Displaying publications 1 - 20 of 29 in total

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  1. Suhaimi NSM, Goh SY, Ajam N, Othman RY, Chan KG, Thong KL
    World J Microbiol Biotechnol, 2017 Aug 21;33(9):168.
    PMID: 28828756 DOI: 10.1007/s11274-017-2336-0
    Banana is one of the most important fruits cultivated in Malaysia, and it provides many health benefits. However, bacterial wilt disease, which attacks bananas, inflicts major losses on the banana industry in Malaysia. To understand the complex interactions of the microbiota of bacterial wilt-diseased banana plants, we first determined the bacterial communities residing in the pseudostems of infected (symptomatic) and diseased-free (non-symptomatic) banana plants. We characterized the associated microorganisms using the targeted 16S rRNA metagenomics sequencing on the Illumina MiSeq platform. Taxonomic classifications revealed 17 and nine known bacterial phyla in the tissues of non-symptomatic and symptomatic plants, respectively. Cyanobacteria and Proteobacteria (accounted for more than 99% of the 16S rRNA gene fragments) were the two most abundant phyla in both plants. The five major genera found in both plant samples were Ralstonia, Sphingomonas, Methylobacterium, Flavobacterium, and Pseudomonas. Ralstonia was more abundant in symptomatic plant (59% out of the entire genera) as compared to those in the non-symptomatic plant (only 36%). Our data revealed that 102 bacterial genera were only assigned to the non-symptomatic plant. Overall, this study indicated that more diverse and abundant microbiota were associated with the non-symptomatic bacterial wilt-diseased banana plant as compared to the symptomatic plant. The higher diversity of endophytic microbiota in the non-symptomatic banana plant could be an indication of pathogen suppression which delayed or prevented the disease expression. This comparative study of the microbiota in the two plant conditions might provide caveats for potential biological control strategies.
    Matched MeSH terms: Cyanobacteria/classification; Cyanobacteria/genetics; Cyanobacteria/isolation & purification
  2. Shaari AL, Surif M, Latiff FA, Omar WM, Ahmad MN
    Trop Life Sci Res, 2011 May;22(1):51-69.
    PMID: 24575209
    Many reports have revealed that the abundance of microalgae in shrimp ponds vary with changes in environmental factors such as light, temperature, pH, salinity and nutrient level throughout a shrimp culture period. In this study, shrimp cultivation period was divided into three stages (initial = week 0-5, mid = week 6-10 and final = week 11-15). Physical and chemical parameters throughout the cultivation period were studied and species composition of microalgae was monitored. Physical parameters were found to fluctuate widely with light intensity ranging between 182.23-1278 μmol photon m(-2)s(-1), temperature between 29.56°C -31.59°C, dissolved oxygen (DO) between 4.56-8.21 mg/l, pH between 7.65-8.49 and salinity between 20‰-30‰. Ammonium (NH4 (+)-N), nitrite (NO2 (-)-N), nitrate (NO3 (-)-N), and orthophosphate (PO4 (3-)-P) concentrations in the pond at all cultivation stages ranged from 0.017 to 0.38 mg/l, 0.24 to 2.12 mg/l, 0.06 to 0.98 mg/l and 0.16 to 1.93 mg/l respectively. Statistical test (ANOVA) showed that there were no significant difference (p<0.05) in nutrients concentrations among the cultivation stages. All nutrients concentrations however were still in the tolerable level and safe for shrimp culture. The chlorophyll a contents were found to range from 5.03±2.17 to 32.61±0.35 μg/l throughout the cultivation period. A total of 19 microalgae species were found in the shrimp pond, with diatoms contributing up to 72% of the species followed by Chlorophyta (11%) and Cyanophyta (11%). However, weekly species abundance varied through the study period. At the initial stage, when there were no shrimps in the pond, Anabaena spp. and Oscillatoria spp. (Cyanophyta) were the dominant species, followed by Chlorella sp. and Dunaliella sp. (Chlorophyta). When shrimps were introduced into the pond, Amphora sp., Navicula sp. Gyrosigma sp. and Nitzschia sp. (diatoms) started to exist. At the middle and towards the final stage of the shrimp culture period diatoms were the dominant species. The Chlorophyta (Chlorella sp.) domination took place only twice, which was at week 2 and 13. The absence of some of the coastal water microalgae species in the shrimp pond was most likely due to the fact that they could not tolerate the physicochemical factors of harsh environment. In this study, Cylindrotheca closterium was regarded as the most tolerant species among the microalgae due to its ability to exist for 6 weeks out of the 15 weeks of cultivation.
