Displaying publications 1 - 20 of 38 in total

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  1. Sustainable and green pretreatment strategy of Eucheuma denticulatum residues for third-generation l-lactic acid production
    Chai CY, Tan IS, Foo HCY, Lam MK, Tong KTX, Lee KT
    Bioresour Technol, 2021 Jun;330:124930.
    PMID: 33735730 DOI: 10.1016/j.biortech.2021.124930
    Managing plastic waste remains an urgent environmental concern and switching to biodegradable plastics can reduce the dependence on depleting fossil fuels. This study emphasises the efficacy of macroalgae wastes, Eucheuma denticulatum residues (EDRs), as potential alternate feedstock to produce l-lactic acid (l-LA), the monomer of polylactic acid, through fermentation. An innovative environmental friendly strategy was explored in this study to develop a glucose platform from EDRs: pretreatment with microwave-assisted autohydrolysis (MAA) applied to enhance enzymatic hydrolysis of EDRs. The results indicate that MAA pretreatment significantly increased the digestibility of EDRs during the enzymatic hydrolysis process. The optimum pretreatment conditions were 120 °C and 50 min, resulting in 96.5% of enzymatic digestibility after 48 h. The high l-LA yield of 98.6% was obtained using pretreated EDRs and supplemented with yeast extract. The energy analysis implies that MAA pretreatment could further improve the overall energy efficiency of the process.
    Matched MeSH terms: Rhodophyta*
  2. Halocarbon emissions by selected tropical seaweeds exposed to different temperatures
    Keng FS, Phang SM, Abd Rahman N, Yeong HY, Malin G, Leedham Elvidge E, et al.
    Phytochemistry, 2021 Oct;190:112869.
    PMID: 34274551 DOI: 10.1016/j.phytochem.2021.112869
    Four tropical seaweeds, Gracilaria manilaensis Yamamoto & Trono, Ulva reticulata Forsskål, Kappaphycus alvarezii (Doty) L.M.Liao and Turbinaria conoides (J.Agardh) Kützing, collected from various habitats throughout Malaysia, were subjected to temperatures of 40, 35, 30, 25 and 20 °C in the laboratory. An exposure range of 21-38 °C is reported for Malaysian waters. The effect of the temperature exposures on the halocarbon emissions of the seaweeds were determined 4 and 28 h after treatment. The emission rates for a suite of six halocarbons commonly emitted by seaweeds, bromoform (CHBr3), dibromomethane (CH2Br2), diiodomethane (CH2I2), iodomethane (CH3I), dibromochloromethane (CHBr2Cl) and dichlorobromomethane (CHBrCl2), were measured using a cryogenic purge-and-trap sample preparation system coupled to a gas chromatography-mass spectrometry. The emission rate of CHBr3 was the highest of the six halocarbons for all the seaweeds under all the temperatures tested, followed by CH2Br2, and CH2I2. The emission rates were affected by temperature change and exposure duration, but overall responses were unique to each seaweed species. Larger decreases in the emissions of CHBr3, CH2Br2, CH2I2 and CHBr2Cl were found for K. alvarezii and T. conoides after 4 h at 40 °C. In both cases there was a >90% (p 
    Matched MeSH terms: Rhodophyta*
  3. de novo transcriptome assembly for discovering gene expressed in Holothuria leucospilota with exposed to copper
    Leong RZL, Lim LH, Chew YL, Teo SS
    Anim Biotechnol, 2023 Dec;34(9):4474-4487.
