Nanobiotechnology has revolutionized material synthesis by harnessing biological systems for the production of eco-friendly nanoparticles. This review examines the role of diatoms, a unique type of microalgae characterized by intricate biosilica-based frustules, as natural nanofactories for synthesizing nanostructured materials. The review provides an overview of green synthesis methods, emphasizing the advantages of biological routes, specifically microbial, plant-based, and algal systems, over conventional physical and chemical approaches. A dedicated focus on diatom-mediated nanoparticle synthesis highlights the role of frustules as nanostructured templates, the mechanisms of intracellular and extracellular synthesis, and the influence of factors such as pH, precursors, and light. Advances in genetically engineered and functionalized diatoms are discussed alongside recent innovations. The review further details their biomedical applications, encompassing antimicrobial and anticancer activities, drug delivery platforms, and biosensing/bioimaging. Finally, it addresses challenges in scalability, standardization, and future trends, including engineered frustules and hybrid nanomaterials, offering a comprehensive outlook on diatom-based nanotechnology for biomedical advancements.
1,3-propanediol (1,3-PDO) is an important monomer for polyester production with broad industrial applications. Klebsiella pneumoniae is currently recognized as a highly efficient producer of 1,3-PDO. However, the higher cost of glycerol substrate compared with glucose limits the economic feasibility of this route. In the present study, the K. pneumoniae strain FMME-KP was extensively engineered for efficient 1,3-PDO production from glucose. Strategies included the introduction of a glycerol synthetic pathway from glucose, balancing carbon distribution between biomass formation and product synthesis, alleviating carbon catabolite repression, and strengthening the 1,3-PDO biosynthetic route. The optimized strain, K. pneumoniae GZ31, produced 84.7 g/L of 1,3-PDO, achieving a yield of 0.51 g/g and a productivity of 1.74 g/L/h.
Lignin recovery from lignocellulosic material is a prominent solution to environmental concerns and problems and establishes more sustainable and competitive lignocellulosic biorefineries. Lignin has the potential to produce various commodity chemicals, biofuels, plastics, dyes, adhesives, concrete binders, foaming agents, lubricants, and nanomaterials, and is a commitment step for a safer and sustainable circular bioeconomy development. However, lignin valorization is hindered by a series of factors, i.e., heterogeneous nature, intrinsic recalcitrance, and the presence of strong intermolecular bonding and functionalities. Most of the lignin residue generated during cellulosic or pulp industries is combusted for electricity production in an uneconomic manner. Therefore, we have critically assessed and discussed the main constraints of novel strategies concerning lignin isolation and valorization, which is widely used in the landscape of lignocellulose biomass-based biorefining to reduce the dependency on fossil reserves and indirectly impacts the circular economy and lifestyle of people. Finally, this review highlights the integrated approach linked to enzyme-to-microbe, microbe-to-microbe interactions, or modified lignin fraction via employing metabolic engineering, discusses the commercial aspects of lignin in the market, and describes the future perspectives as well. Additionally, various advanced catalytic approaches under oxidative/reductive environments and hydrodeoxygenation are well explored, illustrating their influence on the selectivity of lignin depolymerization. The article will consolidate existing knowledge but also incorporate some novel perspectives for future advancement concerning lignin valorization in a sustainable way, which is a prerequisite objective for various biorefinery developments.
Dairy-derived carbohydrates are traditionally used as prebiotics; however, considering allergies, intolerance, and vegan lifestyles, plant-based prebiotics are being explored. This study investigated the prebiotic effects of banana fruit, oats grain and chicory root powders on indigenous lactic acid bacteria with the aim to develop a synbiotic instant mix that offers therapeutic benefits. It was seen that the water binding capacity was highest in banan fruit powder while Oat grain powder had the highest oil binding capacity. Chicory root showed the highest antioxidant potential for DPPH as well as ABTS with an IC50 (mg mL−1) of 3.76 ± 0.01(methnolic extract) and 1.61 ± 0.31 (Aqueous extract) respectively. The solvent type was seen to strongly affect the antioxidant capacity. No significant difference between the amylase hydrolysis of chicory root powder and standard inulin indicating its ability to remain undigested till it reaches the GI tract. The plant based prebiotics was able to support growth of probiotics however no significant difference (p = 0.48) in Δ log CFU/mL values of probiotic strains among tested prebiotic source were observed. A non dairy synbiotic product was formulated using L. plantarum KCFe6 and chicory with a total carbohydrate content of around 80%. There were no significant differences in the viable cell counts between the probiotic and synbiotic produced stored at (28 °C) and refrigerated conditions (4 °C) the cell count remained above 8 log CFU throughout the study period. The synbiotic product showed higher antimicrobial zones than the probiotic at room temperature and refrigerated conditions for all pathogens except S.typhimurium. The synbiotic product demonstrated higher antioxidant and anti-cholesterol abilities throughout the storage period compared to only probiotics, and storage at 4 °C was found to be better in preservation of functional properties. Overall this study supports the potential of using plant based prebiotics for developing a dry shelf stable synbiotic formulation for enhancing the probiotic viability and its functional properties.