    Matched MeSH terms: Cyanobacteria
  3. Ait Abderrahim L, Taïbi K, Abderrahim NA, Alomery AM, Abdellah F, Alhazmi AS, et al.
    Toxicon, 2019 Aug 26;169:38-44.
    PMID: 31465783 DOI: 10.1016/j.toxicon.2019.08.005
    Microcystin Leucine-Arginine (MC-LR) is a toxin produced by the cyanobacteria Microcystis aeruginosa. It is the most encountered and toxic type of cyanotoxins. Oxidative stress was shown to play a role in the pathogenesis of microcystin LR by the induction of intracellular reactive oxygen species (ROS) formation that oxidize and damage cellular macromolecules. In the present study we examined the effect of acute MC-LR dose on the cardiac muscle of BALB/c mice. Afterwards, melatonin and N-acetyl cysteine (NAC) were assayed and evaluated as potential protective and antioxidant agents against damages generated by MC-LR. For this purpose, thirty mice were assigned into six groups of five mice each. The effect of MC-LR was first compared to the control group supplied with distilled water, then compared to the other groups supplied with melatonin and NAC. The experiment lasted 10 days after which animals were euthanized. Biomarkers of toxicity such as alkaline phosphatase activity, lipid peroxidation, protein carbonyl content, reduced glutathione content, serum lactate dehydrogenase and serum sorbitol dehydrogenase were assayed. Results showed that toxin treated mice have experienced significant oxidative damage in their myocardial tissue as revealed by noticeable levels of oxidative stress biomarkers and by the reduction in alkaline phosphatase activity. Whereas, melatonin and NAC treated mice manifested lesser oxidative damages. Our findings suggest a potential therapeutic use of melatonin and N-acetyl cysteine as antioxidant protective agents against oxidative damage induced by MC-LR.
    Matched MeSH terms: Cyanobacteria
  4. Nakamoto H, Amaya Y, Komatsu T, Suzuki T, Dohmae N, Nakamura Y, et al.
    Biochem. J., 2018 08 16;475(15):2559-2576.
    PMID: 30045873 DOI: 10.1042/BCJ20180230
    Hsp90 is an ATP-dependent molecular chaperone that assists folding and conformational maturation/maintenance of many proteins. It is a potential cancer drug target because it chaperones oncoproteins. A prokaryotic homolog of Hsp90 (HtpG) is essential for thermo-tolerance in some bacteria and virulence of zoonotic pathogens. To identify a new class of small molecules which target prokaryotic and eukaryotic Hsp90s, we studied the effects of a naturally occurring cyclic sesquiterpene, zerumbone, which inhibits proliferation of a wide variety of tumor cells, on the activity of Hsp90. Zerumbone enhanced the ATPase activity of cyanobacterial Hsp90 (Hsp90SE), yeast Hsp90, and human Hsp90α. It also enhanced the catalytic efficiency of Hsp90SE by greatly increasing kcat Mass analysis showed that zerumbone binds to cysteine side chains of Hsp90SE covalently. Mutational studies identified 3 cysteine residues (one per each domain of Hsp90SE) that are involved in the enhancement, suggesting the presence of allosteric sites in the middle and C-terminal domains of Hsp90SE Treatment of cyanobacterial cells with zerumbone caused them to become very temperature-sensitive, a phenotype reminiscent of cyanobacterial Hsp90 mutants, and also decreased the cellular level of linker polypeptides that are clients for Hsp90SE Zerumbone showed cellular toxicity on cancer-derived mammalian cells by inducing apoptosis. In addition, zerumbone inhibited the binding of Hsp90/Cdc37 to client kinases. Altogether, we conclude that modification of cysteine residues of Hsp90 by zerumbone enhances its ATPase activity and inhibits physiological Hsp90 function. The activation of Hsp90 may provide new strategies to inhibit its chaperone function in cells.
