Conventional bioplastic production from seaweed often relies on extraction processes that are costly,time-consuming,and yield limited product.This study presents a direct fabrication method using Gracilaria sp.,a red ...Conventional bioplastic production from seaweed often relies on extraction processes that are costly,time-consuming,and yield limited product.This study presents a direct fabrication method using Gracilaria sp.,a red seaweed rich in polysaccharides,to produce bioplastic films without the need for extraction.Sorbitol was incorporated as a plasticizer at concentrations of 0%–10%(w/w)to modify film characteristics.Thermal analysis revealed improved stability at moderate sorbitol levels(5%–7%),while excessive plasticizer slightly reduced thermal resistance.Mechanical testing showed that sorbitol increased film flexibility and elongation at break,though tensile strength and stiffness declined.Tear strength followed a non-linear trend,with improvement observed at higher sorbitol concentrations.Seal strength also increased,peaking at 7%,indicating stronger interfacial bonding between film layers.Biodegradation tests demonstrated accelerated decomposition with increased sorbitol content,achieving complete degradation within 30 days at 10% concentration.Color analysis showed increased brightness and reduced yellowing,enhancing the visual quality of the films.These results confirm that direct conversion of bioplastic is both feasible and effective.Sorbitol plays a key role in tuning film properties,offering a low-cost,scalable pathway to biodegradable materials suitable for environmentally friendly packaging applications.展开更多
Objective:To isolate and identify active constituents from Gracilaria chorda extract prepared under subcritical water conditions at 210℃(GCSW210)and evaluate their anti-obesity and anti-diabetic effects in 3T3-L1 adi...Objective:To isolate and identify active constituents from Gracilaria chorda extract prepared under subcritical water conditions at 210℃(GCSW210)and evaluate their anti-obesity and anti-diabetic effects in 3T3-L1 adipocytes and high-fat diet(HFD)-induced obese zebrafish larvae.Methods:GCSW210 was fractionated through solvent partitioning,ion-exchange chromatography,and silica gel medium-pressure liquid chromatography,followed by preparative high performance liquid chromatography.At each step,bioactivities were assessed in 3T3-L1 adipocytes by Oil Red O staining and 2-NBDG uptake assays.The most active fractions were further purified,and isolated compounds were tested in HFD-induced obese zebrafish larvae.Results:Liquid chromatography-hyphenated analysis with reference standards identified two major compounds in GCSW210:5-hydroxymethylfurfural and bis(5-formylfurfuryl)ether.Both compounds significantly inhibited lipid accumulation in 3T3-L1 adipocytes and modulated gene expression associated with adipogenesis,glucose metabolism,and inflammation in zebrafish.They also enhanced glucose uptake,reduced circulating glucose levels,and improved insulin sensitivity.Notably,the effects were comparable to those of the crude GCSW210 extract.In silico docking studies confirmed stable interactions of both compounds with key metabolic and inflammatory targets,with bis(5-formylfurfuryl)ether showing stronger binding affinities.Conclusions:These findings suggest that 5-hydroxymethylfurfural and bis(5-formylfurfuryl)ether are key contributors to the therapeutic activity of Gracilaria chorda,highlighting its potential as a functional food ingredient for the prevention or management of metabolic disorders.展开更多
Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-c...Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-cies which are important resources for the production of special proteins, phycobilisomes, special carbo-hydrates, and agar in China. In this study, de novo transcriptome sequencing on these four species using the next generation sequencing technology was performed for the first time. Functional annotations on assembled sequencing reads showed that the transcriptomic profiles were quite different between G. lema-neiformis and other three Gracilaria species. Comparative analysis of differential gene expression related to carbohydrate and phycobiliprotein metabolisms also showed that the expression profiles of these essential genes were different in four species. The genes encoding allophycocyanin, phycocyanin and phycoerythrin were further examined in four species and their deduced amino acid sequences were used for phylogenetic analysis to confirm that G. lemaneiformis had close relationship to genus Gracilaria, as well as that within genus Gracilaria, G. chouae had closer relationship to G. vermiculophylla rather than to G. blodgettii. The de novo transcriptome study on four species provided a valuable genomic resource for further understanding and analysis on biological and evolutionary study among marine algae.展开更多
