In this study, the natural fibers from Coconuts of the species Coco nucifera L. were Chemically extracted in different solvents such as sodium hydroxide (SH), acetone (AC) and sodium hydroxide-acetone (SHA) for their ...In this study, the natural fibers from Coconuts of the species Coco nucifera L. were Chemically extracted in different solvents such as sodium hydroxide (SH), acetone (AC) and sodium hydroxide-acetone (SHA) for their applications in the textile industries. Structural, morphological and physico-mechanical characterizations such as X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), scanned electron microscopy (SEM), measurements of density, Young’s modulus, water absorption rate and humidity were evaluated. The XRD and FTIR results show that Coco nucifera L. fibers contains type I cellulose. Mechanical characterizations were also carried out. These results show that by varying the different solvents used, the physico-chemical, mechanical and morphological properties of the fibers change, which implies that the solvent has an influence on the properties of these fibers. The fibers extracted by the sodium hydroxide-acetone mixture have a linear density of 1.636, the percentage of water absorption is 62.428%, the percentage of moisture absorption 9.605% compared to other values in the literature shows that this solvent mixture improves the properties of coconut fibers which contain type I cellulose. The tensile stress is 0.013 GPa, the percentage strain is 49.836% and the Young’s modulus is 0.114 GPa as well as the percentage elongation show that these fibers are elasto-plastic. The values obtained mean that these fibers are suitable for use in textiles.展开更多
The ability of Cocos nucifera L.water（CW） as non-toxic corrosion inhibitor for acid corrosion of aluminium in 0.5 mol/L HCl has been studied using chemical technique.CW shows significant inhibition as corrosion inhi...The ability of Cocos nucifera L.water（CW） as non-toxic corrosion inhibitor for acid corrosion of aluminium in 0.5 mol/L HCl has been studied using chemical technique.CW shows significant inhibition as corrosion inhibitor,with 93%efficiency at the highest concentration of the inhibitor.The inhibitive action is attributed to the adsorption of the inhibitor molecules on metal surface following Langmuir adsorption isotherm.展开更多
To investigate the gene expression profile of endosperm development, a cDNA library was constructed and characterized from the pulp of coconut at different developmental stages. The constructed cDNA library incorporat...To investigate the gene expression profile of endosperm development, a cDNA library was constructed and characterized from the pulp of coconut at different developmental stages. The constructed cDNA library incorporated approximately 1 × 10^7 clones in total, and the size of the insertion fragments ranged from 800 to 2 000 bp. Sequencing results of 100 randomly picked clones showed that the recombination rate was 96%. In subsequent sequence analysis, 41 clones （41%） were homologous to known function proteins, and 23 clones showed high amino acid identity （more than 80%） with the corresponding genes of different plants. Semi-quantitative RT-PCR indicated that oleosin and globulin genes are pulpspecific expression, and have differential expression level in different developmental stage. Clone 29, recognized as homologous to KIAA1239 protein （Homo sapiens）, was observed to occur nine times, indicating that this gene may be over-expressed during the endosperm development stage. However, the homologous protein was found only in mammals, and the detailed function is still unknown. Elucidation of the functional characterization of these genes will be carried out immediately.展开更多
The study aimed to evaluate the endophytic fungi isolated from <em>Cocos nucifera</em> (L.) cotyledon for their possible antimicrobial activity. A total of twelve endophytic fungal species were successfull...The study aimed to evaluate the endophytic fungi isolated from <em>Cocos nucifera</em> (L.) cotyledon for their possible antimicrobial activity. A total of twelve endophytic fungal species were successfully isolated, from which five were selected and presumptively identified, including <em>Aspergillus niger</em>, <em>Raffaelea sp.</em>, <em>Aspergillus flavus</em>, <em>Cladosporium sp.</em> and <em>Pseudallescheria spp.