Swine manure valorization for phosphorus and nitrogen recovery by catalytic-thermal hydrolysis and struvite crystallization

Phosphorus (P) and nitrogen (N) recovery from swine manure has attracted considerable interest for biomass valorization. In this study, a catalytic-thermal hydrolysis (TH) process combined with struvite crystallization was investigated to promote P and N conversion from swine manure. Its potential as a phosphate-based fertilizer was investigated. Two periods for P solubilization and transformation were observed, i.e., an initial increase with reaction time followed by a decrease as treatment continued. Nitrogen conversion efficiency increased with increasing temperature and time. Treatment of swine manure by catalytic-TH with HCl + H₂O₂ showed the best performance for P and N solubilization and transformation. With a Mg²⁺/PO₄^3- molar ratio of 2.49 and a pH of 9.11, the struvite crystallization efficiency from the supernatant after catalytic-TH with HCl + H₂O₂ reached 99.2%. Hydroculture bioassay showed that struvite had a positive effect on the early growth of wheat. The P concentrations in both root and shoot tissues for struvite treatment were more than two times higher than that of soluble P. These encouraging results warrant further studies on the conversion of biowaste given that recycling nutrients sources may outperform traditional synthetic fertilizers.

Tag-assisted liquid-phase peptide synthesis using hydrophobic benzyl alcohols as supports

A soluble tag-assisted liquid-phase peptide synthesis was successfully established based on simple hydrophobic benzyl alcohols, which can be easily prepared from naturally abundant materials. Excellent precipitation yields can be obtained at each step, combining the best properties of solid-phase and liquid-phase techniques. This approach can also be applied efficiently to fragment couplings, allowing chemical synthesis of several bioactive peptides.

Soluble-support-assisted electrochemical reactions: application to anodic disulfide bond formation

A soluble-support-assisted technique was successfully applied to electrochemical reactions, leading to anodic disulfide bond formation. The support-bound peptide was soluble in electrolyte solution, allowing electron transfer at the surface of the electrodes. After completion of the reaction, the support-bound product was recovered as a precipitate by simple dilution of the reaction mixture with poor solvent.

Oligomethylene spacer length dependent interaction of synthetic galactolipids incorporated in phospholipid layers with ricin

As models of naturally occurring glycolipids, structurally well-determined amphiphilic compounds were prepared. The synthetic molecules have beta-D-galactopyranosyl or alpha-D-mannopyranosyl and two dodecyl groups as terminal hydrophilic sugar and hydrophobic hydrocarbon moieties, respectively. The two long alkyl chains are connected by 3,5-dioxybenzamide through ether linkages to give a lipid analog purified easily due to its absorbance of ultraviolet light. In the synthetic glycolipids, the glycoside and lipid parts are covalently bound via an oligomethylene spacer. The glycolipids could be easily incorporated into liposomes of L-alpha-phosphatidylcholine. The monoglycosyl moiety of the synthetic glycolipids possessing a hexamethylene spacer was present on the surface of the liposomes and interacted specifically with a lectin to give liposomal assemblies. Such agglutination of these liposomes induced by lectins was determined by analyses of turbidity and particle size based on dynamic light scattering and laser diffraction methods. The other liposomes possessing a shorter ethylene or longer decamethylene linker gave few lectin-induced agglutinates, indicating that these spacers were not effective for the presentation of the galacto-terminal on the liposomal surfaces. Similar spacer-dependent recognition of ricin with a galactolipid-incorporated phospholipid monolayer was confirmed by surface plasmon resonance technique on a substrate.

Novel Carbohydrate-binding Activity of Pancreatic Trypsins to N-Linked Glycans of Glycoproteins

How glycosylation affects the reactivity of proteins to trypsin is not well understood. Bovine and porcine pancreatic trypsins were discovered to bind to alpha-Man, Neu5Acalpha2,6Galbeta1,4Glc, and alpha-galactose sequences by binding studies with biotinylated sugar-polymers. Quantitative kinetic studies supported that phenylmethylsulfonyl fluoride (PMSF)-treated trypsin binds to glycolipid analogues possessing alpha-Man or alpha-NeuAc but not to those possessing beta-galactose or beta-GlcNAc residue. Enzyme-linked immunosorbent assay (ELISA) showed that trypsin binds to six kinds of biotinylated glycoproteins possessing high mannose-type and complex-type N-glycans but not to bovine submaxillary mucin, which possesses only O-glycans. Further, the binding of trypsin to glycoproteins was differentially changed by treatments with sequential exoglycosidases, endoglycosidase H, or N-glycosidase F. Quantitative kinetic studies indicated that PMSF-treated trypsin binds with bovine thyroglobulin with the affinity constant of 10(10) m(-1), which was the highest among the glycoproteins examined, and that alpha-galactosidase treatment decreased it to 10(5) m(-1). PMSF-treated trypsin bound to other glycoproteins, including ovomucoid, a trypsin inhibitor, with the affinity constants of 10(8)-10(5) mol(-1) and were markedly changed by glycosidase treatments in manners consistent with the sugar-binding specificities suggested by ELISA. Thus, the binding site for glycans was shown to be distinct from the catalytic site, allowing trypsin to function as an uncompetitive activator in the hydrolysis of a synthetic peptide substrate. Correspondingly the carbohydrate-binding activities of trypsin were unaffected by treatment with PMSF or soybean trypsin inhibitor. The results indicate the presence of an allosteric regulatory site on trypsin that sugar-specifically interacts with glycoproteins in addition to the proteolytic catalytic site.

Survey of the year 2004 commercial optical biosensor literature

The year 2004 represents a milestone for the biosensor research community: in this year, over 1000 articles were published describing experiments performed using commercially available systems. The 1038 papers we found represent an approximately 10% increase over the past year and demonstrate that the implementation of biosensors continues to expand at a healthy pace. We evaluated the data presented in each paper and compiled a 'top 10' list. These 10 articles, which we recommend every biosensor user reads, describe well-performed kinetic, equilibrium and qualitative/screening studies, provide comparisons between binding parameters obtained from different biosensor users, as well as from biosensor- and solution-based interaction analyses, and summarize the cutting-edge applications of the technology. We also re-iterate some of the experimental pitfalls that lead to sub-optimal data and over-interpreted results. We are hopeful that the biosensor community, by applying the hints we outline, will obtain data on a par with that presented in the 10 spotlighted articles. This will ensure that the scientific community at large can be confident in the data we report from optical biosensors.