Molecular Composition of Size-Fractionated Fulvic Acid-Like Substances Extracted from Spent Cooking Liquor and Its Relationship with Biological Activity

Abstract

The treatment of spent cooking liquor is critical for clean production of pulp and paper industry. There is a compelling need to develop a cost-effective and green technology for reuse of organic matter in spent cooking liquor to mitigate the negative impacts on the environment. The objective of this study is to examine the chemical structure of fulvic acid-like substances extracted from spent cooking liquor (PFA) and their relationship with bioactivity in plant growth. Compared with the benchmark Pahokee peat fulvic acid (PPFA), PFA has less aromatic structure, but higher content of lignin, carbohydrates, and amino acid. After fractionation, protein/amino proportion decreased with increasing molecular weight, but the aromaticity increased. Under salt stress, rice seedling growth was promoted by PFA with low molecular weight (<5 kDa), but inhibited by fraction with high molecular weight (>10 kDa). Principal component analysis suggested that promoted growth was more related with chemical structure (O- and N-alkyl moieties) than with molecular weight. This study provided the theoretical basis for development of an innovative green technology of sustainable reuse of spent cooking liquor in agriculture.

Activation of Humic Acid in Lignite Using Molybdate-Phosphorus Hierarchical Hollow Nanosphere Catalyst Oxidation: Molecular Characterization and Rice Seed Germination-Promoting Performances

“…The result agrees with the previous findings of molecular size fraction of humic acid. The average double bond equivalents (aDBEs) could reflect the aromaticity of the compound, and the decrease of aDBE after activation indicates that activation reduced the aromaticity of humic acid (Figure f).…”

“…Yao et al. also found the molecular composition of fulvic acid from spent cooking liquor by FT-ICR MS . Therefore, our first objective of this study is to synthesize the Mo-P-HH catalyst through a simple method and then apply to the activation of humic acid in lignite.…”

“…Recently, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) as a remarkable technique has been successfully utilized in soil, air, and water samples for the analysis of the natural organic compound molecular structure. 31−33 For example, Yuan et al studied the molecular compositions of water-soluble organic matter using FT-ICR MS. 34 Yao et al also found the molecular composition of fulvic acid from spent cooking liquor by FT-ICR MS. 35 Therefore, our first objective of this study is to synthesize the Mo-P-HH catalyst through a simple method and then apply to the activation of humic acid in lignite. The second objective is to characterize the humic acid using FT-ICR MS to better understand its molecular composition and to determine the underlying activation mechanism.…”

The Combined Application of Urea and Fulvic Acid Solution Improved Maize Carbon and Nitrogen Metabolism

“…Natural fulvic acid is a kind of macromolecule organic weak acid mixture formed by a series of decomposition and transformation of animal and plant remains under microbial, geophysical and chemical action, which can be extracted from soil, water and coal [18][19][20]. Biochemical fulvic acid is a type of weakly acidic organic matter extracted from agricultural waste by microbial fermentation technology or straw-based ammonium sulfite pulping process [21]. Its chemical properties are similar to those of natural fulvic acid [22,23].…”

Highly active biostimulant Paecilomyces variotii extracts reduced controlled‐release urea application while maintaining rice yield

“…Biostimulants were classified into eight categories by the European Biostimulant Industry Council (EBIC), including humic substances, complex organic materials, beneficial chemical elements, inorganic salts, seaweed extracts, chitin and chitosan derivatives, antitranspirants, and free amino acids and other N‐containing substances 20 . Substantial progress has recently been made with respect to the functionalities of biostimulants in boosting plant growth and development, regulating metabolic changes in tissues, and enhancing plant tolerance to various abiotic/biotic stresses 21‐24 . Furthermore, some biostimulants play a signaling role in regulating N acquisition by roots, 25 stimulating N metabolism and assimilation, 20 and positively promoting the absorption of N by changed root morphology 21 .…”