MyMedR

Displaying all 10 publications

Abstract:

Sort:

Draft genome sequence of a marine actinobacteria Sciscionella strain SE31

Teo WF, Wee WY, Choo SW, Tan GY

Mar Genomics, 2015 Apr;20:11-2.
PMID: 25554669 DOI: 10.1016/j.margen.2014.12.006

The bacterium strain SE31, a member of the genus Sciscionella, was isolated from intertidal sediments collected from Cape Rachado, Malaysia. The high quality draft genome sequence of Sciscionella strain SE31 with a genome size of approximately 7.4 Mbp is reported. Preliminary analysis revealed 46 putative gene clusters involved in the biosynthesis of secondary metabolites and 113 putative genes that are associated with bacterial virulence, disease and defense. Availability of the genome sequence of Sciscionella SE31 will contribute to a better understanding of the genus Sciscionella.
Effect of biofilm formation on the performance of microbial fuel cell for the treatment of palm oil mill effluent

Baranitharan E, Khan MR, Prasad DM, Teo WF, Tan GY, Jose R

Bioprocess Biosyst Eng, 2015 Jan;38(1):15-24.
PMID: 24981021 DOI: 10.1007/s00449-014-1239-9

Anode biofilm is a crucial component in microbial fuel cells (MFCs) for electrogenesis. Better knowledge about the biofilm development process on electrode surface is believed to improve MFC performance. In this study, double-chamber microbial fuel cell was operated with diluted POME (initial COD = 1,000 mg L(-1)) and polyacrylonitrile carbon felt was used as electrode. The maximum power density, COD removal efficiency and Coulombic efficiency were found as 22 mW m(-2), 70 and 24 %, respectively. FTIR and TGA analysis confirmed the formation of biofilm on the electrode surface during MFC operation. The impact of anode biofilm on anodic polarization resistance was investigated using electrochemical impedance spectroscopy (EIS) and microbial community changes during MFC operation using denaturing gradient gel electrophoresis (DGGE). The EIS-simulated results showed the reduction of charge transfer resistance (R ct) by 16.9 % after 14 days of operation of the cell, which confirms that the development of the microbial biofilm on the anode decreases the R ct and therefore improves power generation. DGGE analysis showed the variation in the biofilm composition during the biofilm growth until it forms an initial stable microbial community, thereafter the change in the diversity would be less. The power density showed was directly dependent on the biofilm development and increased significantly during the initial biofilm development period. Furthermore, DGGE patterns obtained from 7th and 14th day suggest the presence of less diversity and probable functional redundancy within the anodic communities possibly responsible for the stable MFC performance in changing environmental conditions.
Fulltext Microbial diversity of thermophiles with biomass deconstruction potential in a foliage-rich hot spring

Lee LS, Goh KM, Chan CS, Annie Tan GY, Yin WF, Chong CS, et al.

Microbiologyopen, 2018 12;7(6):e00615.
PMID: 29602271 DOI: 10.1002/mbo3.615

The ability of thermophilic microorganisms and their enzymes to decompose biomass have attracted attention due to their quick reaction time, thermostability, and decreased risk of contamination. Exploitation of efficient thermostable glycoside hydrolases (GHs) could accelerate the industrialization of biofuels and biochemicals. However, the full spectrum of thermophiles and their enzymes that are important for biomass degradation at high temperatures have not yet been thoroughly studied. We examined a Malaysian Y-shaped Sungai Klah hot spring located within a wooded area. The fallen foliage that formed a thick layer of biomass bed under the heated water of the Y-shaped Sungai Klah hot spring was an ideal environment for the discovery and analysis of microbial biomass decay communities. We sequenced the hypervariable regions of bacterial and archaeal 16S rRNA genes using total community DNA extracted from the hot spring. Data suggested that 25 phyla, 58 classes, 110 orders, 171 families, and 328 genera inhabited this hot spring. Among the detected genera, members of Acidimicrobium, Aeropyrum, Caldilinea, Caldisphaera, Chloracidobacterium, Chloroflexus, Desulfurobacterium, Fervidobacterium, Geobacillus, Meiothermus, Melioribacter, Methanothermococcus, Methanotorris, Roseiflexus, Thermoanaerobacter, Thermoanaerobacterium, Thermoanaerobaculum, and Thermosipho were the main thermophiles containing various GHs that play an important role in cellulose and hemicellulose breakdown. Collectively, the results suggest that the microbial community in this hot spring represents a good source for isolating efficient biomass degrading thermophiles and thermozymes.
Streptomyces sanglieri which colonised and enhanced the growth of Elaeis guineensis Jacq. seedlings was antagonistic to Ganoderma boninense in in vitro studies