Gamma-aminobutyric acid (GABA) is a bioactive, non-protein forming amino acid renowned for its role as a suppressive neurotransmitter in the mammalian nervous system and its diverse health benefits, including antihypertensive, antidiabetic, antidepressant, and anti-insomnia effects. Rising interest in GABA-enriched health-promoting foods has accelerated efforts towards sustainable and efficient production methods. This study aimed to maximise GABA production in fermented milk using a promising probiotic strain, Lactiplantibacillus plantarum B7, through fermentation conditions optimisation via the one-factor-at-a-time (OFAT) technique. Optimisation with research-grade and food-grade MSG and PLP resulted in GABA yields of 4.715 ± 0.071 g/L (265.89% increase) and 4.846 ± 0.078 g/L (275.97% increase), respectively. Food-grade medium was selected for subsequent development due to safety and cost considerations. Furthermore, L. plantarum B7 cells were immobilised on natural supports (watermelon rind and apple) to enhance cell protection during cold storage of GABA-enriched fermented milk. Both immobilised systems WRBFM (watermelon rind-based) and ABFM (apple-based) demonstrated superior GABA content, lactic acid production, antioxidant activity, and viable cell retention over a 28-day cold storage period compared to free-cell fermented milk (FCFM). These formulations also showed enhanced physicochemical properties, including greater viscosity and better moisture retention, and received higher preference scores in sensory evaluations. Overall, the study highlights the potential of combining fermentation optimisation and natural matrix-based immobilisation to produce stable, high-quality GABA-enriched fermented milk with promising functional and sensory attributes, supporting its application in the development of innovative health-promoting dairy products.
This study developed an enhanced reliability-based integrating (RBI) algorithm by incorporating metaheuristic optimization algorithms into the RBI framework in order to identify optimal gene knockout for strain optimization. To enhance the RBI algorithm, nine metaheuristic optimizations were used: aquila optimization (AO), differential search algorithm (DSA), genetic algorithm (GA), genetic algorithm based on natural selection theory (GABONST), grey wolf optimizer (GWO), komodo mlipir algorithm (KMA), particle swarm optimization (PSO), simulated annealing (SA), and whale optimization algorithm (WOA). The algorithms were simulated with six microbial strain models to optimize the production of succinate and ethanol under aerobic and anaerobic conditions. The analysis indicated that the enhanced algorithms have effectively identified the optimal gene knockout. Furthermore, the three most effective algorithms identified were WOARBI, GWORBI, and GABONSTRBI, which produced optimal mutant strains with the highest succinate or ethanol production rates. This study’s results demonstrated that the metaheuristic optimization algorithms effectively improved the performance of the RBI algorithm.
L-Asparaginase (L-ASNase) is an enzyme widely used on protocols for the treatment of acute lymphoblastic leukemia (ALL) and some solid tumors. It works by depleting asparagine, an essential amino acid for the growth of neoplastic cells, while normal cells can synthesize it independently. Today, only L-ASNase isolated from Escherichia coli and Erwinia chrysanthemi is approved and commercially available for clinical use. However, its application is often limited due to adverse effects and the development of resistance. To circumvent these challenges, researchers are exploring new sources of L-ASNase, mainly in bacteria, aiming advantages, like greater stability, reduced immunogenicity and, improved pharmacokinetic properties. Recent studies have identified promising L-ASNase candidates from Bacillus genus. In this context, we review recent data on the isolation of novel L-ASNase from Bacillus species, highlighting the importance of bioprospection for improving oncologic therapies.
Four different species of filamentous green algae were cultivated in separate ponds for 21 days to examine their biomass productivity, carbon dioxide sequestration potential, nutrient removal ability, and the generation of value-added products from the derived biomass. Among the tested algae, Spirogyra sahnii exhibited the highest dry biomass (1.30±0.15 kg), resulting in a carbon sequestration potential of 0.80±0.15 g CO2/m2/d. Harvested dry biomass was converted into pulp (including with additives) for the generation of possible value-added products, especially filter paper. Various characteristics of paper derived from algal pulp, including its tensile strength, flexibility, biodegradability, water resistance, softness, weight, porosity, water absorption capacity, and water retention capability, were measured to assess the quality of value-added products. The paper made from the pulp of Cladophora glomerata exhibited properties similar to those of commercially available filter papers. The obtained paper was also used for writing, and it showed comparable performance with the augmented paper derived from wood pulp. To enhance the mechanical strength and brightness of the algal papers, certain chemical additives, including starch, sulphur, and glycerol, were mixed with pulp in varying proportions. Making packaging materials and embossed religious objects from algal pulp has also been demonstrated. Overall, this study concludes that filamentous freshwater algae are a promising agent for sequestering carbon dioxide, and their biomass is a potential material for generating local income through the production of value-added products, which will also contribute to achieving sustainable development goals (SDGs) in an eco-friendly and cost-effective manner.
