which can be derived from different renewable sources. A total of two squalane products were evaluated for thermal-oxidative stability and benchmarked against a polyalphaolefin, PAO 4, of the same total carbon number. Oils artificially altered in a closed reactor were sampled and subjected to conventional lubricant analyses, including infrared spectroscopy, to determine the changes due to autoxidation over time. For in-depth information, direct-infusion high-resolution mass spectrometry and gas chromatography coupled with triple quadrupole mass spectrometry were employed to identify degradation products from thermo-oxidative stress. The results revealed substantial variability in the stability of squalane products, suggesting that differences in raw materials and production processes have a major impact on their performance, including rheological properties. The degradation products of polyalphaolefin and squalane, identified through detailed mass spectrometry, were analyzed to understand their impact on conventional physicochemical properties. While polyalphaolefin predominantly generated carboxylic acids with short to medium chain lengths as degradation products, squalane oxidation produced carboxylic acids with medium to long chain lengths as well as several alcohols and ketones. Despite these differences, squalane demonstrates its potential as a non-fossil hydrocarbon base oil, as squalane products matched and even exceeded PAO 4 stability.