Natural sources like starch and lignin used during manufacturing of polyurethane (PU) foam have been used extensively from last decades and replaced petro-chemical based PU foam due to their lower environmental impact...Natural sources like starch and lignin used during manufacturing of polyurethane (PU) foam have been used extensively from last decades and replaced petro-chemical based PU foam due to their lower environmental impact, easy availability, low cost and biodegradability. Bio-renewable sources, such as lignin which is an abundant, underutilized component of cellulosic biomass, constitute a rich source of polyol which are being considered as polyol for the production of “eco-friendly and bio-degradable” PU foam. Lignin was mainly used for production of high fungal degradable polyurethane foams, followed by elastomers as well as wood adhesives. This review paper will focus on the progress of research in lignin based polyurethane materials for foam application.展开更多
Lignin is the most abundant heteropolymer based on aromatic subunits in nature.Large quantities of lignin are annually produced from pulping processes and biorefinery industries.Its unclearly defined structure and dif...Lignin is the most abundant heteropolymer based on aromatic subunits in nature.Large quantities of lignin are annually produced from pulping processes and biorefinery industries.Its unclearly defined structure and difficult biodegradation mainly limit its utilization.This work focused on the effect of hydroxylation of lignin on its microbial degradation.Butyloxy carbonyl-modified lignin,and hydroxylated-lignin were synthesized with di-tert-butyl dicarbonate and hydrogen peroxide,respectively,using lignin as raw material.The degradation of the modifiedlignins both by P.chrysosporium and B.subtilis were analyzed using UV-vis spectroscopy.Results revealed that the lignin degradation velocity raises with the increase hydroxylation level of lignin.Moreover,FTIR and 1H NMR analysis of the biodegradation products of lignin further indicated that higher content of hydroxyl groups in lignin facilitated the demethylation combined with the aromatic ring cracking in the presence of fungus and bacteria.展开更多
Low lignin solubility in aqueous solution is one of the major bottlenecks for lignin biodegradation and bioconversion.Alkaline solution contributes to improving lignin solubility,whereas most microbes can not survive ...Low lignin solubility in aqueous solution is one of the major bottlenecks for lignin biodegradation and bioconversion.Alkaline solution contributes to improving lignin solubility,whereas most microbes can not survive in alkaline conditions.Herein,lignin dissolution behaviors in different pH solutions were systematically investigated,which indicated that solution pH above 10.5 contributed to high solubility of alkali lignin.To match with alkaline lignin aqueous system,several alkali-tolerant ligninolytic bacteria were isolated,most of which are distinct to previously reported ones.Then,the ligninolytic capabilities of these isolates were assessed in different pH conditions by determining their assimilation on alkali lignin,lignin-derived monomers and dimers,their decolorization capabilities,and their lignin peroxidase activities.Thereafter,the underlying ligninolytic and alkali-tolerant mechanisms of Sutcliffiella sp.NC1,an alkalophilic bacterium,was analyzed on the basis of its genome information.The results not only provide valuable information for lignin biodegradation and lignin valorization,but also expand knowledge on alkali-tolerant bacteria.展开更多
Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin...Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt%due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transitio...展开更多
A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy,and identified as Pandoraea sp.by 16S rRNA gene sequence analysis.The biodegrada...A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy,and identified as Pandoraea sp.by 16S rRNA gene sequence analysis.The biodegradation experiment was carried out in mineral salt medium,containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30 °C.Under these conditions,significant reduction in color and lignin content by the strain was observed after incubation for 5 d.The strain attains maximum reduction capability in color(44.6%) and lignin content(39.9%) within 5 d of incubation,and reduced chemical oxygen demand(COD) from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day.The total ion chromatograph(TIC) of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments,indicating a strong destruction in the lignin structure.展开更多
By using the cyclic liquid-liquid extraction method the lignin biodegradated derivatives can be effectively extracted from the effluent liquors in ligninolytic enzymes treated kraft pulps. More than forty compounds we...By using the cyclic liquid-liquid extraction method the lignin biodegradated derivatives can be effectively extracted from the effluent liquors in ligninolytic enzymes treated kraft pulps. More than forty compounds were identified from the extractives by gas chromatography-mass spectrometry analysis. The result showed that lignin is treated with different ligninolytic enzymes, and the composition and content of the extractives differ obviously. These results suggest that the cyclic liquid-liquid extraction method can be used effectively as one new technique for the study of lignin biodegrada-tion mechanisms.展开更多
文摘Natural sources like starch and lignin used during manufacturing of polyurethane (PU) foam have been used extensively from last decades and replaced petro-chemical based PU foam due to their lower environmental impact, easy availability, low cost and biodegradability. Bio-renewable sources, such as lignin which is an abundant, underutilized component of cellulosic biomass, constitute a rich source of polyol which are being considered as polyol for the production of “eco-friendly and bio-degradable” PU foam. Lignin was mainly used for production of high fungal degradable polyurethane foams, followed by elastomers as well as wood adhesives. This review paper will focus on the progress of research in lignin based polyurethane materials for foam application.
