Adsorption Study of Lignin Removal from Recycled Alkali Black Liquor by Adsorption Resins for Improved Cellulase Hydrolysis of Corn Straw

Necessity of Different Lignocellulose on Exopolysaccharide Synthesis and Its Hypoglycemic Activity In Vitro of Inonotus obliquus

Current work proposes elm sawdust, poplar sawdust, pine sawdust, and cotton straw with different lignocellulose compositions and structures as the research objects to investigate the relationship between the hypoglycemic activity of mycelium polysaccharides from Inonotus obliquus and lignocellulose biodegradation. Four kinds of lignocellulosic materials could significantly increase the exopolysaccharide content and α-glucosidase inhibition rate and advance the occurrence time of α-glucosidase inhibition activity. Among all groups, the polysaccharide synthesis promotion effect of the cotton straw group was the best, which exopolysaccharide yield was 92.05% higher than that of the control group after 11-day fermentation. Meanwhile, the highest α-glucosidase inhibitory activity was found in the elm sawdust group on the 11th day (30.99%, which was 137.47% higher than control), and the exopolysaccharide in the elm sawdust group showed its effectiveness on glucose consumption of insulin resistant HepG2 cells at the concentration of 20 µg/mL, significantly higher than that of the metformin group (P < 0.05). The cellulose in the non-crystalline region of elm and pine and the hemicellulose of poplar were mainly used in the fermentation of I. obliquus, while the cellulose in the crystalline zone and amorphous zone of cotton straw was degraded to improve the exopolysaccharide content of I. obliquus. This paper revealed the necessity of different kinds of lignocellulose for the synthesis of active polysaccharide from I. obliquus and provided a new idea for the regulation of polysaccharide synthesis pathway.

Efficient polymalic acid production from corn straw hydrolysate by detoxification of phenolic inhibitors

Inhibitory compounds generated from lignocellulose pretreatment would inhibit Poly (malic acid) (PMA) production by Aureobasidium pullulans, but the tolerance mechanism of A. pullulans to lignocellulosic inhibitor is poorly understood. In this study, the cellular response of A. pullulans to lignocellulosic inhibitor stress was studied. Among the three groups of inhibitors (furans, weak acids and phenolic aldehydes), phenolic aldehyde was the dominant inhibitor for PMA production. Phenolic aldehyde was mainly converted into phenolic alcohol by A. pullulans, and phenolic alcohol also exhibited severe inhibition on PMA production. Furthermore, the effect of detoxification methods on inhibitor-removal and PMA fermentation was investigated, both CaCO3 and overliming presented poor detoxification effect, whereas resin H103 could remove both furan derivatives and phenolic compounds efficiently, thereby producing 26.27 g/L of PMA with a yield of 0.30 g/g in batch fermentation. This study will be beneficial for the development of PMA production from lignocellulosic biomass.

Enhancing the compost maturation of deer manure and corn straw by supplementation via black liquor

In this paper, the relationship between black liquor and microbial growth, enzymatic secretion and humus formation in composting was studied. The results showed that black liquor inoculation is an effective way to promote fermentation process. After black liquor inoculation, the abundance of Corynebacterium, Aequorivita, and Pedobacter, which have the catalase and oxidase activity, has been significantly increased. The enzymatic activity of alkaline phosphatase, catalase, peroxidase and invertase was 40 mg/(g·24h), 6.5 mg/(g·20 min), 13 100 mg/(g·24h), and 6100 mg/(g·24h) respectively at day 18. Humic acid and fulvic acid concentration was 12 g/kg and 11 g/kg which is higher than that of the treatments of no black liquor inoculation. The results suggested that black liquor inoculation was beneficial to indigenous microorganisms reproduce efficiently, then the secretion of enzymes related to cellulose, hemicellulose, and lipid hydrolysis, and the formation of humic substances.

Biosequestration of lignin in municipal landfill leachate by tailored cationic lipoprotein biosurfactant through Bacillus tropicus valorized tannery solid waste

Bioremediation of municipal landfill leachate (MLL) is often intricate due to presence of refractory lignin. In the present study, it was attempted to tailor the histidine rich protein moiety of cationic lipoprotein biosurfactant (CLB) to sequester the lignin from MLL. Animal fleshing (AF), the solid waste generated in tanning industry was utilized for the production of histidine rich CLB by de novo substrate dependent synthesis pathway involving Bacillus tropicus. The optimum conditions for the maximum production of CLB were determined using response surface methodology. At the optimized conditions, the maximum yield of CLB was 217.4 mg/g AF (on dry basis). The produced histidine rich CLB was purified using Immobilized metal affinity chromatography at the optimum binding and elution conditions. The histidine residues were more pronounced in the CLB, as determined by HPLC analysis. The CLB was further characterized by SDS-PAGE, Zeta potential, XRD, FT-IR, Raman, NMR, GC-MS and TG analyses. The CLB was immobilized onto functionalized nanoporous activated bio carbon (FNABC) and the optimum immobilization capacity was found to be 211.6 mg/g FNABC. The immobilization of CLB onto FNABC was confirmed using SEM, FT-IR, XRD and TG analyses. The isotherm models, kinetic and thermodynamics studies of CLB immobilization onto FNABC were performed to evaluate its field level application. Subsequently, the CLB-FNABC was then applied for the sequestration of lignin in MLL. The maximum lignin sequestration was achieved by 92.5 mg/g CLB-FNABC at the optimized sequestration time, 180 min; pH, 5; temperature, 45 °C and mass of CLB-FNABC, 1.0 g. The sequestration of lignin by CLB- FNABC was confirmed by SEM, FT-IR and UV-Vis analyses. Further, the mechanistic study revealed the anchoring of CLB onto the surface of lignin through electrostatic interaction.