Comparative studies of absorption spectra of phycobiliproteins of Gracilaria lemaneiformis Greville and its pigmental mutants were conducted in this study. The results showed that the absorption spectra of phycoerythr...Comparative studies of absorption spectra of phycobiliproteins of Gracilaria lemaneiformis Greville and its pigmental mutants were conducted in this study. The results showed that the absorption spectra of phycoerythrins ( PE) from different material changed significantly, while those of phycocyanins (PC) and allophycocyanins (APC) were basically similar. In order to disclose the essence of die difference, partial sequences of die subunit genes of PE of Qingdao strain of G. lemaneiformis (qd) and its pigmental mutants were determined. The amino acid sequences were deduced and used to explain spectral shifts of PE from the pigmental mutants. The amino acid sequences of PE resembled each other, and several residues changed among qd and its pigmental mutants. Residue substitutions were found in a region consisting of amino acids which determined are secondary structure and subunits interactions, thus might influence the confirmation and interaction of subunits, and further caused spectral deviation.展开更多
In order to find out whether long interspersed elements （LINEs） existed in macro-algae gehomes or not, we tested the LINE homologues in representative families （species）： Gracilaria （G. eucheumoides Harv., G. te...In order to find out whether long interspersed elements （LINEs） existed in macro-algae gehomes or not, we tested the LINE homologues in representative families （species）： Gracilaria （G. eucheumoides Harv., G. tenuistipitata Chang et Xia, and G. textorii （Sur） De-Toni）, Laminaria （L. longissima Miyabe and L. japonica Aresch.）, and Ulva （U. lactuca L. and U. pertusa Kjellm.） during 2004 to 2005. Polymerase Chain Reaction （PCR） was carried out with degenerate oligonucleotide primers designed from LINEs of rice homologues and Cin4 of maize. Cloning and nucleotide sequencing of the PCR products revealed that 4 clones that derived from 3 species of Gracilaria have LINE homologues. The nucleotide sequences of the 4 LINE homologues diverged greatly, but the amino acid sequences deduced from them were relatively conserved. The endonuclease regions of the LINE homologues greatly diverged from that of other plants, but they had closer phylogenetic relationship to Zepp elements in Chlorella sp., which indicated that sequence divergence by vertical transmission has been a major influence on the evolution of algal LINEs.展开更多
在2011-2013年间对粤东地区进行了20余次野外大型海藻资源调查，采集了大量标本。利用形态特征，对部分标本进行了分类学研究。经鉴定，标本中包含江蓠属5个种及变种，即芋根江蓠Gracilaria blodgettii Harvey、异枝江蓠G. bailinae Cha...在2011-2013年间对粤东地区进行了20余次野外大型海藻资源调查，采集了大量标本。利用形态特征，对部分标本进行了分类学研究。经鉴定，标本中包含江蓠属5个种及变种，即芋根江蓠Gracilaria blodgettii Harvey、异枝江蓠G. bailinae Chang et Xia、细基江蓠G. tenuistipitata Chang et Xia、细基江蓠繁枝变种G. tenuistipitata var. liui Zhang et Xia、长喙江蓠G. longirostris Zhang et Wang。它们的主要鉴定特征分别为：芋根江蓠的分枝基部明显缢缩；异枝江蓠的藻体暗绿色，初级分枝围绕主轴互生、偏生或叉分；细基江蓠的藻体主轴基部纤细，分枝简单；细基江蓠繁枝变种的藻体纤细，分枝繁多；长喙江蓠的囊果具有明显的长喙状突起。其中，芋根江蓠和异枝江蓠在粤东地区属首次报道，文章对其进行了较详细的介绍。该研究结果丰富了粤东江蓠属的物种多样性，为粤东地区江蓠属物种资源的保护和利用提供了分类学依据。展开更多
