Polymers

Research

14 pages, 3646 KiB

Open AccessArticle

Preparation and Application of Light-Colored Lignin Nanoparticles for Broad-Spectrum Sunscreens

by Sang Cheon Lee, Eunjin Yoo, Sang Hyun Lee and Keehoon Won

Polymers 2020, 12(3), 699; https://doi.org/10.3390/polym12030699 - 21 Mar 2020

Cited by 56 | Viewed by 4940

Recently, natural sun blockers have been drawing considerable attention because synthetic UV filters could have adverse effects not only on humans but also on the environment. Even though lignin, the second most abundant renewable resource on earth, is a natural UV-absorbing polymer, its [...] Read more.

Recently, natural sun blockers have been drawing considerable attention because synthetic UV filters could have adverse effects not only on humans but also on the environment. Even though lignin, the second most abundant renewable resource on earth, is a natural UV-absorbing polymer, its unfavorable dark color hampers its applications in sunscreens. In this work, we obtained light-colored lignin (CEL) from rice husks through cellulolytic enzyme treatment and subsequent solvent extraction under mild conditions and compared CEL to technical lignin from rice husks using the International Commission on Illumination L*a*b* (CIELAB) color space. Spherical nanoparticles of CEL (CEL-NP) were also prepared using a solvent shifting method and evaluated for broad-spectrum sunscreens. A moisturizing cream blended with CEL-NP exhibited higher sun protection factor (SPF) and UVA PF (protection factor) values than that with CEL. In addition, CEL-NP had synergistic effects when blended with an organic UV-filter sunscreen: CEL-NP enhanced the SPF and UVA PF values of the sunscreen greatly. However, there was no synergistic effect between CEL-NP and inorganic sunscreens. We expect nanoparticles of light-colored lignin to find high-value-added applications as a natural UV-blocking additive in sunscreens and cosmetics. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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12 pages, 1589 KiB

Open AccessArticle

Multi-Step Enzymatic Synthesis of 1,9-Nonanedioic Acid from a Renewable Fatty Acid and Its Application for the Enzymatic Production of Biopolyesters

by Hyun-Ju Lee, Young-Seo Kang, Chae-Yun Kim, Eun-Ji Seo, Sang-Hyun Pyo and Jin-Byung Park

Polymers 2019, 11(10), 1690; https://doi.org/10.3390/polym11101690 - 15 Oct 2019

Cited by 5 | Viewed by 3563

Abstract

1,9-Nonanedioic acid is one of the valuable building blocks for producing polyesters and polyamides. Thereby, whole-cell biosynthesis of 1,9-nonanedioic acid from oleic acid has been investigated. A recombinant Corynebacterium glutamicum, expressing the alcohol/aldehyde dehydrogenases (ChnDE) of Acinetobacter sp. NCIMB 9871, was constructed [...] Read more.

1,9-Nonanedioic acid is one of the valuable building blocks for producing polyesters and polyamides. Thereby, whole-cell biosynthesis of 1,9-nonanedioic acid from oleic acid has been investigated. A recombinant Corynebacterium glutamicum, expressing the alcohol/aldehyde dehydrogenases (ChnDE) of Acinetobacter sp. NCIMB 9871, was constructed and used for the production of 1,9-nonanedioic acid from 9-hydroxynonanoic acid, which had been produced from oleic acid. When 9-hydroxynonanoic acid was added to a concentration of 20 mM in the reaction medium, 1,9-nonanedioic acid was produced to 16 mM within 8 h by the recombinant C. glutamicum. The dicarboxylic acid was isolated via crystallization and then used for the production of biopolyester by a lipase. For instance, the polyesterification of 1,9-nonanedioic acid and 1,8-octanediol in diphenyl ether by the immobilized lipase B from Candida antarctica led to formation of the polymer product with the number-average molecular weight (M_n) of approximately 21,000. Thereby, this study will contribute to biological synthesis of long chain dicarboxylic acids and their application for the enzymatic production of long chain biopolyesters. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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11 pages, 4267 KiB