    Matched MeSH terms: Cyanobacteria/enzymology*
  5. Shing WL, Heng LY, Surif S
    Sensors (Basel), 2013;13(5):6394-404.
    PMID: 23673679 DOI: 10.3390/s130506394
    Whole cell biosensors always face the challenge of low stability of biological components and short storage life. This paper reports the effects of poly(2-hydroxyethyl methacrylate) (pHEMA) immobilization on a whole cell fluorescence biosensor for the detection of heavy metals (Cu, Pb, Cd), and pesticides (dichlorophenoxyacetic acid (2,4-D), and chlorpyrifos). The biosensor was produced by entrapping the cyanobacterium Anabaena torulosa on a cellulose membrane, followed by applying a layer of pHEMA, and attaching it to a well. The well was then fixed to an optical probe which was connected to a fluorescence spectrophotometer and an electronic reader. The optimization of the biosensor using several factors such as amount of HEMA and drying temperature were undertaken. The detection limits of biosensor without pHEMA for Cu, Cd, Pb, 2,4-D and chlorpyrifos were 1.195, 0.027, 0.0100, 0.025 and 0.025 µg/L respectively. The presence of pHEMA increased the limits of detection to 1.410, 0.250, 0.500, 0.235 and 0.117 µg/L respectively. pHEMA is known to enhance the reproducibility of the biosensor with average relative standard deviation (RSD) of ±1.76% for all the pollutants tested, 48% better than the biosensor without pHEMA (RSD = ±3.73%). In storability test with Cu 5 µg/L, the biosensor with pHEMA performed 11.5% better than the test without pHEMA on day-10 and 5.2% better on day-25. pHEMA is therefore a good candidate to be used in whole cell biosensors as it increases reproducibility and enhances biosensor storability.
    Matched MeSH terms: Cyanobacteria/cytology; Cyanobacteria/drug effects; Cyanobacteria/growth & development; Cyanobacteria/metabolism*
  6. Khairiah Jusoh, Nik Marzuki Sidik, Mohd. Fahmi Ismail, Shaanaz Mohd. Yusof, Tunisah Risman, Ahmad Mahir Razali, et al.
    The aim of this work is to investigate the effect of exposure of heavy metals such as Ni, Fe and Mn on the growth of the cyanobacteria Anabaena flos-aquae, which can be found in fresh water environment. Results of the experiments showed that exposure of A. flos-aquae to Ni caused the most toxic effect as compared to exposure with Fe and Mn. The 96 hr LC50 value for Ni exposure was 0.321 mg/mL (approximately 30% inhibition), whereas Mn was the second most toxic metal followed by Fe with the 96 hr LC50 values of 0.684 mg/mL and 3.020 mg/mL respectively. This study demonstrated that even though Fe and Mn are essential micronutrients for A. flos-aquae, both show toxic effects at high concentrations. The difference in the toxicity value between Fe and Mn for A. flos-aquae is five times and this indicates that Mn was five times more toxic to A. flos-aquae than Fe suggesting that the Cyanobacteria is more tolerant to Fe when compared with Mn.
    Matched MeSH terms: Cyanobacteria
  7. Lee JYN, Tan IKP
    Sains Malaysiana, 2018;47:243-251.
    Bacteria play an important roles in the soil ecosystem and in the rhizosphere, they are intricately linked to nutrient content
    and its accessibility to plants, plant protection and sometimes pathogenicity. Banana grows well in the tropics and it is
    popularly grown in Orang Asli (OA) (indigenous people) settlements. Banana is also grown in commercial plantations.
