Production optimization and antioxidant potential of exopolysaccharide produced by a moderately halophilic bacterium Virgibacillus dokdonensis VITP14.

This study aimed to enhance the extracellular polymeric substances (EPS) production of Virgibacillus dokdonensis VITP14 and explore its antioxidant potential. EPS and biomass production by VITP14 strain were studied under different culture parameters and media compositions using one factor at a time method. Among different nutrient sources, glucose and peptone were identified as suitable carbon and nitrogen sources. Furthermore, the maximum EPS production was observed at 5% of inoculum size, 5 g/L of NaCl, and 96 h of fermentation. Response surface methodology was employed to augment EPS production and investigate the optimal levels of nutrient sources with their interaction. The strain was observed to produce actual maximum EPS of about 26.4 g/L for finalized optimum medium containing glucose 20 g/L, peptone 10 g/L, and NaCl 50 g/L while the predicted maximum EPS was 26.5 g/L. There was a nine fold increase in EPS production after optimization study. Additionally, EPS has exhibited significant scavenging, reducing, and chelating potential (>85%) at their higher concentration. This study imparts valuable insights into optimizing moderately halophilic bacterial EPS production and evaluating its natural antioxidant properties. According to findings, V. dokdonensis VITP14 was a promising isolate that will provide significant benefits to biopolymer producing industries.

Comparative assessment of the acute toxicity of commercial bio-based polymer leachates on marine plankton.

Conventional plastics have become a major environmental concern due to their persistence and accumulation in marine ecosystems. The development of potential degradable polymers (PBP), such as polyhydroxyalkanoates (PHAs) and polylactic acid (PLA), has gained attention as an alternative to mitigate plastic pollution, since they have the potential to biodegrade under certain conditions, and their production is increasing as replacement of conventional polyolefins. This study aimed to assess and compare the toxicity of leachates of pre-compounding PBP (PLA and the PHA, polyhydroxybutyrate-covalerate (PHBv)) and polypropylene (PP) on five marine planktonic species. A battery of standard bioassays using bacteria, microalgae, sea urchin embryos, mussel embryos and copepod nauplii was conducted to assess the toxicity of leachates from those polymers. Additionally, the presence of chemical additives in the leachates was also verified through GC-MS and LC-HRMS analysis. Results showed that PHBv leachates exhibited higher toxicity compared to other polymers, with the microalgae Rhodomonas salina, being the most sensitive species to the tested leachates. On the other hand, PP and PLA generally displayed minimal to no toxicity in the studied species. Estimated species sensitivity distribution curves (SSD) show that PHBv leachates can be 10 times more hazardous to marine plankton than PP or PLA leachates, as demonstrated by the calculated Hazardous Concentration for 5 % of species (HC5). Qualitative chemical analysis supports the toxicological results, with 80 % of compounds being identified in PHBv leachates of which 2,4,6-trichlorophenol is worth mentioning due to the deleterious effects to aquatic biota described in literature. These findings underscore the fact that whereas environmental persistence can be targeted using PBP, the issue of chemical safety remains unsolved by some alternatives, such as PHBv. Gaining a comprehensive understanding of the toxicity profiles of PBP materials through a priori toxicological risk assessment is vital for their responsible application as alternatives to conventional plastics.

Use of Silk Fibroin Material Composites for Green, Flexible Supercapacitors.

Within the context of seeking eco-friendly and readily available materials for energy storage, there is a pressing demand for energy storage solutions that employ environmentally sustainable, high-performance, and adaptable constituents. Specifically, such materials are essential for use in wearable technology, smart sensors, and implantable medical devices, whereas, more broadly, their use plays a pivotal role in shaping their efficiency and ecological footprint. Here, we demonstrate an entirely biopolymer-based supercapacitor with a remarkable performance, achieving a capacitance greater than 0.2 F cm-2 at a charge-discharge current of 10 mA cm-2 with 94% capacitance retention after 20,000 cycles. The supercapacitor is composed of three distinct silk fibroin (SF) composite materials, namely, photo-cross-linkable SF (Sil-MA) hydrogel, SF-polydopamine (SF-PDA), and SF bioplastic, to create a gel electrolyte, electrode binder, and encapsulation, respectively. Together, these elements form a mechanically and electrochemically robust skeleton for biofriendly energy storage devices. Moreover, these biomaterial-based supercapacitor devices show stretchability, flexibility, and compressibility while maintaining their electrochemical performance. The biomaterials and fabrication techniques presented can serve as a foundation for investigating various aqueous electrochemical energy storage systems, especially for emerging applications in wearable electronics and environmentally friendly material systems.

