Metagenomic SMRT Sequencing-Based Exploration of Novel Lignocellulose-Degrading Capability in Wood Detritus from Torreya nucifera in Bija Forest on Jeju Island

( Han Na Oh ),( Tae Kwon Lee ),( Jae Wan Park ),( Jee Hyun No ),( Dockyu Kim ),( Woo Jun Sul ) 한국미생물생명공학회(구 한국산업미생물학회) 2017 Journal of microbiology and biotechnology Vol.27 No.9

Lignocellulose, composed mostly of cellulose, hemicellulose, and lignin generated through secondary growth of woody plant, is considered as promising resources for biofuel. In order to use lignocellulose as a biofuel, biodegradation besides high-cost chemical treatments were applied, but knowledge on the decomposition of lignocellulose occurring in a natural environment is insufficient. We analyzed the 16S rRNA gene and metagenome to understand how the lignocellulose is decomposed naturally in decayed Torreya nucifera (L) of Bija forest (Bijarim) in Gotjawal, an ecologically distinct environment. A total of 464,360 reads were obtained from 16S rRNA gene sequencing, representing diverse phyla; Proteobacteria (51%), Bacteroidetes (11%) and Actinobacteria (10%). The metagenome analysis using single molecules real-time sequencing revealed that the assembled contigs determined originated from Proteobacteria (58%) and Actinobacteria (10.3%). Carbohydrate Active enZYmes (CAZy)- and Protein families (Pfam)-based analysis showed that Proteobacteria was involved in degrading whole lignocellulose, and Actinobacteria played a role only in a part of hemicellulose degradation. Combining these results, it suggested that Proteobacteria and Actinobacteria had selective biodegradation potential for different lignocellulose substrates. Thus, it is considered that understanding of the systemic microbial degradation pathways may be a useful strategy for recycle of lignocellulosic biomass, and the microbial enzymes in Bija forest can be useful natural resources in industrial processes.

Antarctic tundra soil metagenome as useful natural resources of cold-active lignocelluolytic enzymes

Han Na Oh,Doyoung Park,Hoon Je Seong,Dockyu Kim,Woo Jun Sul 한국미생물학회 2019 The journal of microbiology Vol.57 No.10

Lignocellulose composed of complex carbohydrates and aromatic heteropolymers is one of the principal materials for the production of renewable biofuels. Lignocellulose-degrading genes from cold-adapted bacteria have a potential to increase the productivity of biological treatment of lignocellulose biomass by providing a broad range of treatment temperatures. Antarctic soil metagenomes allow to access novel genes encoding for the cold-active lignocellulose-degrading enzymes, for biotechnological and industrial applications. Here, we investigated the metagenome targeting cold-adapted microbes in Antarctic organic matter-rich soil (KS 2-1) to mine lignolytic and celluloytic enzymes by performing single molecule, real-time metagenomic (SMRT) sequencing. In the assembled Antarctic metagenomic contigs with relative long reads, we found that 162 (1.42%) of total 11,436 genes were annotated as carbohydrate-active enzymes (CAZy). Actinobacteria, the dominant phylum in this soil’s metagenome, possessed most of candidates of lignocellulose catabolic genes like glycoside hydrolase families (GH13, GH26, and GH5) and auxiliary activity families (AA7 and AA3). The predicted lignocellulose degradation pathways in Antarctic soil metagenome showed synergistic role of various CAZyme harboring bacterial genera including Streptomyces, Streptosporangium, and Amycolatopsis. From phylogenetic relationships with cellular and environmental enzymes, several genes having potential for participating in overall lignocellulose degradation were also found. The results indicated the presence of lignocellulose-degrading bacteria in Antarctic tundra soil and the potential benefits of the lignocelluolytic enzymes as candidates for cold-active enzymes which will be used for the future biofuel-production industry.

Crack Resistance and Strength Properties of Red Clay Modified with Lignocellulose and Guar gum

Hong-Yuan Fu,Guang-Tao Yu,Qian-Feng Gao,Ling Zeng,Shuo-Peng Cao 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

Desiccation cracking is a common problem of red clay under wet and dry conditions. The presence of cracks could reduce soil strength properties, which is the major reason for shallow failure of red clay slopes. This study aims to propose some additives to improve the crack resistance as well as the strength of red clay. To this end, three natural fibers and three natural gels were primarily selected to modify red clay. Desiccation crack tests were conducted to identify the best fiber and gel in terms of crack resistance. Then, direct shear tests and uniaxial tensile tests were performed on the soil specimens modified by the best fiber and gel to determine the optimal dosages regarding strength improvements. The results demonstrated that natural gels reduced the crack resistance of red clay, while natural fibers could enhance the crack resistance. Lignocellulose was the best additive in improving the crack resistance of red clay, and the modified effect was positively correlated with the fiber dosage. Adding 1.5% lignocellulose into red clay could reduce the crack rate from 2.19% to 0.30%, with a reduction of 0.86 times. The tensile strength, shear strength and its parameters of lignocellulose-modified red clay showed a trend of increasing first and then decreasing with increasing lignocellulose dosage. At the optimal lignocellulose dosage of 0.75%, the shear strength and tensile strength were increased by 44.63% and 18.21%, respectively. The strength of red clay modified by both lignocellulose and guar gum was positively correlated with the dosage of guar gum, and the desirable dosage of guar gum was 1.0%. In engineering practice, the wet red clay mixed with 0.75% lignocellulose and grass seeds can be employed as planting soil and is sprayed uniformly onto the slope surface after excavation using a spraying planting machine. To further improve the strength of the planting soil, 1.0% guar gum solution can be sprayed on the soil surface. The findings could provide useful guidance for the protection of red clay slopes.

