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47 results on '"Hui, Lanfeng"'

30. Pulping and Papermaking of Non-Wood Fibers

Author

Hui Lanfeng, Liu Zhong, and Huimei Wang

Subjects
0106 biological sciences, Chemistry, 010608 biotechnology, Papermaking, 02 engineering and technology, 021001 nanoscience & nanotechnology, 0210 nano-technology, Pulp and paper industry, 01 natural sciences
Published
2018

31. Assessment on temperature-pressure severally controlled explosion pretreatment of poplar

Author

Zheng Xu, Hui Lanfeng, Xuejun Pan, Liu Zhong, Huimei Wang, Hao Zhang, and Jingzhi Li

Subjects
Langmuir, Polymers and Plastics, biology, fungi, Organic Chemistry, food and beverages, 02 engineering and technology, Cellulase, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, chemistry.chemical_compound, Hydrolysis, chemistry, Enzymatic hydrolysis, Materials Chemistry, biology.protein, Lignin, Hemicellulose, Cellulose, 0210 nano-technology, Steam explosion, Nuclear chemistry
Abstract

In this work, temperature-pressure severally controlled explosion pretreatment (TPE) was proposed to pretreat poplar chips to improve the cellulase hydrolysis yield. In TPE process, native poplar chips (NP) were mixed with steam and N2 under pressure of 2.6, 2.8 and 3.0 MPa at 209 °C for 7 min. Meanwhile, steam explosion (SE) was also used to pretreat poplar chips for comparison at 209 °C (1.9 MPa) for 7 min. Results showed that the contents of hemicellulose and lignin were decreased from 19.4 % to 4.6 % and from 27.8 %–19.5 % with increasing pressure, respectively. For cellulase hydrolysis process, TPE was more advantageous than SE due to lower contents of hemicellulose and lignin, resulting in a higher cellulose conversion (40.7 %) in relation to SE sample (34.9 %). The Langmuir isothermal- type equation expressed the factors related to the hydrolysis capacity, and the results showed that this model can well describe the kinetics of the enzymatic hydrolysis.

Published
2020

35. Effects of calcium silicate synthesized in situ on Fiber loadingand paper properties

Author

An, Yongzhen, Liu, Haitang, Liu, Jing, Li, Xuexiu, Li, Jie, Chen, Lin, Jin, Xin, Xu, Yan, Zhao, Zhiqiang, Song, Shunxi, Hui, Lanfeng, Liu, Zhong, and Huang, Yingjian

Abstract

The in-situ synthesis of calcium silicate in the fiber can not only meet the requirements for high loading of paper, but also make up and improve the reduction of paper performance caused by filling. In this investigation, the effects of pulp type, beating degree, fiber ratio, reaction time, rotational speed, dosage of lime milk and dispersant on calcium silicate loading and paper properties were investigated. The results showed that when the beating degree was 40 °SR, the ratio of softwood and hardwood pulp was 1:1, the reaction time was 60 min, the rotation speed was 600 r·min−1, the dosage of lime milk was 1.33 times of the theoretical amount, and the dosage of cationic polyacrylamide was 0.3 % (absolutely dry pulp), the ash content of hand-made sheet was 41.2 %, and the loading amount of calcium silicate was 26.3 %. Under this condition, the comprehensive performance of paper was the best.

Published
2021
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36. Understanding the structural changes of lignin in poplar following steam explosion pretreatment.

Author

Wang, Huimei, Liu, Zhong, Hui, Lanfeng, Ma, Lan, Zheng, Xu, Li, Jingzhi, and Zhang, Yan

Subjects
LIGNINS, GEL permeation chromatography, FOURIER transform infrared spectroscopy, LIGNIN structure, NUCLEAR magnetic resonance, QUANTUM correlations
Abstract

To understand the modifications of lignin in the steam explosion process (209°C, 7 min), lignin samples in native poplar (LP), steam explosion solid residue (LS) and steam explosion liquid (LL) were separated and studied. The lignin samples (LP, LS and LL) were characterized and analyzed by size exclusion chromatography (SEC), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance [carbon 13 numclear magnetic resonance (13C-NMR) and heteronuclear single quantum coherence or heteronuclear single quantum correlation experiment NMR (HSQC) NMR] analysis. The results revealed that the pretreatment induced reductions in amounts of β-O-4′, β-β′, and spirodienone structure, and increases in the syringyl/guaiacyl (S/G) ratio from 1.14 (LP) to 1.70 (LS) and 1.86 (LL). The HSQC NMR spectra also gave more information about the predominance of G and S units, and only small amounts of p-hydroxyphenyl (H) units. Moreover, SEC demonstrated the depolymerization and repolymerization of lignin, which were the main reasons for the increase in the average molecular weight of LS and the decrease in average molecular weight of LL, respectively. In brief, after steam explosion treatment, the lignin structure changed, but the backbone structure was not noticeably modified. [ABSTRACT FROM AUTHOR]

Published
2020
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47. Identification of functional butanol-tolerant genes from Escherichia coli mutants derived from error-prone PCR-based whole-genome shuffling.

Author

Zhang, Junyan, Hong, Jiefang, He, Xueting, Xue, Tingli, Wang, Zhiquan, Zhang, Minhua, Ma, Yuanyuan, Qiao, Jianjun, Song, Hao, and Hui, Lanfeng

Subjects
ESCHERICHIA coli, GENOMES, BUTANOL, QUORUM sensing, SINGLE nucleotide polymorphisms
Abstract

Background: Butanol is an important biofuel and chemical. The development of butanol-tolerant strains and the identification of functional butanol-tolerant genes is essential for high-yield bio-butanol production due to the toxicity of butanol. Results: Escherichia coli BW25113 was subjected for the first time to error-prone PCR-based whole-genome shuffling. The resulting mutants BW1847 and BW1857 were found to tolerate 2% (v/v) butanol and short-chain alcohols, including ethanol, isobutanol, and 1-pentanol. The mutants exhibited good stability under butanol stress, indicating that they are potential host strains for the construction of butanol pathways. BW1847 had better butanol tolerance than BW1857 under 0–0.75% (v/v) butanol stress, but showed a lower tolerance than BW1857 under 1.25–2% (v/v) butanol stress. Genome resequencing and PCR confirmation revealed that BW1847 and BW1857 had nine and seven single nucleotide polymorphisms, respectively, and a common 14-kb deletion. Functional complementation experiments of the SNPs and deleted genes demonstrated that the mutations of acrB and rob gene and the deletion of TqsA increased the tolerance of the two mutants to butanol. Genome-wide site-specific mutated strains DT385 (acrB C1198T) and DT900 (rob AT686–7) also showed significant tolerance to butanol and had higher butanol efflux ability than the control, further demonstrating that their mutations yield an inactive protein that enhances butanol resistance characteristics. Conclusions: Stable E. coli mutants with enhanced short alcohols and high concentrations of butanol tolerance were obtained through a rapid and effective method. The key genes of butanol tolerance in the two mutants were identified by comparative functional genomic analysis. [ABSTRACT FROM AUTHOR]

Published
2019
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