Gracilaria lemaneiformis Bory is an economically important alga that is primarily used for agar production.Although tetraspores are ideal seeds for the cultivation of G.lemaneiformis,the most popular culture method is...Gracilaria lemaneiformis Bory is an economically important alga that is primarily used for agar production.Although tetraspores are ideal seeds for the cultivation of G.lemaneiformis,the most popular culture method is currently based on vegetative fragments,which is labor-intensive and time-consuming.In this study,we optimized the conditions for tetraspore release and evaluated the photosynthetic activities of different colonies formed from the branches of G.lemaneiformis using a PAM(pulse-amplitude-modulated) measuring system.The results showed that variations in temperature and salinityhad significant effects on tetraspore yield.However,variations in the photon flux density(from 15 μmol m-2 s-1 to 480 μmol m-2 s-1) had no apparent effect on tetraspore yield.Moreover,the PAM-parameters Y(I),Y(Ⅱ),ETR(I),ETR(Ⅱ) and Fv/Fm of colonies formed from different branches showed the same trend:parameter values of first generation branches>second generation branches>third generation branches.These results suggest that the photosynthetic activities of different colonies of branches changed with the same trend.Furthermore,photosynthesis in G.lemaneiformis was found to be involved in vegetative reproduction and tetraspore formation.Finally,the first generation branches grew slowly,but accumulated organic compounds to form large numbers of tetraspores.Taken together,these results showed that the first generation branches are ideal materials for the release of tetraspores.展开更多
基金funded by IAEA Coordinated Research Project F22081.
文摘Conventional bioplastic production from seaweed often relies on extraction processes that are costly,time-consuming,and yield limited product.This study presents a direct fabrication method using Gracilaria sp.,a red seaweed rich in polysaccharides,to produce bioplastic films without the need for extraction.Sorbitol was incorporated as a plasticizer at concentrations of 0%–10%(w/w)to modify film characteristics.Thermal analysis revealed improved stability at moderate sorbitol levels(5%–7%),while excessive plasticizer slightly reduced thermal resistance.Mechanical testing showed that sorbitol increased film flexibility and elongation at break,though tensile strength and stiffness declined.Tear strength followed a non-linear trend,with improvement observed at higher sorbitol concentrations.Seal strength also increased,peaking at 7%,indicating stronger interfacial bonding between film layers.Biodegradation tests demonstrated accelerated decomposition with increased sorbitol content,achieving complete degradation within 30 days at 10% concentration.Color analysis showed increased brightness and reduced yellowing,enhancing the visual quality of the films.These results confirm that direct conversion of bioplastic is both feasible and effective.Sorbitol plays a key role in tuning film properties,offering a low-cost,scalable pathway to biodegradable materials suitable for environmentally friendly packaging applications.
文摘Objective:To isolate and identify active constituents from Gracilaria chorda extract prepared under subcritical water conditions at 210℃(GCSW210)and evaluate their anti-obesity and anti-diabetic effects in 3T3-L1 adipocytes and high-fat diet(HFD)-induced obese zebrafish larvae.Methods:GCSW210 was fractionated through solvent partitioning,ion-exchange chromatography,and silica gel medium-pressure liquid chromatography,followed by preparative high performance liquid chromatography.At each step,bioactivities were assessed in 3T3-L1 adipocytes by Oil Red O staining and 2-NBDG uptake assays.The most active fractions were further purified,and isolated compounds were tested in HFD-induced obese zebrafish larvae.Results:Liquid chromatography-hyphenated analysis with reference standards identified two major compounds in GCSW210:5-hydroxymethylfurfural and bis(5-formylfurfuryl)ether.Both compounds significantly inhibited lipid accumulation in 3T3-L1 adipocytes and modulated gene expression associated with adipogenesis,glucose metabolism,and inflammation in zebrafish.They also enhanced glucose uptake,reduced circulating glucose levels,and improved insulin sensitivity.Notably,the effects were comparable to those of the crude GCSW210 extract.In silico docking studies confirmed stable interactions of both compounds with key metabolic and inflammatory targets,with bis(5-formylfurfuryl)ether showing stronger binding affinities.Conclusions:These findings suggest that 5-hydroxymethylfurfural and bis(5-formylfurfuryl)ether are key contributors to the therapeutic activity of Gracilaria chorda,highlighting its potential as a functional food ingredient for the prevention or management of metabolic disorders.
