Polysaccharide Molecules Research Articles

Removal of Surface Radioactive Uranium(Ⅵ) by Graphene Oxide Modified κ-carrageenan/Konjac Glucomannan Composite Hydrogel

Hydrogel is an effective surface decontamination technology. However, traditional colloid decontaminants face a long curing time and low decontamination rate. A peelable hydrogel coating composed of carrageenan, konjac glucan, and graphene oxide with excellent film-forming performance and decontamination efficiency was explored in this study. The results showed that the graphene oxide was effectively dispersed inside the hydrogel, improving the crosslink density and thermal stability of the hydrogel by forming hydrogen bonds with polysaccharide molecules. The graphene oxide can effectively enhance the decontamination performance of the hydrogel. For stainless steel, ceramic, glass, and rubber surfaces, the decontamination rates of the hydrogel for 30min were 96.95%, 87.6%, 96.27%, and 74.5%, respectively. The decontamination effect was stable to temperature. For cement surfaces, the hydrogel could reach a maximum decontamination rate of 70.68% after 24h. The decontamination efficiency of hydrogel was affected by porosity, surface roughness, and graphene oxide addition. The characterization results of XPS, FT-IR, and SEM/EDS showed that the decontamination process of the composite hydrogel may involve surface wetting, ion diffusion, electrostatic attraction, and physical entanglement.

Fabrication of functionalized bio synthetic hydrogels using poly vinyl alcohol and Fucoidan

Abstract Background: Animal bodies are mostly made up of hydrogels, which are networks of hydrophilic polymers that have been permeated with water. These hydrogels make up the bulk of the cells and tissues in animals. Polyvinyl alcohol (PVA) hydrogels are of particular interest due to their various benefits such as biocompatibility, non-immunogenicity, and low biodegradability. Fucoidan is a sulfated polysaccharide molecule found in brown algae cell walls. They are nontoxic, non-irritating and bioactive. Rutin trihydrate is an antioxidant flavonoid and nitric oxide scavenger. The current study aimed to fabricate a functional biosynthetic polymer by combining fucoidan, PVA and Rutin trihydrate. This study also involves characterization and evaluation of antimicrobial activity of the obtained material. Commercial fucoidan(1g), PVA(0.5g) and Rutin (0.5g) was added to distilled water(50ml). The sample was kept in a magnetic stirrer for at 60°C,430 rpm for 30 min and dried in the hot air oven for 24hrs. The dried sample was studied by SEM and FTIR. Contact angle of the sample was also evaluated. Antimicrobial activity of the fabricated hydrogel was determined by agar diffusion method. The synthesized hydrogel is found to be hydrophilic in nature since the contact angle is 31.1°. The surface area of the synthesized hydrogel is found to be rough, irregular, porous and crystalline. Functional groups and compatibility between the polymers were determined by FTIR. Acceptable antimicrobial activity was demonstrated by the synthesized hydrogel against S.aureus and S.mutans (Zone of inhibition 12 mm and 12mm respectively). From the current study, it is concluded that the (Fucoidan- PVA) - Rutin, hydrogel fabricated is hydrophilic in nature and exhibits acceptable antimicrobial activity. Physical properties show that the hydrogel is suitable for drug delivery, tissue engineering and wound dressing.

Complexation of locust bean gum and κ-carrageenan microgels, from aqueous phase to oil-water interface

Although polysaccharide microgels exhibit potential as clean-label emulsifiers, the stability of emulsions in commercial application is still a challenge. The current work points out that specific complexation between polysaccharide molecules and polysaccharide microgels can benefit the interfacial adsorption of polysaccharide microgels and emulsion stability. The complexation of κ-carrageenan microgels (KCMs) and locust bean gum (LBG) was investigated for the first time, which was evaluated by visual appearance, rheological behavior, thermal stability, and microscopic morphology. Results indicate the low concentration of LBG promotes the clustering of KCMs, whereas high concentration of LBG can envelop and segregate KCMs. Subsequent blending with LBG could enhance the interfacial adsorption of KCMs, and multi-layers are observed when LBG concentration exceeds 0.3 wt%. LBG can obviously decrease the emulsion droplets size and improve the storage stability of emulsions, KCMs + LBG (0.2–0.5 wt%) stabilized emulsions could keep stable after three consecutive freeze-thaw cycles. Based on the specific complexation between KCMs and LBG, the layer-by-layer emulsification could be achieved. This strategy can inspire other polysaccharide microgel emulsifiers, which could be a feasible solution for improving the stability of polysaccharides microgels stabilized emulsions.

