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Yang B, Wu Y, Wu X, Hao J, Li X, Hao X. Lightweight reinforced wood beams through compression of its surface layers combined with the removal of lignin and hemicellulose. Int J Biol Macromol 2024; 259:129306. [PMID: 38216008 DOI: 10.1016/j.ijbiomac.2024.129306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 01/04/2024] [Accepted: 01/05/2024] [Indexed: 01/14/2024]
Abstract
When wood is used as a stressed component of building materials, the parts most prone to failure are the upper and lower surfaces which can be called the weak structure. In a hydrothermal environment, lignin and hemicellulose in wood readily soften and dissolve, thus leading to their designation as the weak structure. The weak structures results in the wood having a low strength. In this paper, the sandwich beam material can be obtained by two steps from the skin self-reinforcement method, whereby the weak structure of the wood surface was removed by the delignification, and then the wood surface was densified. The authenticity of the sandwich structure is proved by a scanning electron microscope (SEM) and density profile analysis. When the moisture content (MC) is 10 %-12 % and the mass loss ratio is 23.04 %, the optimal resilience of the sandwich beam is only 1 %, the maximum modulus of rupture (MOR) and modulus of elasticity (MOE) are 1.42 and 2.1 times greater than those of natural wood, respectively. This finding shows that our method strengthens the weak structure of natural wood, which has good flexural performance and springback ratio.
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Affiliation(s)
- Bin Yang
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
| | - Yiqiang Wu
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
| | - Xinfeng Wu
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
| | - Jingxin Hao
- College of Furniture and Art Design, Central South University of Forestry and Technology, Changsha 410004, Hunan, China.
| | - Xianjun Li
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, China.
| | - Xiaofeng Hao
- College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, Hunan, China
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Liang S, Zhang Y, Lyu L, Wang S, Zhao ZK. Secretory expression of β-1,3-glucomannanase in the oleaginous yeast Rhodosporidium toruloides for improved lipid extraction. BIORESOUR BIOPROCESS 2023; 10:16. [PMID: 38647878 PMCID: PMC10991151 DOI: 10.1186/s40643-023-00639-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 02/26/2023] [Indexed: 03/05/2023] Open
Abstract
Lipids produced by oleaginous yeasts are considered as sustainable sources for the production of biofuels and oleochemicals. The red yeast Rhodosporidium toruloides can accumulate lipids to over 70% of its dry cell mass. To facilitate lipid extraction, a recombinant β-1,3-glucomannanase, MAN5C, has been applied to partially breakdown R. toruloides cell wall. In this study, R. toruloides NP11 was engineered for secretory expression of MAN5C to simplify the lipid extraction process. Specifically, a cassette contained a codon-optimized gene MAN5C was integrated into the genome of R. toruloides by Agrobacterium-mediated transformation. The engineered strain NP11-MAN5C was found with proper expression and secretion of active MAN5C, yet no notable compromise in terms of cell growth and lipid production. When NP11-MAN5C cell cultures were extracted with ethyl acetate without any pretreatment, 20% of total lipids were recovered, 4.3-fold higher than that of the parental strain NP11. When the cells were heat-treated followed by extraction with ethyl acetate in the presence of the culture broth supernatants, up to 93% of total lipids were recovered, confirming beneficial effects of MAN5C produced in situ. This study provides a new strategy to engineer oleaginous yeasts for more viable lipid extraction and down-stream processes.
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Affiliation(s)
- Shiyu Liang
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yue Zhang
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Liting Lyu
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, China
| | - Shuang Wang
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zongbao K Zhao
- Laboratory of Biotechnology, Dalian Institute of Chemical Physics, CAS, 457 Zhongshan Road, Dalian, 116023, China.
- Dalian Key Laboratory of Energy Biotechnology, Dalian Institute of Chemical Physics, CAS, Dalian, 116023, China.
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