    In traditional planting practices, the OA do not add pesticide nor fertilizer to their crops which are planted for selfsustenance
    mainly. On the other hand, fertilizer and pesticide are added to commercial banana plantations to maximise
    yield. Rhizosphere bacteria from the banana plant, Pisang Nipah, grown in OA fields and commercial plantations were
    identified by clone library construction of the 16S rRNA gene. This was to determine whether farming practices influenced
    the bacterial community in the banana plant rhizosphere. Acidobacteria, Proteobacteria and Actinobacteria were found in
    all the soil. Other common phyla found in some soil (but not all) were Nitrospirae, Firmicutes, Bacteroidetes, Chloroflexi,
    Verrumicrobia, Gemmatimonadetes and Cyanobacteria. The bacterial diversity was a little more diverse in the OA fields
    than the commercial plantations. The latter had higher contents of nitrogen, phosphorus and potassium. These could
    have exerted selective pressure to reduce the bacterial diversity in the commercial plantations.
    Matched MeSH terms: Cyanobacteria
  8. Radzi R, Muangmai N, Broady P, Wan Omar WM, Lavoue S, Convey P, et al.
    PLoS One, 2019;14(11):e0224395.
    PMID: 31682631 DOI: 10.1371/journal.pone.0224395
    Terrestrial cyanobacteria are very diverse and widely distributed in Antarctica, where they can form macroscopically visible biofilms on the surfaces of soils and rocks, and on benthic surfaces in fresh waters. We recently isolated several terrestrial cyanobacteria from soils collected on Signy Island, South Orkney Islands, Antarctica. Among them, we found a novel species of Nodosilinea, named here as Nodosilinea signiensis sp. nov. This new species is morphologically and genetically distinct from other described species. Morphological examination indicated that the new species is differentiated from others in the genus by cell size, cell shape, filament attenuation, sheath morphology and granulation. 16S rDNA phylogenetic analyses clearly confirmed that N. signiensis belongs to the genus Nodosilinea, but that it is genetically distinct from other known species of Nodosilinea. The D1-D1´ helix of the 16S-23S ITS region of the new species was also different from previously described Nodosilinea species. This is the first detailed characterization of a member of the genus Nodosilinea from Antarctica as well as being a newly described species.
    Matched MeSH terms: Cyanobacteria/classification*; Cyanobacteria/genetics; Cyanobacteria/isolation & purification
  9. Ng FL, Phang SM, Periasamy V, Yunus K, Fisher AC
    PLoS One, 2014;9(5):e97643.
    PMID: 24874081 DOI: 10.1371/journal.pone.0097643
    In photosynthesis, a very small amount of the solar energy absorbed is transformed into chemical energy, while the rest is wasted as heat and fluorescence. This excess energy can be harvested through biophotovoltaic platforms to generate electrical energy. In this study, algal biofilms formed on ITO anodes were investigated for use in the algal biophotovoltaic platforms. Sixteen algal strains, comprising local isolates and two diatoms obtained from the Culture Collection of Marine Phytoplankton (CCMP), USA, were screened and eight were selected based on the growth rate, biochemical composition and photosynthesis performance using suspension cultures. Differences in biofilm formation between the eight algal strains as well as their rapid light curve (RLC) generated using a pulse amplitude modulation (PAM) fluorometer, were examined. The RLC provides detailed information on the saturation characteristics of electron transport and overall photosynthetic performance of the algae. Four algal strains, belonging to the Cyanophyta (Cyanobacteria) Synechococcus elongatus (UMACC 105), Spirulina platensis. (UMACC 159) and the Chlorophyta Chlorella vulgaris (UMACC 051), and Chlorella sp. (UMACC 313) were finally selected for investigation using biophotovoltaic platforms. Based on power output per Chl-a content, the algae can be ranked as follows: Synechococcus elongatus (UMACC 105) (6.38×10(-5) Wm(-2)/µgChl-a)>Chlorella vulgaris UMACC 051 (2.24×10(-5) Wm(-2)/µgChl-a)>Chlorella sp.(UMACC 313) (1.43×10(-5) Wm(-2)/µgChl-a)>Spirulina platensis (UMACC 159) (4.90×10(-6) Wm(-2)/µgChl-a). Our study showed that local algal strains have potential for use in biophotovoltaic platforms due to their high photosynthetic performance, ability to produce biofilm and generation of electrical power.