    PMID: 36576030 DOI: 10.1080/10495398.2022.2158094
    Sea cucumber is a bioremediator as it can composite organic matter and excrete inorganic matter. Sea cucumber has the potential to serve as a bioindicator in marine habitat as they provide an integrated insight into the status of their environment over long periods. Sea cucumbers are sensitive to the organic concentration in the marine environment and can effectively provide an early warning system for any organic contamination that can negatively impact the ecosystem. The availability of a reference transcriptome for sea cucumber would constitute an essential tool for identifying genes involved in crucial steps of the defence pathway. De novo assembly of RNA-seq data enables researchers to study the transcriptomes without needing a genome sequence. In this study, sea cucumbers fed with Kappaphycus alvarezii powder were treated with 0.20 mg/L copper concentration comprehensive transcriptome data containing 75,149 Unigenes, with a total length of 20,460,032 bp. A total of 8820 genes were predicted from the unigenes, annotated, and functionally categorized into 25 functional groups with approximately 20% cluster in signal transduction mechanism. The reference transcriptome presented and validated in this study is meaningful for identifying a wide range of gene(s) related to the bioindication of sea cucumber in a high copper environment.
    Matched MeSH terms: Rhodophyta*
  4. Fulltext Radiation of the red algal parasite Congracilaria babae onto a secondary host species, Hydropuntia sp. (Gracilariaceae, Rhodophyta)
    Ng PK, Lim PE, Phang SM
    PLoS One, 2014;9(5):e97450.
    PMID: 24820330 DOI: 10.1371/journal.pone.0097450
    Congracilaria babae was first reported as a red alga parasitic on the thallus of Gracilaria salicornia based on Japanese materials. It was circumscribed to have deep spermatangial cavities, coloration similar to its host and the absence of rhizoids. We observed a parasitic red alga with morphological and anatomical features suggestive of C. babae on a Hydropuntia species collected from Sabah, East Malaysia. We addressed the taxonomic affinities of the parasite growing on Hydropuntia sp. based on the DNA sequence of molecular markers from the nuclear, mitochondrial and plastid genomes (nuclear ITS region, mitochondrial cox1 gene and plastid rbcL gene). Phylogenetic analyses based on all genetic markers also implied the monophyly of the parasite from Hydropuntia sp. and C. babae, suggesting their conspecificity. The parasite from Hydropuntia sp. has a DNA signature characteristic to C. babae in having plastid rbcL gene sequence identical to G. salicornia. C. babae is likely to have evolved directly from G. salicornia and subsequently radiated onto a secondary host Hydropuntia sp. We also recommend the transfer of C. babae to the genus Gracilaria and propose a new combination, G. babae, based on the anatomical observations and molecular data.
    Matched MeSH terms: Rhodophyta/anatomy & histology; Rhodophyta/classification; Rhodophyta/genetics; Rhodophyta/physiology*
  5. Fulltext Can algae contribute to the war with Covid-19?
    Chia WY, Kok H, Chew KW, Low SS, Show PL
    Bioengineered, 2021 Dec;12(1):1226-1237.
    PMID: 33858291 DOI: 10.1080/21655979.2021.1910432
    The world at large is facing a new threat with the emergence of the Coronavirus Disease 2019 (COVID-19) pandemic. Though imperceptible by the naked eye, the medical, sociological and economical implications caused by this newly discovered virus have been and will continue to be a great impediment to our lives. This health threat has already caused over two million deaths worldwide in the span of a year and its mortality rate is projected to continue rising. In this review, the potential of algae in combating the spread of COVID-19 is investigated since algal compounds have been tested against viruses and algal anti-inflammatory compounds have the potential to treat the severe symptoms of COVID-19. The possible utilization of algae in producing value-added products such as serological test kits, vaccines, and supplements that would either mitigate or hinder the continued health risks caused by the virus is prominent. Many of the characteristics in algae can provide insights on the development of microalgae to fight against SARS-CoV-2 or other viruses and contribute in manufacturing various green and high-value products.
    Matched MeSH terms: Rhodophyta/genetics; Rhodophyta/metabolism; Rhodophyta/chemistry*
  6. Kappaphycus alvarezii waste biomass: a potential biosorbent for chromium ions removal
    Kang OL, Ramli N, Said M, Ahmad M, Yasir SM, Ariff A
    J Environ Sci (China), 2011;23(6):918-22.