Characterization of a Thermophilic Lignocellulose-Degrading Microbial Consortium with High Extracellular Xylanase Activity

( Dongdong Zhang ),( Yi Wang ),( Chunfang Zhang ),( Dan Zheng ),( Peng Guo ),( Zongjun Cui ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.2

A microbial consortium, TMC7, was enriched for the degradation of natural lignocellulosic materials under high temperature. TMC7 degraded 79.7% of rice straw during 15 days of incubation at 65°C. Extracellular xylanase was effectively secreted and hemicellulose was mainly degraded in the early stage (first 3 days), whereas primary decomposition of cellulose was observed as of day 3. The optimal temperature and initial pH for extracellular xylanase activity and lignocellulose degradation were 65°C and between 7.0 and 9.0, respectively. Extracellular xylanase activity was maintained above 80% and 85% over a wide range of temperature (50-75°C) and pH values (6.0-11.0), respectively. Clostridium likely had the largest contribution to lignocellulose conversion in TMC7 initially, and Geobacillus, Aeribacillus, and Thermoanaerobacterium might have also been involved in the later phase. These results demonstrate the potential practical application of TMC7 for lignocellulosic biomass utilization in the biotechnological industry under hot and alkaline conditions.

Effect of Lignocellulose Nanofibril Addition on the Properties of Lignin-based Plastic Composite

Hyun-Woo Nam-Gung,Won-Jae Youe,Chan-Woo Park,Song-Yi, Han,Pureun-Narae Seo,Yong-Sik Kim,Seung-Hwan Lee 강원대학교 산림과학연구소 2017 강원대학교 산림과학연구소 학술대회 Vol.2017 No.11

Lignin is the most abundant aromatic biopolymer and exists in lignocellulose. Although lignin has been known as difficult material to be utilized as high value added product, research on the development of bioplastics from lignin has attracted attention. In this study, lignocellulose nanofibrill (LCNF) was used as a reinforcing filler to improve the mechanical properties of lignin-based polycaprolactone (PCL) composite, and polymeric methylene diphenyl diisocyanate (pMDI) was added as a coupling agent to improve interfacial adhesion between lignin and PCL matrix. Kraft lignin and PCL were mixed with ratios of 10/90, 30/70 and 50/50, and then extruded using a a twin-screw extruder at 140 ℃ with 100 rpm of screw rotation. LCNF (5, 10, and 20phr) and pMDI (1 and 3 phr) were added to lignin/PCL (30/70) during twin-screw extruding. The effect of lignin content, pMDI and LCNF addition on morphological characteristics, tensile strength, and melt flow index of lignin/PCL composite was investigated. In addition, the effect of lignin plasticization with ε-caprolactone on the properties of plasticized lignin/PCL composite was also investigated.

Efficient Constitutive Expression of Cellulolytic Enzymes in Penicillium oxalicum for Improved Efficiency of Lignocellulose Degradation

( Pankajkumar Ramdas Waghmare ),( Pratima Pankajkumar Waghmare ),( Liwei Gao ),( Wan Sun ),( Yuqi Qin ),( Guodong Liu ),( Yinbo Qu ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.5

Efficient cellulolytic enzyme production is important for the development of lignocellulose-degrading enzyme mixtures. However, purification of cellulases from their native hosts is time- and labor-consuming. In this study, a constitutive expression system was developed in Penicillium oxalicum for the secreted production of proteins. Using a constitutive polyubiquitin gene promoter and cultivating with glucose as the sole carbon source, nine cellulolytic enzymes of different origins with relatively high purity were produced within 48 h. When supplemented to a commercial cellulase preparation, cellobiohydrolase I from P. funiculosum and cellobiohydrolase II from Talaromyces verruculosus showed remarkable enhancing effects on the hydrolysis of steam-exploded corn stover. Additionally, a synergistic effect was observed for these two cellobiohydrolases during the hydrolysis. Taken together, the constitutive expression system provides a convenient tool for the production of cellulolytic enzymes, which is expected to be useful in the development of highly efficient lignocellulose-degrading enzyme mixtures.