The Conformation of Glycosidic Linkages According to Various Force Fields: Monte Carlo Modeling of Polysaccharides Based on Extrapolation of Short-Chain Properties.

The conformational features of the glycosidic linkage are the most important variable to consider when studying di-, oligo-, and polysaccharide molecules using molecular dynamics (MD) simulations. The accuracy of the theoretical model describing this degree of freedom influences the quality of the results obtained from MD calculations based on this model. This article focuses on the following two issues related to the conformation of the glycosidic linkage. First, we describe the results of a comparative analysis of the predictions of three carbohydrate-dedicated classical force fields for MD simulations, namely, CHARMM, GLYCAM, and GROMOS, in the context of different parameters of structural and energetic nature related to the conformation of selected types of glycosidic linkages, α(1 → 4), β(1 → 3), and β(1 → 4), connecting glucopyranose units. This analysis revealed several differences, mainly concerning the energy levels of the secondary and tertiary conformers and the linkage flexibility within the dominant exo-syn conformation for α(1 → 4) and β(1 → 3) linkages. Some aspects of the comparative analysis also included the newly developed, carbohydrate-dedicated Martini 3 coarse-grained force field. Second, to overcome the time-scale problem associated with sampling slow degrees of freedom in polysaccharide chains during MD simulations, we developed a coarse-grained (CG) model based on the data from MD simulations and designed for Monte Carlo modeling. This model (CG MC) is based on information from simulations of short saccharide chains, effectively sampled in atomistic MD simulations, and is capable of extrapolating local conformational properties to the case of polysaccharides of arbitrary length. The CG MC model has the potential to estimate the conformations of very long polysaccharide chains, taking into account the influence of secondary and tertiary conformations of glycosidic linkages. With respect to the comparative analysis of force fields, the application of CG MC modeling showed that relatively small differences in the predictions of individual force fields with respect to a single glycosidic linkage accumulate when considering their effect on the structure of longer chains, leading to drastically different predictions with respect to parameters describing the polymer conformation, such as the persistence length.

Construction and antibacterial activities of walnut green husk polysaccharide based silver nanoparticles (AgNPs)

In this paper, the size-controllable nano‑silver particles (AgNPs) were synthesized from walnut green husk polysaccharide, and its cytotoxicity and antibacterial activity were evaluated. Firstly, acidic polysaccharide WGHP2 was extracted from walnut green husk, and then the silver ion in AgNO3 was reduced in WGHP2 aqueous solution using NaBH4, so as to synthesize the nano‑silver composite. The nano‑silver composite was characterized by transmission electron microscope, Fourier infrared spectroscopy, ultraviolet-visible spectrometer, scanning electron microscope, inductively coupled plasma mass spectrometry and X-ray photoelectron spectroscopy. The results show that AgNPs stabilized by WGHP2 are mainly regular spheres with an average particle size distribution of 15.04–19.23 nm. The particle size distribution and morphology of AgNPs changed with the concentration of silver precursor, which is related to the dispersion of silver precursor in polysaccharide aqueous solution and the formation of AgO coordination bond between silver precursor and polysaccharide molecules. These coordination bonds changed the ability of nanoparticles to produce and release Ag+, and thus regulated their antibacterial activity and cytotoxicity, as evidenced by the experimental result of the cytotoxicity of the nano‑silver particle against PC12 cells and the bacteriostatic effect on E.coli and S.aureus. Conclusively, WGHP2-Ag has good stability, antibacterial activity and low cytotoxicity.

Study on the interaction properties between curdlan polysaccharide and water molecules in coal processing sludge by molecular dynamics simulation

Study on the interaction properties between curdlan polysaccharide and water molecules in coal processing sludge by molecular dynamics simulation

NYMPHA, a natural product for the conservation of ancient wood

In recent years, there has been a significant interest on sustainability and health-safety across various domains. Notably, many traditional chemicals employed in the preservation of Cultural Heritage pose environmental and human health risks. The NYMPHA project aimed to develop an eco-friendly solution using microalgae-derived polysaccharides to remove biological patinas from cultural heritage wooden materials, addressing sustainability and health concerns. To validate its efficacy, the product underwent testing on diverse woods such as silver fir, beech, and sessile oak, selected for their distinct anatomical characteristics. The analytical methodology involves three key steps: 1) determining the optimal extraction and application method through spectro-colorimetric measures and UV imaging; 2) evaluating surface color stability; and 3) assessing the product's effectiveness before and after exposure to a biological attack using spectro-colorimetry. Results indicate that the NYMPHA product can induce a color variation on some wood surfaces. Moreover, although it is reported that algae can have biocidal effects, in this experiment, this action is not observed probably due to the absence of sulphates in the polysaccharide molecule extracted from this specific strain. This emphasizes the necessity for further research and to explore new solutions beyond controlled laboratory conditions, specifically on naturally degraded materials.

