Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Towards Large-scale and Feasible Exploitation of Tunicate Cellulose and Cellulose Nanocrystals for Different Applications
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Wood Chemistry and Pulp Technology.ORCID iD: 0000-0001-8208-4938
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Tunicates are a group of filter-feeding animals that live in the ocean. They are widely distributed throughout the world and are a major contributor to the fouling problem in aquaculture. In addition to their natural abundance, large-scale farming will further render them readily available in high quantities, and they should instead be providing us food, energy, chemicals and materials. As tunicates are the sole known animal group synthesizing cellulose, the primary target for this bioresources exploitation should be cellulose preparation and application. Moreover, cellulose exploitation should be conducted in both a technically and economically feasible manner.

Among the tunicates, Ciona intestinalis (termed Ciona hereafter) is one of the most abundant species in Norwegian and Swedish coastal waters. Upon comprehensive quantification of the principal chemical compositions, cellulose has been confirmed to exist as cellulose-protein fibrils cemented by non-cellulose glycans and lipids and is almost exclusively present in the Ciona tunic fraction. Using the tunic as raw material, Ciona cellulose was prepared following a unique prehydrolysis-kraft cooking-bleaching sequence with a yield of 21.64% and by a modified Updegraff method with a yield of 23.65% on a dried ash-free mass basis. To improve the Ciona cellulose dispersibility and processability, Ciona cellulose nanocrystals (CNs) were prepared using different processes, namely acid hydrolysis, 2,2,6,6‑tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation and enzymatic hydrolysis as well as acid hydrolysis followed by TEMPO-mediated oxidation. The CN preparation yield was 30.0-73.4%, depending on the process applied.

By conducting comprehensive characterizations, it was found that the Ciona cellulose was nearly 100% pure, with a large weight average degree of polymerization (DPw=4200), a high surface area (133 m2/g), a large aspect ratio (length of several micrometres and diameter of ~16 nm), a high crystallinity (89%) in the form of nearly pure Iβ crystals, and a good thermal stability (onset degradation temperature of 226 ºC). When obtained in membrane form, the cellulose preserved the native interwoven microfibril network structure in the original tunic. It had a high ductility (tensile strain of 19.24%) in the wet state and good mechanical strength (tensile strength of 41.19 MPa and Young’s Modulus of 1.98 GPa) when dried. The CNs obtained were smaller in DPw, shorter in morphological size (length), similar or higher in crystallinity and more thermally stable than the starting cellulose to different extents and with different charged structures and charge contents dependent on the method/procedure used.

Several applications have been examined. First, the Ciona cellulose in pulp form was utilized in the fabrication of sponge cloth to replace cotton, and the product obtained was of similar quality to the commercial one made from cotton. Second, the Ciona cellulose in membrane form was tested in the cultivation of human umbilical vein endothelial cells and mouse NIH‑3T3 cells for evaluations of cell proliferation performance and medical application potential. The performance was very positive. Third, the Ciona cellulose membrane and two CNs were applied as the matrix for high-quality zinc-blende CdSe/CdS core/shell nanocrystal quantum dots (QDs) for the development of mechanically strong and high-performance fluorescent material. The QDs were firmly attached to the Ciona CNs with uniform monolayer distribution and a high packing density. The obtained composites preserved both the high-quality optical properties from the QDs and the matrix morphology and thus expectedly the excellent mechanical properties from the cellulose. Finally, the Ciona CNs were processed to composite films cemented by konjac glucomannan for material development. Newly introduced hydrogen bonds between these two compatible polysaccharides and thus strong cementing effects were observed. The composite films showed excellent mechanical properties in addition to improved transparency, thermal stability and hydrophobicity compared with the CN’s neat films.

Feasible tunicate cellulose exploitation demands the sound large-scale farming of Ciona for the highest possible cellulose content in the farmed animal, the exploitation of species other than Ciona, the complete utilization of fractions other than the tunic used and the value-added productions of other by-products. Composition quantification of the adult Ciona specimens collected from different farms showed that the carbohydrate content was linearly correlated with the body weight, which in turn was affected by the farm location, deployment time and sub-sea depth of the settling structures. Through analysing the Ciona intestinal content, it was found that both eukaryotes and prokaryotes contributed to the diet of the animal, and their quantities were positively correlated with the animal size (body weight). The tunics of three other tunicate species, Halocynthia roretzi, Styela plicata, and Ascidia sp., have been examined for tunicate cellulose preparation following the prehydrolysis-kraft cooking‑bleaching procedure. They were all found to be good sources for similar quality tunicate cellulose exploitation, thus verifying the universal applicability of the procedure. Based on more detailed chemical composition analyses, all the fractions other than the tunic, termed the inner body tissues fraction, from all four tunicate species were found to have excellent nutritional values: a high protein content with good quality amino acids and high contents of omega-3 (n-3) fatty acids and essential elements. Their toxic element contents were under the regulated limits for human food. They should therefore all be explored as human food sources. Furthermore, many different chemical structures, many of which were found for the first time, were present in the tunicate animals studied, ranging from collagens, glycosaminoglycans, and sterols to phospholipids. These structures should be explored as various bioactive by‑products during tunicate cellulose exploitation. For example, the prepared Ciona lipids had a high content of n-3 fatty acids, which presented mainly in the form of phospholipids. They should be an excellent alternative to markedly high value fish oils, but with a higher bioavailability.