Open AccessArticle

Production of Novel Polygalacturonase from Bacillus paralicheniformis CBS32 and Application to Depolymerization of Ramie Fiber

by Md. Saifur Rahman, Yoon Seok Choi, Young Kyun Kim, Chulhwan Park and Jin Cheol Yoo

Polymers 2019, 11(9), 1525; https://doi.org/10.3390/polym11091525 - 19 Sep 2019

Cited by 15 | Viewed by 3490

Abstract

Polygalacturonase (EC. 3.2.1.15) is an enzyme that hydrolyzes the alpha-1,4 glycosidic bonds between galacturonic acid. In this study, an alkaline polygalacturonase producer Bacillus paralicheniformis CBS32 was isolated from kimchi (conventional Korean fermented food). The 16S rRNA sequence analysis of the isolated strain revealed [...] Read more.

Polygalacturonase (EC. 3.2.1.15) is an enzyme that hydrolyzes the alpha-1,4 glycosidic bonds between galacturonic acid. In this study, an alkaline polygalacturonase producer Bacillus paralicheniformis CBS32 was isolated from kimchi (conventional Korean fermented food). The 16S rRNA sequence analysis of the isolated strain revealed that it was 99.92% identical to B. paralicheniformis KJ 16LBMN01000156. The polygalacturonase from B. paralicheniformis CBS32 was named PN32, and the purified PN32 showed a 16.8% yield and a 33-fold purity compared to the crude broth. The molecular mass, 110 kDa, was determined by SDS-PAGE, and the active band was confirmed by zymography analysis. The N-terminal amino acid sequence residues of PN32 were determined to be Gly–Val–Lys–Glu–Val–X–Gln–Thr–Phe. In the sequence comparison, PN32 was suggested as a novel polygalacturonase, since the sequence was not matched with the previous reports. In an application study, enzymatic depolymerization of ramie was performed for fiber degumming, and the result showed that the PN32 had a 28% higher depolymerization compared to the commercial pectinase. Overall, based on the results, PN32 has high potential for industrial applications. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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12 pages, 3980 KiB

Open AccessArticle

Enhanced l-Lysine into 1,5-Diaminopentane Conversion via Statistical Optimization of Whole-Cell Decarboxylation System

by Hanyong Kim, Hah Young Yoo, Nohseong Park, Haeun Kim, Jonghwa Lee, Yesol Baek, Taek Lee, Jong-Min Oh, Jaehoon Cho and Chulhwan Park

Polymers 2019, 11(8), 1372; https://doi.org/10.3390/polym11081372 - 20 Aug 2019

Cited by 16 | Viewed by 3695

Abstract

The global lysine companies in the feed industry have steadily built their production facilities due to the high demand for l-lysine in animal farms, and in recent years there have been excessive supply problems and the world market price of l-lysine [...] Read more.

The global lysine companies in the feed industry have steadily built their production facilities due to the high demand for l-lysine in animal farms, and in recent years there have been excessive supply problems and the world market price of l-lysine has fallen. In this study, the conversion of 1,5-diaminopentane (DAP) by decarboxylation of l-lysine was strategically chosen to enhance the value of lysine. The decarboxylation is enzymatically accessible, and Hafnia alvei, which is the producer of l-lysine decarboxylase, was applied as a whole-cell form. In the designed whole-cell biocatalytic system, the major four reaction factors were selected by fundamental investigation and then statistical optimization was performed to estimate the optimum condition. The predicted conversion was assessed at about 94.6% at the optimum conditions (125.1 mM l-lysine and 71.5 g/L acetone concentration at 35.2 °C for 8.4 h). Under the determined conditions, DAP conversions by using analytical, feed and industrial crude l-lysine were found to be 98.3%, 92.5% and 72.4%, respectively. These results could be suggested to solve the problem of excessive supplied lysine and also to provide guidance for improved enzymatic conversion by statistical optimization. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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13 pages, 1400 KiB