基金The National Natural Science Foundation of China under contract Nos 31140070,31271397 and 41206116the algal transcrip-tome sequencing was supported by 1KP Project(www.onekp.com)
文摘Three Gracilaria species, G. chouae, G. blodgettii, G. vermiculophylla and a close relative species, Gracilari-opsis lemaneiformis which is now nominated as Gracilaria lemaneiformis, are the typically indigenous spe-cies which are important resources for the production of special proteins, phycobilisomes, special carbo-hydrates, and agar in China. In this study, de novo transcriptome sequencing on these four species using the next generation sequencing technology was performed for the first time. Functional annotations on assembled sequencing reads showed that the transcriptomic profiles were quite different between G. lema-neiformis and other three Gracilaria species. Comparative analysis of differential gene expression related to carbohydrate and phycobiliprotein metabolisms also showed that the expression profiles of these essential genes were different in four species. The genes encoding allophycocyanin, phycocyanin and phycoerythrin were further examined in four species and their deduced amino acid sequences were used for phylogenetic analysis to confirm that G. lemaneiformis had close relationship to genus Gracilaria, as well as that within genus Gracilaria, G. chouae had closer relationship to G. vermiculophylla rather than to G. blodgettii. The de novo transcriptome study on four species provided a valuable genomic resource for further understanding and analysis on biological and evolutionary study among marine algae.
文摘2006年8～9月,在浙江象山港花鲈（Lateolabrax japonicus）养殖网箱中吊养真江蓠（Gracilaria verrucosa）对网箱养殖造成的水体富营养化进行生态修复研究。通过45d内的平面监测、定点跟踪监测和断面监测,结果表明：该网箱养殖区水体呈严重富营养化状态,营养状态指数（E）为32.00,其营养盐分布由高浓度的中心区向周围150m非养殖水域扩散;真江蓠对养殖区的富营养化海水具有较好的修复效果：江蓠生态修复区及其相邻网箱中水体PO4-P、NO2-N、NH4-N和NO3-N含量显著低于非修复区（P〈0.01）,修复区海水PO4-P、NO2-N、NH4-N和NO3-N浓度比非修复区分别降低22%～58%、24%～48%、22%～61%和24%～47%。养殖真江蓠45d后,修复区水体DO浓度和透明度显著高于非修复区（P〈0.05）,DO平均提高28%,透明度平均提高30%;而修复区水体Chl-a浓度显著低于非修复区（P〈0.05）,平均降低49%。通过建立基于N平衡的鱼藻生态养殖模式,每收获1kg花鲈至少需要匹配江蓠4.7 kg wetwt才可实现对鱼类排放N的完全吸收。因此网箱内栽培江蓠的混合生态养殖模式,可平衡因经济动物养殖所带来的额外营养负荷,有利于实现动物养殖环境的自我修复。
文摘Comparative studies of absorption spectra of phycobiliproteins of Gracilaria lemaneiformis Greville and its pigmental mutants were conducted in this study. The results showed that the absorption spectra of phycoerythrins ( PE) from different material changed significantly, while those of phycocyanins (PC) and allophycocyanins (APC) were basically similar. In order to disclose the essence of die difference, partial sequences of die subunit genes of PE of Qingdao strain of G. lemaneiformis (qd) and its pigmental mutants were determined. The amino acid sequences were deduced and used to explain spectral shifts of PE from the pigmental mutants. The amino acid sequences of PE resembled each other, and several residues changed among qd and its pigmental mutants. Residue substitutions were found in a region consisting of amino acids which determined are secondary structure and subunits interactions, thus might influence the confirmation and interaction of subunits, and further caused spectral deviation.