    Matched MeSH terms: Cyanobacteria/physiology*; Cyanobacteria/chemistry
  10. Lopez JAV, Petitbois JG, Vairappan CS, Umezawa T, Matsuda F, Okino T
    Org. Lett., 2017 08 18;19(16):4231-4234.
    PMID: 28783344 DOI: 10.1021/acs.orglett.7b01869
    Two new chlorinated fatty acid amides, columbamides D (1) and E (2), along with apratoxins A and C and wewakazole, were isolated from the organic extract of a Moorea bouillonii sample from Sabah, Malaysia. Structure elucidation was accomplished by a combination of MS and NMR analyses. The total synthesis of all four stereoisomers of 1 was completed, and the absolute configuration was determined by chiral-phase HPLC and Marfey's analysis.
    Matched MeSH terms: Cyanobacteria/chemistry*
  11. Fathoni I, Petitbois JG, Alarif WM, Abdel-Lateff A, Al-Lihaibi SS, Yoshimura E, et al.
    Molecules, 2020 Sep 01;25(17).
    PMID: 32882989 DOI: 10.3390/molecules25173986
    Cyanobacteria are reported as rich sources of secondary metabolites that provide biological activities such as enzyme inhibition and cytotoxicity. Ten depsipeptide derivatives (lyngbyabellins) were isolated from a Malaysian Moorea bouillonii and a Red Sea Okeania sp.: lyngbyabellins G (1), O (2), P (3), H (4), A (7), 27-deoxylyngbyabellin A (5), and homohydroxydolabellin (6). This study indicated that lyngbyabellins displayed cytotoxicity, antimalarial, and antifouling activities. The isolated compounds were tested for cytotoxic effect against human breast cancer cells (MCF7), for antifouling activity against Amphibalanus amphitrite barnacle larvae, and for antiplasmodial effect towards Plasmodium falciparum. Lyngbyabellins A and G displayed potent antiplasmodial effect against Plasmodium, whereas homohydroxydolabellin showed moderate effect. For antifouling activity, the side chain decreases the activity slightly, but the essential feature is the acyclic structure. As previously reported, the acyclic lyngbyabellins are less cytotoxic than the corresponding cyclic ones, and the side chain increases cytotoxicity. This study revealed that lyngbyabellins, despite being cytotoxic agents as previously reported, also exhibit antimalarial and antifouling activities. The unique chemical structures and functionalities of lyngbyabellin play an essential role in their biological activities.
    Matched MeSH terms: Cyanobacteria/chemistry*
  12. Dayang Najwa AB, Elexson N, Dalene L, Teng ST
    Microb Ecol, 2024 Mar 15;87(1):51.
    PMID: 38488929 DOI: 10.1007/s00248-024-02356-5
    In aquatic environments, Vibrio and cyanobacteria establish varying relationships influenced by environmental factors. To investigate their association, this study spanned 5 months at a local shrimp farm, covering the shrimp larvae stocking cycle until harvesting. A total of 32 samples were collected from pond A (n = 6), pond B (n = 6), effluent (n = 10), and influent (n = 10). Vibrio species and cyanobacteria density were observed, and canonical correspondence analysis (CCA) assessed their correlation. CCA revealed a minor correlation (p = 0.847, 0.255, 0.288, and 0.304) between Vibrio and cyanobacteria in pond A, pond B, effluent, and influent water, respectively. Notably, Vibrio showed a stronger correlation with pH (6.14-7.64), while cyanobacteria correlated with pH, salinity (17.4-24 ppt), and temperature (30.8-31.5 °C), with salinity as the most influential factor. This suggests that factors beyond cyanobacteria influence Vibrio survival. Future research could explore species-specific relationships, regional dynamics, and multidimensional landscapes to better understand Vibrio-cyanobacteria connections. Managing water parameters may prove more efficient in controlling vibriosis in shrimp farms than targeting cyanobacterial populations.
    Matched MeSH terms: Cyanobacteria*
  13. Akbar MA, Mohd Yusof NY, Tahir NI, Ahmad A, Usup G, Sahrani FK, et al.
    Mar Drugs, 2020 Feb 05;18(2).