基金Foundation item： Project（50925417） supported by the National Science Fund for Distinguished Young Scholars of China Project（50830301） supported by the National Natural Science Foundation of China Project（2011467062） supported by National Research Fund for Public Benefit （Environmental Protection） Industries, China
基金This work was financially supported by the Science and Technology Innovation Program of Hunan Province(Contract Grant No.2018RS3101).
文摘Lignin is the most abundant heteropolymer based on aromatic subunits in nature.Large quantities of lignin are annually produced from pulping processes and biorefinery industries.Its unclearly defined structure and difficult biodegradation mainly limit its utilization.This work focused on the effect of hydroxylation of lignin on its microbial degradation.Butyloxy carbonyl-modified lignin,and hydroxylated-lignin were synthesized with di-tert-butyl dicarbonate and hydrogen peroxide,respectively,using lignin as raw material.The degradation of the modifiedlignins both by P.chrysosporium and B.subtilis were analyzed using UV-vis spectroscopy.Results revealed that the lignin degradation velocity raises with the increase hydroxylation level of lignin.Moreover,FTIR and 1H NMR analysis of the biodegradation products of lignin further indicated that higher content of hydroxyl groups in lignin facilitated the demethylation combined with the aromatic ring cracking in the presence of fungus and bacteria.
基金National Key R&D Program of China(No.2021YFC2101301)National Natural Science Foundation of China(No.22278227).
文摘Low lignin solubility in aqueous solution is one of the major bottlenecks for lignin biodegradation and bioconversion.Alkaline solution contributes to improving lignin solubility,whereas most microbes can not survive in alkaline conditions.Herein,lignin dissolution behaviors in different pH solutions were systematically investigated,which indicated that solution pH above 10.5 contributed to high solubility of alkali lignin.To match with alkaline lignin aqueous system,several alkali-tolerant ligninolytic bacteria were isolated,most of which are distinct to previously reported ones.Then,the ligninolytic capabilities of these isolates were assessed in different pH conditions by determining their assimilation on alkali lignin,lignin-derived monomers and dimers,their decolorization capabilities,and their lignin peroxidase activities.Thereafter,the underlying ligninolytic and alkali-tolerant mechanisms of Sutcliffiella sp.NC1,an alkalophilic bacterium,was analyzed on the basis of its genome information.The results not only provide valuable information for lignin biodegradation and lignin valorization,but also expand knowledge on alkali-tolerant bacteria.
基金supported by the National Natural Science Foundation of China(No50533050)
文摘Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt%due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transitio...
基金Project(50925417) supported by the National Funds for Distinguished Young Scientists,ChinaProject(50830301) supported by the Key program of the National Natural Science Foundation of ChinaProject(2012BAC12B03) supported by the National 12th Five-year Plan for Science and Technology Support,China
文摘A newly isolated bacterium was screened out for its survival on medium with 6 000 mg/L kraft lignin as the sole carbon source and energy,and identified as Pandoraea sp.by 16S rRNA gene sequence analysis.The biodegradation experiment was carried out in mineral salt medium,containing 5 000 mg/L kraft lignin as only carbon and energy at pH 8.0 and 30 °C.Under these conditions,significant reduction in color and lignin content by the strain was observed after incubation for 5 d.The strain attains maximum reduction capability in color(44.6%) and lignin content(39.9%) within 5 d of incubation,and reduced chemical oxygen demand(COD) from initial concentration 7 399 to 3 980 mg/L at maximum reduction level of 46.2% on the 4th day.The total ion chromatograph(TIC) of compounds presented in the chloroform extract of control and bacterial treated samples shows the formation of several lignin-related aromatic compounds including some small molecular lignin fragments,indicating a strong destruction in the lignin structure.
基金Project supported by the National Natural Science Foundation of China (Grant No.39770019).
文摘By using the cyclic liquid-liquid extraction method the lignin biodegradated derivatives can be effectively extracted from the effluent liquors in ligninolytic enzymes treated kraft pulps. More than forty compounds were identified from the extractives by gas chromatography-mass spectrometry analysis. The result showed that lignin is treated with different ligninolytic enzymes, and the composition and content of the extractives differ obviously. These results suggest that the cyclic liquid-liquid extraction method can be used effectively as one new technique for the study of lignin biodegrada-tion mechanisms.