    PMID: 22066214
    The Cr(III) sorption experiments onto Kappaphycus alvarezii waste biomass were conducted at different pH values (2-6) under the conditions of initial metal concentration of 10-50 mg/L and the chemical compositions of Cr-Cu and Cr-Cd. The Cr(III) sorption capacities were slightly dependent on pH, and the maximum sorption capacity was 0.86 mg/g at pH 3. The sorption capacities increased with increase in the initial metal concentration, whereas it was suppressed by the presence of Cu(II) and Cd(III) in the solution. The Cr(III) sorption equilibrium was evaluated using Langmuir, Freundlich and BET isotherms. The sorption mechanisms were characterised using scanning electron microscopy and Fourier transform infrared spectroscopy. The main mechanisms were ion exchange coupled with a complexation mechanism. Kappaphycus alvarezii waste biomass represents a potential for Cr(III) ion removal from aqueous solution.
    Matched MeSH terms: Rhodophyta/ultrastructure; Rhodophyta/chemistry*
  7. High-performance porous biochar from the pyrolysis of natural and renewable seaweed (Gelidiella acerosa) and its application for the adsorption of methylene blue
    Ahmed MJ, Okoye PU, Hummadi EH, Hameed BH
    Bioresour Technol, 2019 Apr;278:159-164.
    PMID: 30685620 DOI: 10.1016/j.biortech.2019.01.054
    A high-performance porous biochar adsorbent prepared by facile thermal pyrolysis of seaweed (Gelidiella acerosa) is reported. The textural characteristics of the prepared seaweed biochar (SWBC) and the performance in the adsorption of methylene blue (MB) dye were evaluated. The batch experiment for the adsorption of MB was conducted under different parameters, such as temperature, pH, and initial concentration of MB in the range of 25-400 mg/L. The developed SWBC exhibited a relatively high surface area, average pore size, and pore volume of 926.39 m2/g, 2.45 nm, and 0.57 cm3/g, respectively. The high surface area and pristine mineral constituents of the biochar promoted a high adsorption capacity of 512.67 mg/g of MB at 30 °C. The adsorption isotherm and kinetics data best fitted the Langmuir and pseudo-second-order equations. The results indicate that SWBC is efficient for MB adsorption and could be a potential adsorbent for wastewater treatment.
    Matched MeSH terms: Rhodophyta/metabolism*
  8. In vitro evaluation of antioxidant and antibacterial activities of Eucheuma cottonii extract and its in vivo evaluation of the wound-healing activity in mice
    Teo BSX, Gan RY, Abdul Aziz S, Sirirak T, Mohd Asmani MF, Yusuf E
    J Cosmet Dermatol, 2021 Mar;20(3):993-1001.
    PMID: 32659861 DOI: 10.1111/jocd.13624
    BACKGROUND: Eucheuma Cottonii is a type of red algae obtained from Sabah with main active component, sulfated polysaccharide or k-carrageenan.

    AIMS: The objective of this research was to evaluate the antioxidant, antibacterial and potential wound-healing properties in aqueous extraction of E cottonii in order to meet the increasing demand for halal and natural cosmeceutical products.

    METHODS AND RESULTS: Aqueous extract of E cottonii was investigated for active compounds by phytochemical screening and IR spectroscopy. Antioxidant activity was carried out using DPPH method, and the IC50 value was 1.99 mg/mL. Antibacterial activity was examined against Staphylococcus Aureus using Kirby-Bauer disk diffusion method and showed 10.03 ± 0.06 mm zone of inhibition, achieved by 200 mg/mL of extracts. A wound was made by skin excision of area around 100 mm2 on each mouse. Test group was treated with aqueous extract gel (10% w/w); meanwhile, the mice that were treated with honey acted as the positive control group and the untreated mice as negative control group. Results showed that the wound contraction rate inclined to aqueous extracts as compared to untreated group (P 

    Matched MeSH terms: Rhodophyta*
  9. Production of new cellulose nanomaterial from red algae marine biomass Gelidium elegans
    Chen YW, Lee HV, Juan JC, Phang SM
    Carbohydr Polym, 2016 Oct 20;151:1210-1219.