Nur Azura AB, Yusoff M, Tan GY, Jegadeesh R, Appleton DR, Vikineswary S

J Ind Microbiol Biotechnol, 2016 Apr;43(4):485-93.
PMID: 26721619 DOI: 10.1007/s10295-015-1724-4

Actinomycete strain AUM 00500 was 99.5 % similar to Streptomyces sanglieri NBRC 100784(T) and was evaluated for antagonistic activity towards Ganoderma boninense, the causative fungus of basal stem rot of oil palm. The strain showed strong antifungal activity towards G. boninense in in vitro and SEM analysis showed various modes of inhibition of the fungus. Ethyl acetate extracts of single culture and inhibition zone of cross-plug culture by HPLC indicated that strain AUM 00500 produced two different antibiotics of the glutarimide group namely cycloheximide and actiphenol. In greenhouse trials, oil palm seed treated with spores of S. sanglieri strain AUM 00500 at 10(9) cfu/ml showed significant (P
Surfactant as an Additive for the Recovery of Potent Antioxidants from Garcinia mangostana Pericarps Using a Polymer/Salt Aqueous Biphasic System

Ng HS, Kee PE, Tan GY, Yim HS, Lan JC

Appl Biochem Biotechnol, 2020 May;191(1):273-283.
PMID: 32335865 DOI: 10.1007/s12010-020-03284-z

Garcinia mangostana pericarp is a good source of natural antioxidants with numerous functional properties. The conventional approaches for the recovery of antioxidants from Garcinia mangostana pericarp require long processing time and high temperature, which may cause degradation or loss of bioactivity of antioxidants, and often result in low recovery efficiency. In this study, the extraction of antioxidants from Garcinia mangostana pericarp was investigated using a polyethylene glycol (PEG)/citrate aqueous biphasic system (ABS) with the addition of surfactants. The optimum condition for the recovery of antioxidants was achieved in PEG 1000/citrate ABS of pH 8 with tie-line length (TLL) of 48.3% (w/w), volume ratio (VR) of 1.6, 0.2% (w/w) sample loading and addition of 1.0% (w/w) Tween 85. The antioxidants were recovered in the PEG-rich top phase with a high K value of 18.23 ± 0.33 and a recovery yield of 92.01% ± 0.09. The findings suggested that the addition of surfactants to polymer/salt ABS can enhance the recovery of antioxidants from Garcinia mangostana pericarps by conserving the antioxidative properties.
Fulltext Examination Approaches to Brachial Plexus Injury for Neurosurgical Residents

Saleh U, Tan GY, Fuad M, Abdullah JM, Idris Z, Ghani ARI, et al.

Malays J Med Sci, 2023 Dec;30(6):61-69.
PMID: 38239251 DOI: 10.21315/mjms2023.30.6.7

BACKGROUND: Brachial plexus injury is a severe peripheral nerve injury that affects the upper extremities and causes functional damage and disability. A detailed and accurate clinical examination is required to accurately localise the site of injury. This video manuscript aims to provide guidelines for the structured assessment of a patient with brachial plexus injury, specifically tailored to Malaysian medical students and trainees.
METHODS: A video demonstrating the examination of the brachial plexus was made. This video, created at the School of Medical Sciences at Universiti Sains Malaysia (USM), demonstrates the proper examination technique for brachial plexus.
CONCLUSION: We hope that this video will help students and young doctors evaluate patients with brachial plexus injury and reach accurate localisation of the injury.
Langkocyclines: novel angucycline antibiotics from Streptomyces sp. Acta 3034(*)

Kalyon B, Tan GY, Pinto JM, Foo CY, Wiese J, Imhoff JF, et al.