    PMID: 32033403 DOI: 10.3390/md18020103
    Saxitoxin is an alkaloid neurotoxin originally isolated from the clam Saxidomus giganteus in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.7 kb to 35 kb in sequence length. Due to the complexity of the genomic landscape, saxitoxin biosynthesis in dinoflagellates remains unknown. In order to reveal and understand the dynamics of the activity in such impressive unicellular organisms with a complex genome, a strategy that can carefully engage them in a systems view is necessary. Advances in omics technology (the collective tools of biological sciences) facilitated high-throughput studies of the genome, transcriptome, proteome, and metabolome of dinoflagellates. The omics approach was utilized to address saxitoxin-producing dinoflagellates in response to environmental stresses to improve understanding of dinoflagellates gene-environment interactions. Therefore, in this review, the progress in understanding dinoflagellate saxitoxin biosynthesis using an omics approach is emphasized. Further potential applications of metabolomics and genomics to unravel novel insights into saxitoxin biosynthesis in dinoflagellates are also reviewed.
    Matched MeSH terms: Cyanobacteria/metabolism
  14. Mehjabin JJ, Wei L, Petitbois JG, Umezawa T, Matsuda F, Vairappan CS, et al.
    J Nat Prod, 2020 06 26;83(6):1925-1930.
    PMID: 32432877 DOI: 10.1021/acs.jnatprod.0c00164
    Chemical investigation of the organic extract from Moorea bouillonii, collected in Sabah, Malaysia, led to the isolation of three new chlorinated fatty acid amides, columbamides F (1), G (2), and H (3). The planar structures of 1-3 were established by a combination of mass spectrometric and NMR spectroscopic analyses. The absolute configuration of 1 was determined by Marfey's analysis of its hydrolysate and chiral-phase HPLC analysis after conversion and esterification with Ohrui's acid, (1S,2S)-2-(anthracene-2,3-dicarboximido)cyclohexanecarboxylic acid. Compound 1 showed biosurfactant activity by an oil displacement assay. Related known fatty acid amides columbamide D and serinolamide C exhibited biosurfactant activity with critical micelle concentrations of about 0.34 and 0.78 mM, respectively.
    Matched MeSH terms: Cyanobacteria/chemistry*
  15. Kasan NA, Yusof SZM, Manan H, Khairul WM, Zakeri HA
    J Environ Manage, 2021 Sep 15;294:113008.
    PMID: 34119989 DOI: 10.1016/j.jenvman.2021.113008
    High nutrient loading in aquatic environment has become the main causative of harmful algae blooms (HABs) in water resources particularly pond, lake and river. HABs are mostly dominated by microalgae derived from the group of blue-green algae which are capable of releasing harmful toxins. Therefore, this study aims to investigate the inhibitory effects of thiourea derivatives on the growth of such blue-green algae. Thiourea derivatives have been proven to exhibit antifungal and antibacterial effects. However, there is still limited study had been conducted on the effect of thiourea derivatives toward blue-green algae species in recent years. In this research, a species of blue-green algae from Kenyir Lake, Terengganu, Malaysia was successfully isolated using morphological characters and molecularly identified as Synechoccus elongatus. Four new thiourea derivative compounds were also successfully synthesised. The compounds were designed with variation on different R-substitution group and characterised using Nuclear Magnetic Resonance (NMR) to confirm their molecular structure. Those compounds were characterised as 1-Benzyl-3-(3,5-dimethoxy-benzoyl)-thiourea (C1), 1-(3-Chloro-benzyl)-3-(3,5-dimethoxy-benzoyl)-thiourea (C2), 1-(3,5-Dimethoxy-benzoyl)-3-(3-methyl-benzyl)-thiourea (C3) and 1-(3,5-Dimethoxy-benzoyl)-3-(3-trifluoromethyl-benzyl)-thiourea (C4). For the inhibition assessment,S. elongatus were treated with C1-C4 for 5 day at concentration of 2, 5, 10 and 20 μg/ml, respectively. C3 compound showed the highest inhibition percentage with 98% of inhibition after 5 days treatment. By using Bradford method, protein extraction of S. elongatus was conducted at the highest inhibition percentage. Protein concentration of treated species was observed with 3.28 μg/ml as compared to protein concentration of control with 6.48 μg/ml. This result indicated the reduction of protein content after the treatment. Protein band pattern was identified intensed after the treatment SDS PAGE was carried out. The thiourea derivatives compound proved to have successfully inhibited the growth of blue-green algae. Hence, further study should be carried out to ensure the compound can be practically utilized in the pond and in natural environment.
