• Title/Summary/Keyword: lignin deposition

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Comparative study of calcium carbonate deposition induced by microorganisms and plant ureases in fortified peat soils

  • Chao Wang;Jianbin Xie;Yinlei Sun;Jianjun Li;Jie Li;Ronggu Jia
    • Structural Monitoring and Maintenance
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    • v.11 no.3
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    • pp.187-202
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    • 2024
  • For the problems of high compressibility and low strength of peat soil formed by lake-phase deposition in Dianchi Lake, microbial-induced calcium carbonate deposition (MICP), phyto-urease-induced calcium carbonate deposition (EICP) and phyto-urease-induced calcium carbonate deposition combined with lignin (EICP combined with lignin) were used to reinforce the peat soil, the changes in mechanical properties of the soil before and after the reinforcement of the peat soil were experimentally investigated, and the effect and mechanism of peat soil reinforcing by the three reinforcing techniques were tested and analyzed using X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show that: compared to the unreinforced remolded peat soil specimens, the unconfined compressive strength (UCS), cohesion and internal friction angle of the specimens reinforced by MICP, EICP and EICP combined with lignin techniques have been greatly improved, and the permeability resistance has been improved by two, two and three orders of magnitude, respectively; the different methods of reinforcing generate different calcium carbonate crystalline phases, with the EICP combined with lignin technique generating the most stable calcite, and the MICP and EICP techniques generating a mixed phase of calcite and spherulitic chalcocite. Analyses showed that for peat soil reinforcement, the acidic environment of peat soil inhibited the growth and reproduction of bacteria, EICP technology was superior to MICP technology, and the addition of lignin solved the defect of the EICP technology that did not have a "nucleation site", so EICP combined with lignin reinforcement was preferred for the improvement of peat soil.

Caffeoyl Shikimate Esterase has a Role in Endocarp Lignification in Peach (Prunus persica L.) Fruit

  • Liu, Jinyi;Hu, Xiao;Yu, Jia;Yang, Aizhen;Liu, Yueping
    • Horticultural Science & Technology
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    • v.35 no.1
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    • pp.59-68
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    • 2017
  • Caffeoyl shikimate esterase (CSE) is a key enzyme in lignin synthesis in Arabidopsis thaliana. To determine the role of CSE in lignification of the endocarp in peach (Prunus persica L.) fruit, we cloned and characterized the P. persica CSE homolog, which we designated PpCSE. The 954 - bp PpCSE gene encoded a 317 - amino acid polypeptide. PpCSE expression patterns in the mesocarp and endocarp changed during peach fruit development. There was no significant difference between the expression levels of PpCSE in the mesocarp and endocarp at 39 and 44 days after full bloom (DAFB), but the expression level of PpCSE in the endocarp at 50 and 55 DAFB was 80.73 and 72.75 times higher, respectively, than that in the mesocarp. During peach fruit development, PpCSE expression in the endocarp increased rapidly; the relative PpCSE expression level at 50 DAFB was 122.70 times higher than that at 39 DAFB. At the protein level, CSE was detected in the peach fruit endocarp at 50 and 55 DAFB. Our study suggests that PpCSE expression during peach fruit development is closely related to the degree of endocarp lignification.

New curing method using gaseous oxidant on sweet potato (Ipomoea batatas)

  • Jin, Hyunjung;Kim, Wook
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.39-39
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    • 2017
  • In Asia, sweet potato (Ipomoea batatas) is a very important crop for starch production. Approximately 74.3% of the total sweet potato production quantity is produced in Asia (FAO, 2014) and China is the largest producer of sweet potato. Post-harvest management is particularly important because it is difficult to maintain the quality as well as quantity of sweet potatoes. Despite the importance of post-harvest management, researches on sweet potato have been focused on production-related study such as breeding of new variety, improved techniques of cultivation, so there is limited research on storage after harvest. Curing is a normal practice after sweet potato harvest to promote wound healing and extend postharvest storage life. In Korea, harvested sweet potatoes are usually cured for 4 to 7 days at $30-33^{\circ}C$ and 80-95% relative humidity within one week. Since the optimum storage temperature of sweet potato is regarded as $15-20^{\circ}C$, additional facilities and costs are required to raise the temperature for curing. However, the majority of small farmers do not have the capacity to provide additional facilities and costs. This study was initiated to suggest a new curing method to accelerate the wound healing by applying chemical oxidation to the wound surface of sweet potato. Oxidative stress is known to play an important role in the synthesis of secondary metabolites including lignin. In addition, chemical oxidation can be applied to prevent spoilage caused by microorganisms. Powerful gaseous oxidant with excellent penetration ability and superior sterilization effect was selected for this study. Lignification, weight loss, and spoilage rate of artificially wounded sweet potatoes were investigated after oxidant fumigation. There were clear differences in morphological analysis such as lignification pattern, lignin deposition color, and continuity of lignified cell layers between oxidant-fumigated sweet potatoes and control. These results show that gaseous oxidant can be used to supplement or replace the curing practice, to improve shelf-life as well as curing cost reduction.