Proteins are an essential part of human diets as they provide the amino acids required to build structural tissues, enzymes, hormones, antibodies, and several other bioactive molecules. Conventional meat, eggs, and milk are the main sources of protein in Western society, providing all essential amino acids with high digestibility. However, discussions around the sustainability of animal-derived products, besides the ethical concerns related to animal welfare, have boosted the search for alternative proteins. Among the possible alternative protein sources, microbial biomass can be produced from agro-industrial substrates with high efficiency, being possibly integrated to conventional production chains in a circular economy. Another category of alternative proteins, the cultivated meat segment, can also take advantage of circularity strategies in the development of culture media and cell culture inputs of renewable origin and reduced cost. This review presents a description of circular economy approaches in the cultivation of protein-rich microbial biomass, including microalgae, fungi, and bacteria, and describes recent applications of agro-industrial products and by-products in animal cell culture for cultivated meat production.
In the present study, a novel biological process has been demonstrated in which Clostridium ljungdahlii DSM 13528, an acetogenic gas-fermenting organism, produces ethanol as the primary metabolic product. The process offers environmental sustainability, as the strain utilizes carbon dioxide and carbon monoxide, as the carbon source and electron donor. Modulation of the headspace gas composition (CO₂:CO ratio) and reactor headspace volume yielded a maximum biomass titer of 159.1 ± 10.8 mg/L with a productivity of 1.5 ± 0.1 mg/L/h. Sequential adaptation over 11–14 cultivation cycles resulted in a 26% increase in the specific growth rate in C. ljungdahlii medium with 1 g/L yeast extract (CLY) and a 160% increase in C. ljungdahlii medium without yeast extract (CLNY). Subsequently, a medium engineering strategy involving modulation of metal ions and nitrogen sources (nitrate and nitrite) was implemented to redirect carbon flux from acetate towards ethanol, as the main product. These combined strategies resulted in a maximum biomass titer of 274.5 ± 26.7 mg/L and a productivity of 2.14 mg/L/h, along with a maximum ethanol titer of 18.5 ± 3.4 mmol/L and a productivity of 13.2 mg/L/h in CLY medium supplemented with tungstate (2.5 mg/L) and nitrite (18.7 mmol/L). These values are among the highest reported for C. ljungdahlii DSM 13528 in batch mode of cultivation. Notably, when nitrite was used as the nitrogen source, the carbon flux was predominantly redirected towards ethanol, with only trace quantities of other products detected.
MicroRNA (miRNA) has emerged as a promising class of non-invasive and sensitive biomarkers for cancer diagnosis due to its close association with tumorigenesis. However, the accurate detection of miRNA remains challenging owing to its short sequence, high sequence homology among family members, and low abundance in biological samples. To address the demands of early cancer diagnosis and clinical prognosis monitoring, this study designed and fabricated a colorimetric microfluidic paper-based analytical device (µPAD) for the quantitative detection of miRNA-21. Leveraging the inherent porous structure and ease of functionalization of paper-based materials, along with the specific binding of streptavidin and biotin, this chip integrates microfluidic technology with the peroxidase-mimicking activity of gold-platinum core-shell nanoparticles (Au@Pt NPs) to achieve rapid and sensitive detection of miRNA-21. In the presence of the target miRNA-21, it preferentially hybridizes with the complementary DNA (cDNA), competitively releasing the pre-hybridized Au@Pt NPs-cDNA conjugate. This conjugate then migrates via capillary action to the detection zone, where the Au@Pt NPs catalyze the oxidation of the colorless 3,3’,5,5’-tetramethylbenzidine, producing a deep blue product, thereby converting the biological recognition event into a detectable optical signal. The miRNA-21 concentration can be conveniently quantified by capturing the image with a smartphone and analyzing the grayscale intensity using the freely available Image J software. Under optimized conditions, the proposed µPAD demonstrated a linear detection range from 1 to 2000 nmol/L with a limit of detection of 0.25 nmol/L. The method also showed good specificity and was successfully applied to the detection of miRNA-21 spiked in human serum samples. This work presents a rapid, simple, and cost-effective paper-based platform with considerable potential for point-of-care testing in early cancer diagnosis.