    Matched MeSH terms: Cyanobacteria*
  16. Jin H, Wang Y, Zhao P, Wang L, Zhang S, Meng D, et al.
    J Agric Food Chem, 2021 Oct 27;69(42):12385-12401.
    PMID: 34649432 DOI: 10.1021/acs.jafc.1c04632
    Numerous plant secondary metabolites have remarkable impacts on both food supplements and pharmaceuticals for human health improvement. However, higher plants can only generate small amounts of these chemicals with specific temporal and spatial arrangements, which are unable to satisfy the expanding market demands. Cyanobacteria can directly utilize CO2, light energy, and inorganic nutrients to synthesize versatile plant-specific photosynthetic intermediates and organic compounds in large-scale photobioreactors with outstanding economic merit. Thus, they have been rapidly developed as a "green" chassis for the synthesis of bioproducts. Flavonoids, chemical compounds based on aromatic amino acids, are considered to be indispensable components in a variety of nutraceutical, pharmaceutical, and cosmetic applications. In contrast to heterotrophic metabolic engineering pioneers, such as yeast and Escherichia coli, information about the biosynthesis flavonoids and their derivatives is less comprehensive than that of their photosynthetic counterparts. Here, we review both benefits and challenges to promote cyanobacterial cell factories for flavonoid biosynthesis. With increasing concerns about global environmental issues and food security, we are confident that energy self-supporting cyanobacteria will attract increasing attention for the generation of different kinds of bioproducts. We hope that the work presented here will serve as an index and encourage more scientists to join in the relevant research area.
    Matched MeSH terms: Cyanobacteria*
  17. Kabirnataj S, Nematzadeh GA, Talebi AF, Saraf A, Suradkar A, Tabatabaei M, et al.
    Int J Syst Evol Microbiol, 2020 May;70(5):3413-3426.
    PMID: 32375955 DOI: 10.1099/ijsem.0.004188
    Five cyanobacterial strains with Nostoc-like morphology from different localities of the Mazandaran province of Iran were characterized using a polyphasic approach. Three strains clustered within the Aliinostoc clade whereas one each of the remaining two strains clustered within the genera Desmonostoc and Desikacharya. The phylogenetic positioning of all the strains by the bayesian inference, neighbour joining and maximum parsimony methods inferred using 16S rRNA gene indicated them to represent novel species of the genera Aliinostoc, Desmonostoc and Desikacharya. The 16S-23S ITS secondary structure analysis revealed that all five strains under study represented novel species unknown to science. In accordance with the International Code of Nomenclature for algae, fungi and plants we describe three novel species of the genus Aliinostoc and one species each of the genera Desmonostoc and Desikacharya.
    Matched MeSH terms: Cyanobacteria/classification*; Cyanobacteria/isolation & purification
  18. Naher UA, Othman R, Latif MA, Panhwar QA, Amaddin PA, Shamsuddin ZH
    Int J Mol Sci, 2013 Aug 30;14(9):17812-29.