The techniques and knowledge obtained by this study will provide a basis for the promising large-scale and feasible exploitation of tunicate cellulose and cellulose nanocrystals for different applications.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2015. , 70 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2015:24
National Category
Polymer Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-169483ISBN: 978-91-7595-576-6 (print)OAI: oai:DiVA.org:kth-169483DiVA: diva2:821563
Public defence
2015-06-11, F3, Lindstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20150615

Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2015-06-15Bibliographically approved
List of papers
1. Chemical composition of Ciona intestinalis under different aquaculture conditions and from different body fraction
Open this publication in new window or tab >>Chemical composition of Ciona intestinalis under different aquaculture conditions and from different body fraction
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Chemical Sciences Biological Sciences
Identifiers
urn:nbn:se:kth:diva-169475 (URN)
Note

QS 2015

Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2015-06-15Bibliographically approved
2. Excellent chemical and material cellulose from tunicates: diversity in cellulose production yield and chemical and morphological structures from different tunicate species
Open this publication in new window or tab >>Excellent chemical and material cellulose from tunicates: diversity in cellulose production yield and chemical and morphological structures from different tunicate species
2014 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 21, no 5, 3427-3441 p.Article in journal (Refereed) Published
Abstract [en]

The high crystallinity and the high microfibrils aspect ratio of tunicate cellulose (TC) indicate TC's excellent chemical and material applications. However, its quantity and quality from different species have never been systematically reported and compared. In this study, the tunics of Ciona intestinalis (CI), Ascidia sp. (AS), Halocynthia roretzi (HR) and Styela plicata (SP) were processed to TC after an identical prehydrolysis-kraft cooking-bleaching sequence, while the tunicate fibrils were chemically and structurally characterized in situ and during the sequence. All tunics studied were composed of crystalline cellulose embedded with protein, lipids, sulfated glycans and mucopolysaccharides. The native composite structures are all very compact. However, the tunics from Phlebobranchia order (CI and AS) are soft, while those from Stolidobranchia, HR and SP, are hard. Fibrous cellulose could be prepared after removing the lipids, sulfated glycans and mucopolysaccharides through prehydrolysis, protein removal through kraft cooking and a final purification by bleaching. The final product is similar to 100 % pure cellulose which is in large molecular masses, composed of highly crystalline I-beta crystals, in elementary microfibrils form, with high specific surface area and thermal stability. There were lower TC yields from the soft tunics than from the hard ones. The cellulose fibrils had a section shape of lozenges with higher crystallinity. This study demonstrates that TC could be obtained in different yields and exhibited different chemical and morphological structures depending on the species. There is a great potential of tunicate resources for preparing excellent chemical and material cellulose.

Keyword
Tunicate cellulose, Ciona intestinalis, Ascidia sp., Halocynthia roretzi, Styela plicata, Chemical processing, Characterization
National Category
Polymer Technologies
Identifiers
urn:nbn:se:kth:diva-153243 (URN)10.1007/s10570-014-0348-6 (DOI)000341489300025 ()
Note

QC 20141016

Available from: 2014-10-16 Created: 2014-10-03 Last updated: 2017-12-05Bibliographically approved
3. Tunicate cellulose nanocrystals: Preparation, neat films and nanocomposite films with glucomannans
Open this publication in new window or tab >>Tunicate cellulose nanocrystals: Preparation, neat films and nanocomposite films with glucomannans
2015 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 117, 286-296 p.Article in journal (Refereed) Published
Abstract [en]

Cellulose nanocrystals (CNs) were prepared from tunicate by enzymatic hydrolysis (ECN), TEMPOmediated oxidation (TCN) and acid hydrolysis (ACN). They were cast alone or blended with glucomannan (GM) from konjac or spruce to prepare films. Different CNs were obtained with a yield of ECN > TCN > ACN with corresponding order of decreased My but increased crystallinity. The CNs' diameters were on the nanometre scale, with lengths of ECN > TCN > ACN. For CN-films, TCN and ACN fibrils were stretched and parallel to each other due to surface charges. For CN-GM films, both components interacted strongly with each other, resulting in changes of crystallinity, specific surface area, fibril diameter and contact angle compared with CN films. The composite films had good thermal, optical and mechanical properties; the last ones are apparently better than similar films reported in the literature. This is the first systematic study of different tunicate CN-GM nanocomposite films and the first ever for spruce GM.