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Electrochemical Characteristics of Supercapacitor Electrode Using MnO2 Electrodeposited Carbon Nanofiber Mats from Lignin-g-PAN Copolymer (이산화망간 전기증착 리그닌 기반 탄소나노섬유 매트를 이용한 슈퍼캐퍼시터용 전극소재의 전기·화학적 특성)

  • Kim, Seok Ju;Youe, Won-Jae;Kim, Yong Sik
    • Journal of the Korean Wood Science and Technology
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    • v.44 no.5
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    • pp.750-759
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    • 2016
  • The $MnO_2$ electrodeposited on the surface of the carbon nanofiber mats ($MnO_2$-LCNFM) were prepared from electrospun lignin-g-PAN copolymer via heat treatments and subsequent $MnO_2$ electrodeposition method. The resulting $MnO_2$-LCNFM was evaluateed for its potential use in a supercapicitor electrode. The increase of $MnO_2$ electric deposition time was revealed to increase diameter of carbon nanofibers as well as $MnO_2$ content on the surface of carbon nanofiber mats as confirmed by scanning electon microscope (SEM) analysis. The electrochemical properties of $MnO_2$-LCNFM electrodes are evaluated through cyclic voltammetry test. It was shown that $MnO_2$-LCNFM electrode exhibited good electrochemical performance with specific capacitance of $168.0mF{\cdot}cm^{-2}$. The $MnO_2$-LCNFM supercapacitor successfully fabricated using the gel electrolyte ($H_3PO_4$/Polyvinyl alcohol) showed to have the capacitance efficiency of ~90%, and stable behavior during 1,000 charging/discharging cycles.

Overcoming Encouragement of Dragon Fruit Plant (Hylocereus undatus) against Stem Brown Spot Disease Caused by Neoscytalidium dimidiatum Using Bacillus subtilis Combined with Sodium Bicarbonate

  • Ratanaprom, Sanan;Nakkanong, Korakot;Nualsri, Charassri;Jiwanit, Palakrit;Rongsawat, Thanyakorn;Woraathakorn, Natthakorn
    • The Plant Pathology Journal
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    • v.37 no.3
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    • pp.205-214
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    • 2021
  • The use of the supernatant from a Bacillus subtilis culture mixed with sodium bicarbonate was explored as a means of controlling stem brown spot disease in dragon fruit plants. In in vitro experiments, the B. subtilis supernatant used with sodium bicarbonate showed a strong inhibition effect on the growth of the fungus, Neoscytalidium dimidiatum, the agent causing stem brown spot disease and was notably effective in preventing fungal invasion of dragon fruit plant. This combination not only directly suppressed the growth of N. dimidiatum, but also indirectly affected the development of the disease by eliciting the dragon-fruit plant's defense response. Substantial levels of the pathogenesis-related proteins, chitinase and glucanase, and the phenylpropanoid biosynthetic pathway enzymes, peroxidase and phenyl alanine ammonia-lyase, were triggered. Significant lignin deposition was also detected in treated cladodes of injured dragon fruit plants in in vivo experiments. In summary, B. subtilis supernatant combined with sodium bicarbonate protected dragon fruit plant loss through stem brown spot disease during plant development in the field through pathogenic fungal inhibition and the induction of defense response mechanisms.

Wood and Leaf Litter Decomposition and Nutrient Release from Tectona grandis Linn. f. in a Tropical Dry Deciduous Forest of Rajasthan, Western India

  • Kumar, J.I. Nirmal;Sajish, P.R.;Kumar, Rita.N.;Bhoi, Rohit Kumar
    • Journal of Forest and Environmental Science
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    • v.26 no.1
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    • pp.17-23
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    • 2010
  • The present study was conducted to quantify wood and leaf litter decomposition and nutrient release of a dominant tree species, Tectona grandis Linn. F. in a tropical dry deciduous forest of Rajasthan, Western India. The mean relative decomposition rate was maximum in the wet summer and minimum during dry summer. Rainfall and its associated variables exhibited greater control over litter decomposition than temperature. The concentrations of N and P increased in decomposing litter with increasing retrieval days. Mass loss was negatively correlated with N and P concentrations. The monthly weight loss was significantly correlated (P < 0.05) with soil moisture and rainfall in both wood and leaf litter. Tectona grandis was found to be most suitable tree species for plantation programmes in dry tropical regions as it has high litter deposition and decomposition rates and thus it has advantages in degraded soil restoration and sustainable land management.