Miniaturized 3D-printed hand-operable dispersive sample pretreatment device with replaceable chitosan/polydopamine thin film metal sorbent for enhanced metal analysis.

To address the increasing demand for sensitive and selective sample preparation methods for metal analysis; preconcentration of intended analyte from complex sample matrices before analysis is required to improve the performance of analysis instruments. In this study, we have engineered a sustainable and portable syringe-based hand-operable three-dimensionally (3D) printed sample pretreatment apparatus equipped with a replaceable bio-based thin- film metal sorbent. This device effectively addresses the challenges of sample matrix interference in metal analysis. A metal sorbent film composed of chitosan (CS) and polydopamine (PDA) leveraged the diverse functional groups in the CS/PDA matrix to significantly enhance the extraction efficiency for various metals. Our approach demonstrated excellent analytical performance, with coefficients of determination (R2) of 0.9982 for copper (Cu) and 0.996 for chromium (Cr). The method achieved low limits of detection (LOD) of 0.3 µg L-1 for Cr and 0.7 µg L-1 for Cu. Precision and practicality assessments using actual urine samples yielded satisfactory relative standard deviations (RSD%) ranging from of 1.6 %-8.5 % for both metals, indicating minimal interference from the sample matrix. Moreover, our approach exhibited robust performance even after seven consecutive extraction and desorption cycles, highlighting its sustainability and practical applicability for laboratory and on-site sample pretreatment.

Organic nanoparticles incorporated starch/carboxymethylcellulose multifunctional coating film for efficient preservation of perishable products.

Most of postharvest agricultural produces are perishable due to microorganisms infections and physiological change. Herein, one kind of multifunctional coating film of SC-ECCNPs was developed by incorporating organic nanoparticles of ECCNPs into starch/carboxymethylcellulose (SC) to prolong shelf life of food with excellent performances. The SC-ECCNPs coating was prepared with starch and sodium carboxymethylcellulose as film substrate (SC) to incorporate with organic nanoparticles of ECCNPs formed by integrating epigallocatechin-3-gallate (EGCG), cysteine (Cys), and cinnamaldehyde (CA). The incorporation of ECCNPs improves the UV-resistance and physical properties of SC-ECCNPs coating and also endows it with excellent antioxidative and broad-spectrum antibacterial activity. The application possibilities of SC-ECCNPs coating were explored with strawberries and oranges as samples, validating that the SC-ECCNPs coating can prolong the shelf life of fruits at room temperature. The biosafety of the coating was further confirmed with hemolysis and MTT experiments. The SC-ECCNPs coating film was prepared with natural substrates via a simple and green method. The investigation provides an instructive way for developing advanced packaging materials with high performances.

Lanthanum-based magnetic biopolymers for brilliant green removal from aqueous solutions.

In this study, lanthanum (La)-based magnetic biopolymers were synthesized, and the first adsorption study was conducted on the removal of brilliant green dye from aqueous water with these biopolymers. For the adsorption study, adsorption parameters were investigated and the ideal adsorption conditions determined for the removal of brilliant green dye from aqueous solutions are pH 11, t 60 min, m 10 mg, C0 25 mg/L, T 298 K. It was determined that the adsorption process was compatible with the single-layer Langmuir isotherm, and maximum adsorption capacity obtained according to the Langmuir isotherm was calculated as 256.41 mg/g. The adsorption process was found to be in accordance with the pseudo-second-order, and the adsorption process was explained by intra-particle diffusion. According to studies of adsorption thermodynamics, it has been established that the nature of the adsorption reaction is spontaneous, and this process is endothermic and has increasing randomness. Moreover, the reusability of magnetic lanthanum/alginate (La/Alg) biopolymers was investigated, and it was determined that the biopolymers could be used successfully. In summary, brilliant green dye has been successfully removed with simple, low-cost, environmentally friendly, and easily obtained magnetic La/Alg biopolymers. It can be stated that even low amounts of these biopolymers can be effective in the treatment of highly concentrated dye wastewaters.