Open AccessArticle

High-Level Conversion of l-lysine into Cadaverine by Escherichia coli Whole Cell Biocatalyst Expressing Hafnia alvei l-lysine Decarboxylase

by Hee Taek Kim, Kei-Anne Baritugo, Young Hoon Oh, Kyoung-Hee Kang, Ye Jean Jung, Seyoung Jang, Bong Keun Song, Il-Kwon Kim, Myung Ock Lee, Yong Taek Hwang, Kyungmoon Park, Si Jae Park and Jeong Chan Joo

Polymers 2019, 11(7), 1184; https://doi.org/10.3390/polym11071184 - 14 Jul 2019

Cited by 21 | Viewed by 5846

Abstract

Cadaverine is a C5 diamine monomer used for the production of bio-based polyamide 510. Cadaverine is produced by the decarboxylation of l-lysine using a lysine decarboxylase (LDC). In this study, we developed recombinant Escherichia coli strains for the expression of LDC from [...] Read more.

Cadaverine is a C5 diamine monomer used for the production of bio-based polyamide 510. Cadaverine is produced by the decarboxylation of l-lysine using a lysine decarboxylase (LDC). In this study, we developed recombinant Escherichia coli strains for the expression of LDC from Hafnia alvei. The resulting recombinant XBHaLDC strain was used as a whole cell biocatalyst for the high-level bioconversion of l-lysine into cadaverine without the supplementation of isopropyl β-d-1-thiogalactopyranoside (IPTG) for the induction of protein expression and pyridoxal phosphate (PLP), a key cofactor for an LDC reaction. The comparison of results from enzyme characterization of E. coli and H. alvei LDC revealed that H. alvei LDC exhibited greater bioconversion ability than E. coli LDC due to higher levels of protein expression in all cellular fractions and a higher specific activity at 37 °C (1825 U/mg protein > 1003 U/mg protein). The recombinant XBHaLDC and XBEcLDC strains were constructed for the high-level production of cadaverine. Recombinant XBHaLDC produced a 1.3-fold higher titer of cadaverine (6.1 g/L) than the XBEcLDC strain (4.8 g/L) from 10 g/L of l-lysine. Furthermore, XBHaLDC, concentrated to an optical density (OD₆₀₀) of 50, efficiently produced 136 g/L of cadaverine from 200 g/L of l-lysine (97% molar yield) via an IPTG- and PLP-free whole cell bioconversion reaction. Cadaverine synthesized via a whole cell biocatalyst reaction using XBHaLDC was purified to polymer grade, and purified cadaverine was successfully used for the synthesis of polyamide 510. In conclusion, an IPTG- and PLP-free whole cell bioconversion process of l-lysine into cadaverine, using recombinant XBHaLDC, was successfully utilized for the production of bio-based polyamide 510, which has physical and thermal properties similar to polyamide 510 synthesized from chemical-grade cadaverine. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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14 pages, 3855 KiB

Open AccessArticle

Enhanced In-Vitro Hemozoin Polymerization by Optimized Process using Histidine-Rich Protein II (HRPII)

by Ju Hun Lee, Hyeong Ryeol Kim, Ja Hyun Lee, Soo Kweon Lee, Youngsang Chun, Sung Ok Han, Hah Young Yoo, Chulhwan Park and Seung Wook Kim

Polymers 2019, 11(7), 1162; https://doi.org/10.3390/polym11071162 - 8 Jul 2019

Cited by 11 | Viewed by 3070

Abstract

Conductive biopolymers, an important class of functional materials, have received attention in various fields because of their unique electrical, optical, and physical properties. In this study, the polymerization of heme into hemozoin was carried out in an in vitro system by the newly [...] Read more.