Emulsions stabilized by okra polysaccharides: Physicochemical, interfacial, and emulsification properties

This study provided a comprehensive investigation about the correlation between okra polysaccharide physicochemical characteristics, interfacial behavior, and emulsification properties. Six okra polysaccharides with distinct physicochemical properties were prepared and evaluated for their emulsification performance. The kind of acid used for extraction affected the molecular weight of polysaccharides, while extraction solutions with different pH influenced the molar ratio of monosaccharides and the degree of methyl-esterification (DM), thereby affecting the behavior of polysaccharides at the oil-water interface and emulsification properties. Okra polysaccharides with higher DM and RG-I exhibited lower oil-water interfacial tension and thicker interfacial layers. Compared to the emulsion stabilized by okra polysaccharide extracted using citric acid solution at pH 2.0 (OPC-2), the emulsion stabilized by okra polysaccharide extracted using hydrochloric acid solution at pH 1.0 (OPH-1) exhibited significant advantages of smaller droplet size (0.56 μm) and less malondialdehyde content (6.25 μmol/kg oil). Under pH 2.0, OPH-1 demonstrated the highest viscosity (290.12 mPa S), along with the strongest G' (42.12 Pa) and G" (25.79 Pa), playing crucial roles in sustaining emulsion stability. Moreover, under conditions of high ionic strength, the interaction between ions and okra polysaccharide molecules diminished the emulsifying ability and emulsion storage stability. This study provides significant insights into the performance of okra polysaccharides and polysaccharide-based emulsions, thereby guiding the development of efficient and stable emulsifiers.

Rheological and tribological properties of seaweed powders as thickeners for liquid foods

Thickened liquid foods are particularly interesting in culinary applications and the management of swallowing disorders. Polysaccharide molecules and suspended soft particles play a major role in increasing viscosity and mouthfeel. In this work, tribo-rheological effects of finely ground particles (less than 75 μm) of Durvillaea antarctica seaweed (SP) as a minimally processed and natural alternative to commercial thickeners were studied. Shear viscosity (η), viscoelastic moduli (G′, G″), and the coefficient of friction (CoF) were determined for SP dispersions, using as controls two commercial thickeners: modified maize starch-based (TE) and xanthan gum-based (TU). SP and SP dispersions were characterized microstructurally and evaluated at concentrations of 1.2%, 2.4%, and 4.8% w/v, with and without artificial saliva (AS). SP dispersions exhibited a pseudoplastic behavior in the range of shear rates 0.1–100 s−1 and viscoelasticity (G’>G”) in the 0.1–80 rad/s frequency range. The incorporation of AS had a dilution effect in SP and TU dispersions, but additionally, in the case of TE, a hydrolyzing effect decreased the values of the responses. In the tribology experiments, all samples followed a Stribeck curve. SP dispersions were more lubricating than AS and controls in the physiological range of velocities during oral processing and swallowing (e.g.,>100 mm/s). The thickening, viscoelastic, and lubrication behavior of SP dispersions were attributed to the soluble solids released from the SP (37%–51% d. w.) and interactions with ghosts of SP particles in the continuous aqueous phase. Fine seaweed particles may be a sustainable and low-cost alternative to commercial thickeners in some food applications.

Development of soybean meal-based adhesive with multiple functions via a dual cross-linked tailoring-making strategy

As a renewable biomass resource, soy protein adhesives are a potential alternative to petroleum-based ones. However, synthesizing soy protein adhesives with excellent performance via a low-cost and facile strategy for practical application in the wood industry remains challenging. Herein, an innovative approach for fabricating a strong, tough, low-cost soy protein adhesive via dual cross-linked tailoring-making technology was proposed to impart multiple excellent performances. Specifically, the new strategy involved using calcium lignosulfonate (CLS), a residue from the pulping industry, as an anionic surfactant to untwist the spherical structure of soy protein, stretch the protein chains, and knit a reversible dynamic network structure with the protein chains and soybean polysaccharide molecules by multiple non-covalent interactions, and synergize with the robust cross-linked network of 1,6-hexanediol diglycidyl ether (HDE) to tailor the adhesive structure system. Notably, this design reflects the vital role of remolding the protein structural and soybean polysaccharide molecules network in optimizing the adhesive properties, including excellent bonding strength, anti-mildew, and flame retardancy performances. Therefore, this facile strategy can be explored to develop green and renewable protein adhesives for industrial wood applications.