Recent Advances of Bio-Based Hydrogel Derived Interfacial Evaporator for Sustainable Water and Collaborative Energy Storage Applications.

Solar interfacial evaporation strategy (SIES) has shown great potential to deal with water scarcity and energy crisis. Biobased hydrogel derived interfacial evaporator can realize efficient evaporation due to the unique structure- properties relationship. As such, increasing studies have focused on water treatment or even potential accompanying advanced energy storage applications with respect of efficiency and mechanism of bio-based hydrogel derived interfacial evaporation from microscale to molecular scale. In this review, the interrelationship between efficient interfacial evaporator and bio-based hydrogel is first presented. Then, special attention is paid on the inherent molecular characteristics of the biopolymer related to the up-to-date studies of promising biopolymers derived interfacial evaporator with the objective to showcase the unique superiority of biopolymer. In addition, the applications of the bio-based hydrogels are highlighted concerning the aspects including water desalination, water decontamination atmospheric water harvesting, energy storage and conversion. Finally, the challenges and future perspectives are given to unveil the bottleneck of the biobased hydrogel derived SIES in sustainable water and other energy storage applications.

PHB+aPHA Blends: From Polymer Bacterial Synthesis through Blend Preparation to Final Processing by Extrusion for Sustainable Materials Design.

The inherent brittleness of polyhydroxybutyrate (PHB), a well-studied polyhydroxyalkanoate (PHA), limits its applicability in flexible and impact-resistant applications. This study explores the potential of blending PHB with a different PHA to overcome brittleness. The synthesis of PHA polymers, including PHB and an amorphous medium-chain-length PHA (aPHA) consisting of various monomers, was achieved in previous works through canola oil fermentation. Detailed characterization of aPHA revealed its amorphous nature, as well as good thermal stability and shear thinning behavior. The blending process was carried out at different mass ratios of aPHA and PHB, and the resulting blends were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The blends exhibited complex DSC curves, indicating the presence of multiple crystalline forms of PHB. SEM images revealed the morphology of the blends, with PHB particles dispersed within the aPHA matrix. TGA showed similar thermal degradation patterns for the blends, with the residue content decreasing as the PHB content increased. The crystallinity of the blends was influenced by the PHB content, with higher PHB ratios resulting in an increased degree of crystallinity. XRD confirmed the presence of both α and ß crystals of PHB in the blends. Overall, the results demonstrate the potential of PHB+aPHA blends to enhance the mechanical properties of biopolymer materials, without com-promising the thermal stability, paving the way for sustainable material design and novel application areas.

An exopolysaccharide pathway from a freshwater Sphingomonas isolate.