    PMID: 27474672 DOI: 10.1016/j.carbpol.2016.06.083
    Nanocellulose was successfully isolated from Gelidium elegans red algae marine biomass. The red algae fiber was treated in three stages namely alkalization, bleaching treatment and acid hydrolysis treatment. Morphological analysis was performed by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). TEM results revealed that the isolated nanocellulose had the average diameter and length of 21.8±11.1nm and of 547.3±23.7nm, respectively. Fourier transform infrared (FTIR) spectroscopy proved that the non-cellulosic polysaccharides components were progressively removed during the chemically treatment, and the final derived materials composed of cellulose parent molecular structure. X-ray diffraction (XRD) study showed that the crystallinity of yielded product had been improved after each successive treatments subjected to the treated fiber. The prepared nano-dimensional cellulose demonstrated a network-like structure with higher crystallinity (73%) than that of untreated fiber (33%), and possessed of good thermal stability which is suitable for nanocomposite material.
    Matched MeSH terms: Rhodophyta/metabolism*
  10. Fulltext Chemistry of Tropical Eucheumatoids: Potential for Food and Feed Applications
    Ariano A, Musco N, Severino L, De Maio A, Tramice A, Tommonaro G, et al.
    Biomolecules, 2021 May 29;11(6).
    PMID: 34072325 DOI: 10.3390/biom11060804
    The use of seaweeds as additives in animal nutrition may be a valid option to traditional feed as they represent a rich source of minerals, carbohydrates and antioxidants. The aim of this study was to analyze the chemical composition and in vitro antioxidant capacity of two tropical eucheumatoids, Kappaphycus alvarezii and Kappaphycus striatus, in Malaysian wild offshore waters. The chemical analysis was performed via inductively coupled plasma-optical emission spectroscopy for evaluating the concentration of toxic (Cd, Pb, Hg, As) and essential elements (Mn, Fe, Cu, Ni, Zn, Se); NMR spectroscopy was used for carrageenans investigation. Furthermore, the soluble and fat-soluble antioxidant capacities were determined by FRAP, DPPH and ABTS assays. The chemical analysis revealed a higher content of trace elements in K. alvarezii as compared to K. striatus, and both exhibited a high mineral content. No significant differences in metal concentrations were found between the two species. Both samples showed a mixture of prevailing κ- and t-carrageenans. Finally, the levels of soluble and fat-soluble antioxidants in K. alvarezii were significantly higher than in K. striatus. Our findings suggest that K. alvarezii could be used as a potential feed additive because of its favorable chemical and nutritional features.
    Matched MeSH terms: Rhodophyta/chemistry*
  11. Fulltext Impact of elevated temperature on the physiological and biochemical responses of Kappaphycus alvarezii (Rhodophyta)
    Kumar YN, Poong SW, Gachon C, Brodie J, Sade A, Lim PE
    PLoS One, 2020;15(9):e0239097.
    PMID: 32925956 DOI: 10.1371/journal.pone.0239097
    The eucheumatoids Kappaphycus and Eucheuma are cultivated in tropical or subtropical regions for the production of carrageenan, a hydrocolloid widely used in the food and cosmetic industries. Kappaphycus alvarezii is a highly valued economic crop in the Coral Triangle, with the Philippines, Indonesia and Malaysia ranked among the largest producers. In the absence of measures to mitigate climate change, extreme events including heatwaves, typhoons, severe El Niño and La Niña, are expected to increase in frequency and magnitude. This inadvertently brings adverse effects to the seaweed cultivation industry, especially in the tropics. Temperatures are rapidly reaching the upper limit of biologically tolerable levels and an increase in reports of ice-ice and pest outbreaks is attributable to these shifts of environmental parameters. Nevertheless, few reports on the response of eucheumatoids to a changing environment, in particular global warming, are available. Understanding the responses and possible mechanisms for acclimation to warming is crucial for a sustainable seaweed cultivation industry. Here, the physiological and biochemical responses of K. alvarezii to acute warming indicated that the strain used in the current study is unlikely to survive sudden increases in temperature above 36°C. As temperature increased, the growth rates, photosynthetic performance, phycocolloid quality (carrageenan yield, gel strength and gel viscosity) and pigment content (chlorophyll-a, carotenoid and phycobiliproteins) were reduced while the production of reactive oxygen species increased indicating the occurrence of stress in the seaweeds. This study provides a basis for future work on long term acclimation to elevated temperature and mesocosm-based multivariate studies to identify heat-tolerant strains for sustainable cultivation.
