Micro-FTIR combined with curve fitting method to study cellulose crystallinity of developing cotton fibers

Utilization of coffee waste as a sustainable feedstock for high-yield lactic acid production through microbial fermentation

Lactic acid is an important industrial precursor; however, high substrate costs are a major challenge in microbial fermentation-based lactic acid production. Coffee waste is a sustainable feedstock alternative for lactic acid production via microbial fermentation. Herein, the feasibility of coffee waste as a feedstock was explored by employing appropriate pretreatment methods and optimizing enzyme combinations. Coffee waste pretreatment with hydrogen peroxide and acetic acid along with a combination of Viscozyme L, Celluclast 1.5 L, and Pectinex Ultra SP-L achieved the 78.9 % sugar conversion rate at a substrate concentration of 4 % (w/v). Lactiplantibacillus plantarum WiKim0126-induced fermentation with a 4 % solid loading yielded a lactic acid concentration of 22.8 g/L (99.6 % of the theoretical maximum yield) and productivity of 0.95 g/L/h within 24 h. These findings highlight the viability of coffee waste as an eco-friendly resource for sustainable lactic acid production.

Chemistry of Hydroxypropyl Cellulose Oxidized by Two Selective Oxidants

Along with the increased usage of cellulose in the manufacture of novel materials, those of its derivatives that have good solubility in water or organic solvents have become increasingly important. In this study, hydroxypropyl cellulose (HPC), a cellulosic derivative with distinct features, was utilized to investigate how two of the most-selective oxidation methods currently available in the literature act on the constituent OH groups of both the side chain and the anhydroglycosidic unit in HPC. The oxidation reactions were carried out first using TEMPO, sodium hypochlorite, and sodium bromide, then sodium periodate (NaIO4), for 5 h. A combination of these two protocols was applied. The amount of aldehyde and number of carboxylic groups introduced after oxidation was determined, while the changes in the morphological features of oxidized HPC were, additionally, assessed. Furthermore, utilizing Fourier-transform infrared spectra, X-ray diffraction, and thermogravimetric studies, the chemical structure, crystallinity, and thermal stability of the oxidized HPC samples were examined and compared.

Plastic ingestion by two cetacean groups: Ziphiidae and Delphinidae

The presence of plastic in our environment is having a massive impact on today's marine biota. Whales and dolphins are becoming sentinels of litter pollution as plastic entanglement and ingestion affect them with unknown consequences. Although information exists about this anthropogenic interaction, the compilation of this data on metastudies is difficult due to the use of varied methodologies. A combination of our own data as well as a review of historical data was used to complete an extensive study of how cetaceans are interacting with macro and micro-litter at a global level. Here, we identify the plastic uptake by two cetacean families: Ziphiidae and Delphinidae, thus allowing for a better understanding in order to offer a global overview of their current status. Additionally, analysis was run on the plastic found in the digestive contents of stranded specimens of two Cuvier's beaked whales and fourteen striped dolphins in the Alboran Sea, in the Western Mediterranean, a hotspot for marine megafauna. Out of 623 stranded cetaceans from datasets, beaked whales displayed the highest concentration of macro, meso and microplastic in the Western Pacific Ocean. Regarding striped dolphins, Eastern Spain was the location with the highest plastic ingestion. Moreover, deep divers such as beaked whales ingested more plastic than striped dolphins which could be as a consequence of their feeding behavior or habitat. Thus, this overview provides useful information concerning conservation issues on how cetacean hotspots are highly affected by marine plastic ingestion.

Ferreira G, Barbosa RFS, Marciano JS, Camani PH, Souza AG, Rosa DS. Multifunctional cotton fabrics with novel antibacterial coatings based on chitosan nanocapsules and polyacrylate

Chitosan is a cationic polysaccharide with intrinsic antimicrobial properties that can be used as an ecological alternative to develop functional materials to inhibit the proliferation of microorganisms. This work evaluates chitosan nanocapsules (CNs) as a self-disinfecting agent to provide bactericidal activity on cotton fabrics (CF), using polyacrylate to bind the CNs on the CF surface. The fabrics were characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle (CA), moisture retention, and antimicrobial tests against Escherichia coli and Bacillus subtilis. The FTIR results showed new peaks related to chitosan structure, indicating the adequate fixation of the CNs on the cotton fibers. SEM images corroborated the polyacrylate binder's efficient adhesion, connecting the CNs and the cotton fiber surface. The CF surface properties were considerably modified, while CN/polyacrylate coating promoted antibacterial activity against the B. subtilis (gram-positive bacteria) for the developed wipe, but they do not display bactericidal effects against E. coli (gram-negative bacteria).

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11998-023-00761-y.