Bacteria embellish their cell envelopes with a variety of specialized polysaccharides. Biosynthesis pathways for these glycans are complex, and final products vary greatly in their chemical structures, physical properties, and biological activities. This tremendous diversity comes from the ability to arrange complex pools of monosaccharide building blocks into polymers with many possible linkage configurations. Due to the complex chemistry of bacterial glycans, very few biosynthetic pathways have been defined in detail. As part of an initiative to characterize novel polysaccharide biosynthesis enzymes, we isolated a bacterium from Lake Michigan called Sphingomonas sp. LM7 that is proficient in exopolysaccharide (EPS) production. We identified genes that contribute to EPS biosynthesis in LM7 by screening a transposon mutant library for colonies displaying altered colony morphology. A gene cluster was identified that appears to encode a complete wzy/wzx-dependent polysaccharide assembly pathway. Deleting individual genes in this cluster caused a non-mucoid phenotype and a corresponding loss of EPS secretion, confirming the role of this gene cluster in polysaccharide production. We extracted EPS from LM7 cultures and determined that it contains a linear chain of 3- and 4-linked glucose, galactose, and glucuronic acid residues. Finally, we show that the EPS pathway in Sphingomonas sp. LM7 diverges from that of sphingan-family EPSs and adhesive polysaccharides such as the holdfast that are present in other Alphaproteobacteria. Our approach of characterizing complete biosynthetic pathways holds promise for engineering polysaccharides with valuable properties. IMPORTANCE: Bacteria produce complex polysaccharides that serve a range of biological functions. These polymers often have properties that make them attractive for industrial applications, but they remain woefully underutilized. In this work, we studied a novel polysaccharide called promonan that is produced by Sphingomonas sp. LM7, a bacterium we isolated from Lake Michigan. We extracted promonan from LM7 cultures and identified which sugars are present in the polymer. We also identified the genes responsible for polysaccharide production. Comparing the promonan genes to those of other bacteria showed that promonan is distinct from previously characterized polysaccharides. We conclude by discussing how the promonan pathway could be used to produce new polysaccharides through genetic engineering.

Molecular Dynamic Simulations for Biopolymers with Biomedical Applications.

Computational modeling (CM) is a versatile scientific methodology used to examine the properties and behavior of complex systems, such as polymeric materials for biomedical bioengineering. CM has emerged as a primary tool for predicting, setting up, and interpreting experimental results. Integrating in silico and in vitro experiments accelerates scientific advancements, yielding quicker results at a reduced cost. While CM is a mature discipline, its use in biomedical engineering for biopolymer materials has only recently gained prominence. In biopolymer biomedical engineering, CM focuses on three key research areas: (A) Computer-aided design (CAD/CAM) utilizes specialized software to design and model biopolymers for various biomedical applications. This technology allows researchers to create precise three-dimensional models of biopolymers, taking into account their chemical, structural, and functional properties. These models can be used to enhance the structure of biopolymers and improve their effectiveness in specific medical applications. (B) Finite element analysis, a computational technique used to analyze and solve problems in engineering and physics. This approach divides the physical domain into small finite elements with simple geometric shapes. This computational technique enables the study and understanding of the mechanical and structural behavior of biopolymers in biomedical environments. (C) Molecular dynamics (MD) simulations involve using advanced computational techniques to study the behavior of biopolymers at the molecular and atomic levels. These simulations are fundamental for better understanding biological processes at the molecular level. Studying the wide-ranging uses of MD simulations in biopolymers involves examining the structural, functional, and evolutionary aspects of biomolecular systems over time. MD simulations solve Newton's equations of motion for all-atom systems, producing spatial trajectories for each atom. This provides valuable insights into properties such as water absorption on biopolymer surfaces and interactions with solid surfaces, which are crucial for assessing biomaterials. This review provides a comprehensive overview of the various applications of MD simulations in biopolymers. Additionally, it highlights the flexibility, robustness, and synergistic relationship between in silico and experimental techniques.

The Influence of Different Sera on the Anti-Infective Properties of Silver Nitrate in Biopolymer Coatings.

The widespread prevalence of periprosthetic joint infections (PJIs) poses significant challenges in orthopedic surgeries, with pathogens such as Staphylococcus epidermidis being particularly problematic due to their capability to form biofilms on implants. This study investigates the efficacy of an innovative silver nitrate-embedded poly-L-lactide biopolymer coating designed to prevent such infections. The methods involved applying varying concentrations of silver nitrate to in vitro setups and recording the resultant bacterial growth inhibition across different serum environments, including human serum and various animal sera. Results highlighted a consistent and significant inhibition of S. epidermidis growth at all tested concentrations in each type of serum without adverse interactions with serum proteins, which commonly compromise antimicrobial efficacy. This study concludes that the silver nitrate-embedded biopolymer coating exhibits potent antibacterial properties and has potential for use in clinical settings to reduce the incidence of PJIs. Furthermore, the findings underscore the importance of considering serum interactions in the design and testing of antimicrobial implants to ensure their effectiveness in actual use scenarios. These promising results pave the way for further research to validate and refine this technology for clinical application, focusing on optimizing silver ion release and assessing biocompatibility in vivo.

