Environmental Microbiology and Microbial Ecology | Open Access Articles

Isolated Bacillus Licheniformis Sp01 From Daqing Oilfield In Reducing Chromium(Iii) Crosslinked Polymer Residue And Enhancing Oil Recovery, Xiao Hui

Student Works (2020-2029)

After polymer gel formation, the residual partially hydrolyzed polyacrylamide (HPAM) and the crosslinker (Cr3+) caused plugging and decreased oil recovery. Microorganisms can degrade HPAM to address the issues, but Cr³⁺ inhibits the process and reduces oil recovery. This study explores the underexamined biodegradation of HPAM and improved oil recovery in the presence of Cr³⁺, offering new perspectives for microbial enhanced oil recovery (MEOR) after polymer gel formation. HPAM and crude oil were innovatively used as the sole nitrogen(N) and carbon(C) sources to isolate the best-growing strain from Daqing Oilfield produced water, identified as Bacillus licheniformis SP01. The oil displacement potential …

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Assessment Of Bacterial Community Structure And Characterisation Of Novel Bacterial Species In Weaver Ants Oecophylla Smaragdina, Chua Kah Ooi

Student Works (2020-2029)

The Asian weaver ant, Oecophylla smaragdina has major workers that exhibit strong territorial behaviour and are aggressive predator of other arthropods. This makes them an effective biocontrol agent against many agricultural-important insect pests. Despite its importance in pest management, microbiome information of O. smaragdina is limited. In this study, the bacterial microbiome of O. smaragdina was characterized using 16S rRNA gene amplicon sequencing. Across all 12 samples, 97.8% of the sequences constituted 16 major operational taxonomic units (OTUs) that were assigned to eight bacterial families. The core bacterial microbiome was dominated by families Acetobacteraceae and Lactobacillaceae. Spatial variation attributed to …

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Evaluation Of Anti-Cancer Function In Natural Killer Cells Generated From Rat Hematopoietic Stem Cells, Alireza Pirahmadian

Student Works (2020-2029)

Natural killer cells (NK) cells are lymphocytes and they are the most important key constituent of mammalian immune system against cancer tumour cells. The genome of NK cells is categorically divided to inhibitory and activator genes that code ligands on the surface of NK cells. Indeed, these ligands are cancer tumour cells destroyer arms of the NK cells. On the other hand, hematopoietic stem cells (HSCs) are the origin of all blood cells, derives from BM and mature to immune cells. NK cells cannot defeat CTCs on their own. The main reason is their population (numbers are low), they cannot …

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Graphene-Based Electrochemical Aptasensor For The Detection Of Salmonella Typhimurium, Shalini Muniandy

Student Works (2020-2029)

Recent foodborne outbreaks in multiple locations necessitate the continuous development of highly sensitive and specific biosensors that offer rapid and sensitive detection of foodborne pathogens. The emergence of electrochemical aptasensor which is a compact analytical device with a combination of an aptamer as the biorecognition element integrated on the transducer surface created a breakthrough in the detection of foodborne bacterial pathogens. Graphene has emerged as a promising nanomaterial for reliable detection of pathogenic bacteria due to its exceptional properties such as high electrical conductivity, large surface to volume ratio, high mechanical strength and its unique interactions with DNA bases of …

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Molecular Characterisation Of Hsp70 Gene Expression, Histopathology And Immune System Of Snakehead Fish, Channa Striata, Under Temperature And Bacterial Stress, Eid Elhussein Ihlam Ibrahim

Student Works (2020-2029)

Snakeheads are air-breathing freshwater fishes containing two genera, Channa (Asia) and Parachanna (Africa). The Asian genus is dominated by Channa striata which is found in southern and Southeastern parts of the continent. In this research, environmental and bacteria stressor to Channa striata were investigated. HSP70 gene was studied as an environmental stress gene (ChHSP70). Results showed a cDNA sequence of the gene to be (~918bp). It was also shown the gene is highly similar to that of other fish species. Constructing a phylogenetic tree of the gene across vertebrate species revealed six main clusters; same class remained conserved by showing …