    Matched MeSH terms: Rhodophyta/growth & development; Rhodophyta/physiology*; Rhodophyta/chemistry
  12. Fulltext Production of refined Carrageenan from Kappaphycus Alvarezii on pilot plant scale: Optimization of water extraction using Response Surface Methodology
    Sitti Nurmiah, Syarief, R., Sukarno, Peranginangin, R., Nurtama, B., Jaswir, I.
    International Food Research Journal, 2017;24(101):522-528.
    MyJurnal
    A refined carrageenan is a form of carrageenan, extracted from red algae and purified. Important factors affecting the commercial production of carrageenan after alkaline extraction are the ratio of seaweed to water, temperature, and extraction time. In this study, extraction of refined carrageenan from Kappaphycus alvarezii was conducted on pilot plan scale. Extraction conditions were varied, affecting the final characteristics of the carrageenan product. The optimum conditions investigated for the extraction process included the ratio of seaweed to water, temperature, and extraction time determined using Response Surface Methodology (RSM). Box-Behnken was used to investigate the interaction effects of three independent variables, namely seaweed to water ratio, extraction temperature and extraction time. The results showed that based on the RSM approach, ratio of seaweed to water, temperature and extraction time had a significant influence on the carrageenan. Optimum extraction conditions obtained were seaweed to water ratio of 1:25.22, extraction temperature of 85.80oC and extraction time of 4 h. Under these optimal conditions, the yield obtained was 31.74 % and gel strength was 1833.37 g.cm-2.
    Matched MeSH terms: Rhodophyta
  13. Molecular cloning, homology modeling and site-directed mutagenesis of vanadium-dependent bromoperoxidase (GcVBPO1) from Gracilaria changii (Rhodophyta)
    Baharum H, Chu WC, Teo SS, Ng KY, Rahim RA, Ho CL
    Phytochemistry, 2013 Aug;92:49-59.
    PMID: 23684235 DOI: 10.1016/j.phytochem.2013.04.014
    Vanadium-dependent haloperoxidases belong to a class of vanadium enzymes that may have potential industrial and pharmaceutical applications due to their high stability. In this study, the 5'-flanking genomic sequence and complete reading frame encoding vanadium-dependent bromoperoxidase (GcVBPO1) was cloned from the red seaweed, Fracilaria changii, and the recombinant protein was biochemically characterized. The deduced amino acid sequence of GcVBPO1 is 1818 nucleotides in length, sharing 49% identity with the vanadium-dependent bromoperoxidases from Corralina officinalis and Cor. pilulifera, respectively. The amino acid residues associated with the binding site of vanadate cofactor were found to be conserved. The Km value of recombinant GcVBPO1 for Br(-) was 4.69 mM, while its Vmax was 10.61 μkat mg(-1) at pH 7. Substitution of Arg(379) with His(379) in the recombinant protein caused a lower affinity for Br(-), while substitution of Arg(379) with Phe(379) not only increased its affinity for Br(-) but also enabled the mutant enzyme to oxidize Cl(-). The mutant Arg(379)Phe was also found to have a lower affinity for I(-), as compared to the wild-type GcVBPO1 and mutant Arg(379)His. In addition, the Arg(379)Phe mutant has a slightly higher affinity for H2O2 compared to the wild-type GcVBPO1. Multiple cis-acting regulatory elements associated with light response, hormone signaling, and meristem expression were detected at the 5'-flanking genomic sequence of GcVBPO1. The transcript abundance of GcVBPO1 was relatively higher in seaweed samples treated with 50 parts per thousand (ppt) artificial seawater (ASW) compared to those treated in 10 and 30 ppt ASW, in support of its role in the abiotic stress response of seaweed.