Eco-Friendly Straws: A Fusion of Soy Protein Isolate and Cassava Starch Coated with Beeswax and Shellac Wax.

This research aimed to produce eco-friendly straws using soy protein isolate (SPI) and cassava starch (CS) at different ratios by the extrusion technique and by coating with beeswax and shellac wax. Three straw formulations (F) (F1: 24.39% SPI-24.39% CS; F2: 19.51% SPI-29.37% CS; and F3: 14.63% SPI-34.15% CS) were prepared, incorporating glycerol (14.6% w/w) and water (36.6% w/w). After extrusion and drying at 80 °C for 20 h, visual assessment favored F2 straws due to smoother surfaces, the absence of particles, and enhanced straightness. For the physical property test, the straws were softened in pH buffer solutions for 5 min. To simulate practical application, mechanical bending strength was studied under different relative humidity (RH) settings. Water absorption reduced the strength as RH increased. F2 straws outperformed other formulations in bending strength at 54% RH. For hydrophobic coatings, F2 was chosen. Beeswax- and shellac wax-coated straws displayed negligible water absorption and sustained their integrity for over 6 h compared to uncoated straws. This study shows that extrusion and natural coatings may make sustainable straws from SPI and CS. These efforts help meet the growing demand for eco-friendly plastic alternatives, opening up new options for single-use straws.

Sodium lignosulfonate as an extracting agent of methylene blue dye using a polymer-enhanced ultrafiltration technique.

The purpose of this research was to evaluate the efficacy of sodium lignosulfonate (LS) as a dye adsorbent in the removal of methylene blue (MB) from water by polymer-enhanced ultrafiltration. Various parameters were evaluated, such as membrane molecular weight cut-off, pH, LS dose, MB concentration, applied pressure, and the effect of interfering ions. The results showed that the use of LS generated a significant increase in MB removal, reaching an elimination of up to 98.0 % with 50.0 mg LS and 100 mg L-1 MB. The maximum MB removal capacity was 21 g g-1 using the enrichment method. In addition, LS was reusable for up to four consecutive cycles of dye removal-elution. The removal test in a simulated liquid industrial waste from the textile industry was also effective, with a MB removal of 97.2 %. These findings indicate that LS is highly effective in removing high concentrations of MB dye, suggesting new prospects for its application in water treatment processes.

Nanocellulose-based porous lightweight materials with flame retardant properties: A review.

This review discusses the development and application of nanocellulose (NC)-aerogels, a sustainable and biodegradable biomaterial, with enhanced flame retardant (FR) properties. NC-aerogels combine the excellent physical and mechanical properties of NC with the low density and thermal conductivity of aerogels, making them promising for thermal insulation and other fields. However, the flammability of NC-aerogels limits their use in some applications, such as electromagnetic interference shielding, oil/water separation, and flame-resistant textiles. The review covers the design, fabrication, modification, and working mechanism of NC porous materials, focusing on how advanced technologies can impart FR properties into them. The review also evaluates the FR performance of NC-aerogels by employing widely recognized tests, such as the limited oxygen index, cone calorimeter, and UL-94. The review also explores the integration of innovative and eco-friendly materials, such as MXene, metal-organic frameworks, dopamine, lignin, and alginate, into NC-aerogels, to improve their FR performance and functionality. The review concludes by outlining the potential, challenges, and limitations of future research on FR NC-aerogels, identifying the obstacles and potential solutions, and understanding the current progress and gaps in the field.

High-amylose starch-based gel as green adhesive for plywood: Adhesive property, water-resistance, and flame-retardancy.