Metabolomic Changes as Key Factors of Green Plant Regeneration Efficiency of Triticale In Vitro Anther Culture

Green plant regeneration efficiency (GPRE) via in vitro anther culture results from biochemical pathways and cycle dysfunctions that may affect DNA and histone methylation, with gene expression influencing whole cell functioning. The reprogramming from gametophytic to sporophytic fate is part of the phenomenon. While DNA methylation and sequence changes related to the GPRE have been described, little attention was paid to the biochemical aspects of the phenomenon. Furthermore, only a few theoretical models that describe the complex relationships between biochemical aspects of GPRE and the role of Cu(II) ions in the induction medium and as cofactors of enzymatic reactions have been developed. Still, none of these models are devoted directly to the biochemical level. Fourier transform infrared (FTIR) spectroscopy was used in the current study to analyze triticale regenerants derived under various in vitro tissue culture conditions, including different Cu(II) and Ag(I) ion concentrations in the induction medium and anther culture times. The FTIR spectra of S-adenosyl-L-methionine (SAM), glutathione, and pectins in parallel with the Cu(II) ions, as well as the evaluated GPRE values, were put into the structural equation model (SEM). The data demonstrate the relationships between SAM, glutathione, pectins, and Cu(II) in the induction medium and how they affect GPRE. The SEM reflects the cell functioning under in vitro conditions and varying Cu(II) concentrations. In the presented model, the players are the Krebs and Yang cycles, the transsulfuration pathway controlled by Cu(II) ions acting as cofactors of enzymatic reactions, and the pectins of the primary cell wall.

Presence and implications of plastics in wild commercial fishes in the Alboran Sea (Mediterranean Sea)

The presence of plastic in the environment has become a major problem for marine ecosystems. The identification of the global micro and mesoplastic uptake by commercial fish populations may allow for a better understanding of their impact. This study aims to determine the presence and composition of plastic in two pelagic fish (Engraulis encrasicolus and Scomber scombrus) and two demersal species (Scyliorinus canicula and Mullus barbatus) from the Alboran Sea (western Mediterranean) to quantify the relationship between plastic prevalence and the environment and feeding behavior in the selected fish species. Samples of these four fish species from sites in the Alboran Sea were studied for ingested plastics. These localized samples were also compared to published values which covered a broader geographical range. Samples from the Alboran Sea study sites showed that the predominant fiber color was black and the predominant plastic polymers were polyethylene and cellulose. At the Alboran Sea study site the highest plastic occurrence was found in S. scombrus, whereas in the published literature the highest occurrence of plastics in digestive tracts was found in E. encrasicolus. The general prevalence of marine plastic pollution and levels of macro- and micro-plastic ingested by commercial fish species in this study support the idea that quantifying plastic presence and composition may be essential to understanding potential impacts on marine ecosystems.

Degradation of Losartan Potassium Highlighted by Correlated Studies of Photoluminescence, Infrared Absorption Spectroscopy and Dielectric Spectroscopy

In this paper, new results on the degradation of losartan potassium (LP, (1)), in the absence and presence of excipients, which was induced by UV light, the acid character of phosphate buffer solution (PBS) and alkaline medium, respectively, are reported through correlated studies of FTIR spectroscopy, photoluminescence and dielectric spectroscopy. The photoluminescence (PL) spectra of LP and the drug marked under the name Lorista (LO) are characterized by intense emission bands, peaking at 378 nm and 380 nm, respectively, accompanied by low intensity bands with a maximum at ~450–460 nm. Photodegradation of LO in a solid state is evidenced by a decrease in the intensity of the PL band at 380 nm, a variation that originates both in the adsorption of water vapors from the air and in the interaction of LP with excipients such as cornstarch, silicon dioxide and cellulose. The LP-water interaction is described, taking into account the main electrical parameters, i.e., complex dielectric permittivity and electrical conductivity. Photodegradation of LP and LO also induces an increase in the intensity of the emission band, at ~450–460 nm. The influence of acid and alkaline medium on the LO degradation is analyzed using phosphate buffer (PBS) and NaOH solutions, respectively. In both cases, a decrease in the intensity of the PL band, at 380 nm, is reported. The intensity diminution of the PL spectra of NaOH-reacted LP and LO is the result of the formation of the photodegradation product N-methanolamide-{[2′-(1H-tetrazol-5-yl)(1,1′-biphenyl)-4-yl]methyl} (2). This compound was proven by the studies of FTIR spectroscopy achieved on LP and NaOH-reacted LP. The appearance of the IR band at 1740 cm−1 and the increase in the absorbance in the IR band at 1423 cm−1 indicate that the photodegradation product (2) contains the C=O and C-OH functional groups.