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Optimisation Of Biomass And Lipid Production Of A Tropical Thraustochytrid Aurantiochytrium Sp. Umacc-T023 In Submerged-Liquid Fermentation For Large-Scale Biodiesel Production, Sohedein Mohamad Nor Azzimi

Student Works (2020-2029)

A tropical thraustochytrid, Aurantiochytrium sp. UMACC-T023, was optimised for high biomass and lipid production in submerged-liquid fermentation (SLF). Biomass and lipid production were optimised based on glucose, polypeptone, and yeast extract concentration using response surface methodology (RSM). In RSM, the applied central composite design (CCD) showed that the optimisation model was significant for all variables studied. Yeast extract and polypeptone were associated with significant effects in UMACC-T023 biomass production with p < 0.05. The model was validated by employing the optimised media composition in shake flasks and in 1.4-L stirred-tank bioreactors. The optimised media composition for both biomass and lipid production was 10 g L-1 glucose, 15.08 g L-1 polypeptone, and 13.56 g L-1 yeast extract. Biomass production in the bioreactor increased 2.12-fold compared with the shake flask culture utilising the same optimised media composition. This result demonstrated that the optimized media composition can be utilised for large-scale lipid production of UMACC-T023 for potential biodiesel feedstock as it also fulfilled the international standards for biodiesel.

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Abundance And Distribution Of Microplastics And Phthalic Acid Esters In Selected Mangrove Areas In Peninsular Malaysia, Anuar Norkhairah

Student Works (2020-2029)

Contamination of microplastics in mangrove has been receiving growing attention as experts reckon 30 billion tonnes of plastics will accumulate in 2050. The vast increase in plastic commodities will increase microplastics abundance in mangroves as mangroves are substantially sinks and traps for plastic debris. Due to persistent properties and high surface to volume ratio of microplastics, Phthalic Acid Esters (PAEs) can be taken up by microplastics, representing a grave threat to the ecosystems. This study investigated the abundance and distribution of microplastics and PAEs in selected mangrove areas in Peninsular Malaysia. The objectives of this study are to identify the …

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Polyhydroxyalkanoates For Innovative Electrodes And Proton Exchange Membrane Modification In Microbial Fuel Cell, Abdul Azeez Olayiwola Sirajudeen

Student Works (2020-2029)

The increase in global energy demand due to increasing population and industrialization demands renewable and environmental-friendly alternatives. Energy from fossil fuel are non-renewable, depleting and detrimental from environmental perspectives. Alternative energy, green and renewable such as hydrogen fuel, biodiesel, bioethanol, microbial fuel cell and many more have been extensively investigated. One possible solution lies with non-combustion method such as microbial fuel cell. A microbial fuel cell is a sustainable and environmental-friendly device that combines electricity generation and wastewater treatment through metabolic activities of microorganisms. However, low power output from inadequate electron transfer to the anode electrode hampers its practical implementation. …

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Isolation Of Plastic-Degrading Fungi From Landfill And Determining The Selected Plastics Biodegradation Capability, Mohan Priya

Student Works (2020-2029)

Polyethylene Terephthalate (PET), Low Density Polyethylene (LDPE) and High Density Polyethylene (HDPE) are the most important polymers used predominantly in present world. Since synthetic polymers hardly undergo degradation and remain in the environment for a very long time, up to 1000 years, these drawbacks increase the percentage of solid wastes in landfill and threaten the environment. To date, Municipal Solid Waste (MSW) landfill is the most favored disposal method especially among the developing countries. The aim of present study is to evaluate the potential of fungus isolated from landfilled plastics to degrade PET, LDPE and HDPE. Besides, effect of different …