Conductive biopolymers, an important class of functional materials, have received attention in various fields because of their unique electrical, optical, and physical properties. In this study, the polymerization of heme into hemozoin was carried out in an in vitro system by the newly developed heme polymerase (histidine-rich protein 2 (HRP-II)). The HRP-II was produced by recombinant E. coli BL21 from the Plasmodium falciparum gene. To improve the hemozoin production, the reaction conditions on the polymerization were investigated and the maximum production was achieved after about 790 μM at 34 °C with 200 rpm for 24 h. As a result, the production was improved about two-fold according to the stepwise optimization in an in vitro system. The produced hemozoin was qualitatively analyzed using the Fourier transform infrared (FTIR) spectroscopy, energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Finally, it was confirmed that the enzymatically polymerized hemozoin had similar physical properties to chemically synthesized hemozoin. These results could represent a significant potential for nano-biotechnology applications, and also provide guidance in research related to hemozoin utilization. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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14 pages, 1722 KiB

Open AccessArticle

Construction of Efficient Platform Escherichia coli Strains for Polyhydroxyalkanoate Production by Engineering Branched Pathway

by Hye-Rim Jung, Su-Yeon Yang, Yu-Mi Moon, Tae-Rim Choi, Hun-Suk Song, Shashi Kant Bhatia, Ranjit Gurav, Eun-Jung Kim, Byung-Gee Kim and Yung-Hun Yang

Polymers 2019, 11(3), 509; https://doi.org/10.3390/polym11030509 - 18 Mar 2019

Cited by 43 | Viewed by 5023

Abstract

Polyhydroxyalkanoate (PHA) is a potential substitute for petroleum-based plastics and can be produced by many microorganisms, including recombinant Escherichia coli. For efficient conversion of substrates and maximum PHA production, we performed multiple engineering of branched pathways in E. coli. We deleted [...] Read more.

Polyhydroxyalkanoate (PHA) is a potential substitute for petroleum-based plastics and can be produced by many microorganisms, including recombinant Escherichia coli. For efficient conversion of substrates and maximum PHA production, we performed multiple engineering of branched pathways in E. coli. We deleted four genes (pflb, ldhA, adhE, and fnr), which contributed to the formation of byproducts, using the CRISPR/Cas9 system and overexpressed pntAB, which catalyzes the interconversion of NADH and NADPH. The constructed strain, HR002, showed accumulation of acetyl-CoA and decreased levels of byproducts, resulting in dramatic increases in cell growth and PHA content. Thus, we demonstrated the effects of multiple engineering for redirecting carbon flux into PHA production without any concerns regarding simultaneous deletion. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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14 pages, 3580 KiB

Open AccessArticle

Solubility Enhancement of Atrazine by Complexation with Cyclosophoraose Isolated from Rhizobium leguminosarum biovar trifolii TA-1

by Yohan Kim, Vijay Vilas Shinde, Daham Jeong, Youngjin Choi and Seunho Jung

Polymers 2019, 11(3), 474; https://doi.org/10.3390/polym11030474 - 12 Mar 2019

Cited by 12 | Viewed by 2714

Abstract

Rhizobium leguminosarum biovar trifolii TA-1, a kind of soil bacteria, produces cyclosophoraoses (Cys). Cyclosophoraoses contain various ring sizes with degrees of polymerization ranging from 17 to 23. Atrazine is a hardly-soluble herbicide that contaminates soil and drinking water, and remains in soil for [...] Read more.

Rhizobium leguminosarum biovar trifolii TA-1, a kind of soil bacteria, produces cyclosophoraoses (Cys). Cyclosophoraoses contain various ring sizes with degrees of polymerization ranging from 17 to 23. Atrazine is a hardly-soluble herbicide that contaminates soil and drinking water, and remains in soil for a long time. To remove this insoluble contaminant from aqueous solutions, we have enhanced the solubility of atrazine by complexation with Cys. The complex formation of Cys and atrazine was confirmed using ¹H nuclear magnetic resonance (NMR), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), rotating frame nuclear overhauser spectroscopy (ROESY), and molecular modeling studies. The aqueous solubility of atrazine was enhanced 3.69-fold according to the added concentrations (20 mM) of Cys, compared to the 1.78-fold enhancements by β-cyclodextrin (β-CD). Cyclosophoraoses as an excellent solubility enhancer with long glucose chains that can effectively capture insoluble materials showed a potential application of microbial polysaccharides in the removal of hazardous hardly-soluble materials from aqueous solutions in the fields of biological and environmental industry. Full article

(This article belongs to the Special Issue Microbial Production and Application of Biopolymers)

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