Superior separation of hemicellulose-derived sugars from eucalyptus with tropic acid pretreatment

Organic acid pretreatments can efficiently separate biomass-based hemicellulose and selectively produce hemicellulose-derived sugars. In this study, hemicellulose is separation as xylose, oligosaccharides in the tropic acid-catalyzed hydrothermal pretreatment of eucalyptus. The maximum yield of hemicellulose-derived sugars (85.78 %) with 71.25 % xylose selectivity (based on the total xylose in raw material) was achieved in the hydrolysate under optimal conditions (5 % TA, 160 ℃, 80 min). The yield of hemicellulose-derived sugar and the separation yield of hemicellulose increased by 11.06 % and 11.45 % compared with glycolic acid pretreatment in the similar severity factor. The separation yield of cellulose and lignin was decreased by 4.23 % and 0.98 %, respectively. This resulted in residual solids with higher biological stability (higher fiber crystallinity index, higher thermal stability, and higher lignin content). Therefore, higher hemicellulose separation selectivity and rich hemicellulose-derived sugars were obtained using TA pretreatment. The work would bring up a new method for biomass refining.

Effect of Reducing Agent on Characteristics and Antibacterial Activity of Copper-Containing Particles in Textile Materials

Textile materials modified with copper-containing particles have antibacterial and antiviral properties that have prospects for use in healthcare. In the study, textile materials were saturated with copper-containing particles in their entire material volume by the absorption/diffusion method. The antibacterial properties of modified textile materials were confirmed by their inhibitory effect on Staphylococcus aureus, a Gram-positive bacterium that spreads predominantly through the respiratory tract. For the modification, ordinary textile materials of various origins and fiber structures were used. Technological conditions and compositions of modifying solutions were established, as well as the most suitable textile materials for modification. To assess the morphological and physical characteristics of copper-containing particles and the textile materials themselves, X-ray diffraction, a scanning electron microscope, and an energy-dispersive X-ray spectrum were used. In modified textile samples, XRD data showed the presence of crystalline phases of copper (Cu) and copper (I) oxide (Cu₂O). On the grounds of the SEM/EDS analysis, the saturation of textile materials with copper-containing particles depends on the structure of the textile materials and the origins of the fibers included in their composition, as well as the modification conditions and the copper precursor.

Investigation into Lewis and Brønsted acid interactions between metal chloride and aqueous choline chloride-oxalic acid for enhanced furfural production from lignocellulosic biomass

Furfural has been identified as a valuable biobased platform chemical that can be further converted into bioenergy and biochemicals. Furfural is derived from lignocellulosic biomass and can also be regarded as a sustainable alternative to petrochemical products. Herein, the performance of trivalent metal chlorides (FeCl₃, AlCl₃) and tetravalent metal chlorides (SnCl₄, TeCl₄) as Lewis acidic cocatalysts was investigated in an aqueous choline chloride-oxalic acid (16.4 wt% H₂O) deep eutectic solvent (DES) system for producing furfural from oil palm fronds (OPFs). The metal chlorides with greater electrical field gradients were stronger Lewis acids that enhanced both furfural production and degradation reactions. The main degradation product in this reaction system was humin, and this result was confirmed by FTIR analysis. By subjecting OPFs to an aqueous DES reaction (120 °C, 45 min) with SnCl₄ (2.50 wt%), a furfural yield of 59.4% was obtained; without incorporated metal chlorides, the furfural yield was 46.1%. Characterization studies showed synergistic Lewis and Brønsted acid interactions between metal chlorides and DES components. Overall, the residual OPFs showed high glucan content, which led to the production of glucose (71.4%) as a byproduct via enzymatic hydrolysis. Additionally, the aqueous DES system was recycled and reused for several additional runs. The proposed aqueous DES system presents a promising biorefinery approach for the conversion of OPFs to biochemicals.

Surface and Thermal Characterization of Cotton Fibers of Phenotypes Differing in Fiber Length

Cotton is one of the most important and widely grown crops in the world. Understanding the synthesis mechanism of cotton fiber elongation can provide valuable tools to the cotton industry for improving cotton fiber yield and quality at the molecular level. In this work, the surface and thermal characteristics of cotton fiber samples collected from a wild type (WT) and three mutant lines (Li1, Li2-short, Li2-long, Li2-mix, and liy) were comparatively investigated. Microimaging revealed a general similarity trend of WT ≥ Li2-long ≈ Li2-mix > Li1 > Li2 short ≈ liy with Ca detected on the surface of the last two. Attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and thermogravimetric measurements also showed that Li2-short and liy were more similar to each other, and Li2-long and Li2-mix closer to WT while Li1 was quite independent. FT-IR results further demonstrated that wax and amorphous cellulose were co-present in fiber structures during the fiber formation processes. The correlation analysis found that the FT-IR-based maturity parameter was well correlated (p ≤ 0.05) to the onset decomposition temperature and all three weight-loss parameters at onset, peak, and end decomposition stages, suggesting that the maturity degree is a better parameter than crystallinity index (CI) and other FT-IR parameters that reflect the thermal stability of the cotton fiber. In summary, this work demonstrated that genetic mutation altered the surface and thermal characteristics in the same way for Li2-short and liy, but with different mechanisms for the other three mutant cotton fiber samples.