Marine polysaccharides: Biological activities and applications in drug delivery systems

The ocean is the common home of a large number of marine organisms, including plants, animals, and microorganisms. Researchers can extract thousands of important bioactive components from the oceans and use them extensively to treat and prevent diseases. In contrast, marine polysaccharide macromolecules such as alginate, carrageenan, Laminarin, fucoidan, chitosan, and hyaluronic acid have excellent physicochemical properties, good biocompatibility, and high bioactivity, which ensures their wide applications and strong therapeutic potentials in drug delivery. Drug delivery systems (DDS) based on marine polysaccharides and modified marine polysaccharide molecules have emerged as an innovative technology for controlling drug distribution on temporal, spatial, and dosage scales. They can detect and respond to external stimuli such as pH, temperature, and electric fields. These properties have led to their wide application in the design of novel drug delivery systems such as hydrogels, polymeric micelles, liposomes, microneedles, microspheres, etc. In addition, marine polysaccharide-based DDS not only have smart response properties but also can combine with the unique biological properties of the marine polysaccharide base to exert synergistic therapeutic effects. The biological activities of marine polysaccharides and the design of marine polysaccharide-based DDS are reviewed. Marine polysaccharide-based responsive DDS are expected to provide new strategies and solutions for disease treatment.

Use of Double Gelled Microspheres to Improve Release Control of Cinnamon-Loaded Nanoemulsions.

The use of nanoemulsions as encapsulation systems for active ingredients, such as cinnamon oil, has been studied. A surfactant based on polyoxyethylene glycerol esters from coconut/palm kernel oil has been used. The nanoemulsions were obtained by the two most commonly low-energy emulsification methods, the composition inversion phase (PIC) and the temperature inversion phase (PIT) methods. Nanoemulsions were successfully obtained by both methods, with very small droplet sizes (5-14 nm) in both cases, but a greater stability was observed when the PIT method was used. Nanoemulsions were encapsulated by external gelation using two different polysaccharides, alginate or chitosan, dissolved in the continuous phase of the nanoemulsion. Then, the nanoemulsion was dropped into a bath with a gelling agent. To improve the release control of cinnamon oil and avoid the burst effect, beads prepared with one of the polysaccharides were coated with the second polysaccharide and then gelled again. Double gelled beads were successfully obtained, the core with chitosan and the outer layer (shell) with alginate. SEM images showed the morphology of the single beads presenting high porosity. When the beads were coated, the porosity decreased because the second polysaccharide molecules covered the pre-existing pores. The smoother surface was obtained when this second layer was, in turn, gelled. The release patterns at pH = 2 and pH = 7 were studied. It was observed that the double gelled bead provided a more gradual release, but maintained approximately the same amount of final released oil. The release patterns were fitted to the Korsmeyer-Peppas model. The fitting parameters reflected the effect of the different coating layers, correlating with different diffusion mechanisms according to the bead core and shell materials.

Isolation, purification, structural analysis and in vitro activity of polysaccharides from Amelanchier alnifolia Nutt.

Amelanchier alnifolia polysaccharides (AAP) were isolated and purified and gave three sequential fractions, AAP1, AAP2 and AAP3. AAP3 was further separated and purified by cellulose chromatography to give three polysaccharide fractions, AAP3-I, AAP3-II and AAP3-III. A polysaccharide (AAP3-Ⅰ) with a molecular weight of 1.64 × 106 Da was mainly composed of rhamnose, glucose, galactose, xylose and arabinose. The Fourier transform infrared spectroscopy (FT-IR) analysis and DEAE-Cellulose-52 column elution results indicated that AAP3-Ⅰ is a neutral polysaccharide. The transmission electron microscopy (TEM) indicated that purified polysaccharide molecules are of higher purity and are in reticulated aggregates. AAP3-I exists in an entangled triple helix conformation. In vitro antioxidant assays showed that all three fractions had good, concentration-dependent, antioxidant properties. The antioxidant capacity was in the order AAP1 < AAP2 < AAP3. Therefore, AAP3 could serve as a potential natural antioxidant to prevent aging.