    Matched MeSH terms: Rhodophyta/enzymology*
  14. Effects of plasticizers on the physicochemical properties of kappa-carrageenan films extracted from Eucheuma cottonii
    Ili Balqis AM, Nor Khaizura MAR, Russly AR, Nur Hanani ZA
    Int J Biol Macromol, 2017 Oct;103:721-732.
    PMID: 28528954 DOI: 10.1016/j.ijbiomac.2017.05.105
    The physicochemical properties of κ-carrageenan films extracted from Eucheuma cottonii (E. cottonii) incorporated with different concentrations and types of plasticizers were studied. Glycerol, sorbitol, and polyethylene glycol-300 (PEG-300) in the range of 10-60% were used as plasticizers. The results showed that the thickness and moisture content (MC) of films increased significantly (p≤0.05) with the increase in plasticizer concentration. Sorbitol-plasticized films had the lowest values. Sorbitol-plasticized films have better mechanical properties and the lowest water vapor permeability (WVP), solubility and water uptake ratio (WUR) compared with glycerol and PEG-plasticized films (p≤0.05). Fourier transform infrared (FTIR) spectra showed the intermolecular reactions between κ-carrageenan and the plasticizers in the films. Scanning electron microscopy (SEM) observations indicated that sorbitol-plasticized films have a compact structure, even at the highest concentration. The melting temperature (Tm) of films decreased (p≤0.05) with an increase in the plasticizer concentration. Here, the glycerol-plasticized films had the lowest values. X-ray diffraction (XRD) showed broad and narrow peaks of the un-plasticized κ-carrageenan film at 2θ=20.0° and 2θ=8.4°, respectively. The intensity of the broad peak increased and the narrow peak disappeared as the concentration of plasticizers increased. In conclusion, films from E. cottonii successfully produced with sorbitol as the plasticizer exhibited good physical properties as packaging films.
    Matched MeSH terms: Rhodophyta/chemistry*
  15. Bioactive Algal-Derived Polysaccharides: Multi-Functionalization, Therapeutic Potential and Biomedical Applications
    Muhamad II, Zulkifli N, Selvakumaran SA, Lazim NAM
    Curr Pharm Des, 2019;25(11):1147-1162.
    PMID: 31258069 DOI: 10.2174/1381612825666190618152133
    BACKGROUND: In recent decades, there has been an increased interest in the utilization of polysaccharides showing biological activity for various novel applications owing to their biocompatibility, biodegradability, non-toxicity, and some specific therapeutic activities. Increasing studies have started in the past few years to develop algal polysaccharides-based biomaterials for various applications.

    METHODS: Saccharide mapping or enzymatic profiling plays a role in quality control of polysaccharides. Whereby, in vitro and in vivo tests as well as toxicity level discriminating polysaccharides biological activities. Extraction and purification methods are performed in obtaining algal derived polysaccharides followed by chromatographic profiles of their active compounds, structural features, physicochemical properties, and reported biological activities.

    RESULTS: Marine algae are capable of synthesizing Glycosaminoglycans (GAGs) and non-GAGs or GAG mimetics such as sulfated glycans. The cell walls of algae are rich in sulfated polysaccharides, including alginate, carrageenan, ulvan and fucoidan. These biopolymers are widely used algal-derived polysaccharides for biological and biomedical applications due to their biocompatibility and availability. They constitute biochemical compounds that have multi-functionalization, therapeutic potential and immunomodulatory abilities, making them promising bioactive products and biomaterials with a wide range of biomedical applications.

    CONCLUSION: Algal-derived polysaccharides with clearly elucidated compositions/structures, identified cellular activities, as well as desirable physical properties have shown the potential that may create new opportunities. They could be maximally exploited to serve as therapeutic tools such as immunoregulatory agents or drug delivery vehicles. Hence, novel strategies could be applied to tailor multi-functionalization of the polysaccharides from algal species with vast biomedical application potentials.