基金Supported by the NSFC (No. 40376049 and No. 30500383)Shandong Agricultural Seed Stock Breeding Project and Knowledge In-novation Program of Chinese Academy of Sciences (KSCX2-YW-N-47-02).
文摘In order to find out whether long interspersed elements （LINEs） existed in macro-algae gehomes or not, we tested the LINE homologues in representative families （species）： Gracilaria （G. eucheumoides Harv., G. tenuistipitata Chang et Xia, and G. textorii （Sur） De-Toni）, Laminaria （L. longissima Miyabe and L. japonica Aresch.）, and Ulva （U. lactuca L. and U. pertusa Kjellm.） during 2004 to 2005. Polymerase Chain Reaction （PCR） was carried out with degenerate oligonucleotide primers designed from LINEs of rice homologues and Cin4 of maize. Cloning and nucleotide sequencing of the PCR products revealed that 4 clones that derived from 3 species of Gracilaria have LINE homologues. The nucleotide sequences of the 4 LINE homologues diverged greatly, but the amino acid sequences deduced from them were relatively conserved. The endonuclease regions of the LINE homologues greatly diverged from that of other plants, but they had closer phylogenetic relationship to Zepp elements in Chlorella sp., which indicated that sequence divergence by vertical transmission has been a major influence on the evolution of algal LINEs.
文摘在2011-2013年间对粤东地区进行了20余次野外大型海藻资源调查，采集了大量标本。利用形态特征，对部分标本进行了分类学研究。经鉴定，标本中包含江蓠属5个种及变种，即芋根江蓠Gracilaria blodgettii Harvey、异枝江蓠G. bailinae Chang et Xia、细基江蓠G. tenuistipitata Chang et Xia、细基江蓠繁枝变种G. tenuistipitata var. liui Zhang et Xia、长喙江蓠G. longirostris Zhang et Wang。它们的主要鉴定特征分别为：芋根江蓠的分枝基部明显缢缩；异枝江蓠的藻体暗绿色，初级分枝围绕主轴互生、偏生或叉分；细基江蓠的藻体主轴基部纤细，分枝简单；细基江蓠繁枝变种的藻体纤细，分枝繁多；长喙江蓠的囊果具有明显的长喙状突起。其中，芋根江蓠和异枝江蓠在粤东地区属首次报道，文章对其进行了较详细的介绍。该研究结果丰富了粤东江蓠属的物种多样性，为粤东地区江蓠属物种资源的保护和利用提供了分类学依据。
基金Supported by the National Natural Science Foundation of China(No.30830015)the National Key Technology Research and Development Program of the 11th Five-Year Plan(No.2006BAD09A04)the National High Technology Research and Development Program of China(863Program,Nos.2006AA10A402,2007AA09Z406,2006AA05Z112,2006AA10A413)
文摘Gracilaria lemaneiformis Bory is an economically important alga that is primarily used for agar production.Although tetraspores are ideal seeds for the cultivation of G.lemaneiformis,the most popular culture method is currently based on vegetative fragments,which is labor-intensive and time-consuming.In this study,we optimized the conditions for tetraspore release and evaluated the photosynthetic activities of different colonies formed from the branches of G.lemaneiformis using a PAM(pulse-amplitude-modulated) measuring system.The results showed that variations in temperature and salinityhad significant effects on tetraspore yield.However,variations in the photon flux density(from 15 μmol m-2 s-1 to 480 μmol m-2 s-1) had no apparent effect on tetraspore yield.Moreover,the PAM-parameters Y(I),Y(Ⅱ),ETR(I),ETR(Ⅱ) and Fv/Fm of colonies formed from different branches showed the same trend:parameter values of first generation branches>second generation branches>third generation branches.These results suggest that the photosynthetic activities of different colonies of branches changed with the same trend.Furthermore,photosynthesis in G.lemaneiformis was found to be involved in vegetative reproduction and tetraspore formation.Finally,the first generation branches grew slowly,but accumulated organic compounds to form large numbers of tetraspores.Taken together,these results showed that the first generation branches are ideal materials for the release of tetraspores.