Morphological Alteration of Cell Organelles Affected by UV-B Radiation in Rice Leaf Tissues (자외선에 의한 벼 엽 세포 소기관의 형태적 변화)

  • Sung, Jwa-Kyung;Song, Beom-Heon;Kim, Hong-Sig;Lee, Chul-Won;Kim, Tae-Wan
    • Korean Journal of Soil Science and Fertilizer
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    • v.37 no.1
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    • pp.31-35
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    • 2004
  • This experiment was performed to observe morphological changes in rice leaf tissue caused by a successive UV-B radiation. Effect of UV-B radiation on the structural alteration of tissue was not visually found, however, Photosynthate containing phosphate was sharply reduced in proportion with an increase of UV-B radiation. Fundamental components of cuticle layer were being degraded after 6 h of UV-B radiation compared to the control. UV-B-induced mesophyll cell appeared altered because of water stress, the shape of chloroplast appeared to be considerably shrunk and chloroplast thylakoid membranes were severely destructed. Primary cell wall of UV-B-stressed tissue was entirely scattered or disappeared, and the secondary cell wall due to lignin synthesis and deposition resulted in being thickened, almost 2-times, compared with the control.

Study of Oil Palm Biomass Resources (Part 5) - Torrefaction of Pellets Made from Oil Palm Biomass - (오일팜 바이오매스의 자원화 연구 V - 오일팜 바이오매스 펠릿의 반탄화 연구 -)

  • Lee, Ji-Young;Kim, Chul-Hwan;Sung, Yong Joo;Nam, Hye-Gyeong;Park, Hyeong-Hun;Kwon, Sol;Park, Dong-Hun;Joo, Su-Yeon;Yim, Hyun-Tek;Lee, Min-Seok;Kim, Se-Bin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.48 no.2
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    • pp.34-45
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    • 2016
  • Global warming and climate change have been caused by combustion of fossil fuels. The greenhouse gases contributed to the rise of temperature between $0.6^{\circ}C$ and $0.9^{\circ}C$ over the past century. Presently, fossil fuels account for about 88% of the commercial energy sources used. In developing countries, fossil fuels are a very attractive energy source because they are available and relatively inexpensive. The environmental problems with fossil fuels have been aggravating stress from already existing factors including acid deposition, urban air pollution, and climate change. In order to control greenhouse gas emissions, particularly CO2, fossil fuels must be replaced by eco-friendly fuels such as biomass. The use of renewable energy sources is becoming increasingly necessary. The biomass resources are the most common form of renewable energy. The conversion of biomass into energy can be achieved in a number of ways. The most common form of converted biomass is pellet fuels as biofuels made from compressed organic matter or biomass. Pellets from lignocellulosic biomass has compared to conventional fuels with a relatively low bulk and energy density and a low degree of homogeneity. Thermal pretreatment technology like torrefaction is applied to improve fuel efficiency of lignocellulosic biomass, i.e., less moisture and oxygen in the product, preferrable grinding properties, storage properties, etc.. During torrefacton, lignocelluosic biomass such as palm kernell shell (PKS) and empty fruit bunch (EFB) was roasted under an oxygen-depleted enviroment at temperature between 200 and $300^{\circ}C$. Low degree of thermal treatment led to the removal of moisture and low molecular volatile matters with low O/C and H/C elemental ratios. The mechanical characteristics of torrefied biomass have also been altered to a brittle and partly hydrophobic materials. Unfortunately, it was much harder to form pellets from torrefied PKS and EFB due to thermal degradation of lignin as a natural binder during torrefaction compared to non-torrefied ones. For easy pelletization of biomass with torrefaction, pellets from PKS and EFB were manufactured before torrefaction, and thereafter they were torrefied at different temperature. Even after torrefaction of pellets from PKS and EFB, their appearance was well preserved with better fuel efficiency than non-torrefied ones. The physical properties of the torrefied pellets largely depended on the torrefaction condition such as reaction time and reaction temperature. Temperature over $250^{\circ}C$ during torrefaction gave a significant impact on the fuel properties of the pellets. In particular, torrefied EFB pellets displayed much faster development of the fuel properties than did torrefied PKS pellets. During torrefaction, extensive carbonization with the increase of fixed carbons, the behavior of thermal degradation of torrefied biomass became significantly different according to the increase of torrefaction temperature. In conclusion, pelletization of PKS and EFB before torrefaction made it much easier to proceed with torrefaction of pellets from PKS and EFB, leading to excellent eco-friendly fuels.