The escalating demand for environmentally sustainable and cost-effective adhesives in the wood processing and manufacturing sector has prompted exploration into innovative solutions. This study introduces a novel gel adhesive composed of chemically unmodified high-amylose starch (G70, with 68 % amylose content) with a minimal proportion of urea-formaldehyde (UF) (UF/starch = 1:10, w/w). This G70/UF gel demonstrates remarkable adhesive capabilities for wooden boards under both dry conditions (with a shear stress of 4.13 ± 0.12 MPa) and wet conditions (with a shear strength of 0.93 ± 0.07 MPa after 2 h of water soaking). The study unveils that the elevated amylose content in the starch, coupled with a meticulously controlled isothermal process during bonding, is crucial for these enhancements. Specifically, the robust cohesion of amylose chains expedites phase separation between starch and UF, while the isothermal process facilitates the migration and enrichment of UF molecules at the gel-board and gel-air interfaces. Lacking these mechanisms, conventional amylopectin-rich starch/UF gels (27 % amylose content) show minimal improvement. Moreover, the G70/UF gel showcases exceptional fire retardancy. In all, the G70/UF gel presents a promising alternative for plywood production, reducing reliance on unhealthy UF resin while offering satisfactory bonding resistance in diverse conditions and superior flame retardancy.

Current trends in medium-chain-length polyhydroxyalkanoates: Microbial production, purification, and characterization.

Polyhydroxyalkanoates (PHAs) have gained interest recently due to their biodegradability and versatility. In particular, the chemical compositions of medium-chain-length (mcl)-PHAs are highly diverse, comprising different monomers containing 6-14 carbon atoms. This review summarizes different feedstocks and fermentation strategies to enhance mcl-PHA production and briefly discusses the downstream processing. This review also provides comprehensive details on analytical tools for determining the composition and properties of mcl-PHA. Moreover, this study provides novel information by statistically analyzing the data collected from several reports on mcl-PHA to determine the optimal fermentation parameters (specific growth rate, PHA productivity, and PHA yield from various structurally related and unrelated substrates), mcl-PHA composition, molecular weight (MW), and thermal and mechanical properties, in addition to other relevant statistical values. The analysis revealed that the median PHA productivity observed in the fed-batch feeding strategy was 0.4 g L-1 h-1, which is eight times higher than that obtained from batch feeding (0.05 g L-1 h-1). Furthermore, 3-hydroxyoctanoate and -decanoate were the primary monomers incorporated into mcl-PHA. The investigation also determined the median glass transition temperature (-43°C) and melting temperature (47°C), which indicated that mcl-PHA is a flexible amorphous polymer at room temperature with a median MW of 104 kDa. However, information on the monomer composition or heterogeneity and the associated physical and mechanical data of mcl-PHAs is inadequate. Based on their mechanical values, the mcl-PHAs can be classified as semi-crystalline polymers (median crystallinity 23%) with rubber-like properties and a median elongation at break of 385%. However, due to the limited mechanical data available for mcl-PHAs with known monomer composition, identifying suitable processing tools and applications to develop mcl-PHAs further is challenging.

A new 3D printing strategy by enhancing shear-induced alignment of gelled nanomaterial inks resulting in stronger and ductile cellulose films.

Cellulose nanofibrils (CNFs) are derived from biomass and have significant potential as fossil-based plastic alternatives used in disposable electronics. Controlling the nanostructure of fibrils is the key to obtaining strong mechanical properties and high optical transparency. Vacuum filtration is usually used to prepare the CNFs film in the literature; however, such a process cannot control the structure of the CNFs film, which limits the transparency and mechanical strength of the film. Here, direct ink writing (DIW), a pressure-controlled extrusion process, is proposed to fabricate the CNFs film, which can significantly harness the alignment of fibrils by exerting shear stress force on the filaments. The printed films by DIW have a compact structure, and the degree of fibril alignment quantified by the small angle X-ray diffraction (SAXS) increases by 24 % compared to the vacuum filtration process. Such a process favors the establishment of the chemical bond (or interaction) between molecules, therefore leading to considerably high tensile strength (245 ± 8 MPa), elongation at break (2.2 ± 0.5 %), and good transparency. Thus, proposed DIW provides a new strategy for fabricating aligned CNFs films in a controlled manner with tunable macroscale properties. Moreover, this work provides theoretical guidance for employing CNFs as structural and reinforcing materials to design disposable electronics.

