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Kim J, Jeong JP, Kim Y, Jung S. Physicochemical and Rheological Properties of Succinoglycan Overproduced by Sinorhizobium meliloti 1021 Mutant. Polymers (Basel) 2024; 16:244. [PMID: 38257044 PMCID: PMC10819756 DOI: 10.3390/polym16020244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/09/2024] [Accepted: 01/10/2024] [Indexed: 01/24/2024] Open
Abstract
Commercial bacterial exopolysaccharide (EPS) applications have been gaining interest; therefore, strains that provide higher yields are required for industrial-scale processes. Succinoglycan (SG) is a type of bacterial anionic exopolysaccharide produced by Rhizobium, Agrobacterium, and other soil bacterial species. SG has been widely used as a pharmaceutical, cosmetic, and food additive based on its properties as a thickener, texture enhancer, emulsifier, stabilizer, and gelling agent. An SG-overproducing mutant strain (SMC1) was developed from Sinorhizobium meliloti 1021 through N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutation, and the physicochemical and rheological properties of SMC1-SG were analyzed. SMC1 produced (22.3 g/L) 3.65-fold more SG than did the wild type. Succinoglycan (SMC1-SG) overproduced by SMC1 was structurally characterized by FT-IR and 1H NMR spectroscopy. The molecular weights of SG and SMC1-SG were 4.20 × 105 and 4.80 × 105 Da, respectively, as determined by GPC. Based on DSC and TGA, SMC1-SG exhibited a higher endothermic peak (90.9 °C) than that of SG (77.2 °C). Storage modulus (G') and loss modulus (G″) measurements during heating and cooling showed that SMC1-SG had improved thermal behavior compared to that of SG, with intersections at 74.9 °C and 72.0 °C, respectively. The SMC1-SG's viscosity reduction pattern was maintained even at high temperatures (65 °C). Gelation by metal cations was observed in Fe3+ and Cr3+ solutions for both SG and SMC1-SG. Antibacterial activities of SG and SMC1-SG against Escherichia coli and Staphylococcus aureus were also observed. Therefore, like SG, SMC1-SG may be a potential biomaterial for pharmaceutical, cosmetic, and food industries.
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Affiliation(s)
- Jaeyul Kim
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; (J.K.); (J.-p.J.); (Y.K.)
| | - Jae-pil Jeong
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; (J.K.); (J.-p.J.); (Y.K.)
| | - Yohan Kim
- Department of Bioscience and Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea; (J.K.); (J.-p.J.); (Y.K.)
| | - Seunho Jung
- Department of System Biotechnology, Microbial Carbohydrate Resource Bank (MCRB), Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 05029, Republic of Korea
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Chen H, Chen F, Xiao Q, Cai M, Yang Q, Weng H, Xiao A. Structure and physicochemical properties of amphiphilic agar modified with octenyl succinic anhydride. Carbohydr Polym 2021; 251:117031. [PMID: 33142590 DOI: 10.1016/j.carbpol.2020.117031] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/16/2020] [Accepted: 08/30/2020] [Indexed: 11/25/2022]
Abstract
A novel amphiphilic agar with high transparency and freeze-thaw stability was prepared using octenyl succinic anhydride (OSA). Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy confirmed that the hydrophobic OS groups were successfully introduced in OSA-modified agar (OSAR) backbone. The OSAR showed higher emulsion stability and oil loading capacity than the native agar (NA). Compared with gel transparency (47.1 %), syneresis (42.1 %) of NA, OSAR exhibited high gel transparency (80 %) and low syneresis (3.3 %) when the degree of substitution (DS) was 0.06 and 0.12, respectively. Meanwhile, the OSAR showed a decreased interface tension and average molecular weight after modification. Thermogravimetric analysis indicated the thermal stability of OSAR was decreased, while texture profile analysis showed the springiness of the OSAR gel was enhanced. Dynamic rheology measurements revealed the OSAR with low gel strength displayed more liquid-like properties. Moreover, the OSAR exhibited lower turbidity and melting temperatures than the NA.
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Affiliation(s)
- Huijing Chen
- College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen, Fujian Province 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen, Fujian Province 361021, China
| | - Fuquan Chen
- College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen, Fujian Province 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen, Fujian Province 361021, China
| | - Qiong Xiao
- College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen, Fujian Province 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen, Fujian Province 361021, China
| | - Menghao Cai
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China
| | - Qiuming Yang
- College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen, Fujian Province 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen, Fujian Province 361021, China
| | - Huifen Weng
- College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen, Fujian Province 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen, Fujian Province 361021, China
| | - Anfeng Xiao
- College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; National R&D Center for Red Alga Processing Technology, Xiamen, Fujian Province 361021, China; Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Xiamen, Fujian Province 361021, China.
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Di Fonzo S, Bellich B, Gamini A, Quadri N, Cesàro A. PEG hydration and conformation in aqueous solution: Hints to macromolecular crowding. POLYMER 2019. [DOI: 10.1016/j.polymer.2019.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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