</em> based on their macro and microscopic characters. The agar blocks of actively growing pure culture were assessed for antibacterial activity against five human pathogenic bacterial and fungal strains: <em>Escherichia coli</em> (BIOTECH 1634), <em>Bacillus subtilis</em> (BIOTECH 1697), <em>Staphylococcus aureus</em> (BIOTECH 1592), <em>Serratia marcescens</em> (BIOTECH 1748), and <em>Candida tropicalis</em> (BIOTECH 2085). Among the selected five endophytic used for antimicrobial activity screening, the <em>Raffaelea sp.</em> (CN-EF 2) has shown a high zone of inhibition of 11 mm against <em>Bacillus subtilis</em>, 18 mm against <em>Escherichia coli</em>, 15 mm against <em>Staphylococcus aureus</em>, and 11 mm against <em>Candida tropicalis</em>. Correspondingly, <em>Aspergillus niger</em> (CN-EF 1) has shown a zone of inhibition of 16 mm against <em>C. tropicalis</em>. The endophytic fungus <em>Raffaelea sp.</em> was effective against all test organisms except for <em>Serratia marcescens</em>, while <em>Aspergillus niger</em> was only effective for pathogenic fungi <em>C. albicans</em>. Hence, further in-depth studies of the isolated endophytic fungi are needed to determine the mechanisms behind the endophytes’ inhibitory effects.展开更多
RAPD markers were used to estimate levels of genetic diversity and structure among twelve East African Tall (EAT) coconut (Cocos nucifera L.) accessions that are maintained at Chambezi station. Ten primers were used i...RAPD markers were used to estimate levels of genetic diversity and structure among twelve East African Tall (EAT) coconut (Cocos nucifera L.) accessions that are maintained at Chambezi station. Ten primers were used in the analysis of 120 accessions. Cluster analysis was performed based on Jaccard’s coefficient and Nei genetic distances. Further analyses included principal coordinate analysis (PCA) and finally bootstrap analysis. The cluster analysis revealed two main clusters. One cluster contained provenances from Lindi and Mtwara regions (south) and those from Coast and Dar es Salaam regions (central);the second had provenances from Tanga region, which is the northern part of the coastal belt. A similar distribution of provenances was shown by the results of the principal coordinate analysis, whose first three coordinates explained 56% of the total variation. The results were able to discriminate between the different provenances and provide evidence of the different origins for the coconut palms in the northern and southern parts of coastal coconut-growing belt. The two major clusters concur well with the history and distribution of coconuts in the coastal belt of Tanzania.展开更多
文摘In this study, the natural fibers from Coconuts of the species Coco nucifera L. were Chemically extracted in different solvents such as sodium hydroxide (SH), acetone (AC) and sodium hydroxide-acetone (SHA) for their applications in the textile industries. Structural, morphological and physico-mechanical characterizations such as X-ray diffraction (XRD), Fourier transform infrared spectrometry (FTIR), scanned electron microscopy (SEM), measurements of density, Young’s modulus, water absorption rate and humidity were evaluated. The XRD and FTIR results show that Coco nucifera L. fibers contains type I cellulose. Mechanical characterizations were also carried out. These results show that by varying the different solvents used, the physico-chemical, mechanical and morphological properties of the fibers change, which implies that the solvent has an influence on the properties of these fibers. The fibers extracted by the sodium hydroxide-acetone mixture have a linear density of 1.636, the percentage of water absorption is 62.428%, the percentage of moisture absorption 9.605% compared to other values in the literature shows that this solvent mixture improves the properties of coconut fibers which contain type I cellulose. The tensile stress is 0.013 GPa, the percentage strain is 49.836% and the Young’s modulus is 0.114 GPa as well as the percentage elongation show that these fibers are elasto-plastic. The values obtained mean that these fibers are suitable for use in textiles.
文摘The ability of Cocos nucifera L.water（CW） as non-toxic corrosion inhibitor for acid corrosion of aluminium in 0.5 mol/L HCl has been studied using chemical technique.CW shows significant inhibition as corrosion inhibitor,with 93%efficiency at the highest concentration of the inhibitor.The inhibitive action is attributed to the adsorption of the inhibitor molecules on metal surface following Langmuir adsorption isotherm.