4-Ethylphenyl Sulfate Detection by an Electrochemical Sensor Based on a MoS2 Nanosheet-Modified Molecularly Imprinted Biopolymer.

One of the gut-derived uremic toxins 4-ethylphenyl sulfate (4-EPS) exhibits significantly elevated plasma levels in chronic kidney diseases and autism, and its early quantification in bodily fluids is important. Therefore, the development of rapid and sensitive technologies for 4-EPS detection is of significant importance for clinical diagnosis. In the current work, the synthesis of a molecularly imprinted biopolymer (MIBP) carrying 4-EPS specific cavities only using the biopolymer polydopamine (PDA) and molybdenum disulfide (MoS2) nanosheets has been reported. The fabricated electrode was prepared using screen-printed carbon electrodes on a polyvinyl chloride substrate. The synthesized material was characterized using several techniques, and electrochemical studies were performed using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The DPV technique for the electrochemical sensing of 4-EPS using the fabricated sensor (PDA@MoS2-MIBP) determined a sensitivity of 0.012 µA/ng mL/cm2 and a limit of detection of 30 ng/mL in a broad linear range of 1-2200 ng/mL. Also, the interferent study was performed to evaluate the selectivity of the fabricated sensor along with the control and stability study. Moreover, the performance of the sensor was evaluated in the spiked urine sample, and a comparison was made with the data obtained by ultraperformance liquid chromatography-tandem mass spectroscopy.

Poly(3-hydroxybutyrate) production using supplemented corn-processing byproducts through Cupriavidus necator via solid-state fermentation: Cultivation on flask and bioreactor scale.

The widespread adoption of Poly(3-hydroxybutyrate) (PHB) encounters challenges due to its higher production costs compared to conventional plastics. To overcome this obstacle, this study investigates the use of low-cost raw materials and optimized production methods. Specifically, food processing byproducts such as corn germ and corn bran were utilized as solid substrates through solid-state fermentation, enriched with molasses and cheese whey. Employing the One Factor at a Time technique, we examined the effects of substrate composition, temperature, initial substrate moisture, molasses, and cheese whey on PHB production at the flask scale. Subsequently, experiments were conducted at the bioreactor scale to evaluate the influence of aeration. In flask-scale experiments, the highest PHB yield, reaching 4.1 (g/kg Initial Dry Weight Substrate) (IDWS) after 72 hours, was achieved using a substrate comprising a 1:1 mass ratio of corn germ to corn bran supplemented with 20 % (v/w) cheese whey. Furthermore, PHB production in a 0.5-L packed-bed bioreactor yielded a maximum of 8.4 (g/kg IDWS), indicating a more than 100 % increase in yield after 72 hours, with optimal results achieved at an aeration rate of 0.5 l/(kg IDWS. h).

Starch-based biodegradable films amended with nano-starch and tannic acid-coated nano-starch exhibit enhanced mechanical and functional attributes with antimicrobial activity.

Starch-based biofilms are biodegradable, but their application is limited by lower mechanical strength and absence of antimicrobial properties. In this context, the present study attempted to unleash the potential of nanotechnology for synthesizing nano-starch (NS) and tannic acid-coated nano-starch (T-NS) for augmenting the tensile strength and antimicrobial properties of starch-based biofilms. Moreover, this study reports one of the first such attempts to improve the commercial viability of starch extracted from the corms of Amorphophallus paeoniifolius. In this study, NS and T-NS samples were first synthesized by the physical and chemical modification of the native starch (S) molecules. The NS and T-NS samples showed significantly smaller granule size, lower moisture content, and swelling power. Further, amendments with NS and T-NS samples (25 % and 50 %) to the native starch molecules were performed to obtain biofilm samples. The NSB (NS amended) and T-NSB (T-NS amended) biofilms showed comparatively higher tensile strength than SB films (100 % starch-based). The T-NSB showed greater antimicrobial activity against gram-positive and gram-negative bacteria. All the biofilms showed almost complete biodegradation in soil (in 10 days). Therefore, it can be concluded that additives like NS and T-NS can improve starch-based biofilms' mechanical strength and antimicrobial properties with considerable biodegradability.