Cadaverine, a key precursor for nylon, is conventionally produced using free whole-cell lysine decarboxylase systems, with poor recoverability and limited reusability undermining industrial viability. Here, CadA-overexpressing E. coli were entrapped in κ-carrageenan and subsequently crosslinked with polyethylenimine (PEI) to enhance stability and operational longevity. Systematic optimization of gel parameters and CTAB permeabilization enabled robust 100-mL packed-bed reactor directly fed with lysine fermentation broth. The reactor maintained stable operation for 200 h, yielding 6.40 L of broth containing 112 g/L cadaverine at 97.4% conversion and productivity of 44.8 g/gDCW/h. Immobilized cells reached a total catalyst productivity of 8.96 kg cadaverine per gram dry cell weight and 19-fold increase over free cells. These advantages position κ-carrageenan/PEI immobilization as a practical and economical strategy for continuous cadaverine production.
Climate change and population growth are intensifying global pressure on food systems, demanding sustainable protein alternatives. While plant-based proteins represent important sustainable alternatives, rising global protein demand, environmental pressures, and limitations in agricultural expansion highlights the need for complementary protein sources such as microbial single-cell protein (SCP). This review examines the potential of bacterial SCP production from agricultural waste as a strategy to enhance food security and reduce environmental impact. This approach also aligns with the principle of circular economy by transforming waste materials into a valuable nutritional resource. Bacteria offer rapid growth, minimal land and water requirements, and broad substrate utilization, enabling efficient valorization of wastes. Key challenges arise from the recalcitrant structure of lignocellulosic residues, which necessitates effective pretreatment using physical, chemical, biological, or combined methods. The combined pretreatment approaches have been proven most effective in enhancing substrate accessibility. This review critically examines the mechanisms and pathways of bacterial SCP production from lignocellulosic wastes, with emphasis on process modelling, computational optimization, and emerging applications of artificial intelligence. Lastly, recent advances, current challenges, and future research directions are discussed. This review concludes that bacterial SCP represents a viable, climate-resilient solution for sustainable food systems, contributing to circular economy principles and global resource sustainability.
Glycyl-L-histidyl-L-lysine–copper (GHK-Cu), an endogenous tripeptide–metal complex, has attracted increasing interest due to its multifaceted biological roles in tissue repair, anti-inflammatory regulation, extracellular matrix remodeling, and redox homeostasis. In recent years, GHK-Cu has evolved from a dermatological bioactive ingredient into a representative model system linking coordination chemistry, peptide bioactivity, and biomanufacturing engineering. This review provides a comprehensive synthesis of the molecular mechanisms, production strategies, quality-control frameworks, and emerging applications of GHK-Cu in advanced biomaterials and delivery systems. Particular emphasis is placed on the key technologies enabling the transition from chemical synthesis to scalable biomanufacturing, including tandem-repeat expression, high-cell-density fermentation, inclusion-body-assisted purification, and Cu(II) complex stabilization. Analytical approaches for structural verification and impurity profiling, as well as global regulatory classifications and formulation-stability considerations, are also summarized. Remaining challenges in clinical translation, production standardization, and large-scale quality assurance are highlighted. This work aims to provide a systematic and forward-looking framework to support the industrial and biomedical deployment of copper–peptide therapeutics.
This study developed a novel hybrid β-farnesene synthase via semi-rational DNA shuffling and site-directed mutagenesis, utilizing the terpenoid-tolerant chassis Serratia marcescens HBQA7 as the host for β-farnesene biosynthesis. Initially, two wild-type enzymes from Artemisia annua and Matricaria chamomilla var. recutita were selected for domain swapping owing to their superior β-farnesene titers and 92.33% sequence identity. Specifically, hotspots within the optimal chimera CH11 were identified through sequence conservation analysis, molecular docking, and virtual saturation mutagenesis. Subsequently, six candidate residues were identified via alanine scanning, followed by site-saturation mutagenesis to evaluate superior single mutations. These beneficial mutations were further combined to construct double and triple variants. The optimal variant CH11 (K197S/F315L/E490D) yielded 8.5 g/L of β-farnesene in shake-flask fermentation, representing 1.50-fold and 1.66-fold increases relative to the parental enzymes. Molecular dynamics simulations revealed that the enhanced catalytic activity was attributable to improved substrate binding, facilitated by hydrogen bonding and the reinforcement of the hydrophobic network within the active site. In 5-L fed-batch fermentation, the β-farnesene titer produced by the triple mutant reached 63.9 g/L at 96 h. This work provides novel insights into the structure-function relationship of β-farnesene synthase and establishes a robust foundation for future enzyme engineering and industrial-scale β-farnesene biosynthesis.