Displaying publications 1 - 20 of 43 in total

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  1. Lau NS, Sudesh K
    AMB Express, 2012;2(1):41.
    PMID: 22877240 DOI: 10.1186/2191-0855-2-41
    The nutrition-versatility of Burkholderia sp. strain USM (JCM 15050) has initiated the studies on the use of this bacterium for polyhydroxyalkanoate (PHA) production. To date, the Burkholderia sp. has been reported to synthesize 3-hydroxybutyrate, 3-hydroxyvalerate and 3-hydroxy-4-methylvalerate monomers. In this study, the PHA biosynthetic genes of this strain were successfully cloned and characterized. The PHA biosynthetic cluster of this strain consisted of a PHA synthase (phaC), β-ketothiolase (phaA), acetoacetyl-CoA reductase (phaB) and PHA synthesis regulator (phaR). The translated products of these genes revealed identities to corresponding proteins of Burkholderia vietnamiensis (99-100 %) and Cupriavidus necator H16 (63-89%). Heterologous expression of phaCBs conferred PHA synthesis to the PHA-negative Cupriavidus necator PHB¯4, confirming that phaCBs encoded functionally active protein. PHA synthase activity measurements revealed that the crude extracts of C. necator PHB¯4 transformant showed higher synthase activity (243 U/g) compared to that of wild-types Burkholderia sp. (151 U/g) and C. necator H16 (180 U/g). Interestingly, the transformant C. necator PHB¯4 harbouring Burkholderia sp. PHA synthase gene accumulated poly(3-hydroxybutyrate-co-4-hydroxybutyrate) with 4-hydroxybutyrate monomer as high as up to 87 mol% from sodium 4-hydroxybutyrate. The wild type Burkholderia sp. did not have the ability to produce this copolymer.
  2. Lau NS, Furusawa G
    Sci Total Environ, 2024 Feb 20;912:169134.
    PMID: 38070563 DOI: 10.1016/j.scitotenv.2023.169134
    In this study, we present the genome characterization of a novel chitin-degrading strain, KSP-S5-2, and comparative genomics of 33 strains of Cellvibrionaceae. Strain KSP-S5-2 was isolated from mangrove sediment collected in Balik Pulau, Penang, Malaysia, and its 16S rRNA gene sequence showed the highest similarity (95.09%) to Teredinibacter franksiae. Genome-wide analyses including 16S rRNA gene sequence similarity, average nucleotide identity, digital DNA-DNA hybridization, and phylogenomics, suggested that KSP-S5-2 represents a novel species in the family Cellvibrionaceae. The Cellvibrionaceae pan-genome exhibited high genomic variability, with only 1.7% representing the core genome, while the flexible genome showed a notable enrichment of genes related to carbohydrate metabolism and transport pathway. This observation sheds light on the genetic plasticity of the Cellvibrionaceae family and the gene pools that form the basis for the evolution of polysaccharide-degrading capabilities. Comparative analysis of the carbohydrate-active enzymes across Cellvibrionaceae strains revealed that the chitinolytic system is not universally present within the family, as only 18 of the 33 genomes encoded chitinases. Strain KSP-S5-2 displayed an expanded repertoire of chitinolytic enzymes (25 GH18, two GH19 chitinases, and five GH20 β-N-acetylhexosaminidases) but lacked genes for agar, xylan, and pectin degradation, indicating specialized enzymatic machinery focused primarily on chitin degradation. Further, the strain degraded 90% of chitin after 10 days of incubation. In summary, our findings provided insights into strain KSP-S5-2's genomic potential, the genetics of its chitinolytic system, genomic diversity within the Cellvibrionaceae family in terms of polysaccharide degradation, and its application for chitin degradation.
  3. Lau NS, Tsuge T, Sudesh K
    Appl Microbiol Biotechnol, 2011 Mar;89(5):1599-609.
    PMID: 21279348 DOI: 10.1007/s00253-011-3097-6
    Burkholderia sp. synthase has been shown to polymerize 3-hydroxybutyrate (3HB), 3-hydroxyvalerate, and 3-hydroxy-4-pentenoic acid monomers. This study was carried out to evaluate the ability of Burkholderia sp. USM (JCM 15050) and its transformant harboring the polyhydroxyalkanoate (PHA) synthase gene of Aeromonas caviae to incorporate the newly reported 3-hydroxy-4-methylvalerate (3H4MV) monomer. Various culture parameters such as concentrations of nutrient rich medium, fructose and 4-methylvaleric acid as well as harvesting time were manipulated to produce P(3HB-co-3H4MV) with different 3H4MV compositions. The structural properties of PHA containing 3H4MV monomer were investigated by using nuclear magnetic resonance and Fourier transform infrared spectroscopy (FTIR). The relative intensities of the bands at 1,183 and 1,228 cm⁻¹ in the FTIR spectra enabled the rapid detection and differentiation of P(3HB-co-3H4MV) from other types of PHA. In addition, the presence of 3H4MV units in the copolymer was found to considerably lower the melting temperature and enthalpy of fusion values compared with poly(3-hydroxybutyrate) (P(3HB)). The copolymer exhibited higher thermo-degradation temperature but similar molecular weight and polydispersity compared with P(3HB).
  4. Sellvam D, Lau NS, Arip YM
    Trop Life Sci Res, 2018 Mar;29(1):37-50.
    PMID: 29644014 DOI: 10.21315/tlsr2018.29.1.3
    Malaysia is one of the countries that are loaded with mega biodiversity which includes microbial communities. Phages constitute the major component in the microbial communities and yet the numbers of discovered phages are just a minute fraction of its population in the biosphere. Taking into account of a huge numbers of waiting to be discovered phages, a new bacteriophage designated as Escherichia phage YD-2008.s was successfully isolated using Escherichia coli ATCC 11303 as the host. Phage YD-2008.s poses icosahedral head measured at 57nm in diameter with a long non-contractile flexible tail measured at 107nm; proving the phage as one of the members of Siphoviridae family under the order of Caudovirales. Genomic sequence analyses revealed phage YD-2008.s genome as linear dsDNA of 44,613 base pairs with 54.6% G+C content. Sixty-two open reading frames (ORFs) were identified on phage YD-2008.s full genome, using bioinformatics annotation software; Rapid Annotation using Subsystem Technology (RAST). Among the ORFs, twenty-eight of them code for functional proteins. Thirty two are classified as hypothetical proteins and there are two unidentified proteins. Even though majority of the coded putative proteins have high amino acids similarities to phages from the genus Hk578likevirus of the Siphoviridae family, yet phage YD-2008.s stands with its' own distinctiveness. Therefore, this is another new finding to Siphoviridae family as well as to the growing list of viruses in International Committee on Taxonomy of Viruses (ICTV) database.
  5. Wirjon IA, Lau NS, Arip YM
    Intervirology, 2016;59(5-6):243-253.
    PMID: 28384626 DOI: 10.1159/000468987
    OBJECTIVES: Phage pPM_01 was previously isolated from a raw sewage treatment facility located in Batu Maung, Penang, Malaysia, and it was highly lytic against Proteus mirabilis, which causes urinary tract infections in humans. In this paper, we characterize the biology and complete genome sequence of the phage.

    METHODS AND RESULTS: Transmission electron microscopy revealed phage pPM_01 to be a siphovirus (the first reported virus to infect P. mirabilis), with its complete genome sequence successfully determined. The genome was sequenced using Illumina technology and the reads obtained were assembled using CLC Genomic Workbench v.7.0.3. The whole genome contains a total of 58,546 bp of linear double-stranded DNA with a G+C content of 46.9%. Seventy putative genes were identified and annotated using various bioinformatics tools including RAST, Geneious v.R7, National Center for Biotechnology Information (NCBI) BLAST, and tRNAscan-SE-v1.3 Search. Functional clusters of related potential genes were defined (structural, lytic, packaging, replication, modification, and modulatory). The whole genome sequence showed a low similarity to known phages (i.e., Enterobacter phage Enc34 and Enterobacteria phage Chi). Host range determination and SDS-PAGE analysis were also performed.

    CONCLUSIONS: The inability to lysogenize a host, the absence of endotoxin genes in the annotated genome, and the lytic behavior suggest phage pPM_01 as a possible safe biological candidate to control P. mirabilis infection.

  6. Furusawa G, Diyana T, Lau NS
    Genomics, 2022 01;114(1):443-455.
    PMID: 33689784 DOI: 10.1016/j.ygeno.2021.02.024
    Bacterial dormancy plays a crucial role in maintaining the functioning and diversity of microbial communities in natural environments. However, the metabolic regulations of the dormancy of bacteria in natural habitats, especially marine habitats, have remained largely unknown. A marine bacterium, Microbulbifer aggregans CCB-MM1 exhibits rod-to-coccus cell shape change during the dormant state. Therefore, to clarify the metabolic regulation of the dormancy, differential gene expression analysis based on RNA-Seq was performed between rod- (vegetative), intermediate, and coccus-shaped cells (dormancy). The RNA-Seq data revealed that one of two distinct electron transfer chains was upregulated in the dormancy. Dissimilatory sulfite reductase and soluble hydrogenase were also highly upregulated in the dormancy. In addition, induction of the dormancy of MM1 in the absence of MgSO4 was slower than that in the presence of MgSO4. These results indicate that the sulfate-reducing pathway plays an important role in entering the dormancy of MM1.
  7. Azami NA, Lau NS, Furusawa G
    Data Brief, 2022 Dec;45:108597.
    PMID: 36164294 DOI: 10.1016/j.dib.2022.108597
    Bacillus sp. CCB-MMP212 is a Gram-positive bacterium isolated from mangrove sediment in Matang Perak, Malaysia (4.85496°E, 100.73495°N). Genome sequencing was performed using the Oxford Nanopore and Illumina platforms. The assembled genome was annotated using the rapid annotation subsystem technology server (RAST) (rast.nmpdr.org). The genome size of the Bacillus sp. CCB-MMP212 was 6,151,644 base pairs (bp) with a G+C content of 34.75%. The genome includes 6,311 coding sequences and 58 RNAs. The sequence has been deposited at Genbank with the accession number of JALDQE000000000. Interestingly, an arsenic resistance (ars) operon consisted of arsenic resistance operon repressor (arsR), ACR3 family arsenite efflux transporter (arsB), and arsenate reductase (arsC) genes were found in the genome. In addition, the arsenic inducible gene (arsI), which encoded a dioxygenase with C•As lyase activity, was also found in the ars operon. The enzyme is crucial for the methylation of methylarsonous acid [MAs(III)] and trivalent roxarsone [Rox(III)]. This dataset reveals the genetic ability of this strain in arsenic resistance. To the best of our knowledge, the arsI encoding C•As lyase is rarely reported within the genus Bacillus. Therefore, the dataset presented in this manuscript provides further insight into the arsenic resistance mechanisms of the genus Bacillus.
  8. Amrina RA, Furusawa G, Lau NS
    Int J Syst Evol Microbiol, 2021 Nov;71(11).
    PMID: 34752210 DOI: 10.1099/ijsem.0.005087
    A novel rod-shaped, Gram-stain-negative, strictly aerobic and alginate-degrading marine bacterium, designated CCB-QB4T, was isolated from a surface of algal turf collected from a coastal area of Penang, Malaysia. The cells showed motility by a lateral flagellum. The rod-shaped cells formed long chains end-to-end. Phylogenetic analysis based on the 16S rRNA gene sequence of strain CCB-QB4T showed 94.07, 92.69, 91.52 and 90.90 % sequence similarity to Algibacillus agarilyticus RQJ05T, Catenovulum maritimum Q1T, Catenovulum agarivorans YM01T and Catenovulum sediminis D2T, respectively. Strain CCB-QB4T formed a cluster with A. agarilyticus RQJ05T. Strain CCB-QB4T was catalase-negative, oxidase-positive, and degraded agar, alginate, and starch. Cell growth was observed at 15-40 °C, at pH 7.0-10.0 and in the presence of 1-6 % (w/v) NaCl and glucose. The major fatty acids were summed feature 3 (C16 : 1 ω7c/iso-C15 : 0 2-OH), C16 : 0 and C18 : 1 ω7c. The polar lipids were phosphatidylethanolamine, two unidentified aminolipids, two unidentified glycolipids, an unidentified phospholipid and unidentified lipid. The major respiratory quinone was ubiquinone-8. The genomic DNA G+C content was 46.7 mol%. Based on the phenotypic, chemotaxonomic and phylogenetic data, strain CCB-BQ4T represents a novel species in a new genus, for which the name Saccharobesus litoralis gen. nov., sp. nov. is proposed. The type strain is CCB-QB4T (=JCM 33513T=CCB-MBL 5008T).
  9. Heng WL, Lau NS, Furusawa G
    Microbiol Resour Announc, 2023 Sep 19;12(9):e0044123.
    PMID: 37589468 DOI: 10.1128/MRA.00441-23
    Here, we report the complete genome sequence of a type strain of the genus Saprospira, Saprospira grandis strain WHT. The genome consists of one circular chromosome and plasmid comprising 4,250,550 bp and 53,161 bp with GC content of 46.6% and 46.8%, respectively.
  10. Lau NS, Matsui M, Abdullah AA
    Biomed Res Int, 2015;2015:754934.
    PMID: 26199945 DOI: 10.1155/2015/754934
    Cyanobacteria are widely distributed Gram-negative bacteria with a long evolutionary history and the only prokaryotes that perform plant-like oxygenic photosynthesis. Cyanobacteria possess several advantages as hosts for biotechnological applications, including simple growth requirements, ease of genetic manipulation, and attractive platforms for carbon neutral production process. The use of photosynthetic cyanobacteria to directly convert carbon dioxide to biofuels is an emerging area of interest. Equipped with the ability to degrade environmental pollutants and remove heavy metals, cyanobacteria are promising tools for bioremediation and wastewater treatment. Cyanobacteria are characterized by the ability to produce a spectrum of bioactive compounds with antibacterial, antifungal, antiviral, and antialgal properties that are of pharmaceutical and agricultural significance. Several strains of cyanobacteria are also sources of high-value chemicals, for example, pigments, vitamins, and enzymes. Recent advances in biotechnological approaches have facilitated researches directed towards maximizing the production of desired products in cyanobacteria and realizing the potential of these bacteria for various industrial applications. In this review, the potential of cyanobacteria as sources of energy, bioactive compounds, high-value chemicals, and tools for aquatic bioremediation and recent progress in engineering cyanobacteria for these bioindustrial applications are discussed.
  11. Lau NS, Foong CP, Kurihara Y, Sudesh K, Matsui M
    PLoS One, 2014;9(1):e86368.
    PMID: 24466058 DOI: 10.1371/journal.pone.0086368
    The photosynthetic cyanobacterium, Synechocystis sp. strain 6803, is a potential platform for the production of various chemicals and biofuels. In this study, direct photosynthetic production of a biopolymer, polyhydroxyalkanoate (PHA), in genetically engineered Synechocystis sp. achieved as high as 14 wt%. This is the highest production reported in Synechocystis sp. under photoautotrophic cultivation conditions without the addition of a carbon source. The addition of acetate increased PHA accumulation to 41 wt%, and this value is comparable to the highest production obtained with cyanobacteria. Transcriptome analysis by RNA-seq coupled with real-time PCR was performed to understand the global changes in transcript levels of cells subjected to conditions suitable for photoautotrophic PHA biosynthesis. There was lower expression of most PHA synthesis-related genes in recombinant Synechocystis sp. with higher PHA accumulation suggesting that the concentration of these enzymes is not the limiting factor to achieving high PHA accumulation. In order to cope with the higher PHA production, cells may utilize enhanced photosynthesis to drive the product formation. Results from this study suggest that the total flux of carbon is the possible driving force for the biosynthesis of PHA and the polymerizing enzyme, PHA synthase, is not the only critical factor affecting PHA-synthesis. Knowledge of the regulation or control points of the biopolymer production pathways will facilitate the further use of cyanobacteria for biotechnological applications.
  12. Chee JY, Lau NS, Samian MR, Tsuge T, Sudesh K
    J Appl Microbiol, 2012 Jan;112(1):45-54.
    PMID: 22054430 DOI: 10.1111/j.1365-2672.2011.05189.x
    Burkholderia sp. USM (JCM15050) isolated from oil-polluted wastewater is capable of utilizing palm oil products and glycerol to synthesize poly(3-hydroxybutyrate) [P(3HB)]. To confer the ability to produce polymer containing 3-hydroxyhexanoate (3HHx), plasmid (pBBREE32d13) harbouring the polyhydroxyalkanoate (PHA) synthase gene of Aeromonas caviae (phaC(Ac)) was transformed into this strain.
  13. Lau NS, Chee JY, Tsuge T, Sudesh K
    Bioresour Technol, 2010 Oct;101(20):7916-23.
    PMID: 20541932 DOI: 10.1016/j.biortech.2010.05.049
    We attempted to synthesize a polyhydroxyalkanoate (PHA) containing newly reported 3-hydroxy-4-methylvalerate (3H4MV) monomer by using wild type Burkholderia sp. USM (JCM15050) and its transformed strain harboring the PHA synthase gene of Aeromonas caviae (phaCAc). The introduction of 3H4MV as a second monomer will improve the material properties of 3HB-based polymers. To promote the accumulation of PHA containing 3H4MV monomer, isocaproic acid was provided as co-carbon source. Approximately 1mol% of 3H4MV was detected in wild type Burkholderia sp. cultures when they were fed glucose or fructose together with isocaproic acid. Thus, the wild type strain can synthesize the 3H4MV monomer. High 3H4MV fractions, of about 40mol%, were obtained when the transformed strain was cultivated on glucose or fructose together with isocaproic acid. In addition, the ability of the transformed strain to mobilize accumulated PHA containing 3H4MV monomer was demonstrated in this study. This is the first report on mobilization of the 3H4MV monomer.
  14. Furusawa G, Lau NS, Suganthi A, Amirul AA
    Microbiologyopen, 2017 02;6(1).
    PMID: 27987272 DOI: 10.1002/mbo3.405
    The agarolytic bacterium Persicobacter sp. CCB-QB2 was isolated from seaweed (genus Ulva) collected from a coastal area of Malaysia. Here, we report a high-quality draft genome sequence for QB2. The Rapid Annotation using Subsystem Technology (RAST) annotation server identified four β-agarases (PdAgaA, PdAgaB, PdAgaC, and PdAgaD) as well as galK, galE, and phosphoglucomutase, which are related to the Leloir pathway. Interestingly, QB2 exhibited a diauxic growth in the presence of two kinds of nutrients, such as tryptone and agar. In cells grown with agar, the profiles of agarase activity and growth rate were very similar. galK, galE, and phosphoglucomutase genes were highly expressed in the second growth phase of diauxic growth, indicating that QB2 cells use galactose hydrolyzed from agar by its agarases and exhibit nutrient prioritization. This is the first report describing diauxic growth for agarolytic bacteria. QB2 is a potential novel model organism for studying diauxic growth in environmental bacteria.
  15. Amelia TSM, Lau NS, Amirul AA, Bhubalan K
    Data Brief, 2020 Aug;31:105971.
    PMID: 32685631 DOI: 10.1016/j.dib.2020.105971
    Marine sponges are acknowledged as a bacterial hotspot and resource of novel natural products or genetic material with industrial or commercial potential. However, sponge-associated bacteria are difficult to be cultivated and the production of their desirable metabolites is inadequate in terms of rate and quantity, yet bioinformatics and metagenomics tools are steadily progressing. Bacterial diversity profiles of high-microbial-abundance wild tropical marine sponges Aaptos aaptos and Xestospongia muta were obtained by sample collection at Pulau Bidong and Pulau Redang islands, 16S rRNA amplicon sequencing on Illumina HiSeq2500 platform (250 bp paired-end) and metagenomics analysis using Ribosomal Database Project (RDP) classifier. Raw sequencing data in fastq format and relative abundance histograms of the dominant 10 species are available in the public repository Discover Mendeley Data (http://dx.doi.org/10.17632/zrcks5s8xp). Filtered sequencing data of operational taxonomic unit (OTU) with chimera removed is available in NCBI accession numbers from MT464469 to MT465036.
  16. Sam KK, Lau NS, Furusawa G, Amirul AA
    Microbiol Resour Announc, 2019 Nov 14;8(46).
    PMID: 31727719 DOI: 10.1128/MRA.01248-19
    Pararhodobacter-like strain CCB-MM2 is a halophilic alphaproteobacterium isolated from estuarine sediment collected from Matang Mangrove Forest in Malaysia. Here, we present the draft genome sequence of CCB-MM2 and provide insights into its physiological roles and metabolic potential.