J Antibiot (Tokyo), 2013 Oct;66(10):609-16.
PMID: 23820614 DOI: 10.1038/ja.2013.53

Langkocyclines A1-A3 and B1 and B2, five new angucycline antibiotics produced by Streptomyces sp. Acta 3034, were detected in the course of our HPLC-diode array screening. The producing strain was isolated from the rhizospheric soil of a Clitorea sp. collected from Burau Bay, Langkawi, Malaysia, and was characterized by morphological, physiological and chemotaxonomic features in addition to 16S ribosomal RNA gene sequence information. Strain Acta 3034 is closely related to Streptomyces psammoticus NBRC 13971(T) and Streptomyces lanatus NBRC 12787(T). Langkocyclines consist of an angular tetracyclic benz[a]anthracene skeleton and hydrolyzable O-glycosidic sugar moieties. The yellow-colored A-type langkocyclines differ in their aglycon from the blue-lilac-colored B-type langkocyclines. The A-type langkocycline aglycon is identical to that of aquayamycin and urdamycin A. The chemical structures of the langkocyclines were elucidated by HR-MS, 1D and 2D NMR experiments. They are biologically active against Gram-positive bacteria and exhibit a moderate antiproliferative activity against various human tumor cell lines.
Langkolide, a 32-membered macrolactone antibiotic produced by Streptomyces sp. Acta 3062

Helaly SE, Kulik A, Zinecker H, Ramachandaran K, Tan GY, Imhoff JF, et al.

J Nat Prod, 2012 Jun 22;75(6):1018-24.
PMID: 22642587 DOI: 10.1021/np200580g

A new 32-membered macrolactone antibiotic, named langkolide, was isolated from the mycelium of Streptomyces sp. Acta 3062. The langkolide structure was determined by HR-MS and 1D and 2D NMR as a 32-membered macrolactone connected from an overhanging polyketide tail to a naphthoquinone unit mediated by two carbohydrate moieties. The producing strain was isolated from a rhizosphere soil of Clitorea sp. collected at Burau Bay, Langkawi, Malaysia, and was characterized by its morphological and chemotaxonomic features in addition to its 16S rRNA gene sequence. It was identified as a member of the Streptomyces galbus clade. Langkolide exhibited various bioactivities including antimicrobial and antiproliferative activities. Furthermore, langkolide inhibited human recombinant phosphodiesterase 4 with an IC(50) value of 0.48 μM.
Classification of thermophilic actinobacteria isolated from arid desert soils, including the description of Amycolatopsis deserti sp. nov

Busarakam K, Brown R, Bull AT, Tan GY, Zucchi TD, da Silva LJ, et al.

Antonie Van Leeuwenhoek, 2016 Feb;109(2):319-34.
PMID: 26809280 DOI: 10.1007/s10482-015-0635-8

The taxonomic position of 26 filamentous actinobacteria isolated from a hyper-arid Atacama Desert soil and 2 from an arid Australian composite soil was established using a polyphasic approach. All of the isolates gave the diagnostic amplification product using 16S rRNA oligonucleotide primers specific for the genus Amycolatopsis. Representative isolates had chemotaxonomic and morphological properties typical of members of the genus Amycolatopsis. 16S rRNA gene analyses showed that all of the isolates belong to the Amycolatopsis methanolica 16S rRNA gene clade. The Atacama Desert isolates were assigned to one or other of two recognised species, namely Amycolatopsis ruanii and Amycolatopsis thermalba, based on 16S rRNA gene sequence, DNA:DNA relatedness and phenotypic data; emended descriptions are given for these species. In contrast, the two strains from the arid Australian composite soil, isolates GY024(T) and GY142, formed a distinct branch at the periphery of the A. methanolica 16S rRNA phyletic line, a taxon that was supported by all of the tree-making algorithms and by a 100 % bootstrap value. These strains shared a high degree of DNA:DNA relatedness and have many phenotypic properties in common, some of which distinguished them from all of the constituent species classified in the A. methanolica 16S rRNA clade. Isolates GY024(T) and GY142 merit recognition as a new species within the A. methanolica group of thermophilic strains. The name proposed for the new species is Amycolatopsis deserti sp. nov.; the type strain is GY024(T) (=NCIMB 14972(T) = NRRL B-65266(T)).
Fulltext Pain as a Guide in Glasgow Coma Scale Status for Neurological Assessment

Nallaluthan V, Tan GY, Murni MF, Saleh U, Abdul Halim S, Idris Z, et al.

Malays J Med Sci, 2023 Oct;30(5):221-235.
PMID: 37928790 DOI: 10.21315/mjms2023.30.5.18

Neurological status is essential and often challenging for neurosurgical residents and also for neurosurgeons to determine surgical management. Pain as a component of the Glasgow Coma Scale (GCS) can be used as a tool in patients, especially an unconscious or comatose patient. In order to elicit this adequate noxious stimulus, a certain amount of pressure-pain threshold is required upon performing either as the central or peripheral technique. The scientific explanation behind each technique is required and needs to be well understood to aid the localisation of the defect in the neurological system. This paper will briefly review the aid of pain as a neurological guide in GCS status assessment.