    PMID: 23999588 DOI: 10.3390/ijms140917812
    This study was conducted to evaluate selected biomolecular characteristics of rice root-associated diazotrophs isolated from the Tanjong Karang rice irrigation project area of Malaysia. Soil and rice plant samples were collected from seven soil series belonging to order Inceptisol (USDA soil taxonomy). A total of 38 diazotrophs were isolated using a nitrogen-free medium. The biochemical properties of the isolated bacteria, such as nitrogenase activity, indoleacetic acid (IAA) production and sugar utilization, were measured. According to a cluster analysis of Jaccard's similarity coefficients, the genetic similarities among the isolated diazotrophs ranged from 10% to 100%. A dendogram constructed using the unweighted pair-group method with arithmetic mean (UPGMA) showed that the isolated diazotrophs clustered into 12 groups. The genomic DNA rep-PCR data were subjected to a principal component analysis, and the first four principal components (PC) accounted for 52.46% of the total variation among the 38 diazotrophs. The 10 diazotrophs that tested highly positive in the acetylene reduction assay (ARA) were identified as Bacillus spp. (9 diazotrophs) and Burkholderia sp. (Sb16) using the partial 16S rRNA gene sequence analysis. In the analysis of the biochemical characteristics, three principal components were accounted for approximately 85% of the total variation among the identified diazotrophs. The examination of root colonization using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) proved that two of the isolated diazotrophs (Sb16 and Sb26) were able to colonize the surface and interior of rice roots and fixed 22%-24% of the total tissue nitrogen from the atmosphere. In general, the tropical soils (Inceptisols) of the Tanjong Karang rice irrigation project area in Malaysia harbor a diverse group of diazotrophs that exhibit a large variation of biomolecular characteristics.
    Matched MeSH terms: Cyanobacteria/enzymology*; Cyanobacteria/metabolism*
  19. Jau MH, Yew SP, Toh PS, Chong AS, Chu WL, Phang SM, et al.
    Int J Biol Macromol, 2005 Aug;36(3):144-51.
    PMID: 16005060
    Three strains of Spirulina platensis isolated from different locations showed capability of synthesizing poly(3-hydroxybutyrate) [P(3HB)] under nitrogen-starved conditions with a maximum accumulation of up to 10 wt.% of the cell dry weight (CDW) under mixotrophic culture conditions. Intracellular degradation (mobilization) of P(3HB) granules by S. platensis was initiated by the restoration of nitrogen source. This mobilization process was affected by both illumination and culture pH. The mobilization of P(3HB) was better under illumination (80% degradation) than in dark conditions (40% degradation) over a period of 4 days. Alkaline conditions (pH 10-11) were optimal for both biosynthesis and mobilization of P(3HB) at which 90% of the accumulated P(3HB) was mobilized. Transmission electron microscopy (TEM) revealed that the mobilization of P(3HB) involved changes in granule quantity and morphology. The P(3HB) granules became irregular in shape and the boundary region was less defined. In contrast to bacteria, in S. platensis the intracellular mobilization of P(3HB) seems to be faster than the biosynthesis process. This is because in cyanobacteria chlorosis delays the P(3HB) accumulation process.
    Matched MeSH terms: Cyanobacteria/metabolism; Cyanobacteria/chemistry
  20. Basri RS, Rahman RNZRA, Kamarudin NHA, Ali MSM
    Int J Biol Macromol, 2020 Dec 01;164:3155-3162.
    PMID: 32841666 DOI: 10.1016/j.ijbiomac.2020.08.162
    The conversion of aldehydes to valuable alkanes via cyanobacterial aldehyde deformylating oxygenase is of great interest. The availability of fossil reserves that keep on decreasing due to human exploitation is worrying, and even more troubling is the combustion emission from the fuel, which contributes to the environmental crisis and health issues. Hence, it is crucial to use a renewable and eco-friendly alternative that yields compound with the closest features as conventional petroleum-based fuel, and that can be used in biofuels production. Cyanobacterial aldehyde deformylating oxygenase (ADO) is a metal-dependent enzyme with an α-helical structure that contains di‑iron at the active site. The substrate enters the active site of every ADO through a hydrophobic channel. This enzyme exhibits catalytic activity toward converting Cn aldehyde to Cn-1 alkane and formate as a co-product. These cyanobacterial enzymes are small and easy to manipulate. Currently, ADOs are broadly studied and engineered for improving their enzymatic activity and substrate specificity for better alkane production. This review provides a summary of recent progress in the study of the structure and function of ADO, structural-based engineering of the enzyme, and highlight its potential in producing biofuels.
    Matched MeSH terms: Cyanobacteria/enzymology*
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