基金the National Natural Science Foundation of China (30560092)
文摘To investigate the gene expression profile of endosperm development, a cDNA library was constructed and characterized from the pulp of coconut at different developmental stages. The constructed cDNA library incorporated approximately 1 × 10^7 clones in total, and the size of the insertion fragments ranged from 800 to 2 000 bp. Sequencing results of 100 randomly picked clones showed that the recombination rate was 96%. In subsequent sequence analysis, 41 clones （41%） were homologous to known function proteins, and 23 clones showed high amino acid identity （more than 80%） with the corresponding genes of different plants. Semi-quantitative RT-PCR indicated that oleosin and globulin genes are pulpspecific expression, and have differential expression level in different developmental stage. Clone 29, recognized as homologous to KIAA1239 protein （Homo sapiens）, was observed to occur nine times, indicating that this gene may be over-expressed during the endosperm development stage. However, the homologous protein was found only in mammals, and the detailed function is still unknown. Elucidation of the functional characterization of these genes will be carried out immediately.
文摘The study aimed to evaluate the endophytic fungi isolated from <em>Cocos nucifera</em> (L.) cotyledon for their possible antimicrobial activity. A total of twelve endophytic fungal species were successfully isolated, from which five were selected and presumptively identified, including <em>Aspergillus niger</em>, <em>Raffaelea sp.</em>, <em>Aspergillus flavus</em>, <em>Cladosporium sp.</em> and <em>Pseudallescheria spp.</em> based on their macro and microscopic characters. The agar blocks of actively growing pure culture were assessed for antibacterial activity against five human pathogenic bacterial and fungal strains: <em>Escherichia coli</em> (BIOTECH 1634), <em>Bacillus subtilis</em> (BIOTECH 1697), <em>Staphylococcus aureus</em> (BIOTECH 1592), <em>Serratia marcescens</em> (BIOTECH 1748), and <em>Candida tropicalis</em> (BIOTECH 2085). Among the selected five endophytic used for antimicrobial activity screening, the <em>Raffaelea sp.</em> (CN-EF 2) has shown a high zone of inhibition of 11 mm against <em>Bacillus subtilis</em>, 18 mm against <em>Escherichia coli</em>, 15 mm against <em>Staphylococcus aureus</em>, and 11 mm against <em>Candida tropicalis</em>. Correspondingly, <em>Aspergillus niger</em> (CN-EF 1) has shown a zone of inhibition of 16 mm against <em>C. tropicalis</em>. The endophytic fungus <em>Raffaelea sp.</em> was effective against all test organisms except for <em>Serratia marcescens</em>, while <em>Aspergillus niger</em> was only effective for pathogenic fungi <em>C. albicans</em>. Hence, further in-depth studies of the isolated endophytic fungi are needed to determine the mechanisms behind the endophytes’ inhibitory effects.
文摘RAPD markers were used to estimate levels of genetic diversity and structure among twelve East African Tall (EAT) coconut (Cocos nucifera L.) accessions that are maintained at Chambezi station. Ten primers were used in the analysis of 120 accessions. Cluster analysis was performed based on Jaccard’s coefficient and Nei genetic distances. Further analyses included principal coordinate analysis (PCA) and finally bootstrap analysis. The cluster analysis revealed two main clusters. One cluster contained provenances from Lindi and Mtwara regions (south) and those from Coast and Dar es Salaam regions (central);the second had provenances from Tanga region, which is the northern part of the coastal belt. A similar distribution of provenances was shown by the results of the principal coordinate analysis, whose first three coordinates explained 56% of the total variation. The results were able to discriminate between the different provenances and provide evidence of the different origins for the coconut palms in the northern and southern parts of coastal coconut-growing belt. The two major clusters concur well with the history and distribution of coconuts in the coastal belt of Tanzania.