    Matched MeSH terms: Rhodophyta/chemistry*
  16. Fulltext Dilute acid-assisted microbubbles-mediated ozonolysis of Eucheuma denticulatum phycocolloid for biobased L-lactic acid production
    Tong KTX, Tan IS, Foo HCY, Hadibarata T, Lam MK, Wong MK
    Bioresour Technol, 2024 Aug;406:131082.
    PMID: 38972432 DOI: 10.1016/j.biortech.2024.131082
    Biobased L-lactic acid (L-LA) appeals to industries; however, existing technologies are plagued by limited productivity and high energy consumption. This study established an integrated process for producing macroalgae-based L-LA from Eucheuma denticulatum phycocolloid (EDP). Dilute acid-assisted microbubbles-mediated ozonolysis (DAMMO) was selected for the ozonolysis of EDP to optimize D-galactose recovery. Through single-factor optimization of DAMMO treatment, a maximum D-galactose recovery efficiency (59.10 %) was achieved using 0.15 M H2SO4 at 80 °C for 75 min. Fermentation with 3 % (w/v) mixed microbial cells (Bacillus coagulans ATCC 7050 and Lactobacillus acidophilus-14) and fermented residues achieved a 97.67 % L-LA yield. Additionally, this culture approach was further evaluated in repeated-batch fermentation and showed an average L-LA yield of 93.30 %, providing a feasible concept for macroalgae-based L-LA production.
    Matched MeSH terms: Rhodophyta/chemistry
  17. Fulltext Assessment of four molecular markers as potential DNA barcodes for red algae Kappaphycus Doty and Eucheuma J. Agardh (Solieriaceae, Rhodophyta)
    Tan J, Lim PE, Phang SM, Hong DD, Sunarpi H, Hurtado AQ
    PLoS One, 2012;7(12):e52905.
    PMID: 23285223 DOI: 10.1371/journal.pone.0052905
    DNA barcoding has been a major advancement in the field of taxonomy, seeing much effort put into the barcoding of wide taxa of organisms, macro and microalgae included. The mitochondrial-encoded cox1 and plastid-encoded rbcL has been proposed as potential DNA barcodes for rhodophytes, but are yet to be tested on the commercially important carrageenophytes Kappaphycus and Eucheuma. This study gauges the effectiveness of four markers, namely the mitochondrial cox1, cox2, cox2-3 spacer and the plastid rbcL in DNA barcoding on selected Kappaphycus and Eucheuma from Southeast Asia. Marker assessments were performed using established distance and tree-based identification criteria from earlier studies. Barcoding patterns on a larger scale were simulated by empirically testing on the commonly used cox2-3 spacer. The phylogeny of these rhodophytes was also briefly described. In this study, the cox2 marker which satisfies the prerequisites of DNA barcodes was found to exhibit moderately high interspecific divergences with no intraspecific variations, thus a promising marker for the DNA barcoding of Kappaphycus and Eucheuma. However, the already extensively used cox2-3 spacer was deemed to be in overall more appropriate as a DNA barcode for these two genera. On a wider scale, cox1 and rbcL were still better DNA barcodes across the rhodophyte taxa when practicality and cost-efficiency were taken into account. The phylogeny of Kappaphycus and Eucheuma were generally similar to those earlier reported. Still, the application of DNA barcoding has demonstrated our relatively poor taxonomic comprehension of these seaweeds, thus suggesting more in-depth efforts in taxonomic restructuring as well as establishment.
    Matched MeSH terms: Rhodophyta/classification*; Rhodophyta/genetics*
  18. Fulltext Phylogeny of Algal Sequences Encoding Carbohydrate Sulfotransferases, Formylglycine-Dependent Sulfatases, and Putative Sulfatase Modifying Factors
    Ho CL
    Front Plant Sci, 2015;6:1057.