Biohydrogen Production from Pretreated Lignocellulose by Clostridium thermocellum

Jingrong Cheng,Ming-Jun Zhu 한국생물공학회 2016 Biotechnology and Bioprocess Engineering Vol.21 No.1

In consolidated bioprocessing (CBP), the difference in optimum temperature between saccharification and fermentation poses a significant technical challenge to producing bioenergy efficiently with lignocellulose. The thermophilic anaerobic strain of Clostridium thermocellum has the potential to overcome this challenge if hydrolysis and fermentation is performed at an elevated temperature. However, this strain is sensitive to structure and components of lignocellulosic materials. To understand biohydrogen production from lignocellulosic materials, C. thermocellum was examined for biohydrogen production as well as bioconversion from different cellulosic materials (Avicel, filter paper and sugarcane bagasse (SCB)). We investigated hydrolysis-inhibitory effects of the cellulosic material types on the substrate degradation and biohydrogen production of C. thermocellum 27405. Within 168 h, the substrate degradation ratios of Avicel, filter paper, and SCB were 83.01, 51.78, and 42.19%, respectively. The substrate utilization and biohydrogen production of SCB reached 81 and 89.77% those of filter paper, respectively, indicating that SCB is a feasible substrate for biohydrogen production. Additionally, optimizing fermentation conditions can improve biohydrogen production, with the optimal conditions being an inoculum size of 7%, substrate concentration of 2%, particle size of 0.074 mm, and yeast extract concentration of 1%. This research provides important clues in relation to the low-cost conversion of renewable biomass to biohydrogen.

Development of an Efficient Microbial Process Using Non-edible Biomass by Engineering Vibrio sp. dhg

Sung Hwa WOO,Hyun Gyu LIM,Dong Hun KWAK,Yong Hee HAN,Sungwoo PARK,Sang Woo SEO,Gyoo Yeol JUNG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

Most microorganisms including industrial host strains were not able to efficiently utilize non-preferred carbon sources contained in non-edible biomass, such as alginate, xylose, and arabinose. Therefore, choosing an appropriate host strain would determine the efficiency of the entire bioprocess. In this regard, due to a broad spectrum of sugar utilization and genetic tractability of Vibrio sp. dhg, it was studied as a platform strain for the processes using non-edible biomass as a feedstock; brown-macroalgae and lignocellulose in this study. In order to efficiently utilize brown macroalgae as a feedstock, Vibrio sp. dhg capable of catabolizing alginate was isolated. After genome sequencing, genetic engineering tools were established. The production strains for ethanol, 2,3-butanediol, and lycopene demonstrated unprecedent productivities from brown macroalgae-derived carbon sources (alginate and mannitol). In order to efficiently utilize lignocellulose as a feedstock, Vibrio sp. dhg was rationally and evolutionary engineered for improved xylose catabolism and removal of carbon catabolite repression (CCR). Lactate-producing strain was constructed based on previously engineered strain and showed high productivity from lignocellulose-derived sugars (glucose, arabinose, and xylose).

리그노셀룰로스의 효소가수분해를 위한 전처리법에 관한 연구

양재경,장준복 中部大學校 農業生命資源科學硏究所 1998 農業生命資源科學硏究論文集 Vol.6 No.-

본 연구는 리그노셀룰로스의 효과적인 효소가 수분해를 위해 폭쇄법으로 전처리한 다음, 냉수, 수산화나트륨, 아염소산나트륨을 사용하여 랄리그닌처리를 실시한 후, 시판 Cellulase를 이용하여 효소가수분해를 시도하였다 그 결과는 다음과 같이 요약할 수 있다. 1. 냉수처리는 폭쇄재의 효소당화율 개선에 효과가 없었다. 2. 폭쇄재의 수산화나트륨 용해처리에 있어서, 탈리그닌 처리효과는 비등처리가 우수하였으나, 효소당화율은 실온처리가 유리하였다. 3. 폭쇄재의 아염소산나트륨 용액처리는 효소당화 측면 뿐만 아니라, 탈리그닌처리 효율면에서 가장 우수하였다. 4. 이태리포플러와 신갈나무의 탈리그닌처리 및 효소가수분해를 위한 최적 폭쇄조건은 25㎏/㎠, 6분처리로 판단되었다. Lignocellulose was composed of three main components; cellulose, hemicellulose and lignin. Woody cellulose was embedded in a matrix of lignin-hemicellulose complexes. Woody cellulose was a crystalline polymer generally associated in a matrix with hemicellulose and lignin, which is highly resistant to enzyme attack. In this study two effective pretreatment of lignocellulose, steam explosion combined with chemical pretreatment, were intensively investigated using chemical agents. Chips of oak wood and poplar wood were treated with steam explosion(25kgf/㎠, 3-9 min.) then chemically treated with distilled water, sodium hydroxide(NaOH), sodiun chlorite(NaCIO₂). The purpose of this study was development of pretreatment-hydrolysis process of lignocellulose. The results of this work were as follows: Cold water treatment of exploded wood was not affect hydrolysis rate. In the sodium htdroxide treatment of exploded wood, boiling treatment was decreased lignin content in the exploded wood, but that was decreased hydrolysis rate of exploded wood. Sodium chlorite treatment of exploded wood was the most effective delinification and enzymatic hydrolysis. Exploded condition of poplar and oak wood for delignification and enzymatic hydrolysis was suggested 25 ㎏/㎠(pressure), 6 minutes(time).

Lignocellulose-based super-adsorbent for wastewater treatment

곽효원 한국공업화학회 2021 한국공업화학회 연구논문 초록집 Vol.2021 No.1