Effects of drying method and oil type on edible polyunsaturated oleogels co-structured by hydroxylpropyl methyl cellulose and xanthan gum

The subtle balance between the interactions of polysaccharide molecules and the interactions of polysaccharide molecules with oil molecules is significantly important for developing polysaccharide-based polyunsaturated oleogels. Here, hydroxylpropyl methyl cellulose and xanthan gum were used to structure edible oleogels via emulsion-template methodology, while the effects of drying methods (hot-air drying (AD) and vacuum-freeze drying (FD)) and oil types (walnut, flaxseed and Moringa seed oil) on the structure, oil binding capacity (OBC), rheological properties, thermal behaviors and stability of oleogels were specially investigated. Compared with AD oleogels, FD oleogels exhibited significantly better OBC, enhanced gelation strength (G' value) and better capacity to holding oil after high temperature processing, which was attributed to the possibly increased oil-polysaccharide interactions. However, the weakened polysaccharide-polysaccharide interactions in FD oleogels failed in providing stronger physical interface or enough rigidity to restrict the migration of oil molecules. Polyunsaturated triacylglycerols in vegetable oils deeply participated in the construction of the network of AD oleogels through weak intermolecular non-covalent interactions, which in turn greatly changed the crystallization and melting behaviors of vegetables oils. In brief, this research may provide useful information for the development of polysaccharide-based polyunsaturated oil oleogels.

Molecular-Scale Exploration of Mechanical Properties and Interactions of Poly(lactic acid) with Cellulose and Chitin.

Poly(lactic acid) (PLA), one of the pillars of the current overarching displacement trend switching from fossil- to natural-based polymers, is often used in association with polysaccharides to increase its mechanical properties. However, the use of PLA/polysaccharide composites is greatly hampered by their poor miscibility, whose underlying nature is still vastly unexplored. This work aims to shed light on the interactions of PLA and two representative polysaccharide molecules (cellulose and chitin) and reveal structure-property relationships from a fundamental perspective using atomistic molecular dynamics. Our computational strategy was able to reproduce key experimental mechanical properties of pure and/or composite materials, reveal a decrease in immiscibility in PLA/chitin compared to PLA/cellulose associations, assert PLA-oriented polysaccharide reorientations, and explore how less effective PLA-polysaccharide hydrogen bonds are related to the poor PLA/polysaccharide miscibility. The connection between the detailed chemical interactions and the composite behavior found in this work is beneficial to the discovery of new biodegradable and natural polymer composite mixtures that can provide needed performance characteristics.

Synthesis, physicochemical and emulsifying properties of OSA-modified tamarind seed polysaccharides with different degrees of substitution

Octenyl succinic anhydride modified tamarind seed polysaccharides (OTSPs) with various degrees of substitution were first synthesized and characterized in this work. The structural, solid-state, solution and emulsifying properties of the OTSPs and the effect of the degree of substitution (DS) were investigated. The structural characterization confirmed the successful grafting of the OSA moiety into TSP and the chain extension of the OTSPs. The hydrophobicity of the modified polysaccharide molecules increased, the absolute value of the zeta potential increased, and the thermal stability decreased, which were positively or negatively correlated with the changes in DS. In contrast, the hydrolysis of polysaccharides in alkaline aqueous solution led to a decrease in molar mass and the rigidity of the molecules, which were not significantly related to DS. Particle size analysis showed that OTSPs tended to aggregate into relatively small agglomerates, which was confirmed by the results of morphological analysis. Most importantly, the instability indices of emulsions stabilized by TSP, arabic gum and OSA-starch were 0.521, 0.715, and 0.804, respectively, while for OTSPs this parameter was between 0.04 and 0.19 under the same conditions, indicating better physical stability of the OTSP-stabilized emulsions, especially for OTSP-30. Overall, OTSP has great potential as an emulsifier for oil-in-water emulsions, especially for emulsification and stabilization in food processing.