Keyword
Tunicate cellulose, Ciona intestinalis, Nanocrystals, Konjac glucomannan, Spruce glucomannan, Nanocomposite films
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-160040 (URN)10.1016/j.carbpol.2014.09.020 (DOI)000346263800036 ()2-s2.0-84922274625 (Scopus ID)
Note

QC 20150309

Available from: 2015-03-09 Created: 2015-02-13 Last updated: 2017-12-04Bibliographically approved
4. Direct incorporation of high-quality zinc-blende CdSe/CdS core/shell nanocrystals onto tunicate cellulose nanocrystals as high performance luminescent functional nanostructural material
Open this publication in new window or tab >>Direct incorporation of high-quality zinc-blende CdSe/CdS core/shell nanocrystals onto tunicate cellulose nanocrystals as high performance luminescent functional nanostructural material
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-169481 (URN)
Note

QS 2015

Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2015-06-15Bibliographically approved
5. Molecular analysis of the tunicate Ciona intestinalis intestine: contribution of prokaryotes and eukaryotic parasites
Open this publication in new window or tab >>Molecular analysis of the tunicate Ciona intestinalis intestine: contribution of prokaryotes and eukaryotic parasites
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-169479 (URN)
Note

QS 2015

Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2015-06-15Bibliographically approved
6. Ascidian bioresources: common and variant chemical compositions and exploitation strategy- Examples of Halocynthia roretzi, Styela plicata, Ascidia sp. and Ciona intestinalis
Open this publication in new window or tab >>Ascidian bioresources: common and variant chemical compositions and exploitation strategy- Examples of Halocynthia roretzi, Styela plicata, Ascidia sp. and Ciona intestinalis
(English)Manuscript (preprint) (Other academic)
Abstract [en]

Four ascidian species have been compared on chemical compositions. All animal tunics have rich carbohydrate contents, while all inner body tissues are richer in proteins. Cellulose is present almost exclusively in the tunics and more in the order Stolidobranchia, while more sulfated polysaccharides are present in Phlebobranchia species. Almost all proteins are collagens with a high essential amino acid index and high delicious amino acid content. All fractions also have high contents of good-quality fatty acids and trace minerals but low toxic element contents, with different sterols and glycosaminoglycans. Therefore, in addition to the present utilizations of tunics for cellulose production and of some species’ inner body tissues as human food, one should explore all species’ inner body tissues as human foods and all tunics as food or animal feed with the contained cellulose as dietary fiber. Collagens, sulfated polysaccharides, glycosaminoglycans, sterols and trace elements could be explored as byproducts.

National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-169473 (URN)
Note

QS 2015

Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2015-06-15Bibliographically approved
7. Fatty acid and lipid profiles with emphasis on n-3 fatty acids and phospholipids from Ciona intestinalis
Open this publication in new window or tab >>Fatty acid and lipid profiles with emphasis on n-3 fatty acids and phospholipids from Ciona intestinalis
2015 (English)In: Lipids, ISSN 0024-4201, E-ISSN 1558-9307, Vol. 50, no 10, 1009-1027 p.Article in journal (Refereed) Published
Abstract [en]

In order to establish Ciona intestinalis as a new bioresource for n-3 fatty acids-rich marine lipids, the animal was fractionated into tunic and inner body tissues prior to lipid extraction. The lipids obtained were further classified into neutral lipids (NL), glycolipids (GL) and phospholipids (PL) followed by qualitative and quantitative analysis using GC-FID, GC-MS, H-1 NMR, 2D NMR, MALDI-TOF-MS and LC-ESI-MS methods. It was found that the tunic and inner body tissues contained 3.42-4.08 % and 15.9-23.4 % of lipids respectively. PL was the dominant lipid class (42-60 %) irrespective of the anatomic fractions. From all lipid fractions and classes, the major fatty acids were 16:0, 18:1n-9, C20:1n-9, C20:5n-3 (EPA) and C22:6n-3 (DHA). The highest amounts of long chain n-3 fatty acids, mainly EPA and DHA, were located in PL from both body fractions. Cholestanol and cholesterol were the dominant sterols together with noticeable amounts of stellasterol, 22 (Z)-dehydrocholesterol and lathosterol. Several other identified and two yet unidentified sterols were observed for the first time from C. intestinalis. Different molecular species of phosphatidylcholine (34 species), sphingomyelin (2 species), phosphatidylethanolamine (2 species), phosphatidylserine (10 species), phosphatidylglycerol (9 species), ceramide (38 species) and lysophospholipid (5 species) were identified, representing the most systematic PL profiling knowledge so far for the animal. It could be concluded that C. intestinalis lipids should be a good alternative for fish oil with high contents of n-3 fatty acids. The lipids would be more bioavailable due to the presence of the fatty acids being mainly in the form of PL.

National Category
Other Biological Topics Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-169478 (URN)10.1007/s11745-015-4049-1 (DOI)000361560900009 ()26233815 (PubMedID)2-s2.0-84942195480 (Scopus ID)
Note

Updated from Manuscirpt to Article.

QC 20151028

Available from: 2015-06-15 Created: 2015-06-15 Last updated: 2017-09-12Bibliographically approved

Open Access in DiVA

No full text

Search in DiVA

By author/editor
Zhao, Yadong
By organisation
Wood Chemistry and Pulp Technology
Polymer Chemistry

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 1058 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf