22 research outputs found
Report on industrial attachment with Jurong Consultants Pte Ltd
No full textThis Industrial Attachment Report serves to provide a concise and vivid account of the exposure the author gained during the 22-week Industrial Attachment at JURONG Consultants Pte Ltd,Marine and Infrastructure department. The author's job scope focused primarily on the planning and design aspects of engineering work. The work nature was highly relevant to her field of study in Civil and Environmental Engineering as it ranges from structural design in the civil engineering aspects to bioswale design and feasibility studies of water sustainability in the environmental engineering aspects. During the attachment, the author gained valuable knowledge through active participation and inquisitive learning. She learnt to build to good rapport with her colleagues and trained herself to communicate confidently with authorities and contractors. In conclusion, this Industrial Attachment had highly supplemented the author's insights in the engineering world. It was undoubtedly a beneficial and educating experience for the author
Toxicity of PCB 105 in the rat liver: an ultrastructural and biochemical study
No full textPCB 105 (2,3,3',4,4'-pentachlorobiphenyl) congener was fed to weanling Sprague-Dawley rats in a diet combined with 4% corn oil. The animals were distributed randomly into 10 groups, each of which contained 10 males and 10 females, and rats in 8 groups received diets containing PCB at concentrations of 0.05, 0.5, 5, and 50 ppm. Animals in the other 2 groups served as controls. After 13 weeks, the animals were humanely killed and liver samples were obtained and prepared for transmission electron microscopy. Ultrastructural alterations revealed in the hepatocytes of animals fed the PCB included smooth endoplasmic reticulum proliferation, atypical mitochondrial cristae, and augmentation of peroxisome numbers (in animals fed high PCB concentrations). Biochemical alterations were estimated by using hepatic microsomal pentoxyresorufin-O-dealkylase (PROD) and ethoxyresorufin-O-deethylase (EROD) activities. A dose-dependent increase in EROD and PROD activities was discovered; only in the animals of highest PCB dose group, however, was EROD found to be significant (p < .05). Based on our previous work, this congener is relatively less toxic than PCB 126, 118, and 153 and is similar in toxicity to 156.PT: J; CR: BICKERS DR, 1972, RES COMMUN PATHOL PH, V3, P505 BURKE MD, 1985, BIOCHEM PHARMACOL, V34, P3337 CHEVILLE NF, 1994, ULTRASTRUCT PATHOL, P40 CHU I, 1995, FUND APPL TOXICOL, V26, P282 CHU I, 1996, J APPL TOXICOL, V16, P121 CHUI YC, 1985, TOXICOL APPL PHARM, V81, P287 CUERVO AM, 1996, SCIENCE, V273, P501 FAWCETT DW, 1994, TXB HISTOLOGY, P23 FISHBEIN L, 1974, ANNU REV PHARMACOL, V14, P139 GHADIALLY FN, 1988, ULTRASTRUCT PATHOL, V1, P192 GILLETTE DM, 1987, FUND APPL TOXICOL, V8, P5 GRANT DL, 1971, B ENVIRON CONTAM TOX, V6, P120 GREENE WB, 1973, PESTICIDES ENV CONTI, P137 HANSELL MM, 1974, TOXICOL APPL PHARM, V28, P418 HARRIS C, 1984, ARCH ENVIRON CON TOX, V13, P715 JONSSON HT, 1981, ARCH ENV CONTAM TOXI, V10, P171 KASZA L, 1976, J TOXICOL ENV HLTH, V1, P689 KASZA L, 1978, J ENVIRON PATHOL TOX, V1, P241 KIMBROUGH RD, 1972, ARCH ENVIRON HEALTH, V25, P354 KIMBROUGH RD, 1987, ANNU REV PHARMACOL, V27, P87 LIN FS, 1979, ARCH ENV CONTAM TOXI, V8, P321 LODISH H, 1995, MOL CELL BIOL, P173 LUBET RA, 1985, MUTAT RES, V142, P127 MACLELLAN K, 1994, HISTOL HISTOPATHOL, V9, P453 MACLELLAN K, 1994, HISTOL HISTOPATHOL, V9, P461 MACLELLAN K, 1994, J SUBMICR CYTOL PATH, V26, P279 MASTERS C, 1995, PEROXISONE VITAL ORG, V2, P203 NISHIHARA Y, 1985, BRIT J IND MED, V42, P128 NISHIHARA Y, 1986, BIOCHEM PHARMACOL, V35, P3335 NISHIZUMI M, 1970, ARCH ENVIRON HEALTH, V21, P620 NORBACK DH, 1972, ENVIRON HEALTH PERSP, V1, P137 PENG J, 1995, MICROSCOPY MICROANAL, P994 PENG J, 1995, THESIS U EDWARD ISLA RAO MS, 1991, HEPATOTOXICOLOGY, P621 RENDER JA, 1982, TOXICOL APPL PHARM, V62, P428 SAFE S, 1984, CRC CRIT R TOXICOL, V13, P319 SAFE SH, 1994, CRIT REV TOXICOL, V24, P87 SATO T, 1968, J ELECTRON MICROSC, V17, P158 SCHECTER A, 1984, BANBURY REPORT, V18, P177 SCHECTER A, 1985, ENVIRON HEALTH PERSP, V60, P241 SEGLEN PO, 1992, EXPERIENTIA, V48, P158 SINGH A, 1981, PATHOLOGY, V13, P487 SINGH A, 1996, ULTRASTRUCT PATHOL, V20, P275 STAUBLI W, 1969, J CELL BIOL, V42, P92 VOS JG, 1972, TOXICOL APPL PHARM, V23, P536 WEISS L, 1988, TISSUE BIOL TXB HIST, P1; NR: 46; TC: 4; J9: ULTRASTRUCT PATHOL; PG: 9; GA: WP181Source type: Prin
Complete genome sequence data of an Antarctic bacterium Arthrobacter sp. EM1 from the freshwater lake of the King George Island
No full textArthrobacter sp. EM1 is a cold-adapted bacterium isolated from the Antarctic region, which was known to exhibit mannan-degrading activity. Accordingly, this strain not only promises a cell factory for mannan-degrading enzymes, widely used in industry but also serves as a model organism to decipher its cold adaptation mechanism. Accordingly, whole genome sequencing of the EM1 strain was performed via Single Molecule Real Time sequencing under the PacBio platform, followed by genome HGAP de novo assembly and genome annotation through Rapid Annotation System Technology (RAST) server. The chromosome of this strain is 3,885,750 bp in size with a GC content of 65.8. The annotation predicted a total of 3607 protein-coding genes and 65 RNA genes, which were classified under 398 subsystems. The subsystem with the highest number of genes is carbohydrate metabolism (397 genes), which includes two genes encoding mannan-degrading enzymes (endoglucanase and α-mannosidase). This confirmed that the EM1 strain is able to produce cold-adapted mannan degrading enzymes. The complete genome sequence data have been submitted to the National Center for Biotechnology Information (NCBI) and have been deposited at GenBank (Bioproject ID Accession Number: PRJNA963062; Biosample ID Accession Number: SAMN34434776; GenBank: CP124836.1; https://www.ncbi.nlm.nih.gov/nuccore/CP124836)
Characterisation Of an Antarctic Yeast, Glaciozyma Antarctica PI12
No full textGlaciozyma antarctica PI12 is a psychrophilic yeast isolated from Antarctica. It has an optimal growth in yeast peptone dextrose (YPD) and yeast mould (YM) broth media but not in potato dextrose (PD) broth medium. Early phase G. antarctica PI12 cells had elongated-shape and became oval-shaped as they aged. G. antarctica PI12 exhibited bipolar budding and formed a chain of cells during the lag and early exponential phases. The number of chains decreased as the yeast aged. It appeared mainly as a single cell at the stationary phase, and a small number of them still produced buds. Some cells at the stationary phase entered the quiescence state (G0) as a long-term survival strategy. The G. antarctica PI12 cell size decreased when they entered the stationary phase. G. antarctica PI12 was found to produce hydrolytic enzymes, chitinase, cellulase, mannanase, and xylanase. A higher glucose concentration of 2% in the PD agar medium inhibited the activities of chitinase but not the cellulase, mananase and xylanase
Genomic Analysis of a Novel Antarctic Bacterium, Cryobacterium sp. SO2 Provides Insights into its Genomic Potential for Production of Antimicrobial Compounds
No full textA novel strain of Cryobacterium designated as SO2, was isolated from the Antarctic. Hence, this study was undertaken to gain further insight into the antimicrobial compounds and secondary metabolites produced by Cryobacterium sp. SO2. It was found that strain SO2 is a Gram-positive that exhibits an irregular rod shape, which formed yellow to orange pigmented colonies on semi-solid media. Strain SO2 grows at temperatures ranging from 4 to 25 ºC. It has a complete genomic size of 4.097 Mb. SO2 has a DNA G+C content of 68.43%, and genomic annotation showed that the genome contained 3,862 CDS, 10 rRNA, 55 tRNA and 1 tm-RNA. Phylogenetic and OrthoANI analysis suggested Cryobacterium sp. strains SO1, N22, TMB1-8, LW097, TMN39-1, C. zongtaii TMN-42, C. arcticum PAMC27867 and C. soli GCJ02 as its closest phylogenetic neighbour. Genome annotation shows that strain SO2 confers β-lactamase class A, cephalosporin-C deacetylases, and 27 drug-resistance or efflux coding genes, and allows resistance to ceftazidime. Functional annotation identifies 28.74% of predicted genes are of unknown functions. Genome mining indicates that there are six putative secondary metabolite gene clusters in strain SO2. They are made up of RRE-containing, terpene, beta-lactone, T3PKS, NAPAA, and 2dos. This finding shows strain SO2 harbours genes that may be involved in the production of compounds with antibacterial and antioxidant activities
Microbial Resilience: Navigating Growth Challenges in Cold Environments
No full textThe 15th Symposium on Polar Science/Ordinary sessions [OB] Polar biology, Wed. 4 Dec. / 3F Conference room, The Institute of Statistical Mathematicsconference outpu
Isolation and characterization of Antarctic actinobacteria with antimicrobial activities
No full textThe 15th Symposium on Polar Science/Ordinary sessions [OB] Polar biology, Wed. 4 Dec. / 3F Conference room, The Institute of Statistical Mathematicsconference outpu
Whole genome sequence data of an Antarctic bacterium, Arthrobacter sp. ES1 from the Schirmacher Oasis, East Antarctica
No full textArthrobacter is a coryneform bacterium in the family of Micrococcaceae. Arthrobacter species isolated from hostile environments are capable of producing interesting bioactive compounds, some of which may be a new class of antibiotics. Here, we present the complete genome sequence of Arthrobacter sp. ES1 isolated from Schirmacher Oasis in East Antarctica. Genomic DNA sequencing was performed using the Illumina MiSeq sequencer. Arthrobacter sp. ES1 has a genome size of 3,964,927 bp and a GC content of 65.73%. The raw genome sequences have been deposited in the NCBI Sequence Read Archive database under the accession number, SRR20664316
Draft genome sequence of Flavobacterium sp. strain PL002, isolated from Antarctic Porphyra algae
No full textHere, we report the draft genome sequence of Flavobacterium sp. strain PL002, isolated from Antarctic Porphyra algae. The 4,299,965-bp genome sequence is assembled into 170 contigs, has 32.92% GC content, and 3,734 predicted genes
Antarctic spore-forming microorganisms from deception island inhibit the growth of various bacterial strains
No full textAntarctic microbes have evolved and adapted unique strategies to survive in the harsh polar environment. Apart from the ability to adapt to the low nutrient soil content and extremely dry and cold polar environment, a particular strategy used by Antarctic bacteria is the production of antimicrobial compounds that can eliminate rivals in the same niche, giving them a competitive edge over other microbes. In contrast, it is unclear whether spore-forming microbes possess similar antimicrobial properties as one of their survival strategies, especially those from the Antarctic volcanic Deception island in the West Antarctic. Hence, this study aims to isolate and characterize the spore-forming microbes in Deception Island, Antarctica, as well as to identify the ones that are equipped with the ability to inhibit other microorganisms. Microbes were isolated using various growth media and were segregated into clusters based on their random amplified polymorphic DNA (RAPD) fingerprints. A total of 90 strains were isolated and clustered into 30 groups at a similarity of 60%. Representative strains from each cluster were assayed for antimicrobial activities against 13 Gram-positive and Gram-negative test bacteria comprising human pathogens. Twenty-five strains exhibited the ability to inhibit at least one test bacterium. The four strains, A60, Im31, Im32 and Im33 that showed the strongest inhibitory activities were subjected to 16S or 18S rDNA sequencing and analysis to identify them. They were identified as Pseudogymnoascus, Bacillus, Leohumicola, and Talaromyces spp. The ability of the aforementioned microbes to thrive in harsh environments and compete with fierce competitors for scarce nutrients is probably due to their ability to produce antimicrobial compounds that target and kill their rivals