  17. Lau NS, Sam KK, Amirul AA
    Stand Genomic Sci, 2017;12:12.
    PMID: 28138356 DOI: 10.1186/s40793-017-0232-8
    Yangia sp. CCB-MM3 was one of several halophilic bacteria isolated from soil sediment in the estuarine Matang Mangrove, Malaysia. So far, no member from the genus Yangia, a member of the Rhodobacteraceae family, has been reported sequenced. In the current study, we present the first complete genome sequence of Yangia sp. strain CCB-MM3. The genome includes two chromosomes and five plasmids with a total length of 5,522,061 bp and an average GC content of 65%. Since a different strain of Yangia sp. (ND199) was reported to produce a polyhydroxyalkanoate copolymer, the ability for this production was tested in vitro and confirmed for strain CCB-MM3. Analysis of its genome sequence confirmed presence of a pathway for production of propionyl-CoA and gene cluster for PHA production in the sequenced strain. The genome sequence described will be a useful resource for understanding the physiology and metabolic potential of Yangia as well as for comparative genomic analysis with other Rhodobacteraceae.
  18. Shafie NA, Lau NS, Ramachandran H, Amirul AA
    Genome Announc, 2017 Jan 19;5(3).
    PMID: 28104662 DOI: 10.1128/genomeA.01498-16
    Cupriavidus sp. USMAA1020, USMAA2-4, and USMAHM13 are capable of producing polyhydroxyalkanoate (PHA). This biopolymer is an alternative solution to synthetic plastics, whereby polyhydroxyalkanoate synthase is the key enzyme involved in PHA biosynthesis. Here, we report the complete genomes of three Cupriavidus sp. strains: USMAA1020, USMAA2-4, and USMAHM13.
  19. Dang CC, Guan YK, Lau NS, Chan SY
    J Oncol Pharm Pract, 2020 Dec;26(8):2034-2037.
    PMID: 32279594 DOI: 10.1177/1078155220915764
    INTRODUCTION: Acute promyelocytic leukemia is an oncologic emergency. The limited cases reported in the literature have led to poor understanding of the safety of management of acute promyelocytic leukemia during pregnancy.

    CASE REPORT: Herein is an acute promyelocytic leukemia case of a 22-year-old young pregnant woman who had various social problems. The patient was diagnosed with acute promyelocytic leukemia in her the second trimester of her first pregnancy.Management and outcome: She was treated with all-trans-retinoic acid with idarubicin and successfully delivered a healthy baby. She completed induction with idarubicin but defaulted her all-trans-retinoic acid, 6-mercaptopurine and methotrexate maintenance. She relapsed after one year and was salvaged with all-trans-retinoic acid high dose cytarabine and arsenic trioxide. She went into remission and had autologous stem cells collected and was planned for an autologous stem cell transplant but she defaulted. She relapsed when she was pregnant with her second baby during her third trimester (29+weeks) 10 months later. Salvage chemotherapy with arsenic trioxide, all-trans-retinoic acid and idarubicin was given. Patient underwent an emergency lower segment caesarian section at 31 weeks of pregnancy due to abnormal fetal cardiotocography. A healthy baby was delivered.

    DISCUSSION: This drug regimen is controversial during pregnancy owing to the teratogenic effects and fatal retinoic acid syndrome especially in early gestation. In this case, patient was started the induction therapy of all-trans-retinoic acid treatment at her second trimester during her first pregnancy.

    CONCLUSION: Our lady demonstrated the possibility of using all-trans-retinoic acid and arsenic trioxide and chemotherapy during second and third trimester with successful pregnancy outcomes.

  20. Sam KK, Lau NS, Furusawa G, Amirul AA
    Genome Announc, 2017 Oct 19;5(42).
    PMID: 29051257 DOI: 10.1128/genomeA.01147-17
    Hahella sp. strain CCB-MM4 is a halophilic bacterium isolated from estuarine mangrove sediment. The genome sequence of Hahella sp. CCB-MM4 provides insights into exopolysaccharide biosynthesis and the lifestyle of the bacterium thriving in a saline mangrove environment.
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