An eco-friendly degumming process of flax roving without acid pickling and NaClO2-bleaching

Assessing the promoting effect of compound microbial agents on flax dew retting: Based on the relationship between metabolites and core genera

In this study, 16S rRNA sequencing and GC-MS (gas chromatography-mass spectrometry) techniques were employed to examine the relationship between bacterial succession and metabolite alterations during the dew retting process of flax. The results indicated that the addition of compound microbial agents may affect the production and transformation of metabolites by re-establishing bacterial communities and promoting the degradation of pectic substances and the release of metabolites, and the best retting effect was achieved under the combined addition (BA). In addition, Chryseobacterium, Bacillus, and Pseudoonas were closely associated with the production of fatty acids and alcohols; the addition of compound microbial agents increased the content of critical metabolites while decreasing the environmental pollutant bis(2-ethylhexyl) phthalate. In summary, the addition of compound microbial agents can positively regulate the retting process of flax, shorten the retting cycle, improve the quality of flax fibre, and reduce the pollution of the environment.

Biosynthesis of silver nanospheres, kinetic profiling and their application in the optical sensing of mercury and chlorite ions in aqueous solutions

Pollution of water linked to microbial decontamination and extensive use of sodium chlorite (NaClO₂) as a disinfectant, especially in the face of the current COVID-19 situation, is a serious water pollution issue that needs to be addressed. In this context, an environmentally friendly and cost-effective method has been developed for the biomimetic synthesis of Ag nanospheres (Ag NSs) using aqueous extract of Piper nigrum for the detection of chlorite (ClO₂^-) and mercury (Hg²⁺) ions. The strong antioxidant properties of the biomolecules present in the Piper nigrum extract reduce silver ions (Ag⁺) to Ag⁰. After optimization of the formulation parameters, it was observed that 1 mL of piper nigrum extract was sufficient to reduce and stabilize 100 mL of 1.5 mM of Ag⁺ in 2.5 h at 30 °C. X-ray diffraction (XRD) pattern of Ag NSs revealed their crystalline nature and the characteristic Bragg's diffraction peaks confirmed their face cubic crystal (FCC) lattice. The characteristic reddish-brown color and absorption surface plasmon resonance (SPR) band at 435 nm confirmed the successful fabrication of Ag NSs. Kinetic analysis revealed a three-phase growth pattern involving nucleation, growth and stabilization. Transmission electron microscopy (TEM) and High-resolution transmission electron microscopy (HRTEM) micrograms, showed spherical NSs with narrow polydispersity with particle size ranging from 10 to 30 nm. The synthesized NSs were exposed to various metal ions and anions. The absorption intensity of Ag NSs quenched in the presence of mercury ions (Hg²⁺) among the cations and Chlorite ions (ClO₂^-) among the anions. The limit of detection (LOD) of 7.47 μM and 1.11 μM was evaluated from the calibration curve for Hg²⁺ and ClO₂^-, respectively. Based on these promising results, it is suggested that the method reported is a low-cost and one step biogenic protocol for the synthesis of Ag NSs and their employment for the detection of Hg²⁺ and ClO₂^-ions.