Sphingosinicella microcystinivorans strain B-9 has the ability to degrade cyanobacterial hepatotoxic cyclic peptides, microcystins, and nodularins. This is the first report of the complete genome sequence of the microcystin-degrading bacterium.

Strain B-9, which has a 99% similarity to Sphingosinicella microcystinivorans strain Y2, is a Gram-negative bacterium with potential for use in the degradation of microcystin-related compounds and nodularin. We attempted to extend the application area of strain B-9 and applied it to mycotoxins produced by fungi. Among the tested mycotoxins, only ochratoxin A was completely hydrolyzed to provide the constituents ochratoxin α and l-phenylalanine, and levels of fumonisin B1 gradually decreased after 96 h. However, although drugs including antibiotics released into the aquatic environment were applied for microbial degradation using strain B-9, no degradation occurred. These results suggest that strain B-9 can only degrade amino acid-containing compounds. As expected, the tested compounds with amide and ester bonds, such as 3,4-dimethyl hippuric acid and 4-benzyl aspartate, were readily hydrolyzed by strain B-9, although the sulfonamides remained unchanged. The ester compounds were characteristically and rapidly hydrolyzed as soon as they came into contact with strain B-9. Furthermore, the degradation of amide and ester compounds with amino acids was not inhibited by the addition of ethylenediaminetetraacetic acid (EDTA), indicating that the responsible enzyme was not MlrC. These results suggest that strain B-9 possesses an additional hydrolytic enzyme that should be designated as MlrE, as well as an esterase.

Cornhusk fiber is a kind of biodegradable lignocellulosic fiber. The conditions of enzyme and NaOH retting were optimized on the basis of weight loss rate and the Fried test score to extract the cornhusks fiber. Taking raw cornhusk fiber as a contrast, physicochemical properties of the fiber extracted from cornhusk was researched in detail by chemical analysis (GB5889-86), X-ray diffraction and Fourier-transform infrared spectroscopy (FTIR). The optimal retting condition of cornhusk fiber is the following: Pectinase 9032 0.5% concentration, at 40–55°C, pH 4.2–5.8, and then 5% NaOH treatment for 15 min. The crystallinity index of raw cornhusk fiber, enzyme-treated cornhusk fiber and enzyme-alkali-treated cornhusk fiber are 20.30%, 35.05% and 51.00%, respectively, and the structure of these fibres all correspond to cellulose I. The FTIR spectra showed that higher amounts of lignin and hemicellulose were removed by NaOH treatment compared with enzyme treatment.

Cornhusk is a renewable and abundant crop by-product whose diverse applications must be studied more extensively. However, thus far, cornhusk, as a raw material, has not been employed for production of cornhusk fiber (CF) nanocellulose (CNC). This study aims to extract and characterize nanocellulose using CF as a raw material by high-shear-assisted enzyme hydrolysis. The extraction process was optimized by investigating the particle size distribution. The optimal extraction conditions of CNC were as follows: cellulase concentration of 1 mg/g, pH of 4.8, temperature of 50 ℃, and 24 h treatment under high-shear conditions for 20 min. The morphological characteristics of the CNC and CF were investigated, and FTIR，XRD, and TGA analyses were performed. Compared with CF, CNC exhibited slenderer nanofibrils with a smoother surface. FTIR analysis showed that the peaks that represented hemicellulose, lignin, and pectin disappeared or diminished in the CNC spectrum. The crystal type of CNC did not change and was identical to that of CF (cellulose type I). The TGA results showed that CNC possessed a lower thermal stability and higher char residuals than those of CF.