Ultrasonic-antisolvent two-step assembly of carboxymethylated corn fiber gum-coated zein particles for enhanced curcumin delivery

Zein particles (ZPs) have garnered considerable interest in delivery system construction for its capacity to encapsulate hydrophobic substances. Nonetheless, the instability of ZPs is an obstacle to application. Coating carboxymethylated corn fiber gum (CMCFG) which is a modified polysaccharide molecule enriched with anionic groups on the surface of ZPs is expected to overcome this limitation. Here, we evaluated the cell viability of CMCFG to Caco-2, proving the safety of CMCFG with different substitution degree (0.42, 0.52 and 0.70) below 20 mg/mL. Furthermore, curcumin, a hydrophobic model compound, was loaded onto ZPs coated with CMCFG using ultrasonic-antisolvent method, achieving a remarkable encapsulation efficiency (91.19%) and enhanced stability and bioaccessibility. Multiple characteristic approaches, such as zeta potential, FTIR, XRD, ultraviolet absorption spectra revealed that the assembly process mainly relied on hydrophobic interactions and electrostatic interactions. This study provides novel insights into encapsulation methods for hydrophobic nutrients.

Reaction Mechanism and Kinetics Study of Wheat Polysaccharide via Modified Reductor Technique in Bead Making Process

The reaction mechanism and kinetics investigation of the substitution of titanium in wheat flour polysaccharide (referred to here as titaniumation) in aqua medium during bead making process was carried out. The use of the Modified Reductor Technique was implored to study the reaction kinetics. The study was carried out at varying temperatures between 25 – 70oC. The study showed that the titaniumation of the wheat polysaccharide molecules increased with time and temperature. Hence, at 25oC, the degree of titaniumation (DT) of the ring increased from 0.41 % to 0.49 % and at elevated temperature of 70oC, DT increased from 0.58 to 0.94 % as time progressed from 30 to 210 mins, respectively, while keeping both amount of wheat polysaccharide and TiO2 constant, and thus achieving &gt;1.9-fold. This also implies that the titaniumation of wheat polysaccharide using TiO2 is favourable at elevated temperature. The study was able to reveal that the reaction mechanism of the titaniumation of the polysaccharide molecules is an electrophilic substitution reaction, favouring the ortho position, while the kinetics study showed that the titaniumation reaction is of first order reaction.

Synthesis and Characterization of Multi-Reducing-End Polysaccharides.

Site-specific modification is a great challenge for polysaccharide scientists. Chemo- and regioselective modification of polysaccharide chains can provide many useful natural-based materials and help us illuminate fundamental structure-property relationships of polysaccharide derivatives. The hemiacetal reducing end of a polysaccharide is in equilibrium with its ring-opened aldehyde form, making it the most uniquely reactive site on the polysaccharide molecule, ideal for regioselective decoration such as imine formation. However, all natural polysaccharides, whether they are branched or not, have only one reducing end per chain, which means that only one aldehyde-reactive substituent can be added. We introduce a new approach to selective functionalization of polysaccharides as an entrée to useful materials, appending multiple reducing ends to each polysaccharide molecule. Herein, we reduce the approach to practice using amide formation. Amine groups on monosaccharides such as glucosamine or galactosamine can react with carboxyl groups of polysaccharides, whether natural uronic acids like alginates, or derivatives with carboxyl-containing substituents such as carboxymethyl cellulose (CMC) or carboxymethyl dextran (CMD). Amide formation is assisted using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM). By linking the C2 amines of monosaccharides to polysaccharides in this way, a new class of polysaccharide derivatives possessing many reducing ends can be obtained. We refer to this class of derivatives as multi-reducing-end polysaccharides (MREPs). This new family of derivatives creates the potential for designing polysaccharide-based materials with many potential applications, including in hydrogels, block copolymers, prodrugs, and as reactive intermediates for other derivatives.

Label-free analysis of biofilm phenotypes by infrared micro- and correlation spectroscopy.

The methodology development for deeply describing the complex biofilm phenotypes is an urgent demand for understanding their basic biology and the central clinic relevance. Here, we developed an infrared microspectroscopy-based method for the quantitative evaluation and description of biofilm phenotypic characteristics by calculating the spectral similarity of the infrared data. Using this approach, we revealed the phenotypic variation during the biofilm formation process and biofilm heterogeneity between two E. coli strains. Two-dimensional correlation spectroscopy was further combined to deeply investigate the biochemical component evolution sequences during E. coli biofilm formation and revealed the first-order of the polysaccharide molecules change, expanding new opportunities for infrared microspectroscopy in revealing molecule evolution in the biofilm formation. This novel development offers a label-free optical toolkit for the bioanalytical analysis of biofilm phenotypes but also paves the way for screening the drugs to modulate the structure and ecology of biofilm microbiome.