    PMID: 26635861 DOI: 10.3389/fpls.2015.01057
    Many algae are rich sources of sulfated polysaccharides with biological activities. The physicochemical/rheological properties and biological activities of sulfated polysaccharides are affected by the pattern and number of sulfate moieties. Sulfation of carbohydrates is catalyzed by carbohydrate sulfotransferases (CHSTs) while modification of sulfate moieties on sulfated polysaccharides was presumably catalyzed by sulfatases including formylglycine-dependent sulfatases (FGly-SULFs). Post-translationally modification of Cys to FGly in FGly-SULFs by sulfatase modifiying factors (SUMFs) is necessary for the activity of this enzyme. The aims of this study are to mine for sequences encoding algal CHSTs, FGly-SULFs and putative SUMFs from the fully sequenced algal genomes and to infer their phylogenetic relationships to their well characterized counterparts from other organisms. Algal sequences encoding CHSTs, FGly-SULFs, SUMFs, and SUMF-like proteins were successfully identified from green and brown algae. However, red algal FGly-SULFs and SUMFs were not identified. In addition, a group of SUMF-like sequences with different gene structure and possibly different functions were identified for green, brown and red algae. The phylogeny of these putative genes contributes to the corpus of knowledge of an unexplored area. The analyses of these putative genes contribute toward future production of existing and new sulfated carbohydrate polymers through enzymatic synthesis and metabolic engineering.
    Matched MeSH terms: Rhodophyta
  19. Fulltext Morphological Characteristics and Habitats of Red Seaweed Gracilaria spp. (Gracilariaceae, Rhodophyta) in Santubong and Asajaya, Sarawak, Malaysia
    Othman MNA, Hassan R, Harith MN, Sah ASRM
    Trop Life Sci Res, 2018 Mar;29(1):87-101.
    PMID: 29644017 MyJurnal DOI: 10.21315/tlsr2018.29.1.6
    Red seaweed Gracilaria, one of the largest genus in Division Rhodophyta inhabits Sarawak coastal water. This study was designed to identify the species of Gracilaria using morphological approach and to assess selected water quality parameters in Gracilaria habitats. Three field samplings were carried out in Santubong and Asajaya, Sarawak from November 2013 to December 2014. Overall, three species were identified namely Gracilaria changii, G. blodgettii and G. coronopifolia, attached to net of cage culture in Santubong and root of mangrove trees in Asajaya. In addition, three different taxa of aquatic macroinvertebrates (polychaete, small crab, bivalve) and single species of red seaweed (Acanthophora sp.) were observed in Gracilaria assemblages. An estimate of 37% to 40% of the upper part of the cage net in Santubong was covered by seaweeds and only 16% to 20% in Asajaya's mangrove. The study had provided better information on identification of Gracilaria and their habitat in Sarawak. Future work involving DNA barcoding of each species is in progress.
    Matched MeSH terms: Rhodophyta
  20. Hydrolysis of macroalgae using heterogeneous catalyst for bioethanol production
    Tan IS, Lam MK, Lee KT
    Carbohydr Polym, 2013 Apr 15;94(1):561-6.
    PMID: 23544575 DOI: 10.1016/j.carbpol.2013.01.042
    Utilization of macroalgae biomass for bioethanol production appears as an alternative source to lignocellulosic materials. In this study, for the first time, Amberlyst (TM)-15 was explored as a potential catalyst to hydrolyze carbohydrates from Eucheuma cottonii extract to simple reducing sugar prior to fermentation process. Several important hydrolysis parameters were studied for process optimization including catalyst loading (2-5%, w/v), reaction temperature (110-130°C), reaction time (0-2.5 h) and biomass loading (5.5-15.5%, w/v). Optimum sugar yield of 39.7% was attained based on the following optimum conditions: reaction temperature at 120°C, catalyst loading of 4% (w/v), 12.5% (w/v) of biomass concentration and reaction time of 1.5h. Fermentation of the hydrolysate using Saccharomyces cerevisiae produced 0.33 g/g of bioethanol yield with an efficiency of 65%. The strategy of combining heterogeneous-catalyzed hydrolysis and fermentation with S. cerevisiae could be a feasible strategy to produce bioethanol from macroalgae biomass.
    Matched MeSH terms: Rhodophyta/chemistry*
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