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Comparison Of Three Analytical Techniques For General Characterisation Of Selected Algae And Cyanobacteria, Mohamed Iqbal Suhaina Nashath

Student Works (2020-2029)

Algae and cyanobacteria maintain the oxygenation of earth, and are utilised as biofuels, biofertilizers and nutrition feed. The characterisation of algae and cyanobacteria through conventional methods require technical expertise, laborious sample preparation, and moderately expensive instruments and reagents. Hence, in this study, selected bioanalytical techniques with minimal sample preparation were incorporated, to simplify the characterisation of algae and cyanobacteria. The objectives of this research were to study the phylogenetic relationship of the selected algae and cyanobacteria via the 23S plastid ribosomal ribonucleic acid (rRNA) and 18S rRNA biomarkers; to validate the presence of the microcystin synthetase (mcy) gene cluster encoding …

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Abundance And Distribution Of Microplastics And Persistent Organic Pollutants In Selected Rivers Of Peninsular Malaysia, Anuar Norkhairiyah

Student Works (2020-2029)

Nearly 70 to 80 percent of microplastics are believed to be transported to the sea through rivers. Yet, less attention has been given to the accumulation of microplastics in the freshwater environment. They are emerging anthropogenic contaminants on account of their potential to adsorb and/or release POPs from and/or to the surrounding environment, and become the vector transferring these pollutants from water to the food web. This study is aimed to explore the abundance and distribution of microplastics and POPs in six rivers of Peninsular Malaysia, which comprised of three rivers from the West Coast (Sepetang River, Serkam River, and …

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Hydrolysis Of Palm Oil Mill Effluent Using Enzymes From Spent Mushroom Substrate Of Pleurotus Pulmonarius (Fr.) Quel, Mat Yunan Nurul Anisa

Student Works (2020-2029)

Mushroom cultivation and palm oil industry in Malaysia have contributed to the large volumes of lignocellulosic residues. Lignocellulolytic enzymes profiles (lignin peroxidase, laccase, xylanase, endoglucanase, and β-glucosidase) of Pleurotus pulmonarius (parents strains UMP001 and UMP 002, and the hybrid UMH004) during growth in sawdust substrate bags were investigated. The enzymes extracted from the spent mushroom substrate (SMS) of the strain with the highest enzymes productivity was used to hydrolyse palm oil mill effluent (POME). Optimization of parameters for POME hydrolysis to release reducing sugar was conducted using central composite design (CCD) of response surface methodology (RSM). The potential of hydrolysed …

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Genomic And Taxonomic Studies Of An Antarctic Psychrotolerant Quorum Quenching Bacterium, Planococcus Versutus L10.15t, See-Too Wah Seng

Student Works (2020-2029)

Quorum quenching (QQ) has been suggested as an alternative to antibiotic treatments for pathogenic infections as it does not affect the viability of the pathogen and imposes minimum selection pressure promoting drug resistance. During an ecological survey for quorum quenching (QQ) bacteria from soil collected in Lagoon Island (Ryder Bay, Adelaide Island, Antarctica), a bacterial strain was isolated and identified as Planococcus species, L10.15T, based on 16S rRNA gene analysis. The genomic, phylogenetic, chemotaxonomic and phenotypic data obtained showed that L10.15T represents a novel species for which the name Planococcus versutus sp. nov. is proposed. Previously, QQ activity of L10.15T …

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Morphology, Molecular Characterization And Habitat Preference Of Harmful Benthic Dinoflagellate Gambierdiscus (Dinophyceae) In Malaysia, Nurin Izzati Mustapa

Student Works (2020-2029)

Ciguatera fish poisoning (CFP) is a type of illness that causes human intoxication after consuming contaminated coral fishes. The neurotoxins, ciguatoxins, are produced by species of Gambierdiscus, one of the harmful benthic dinoflagellates. Identification of harmful dinoflagellate species is important to gain further insights into the global dispersion. In this study, morphological characteristics of species in the genus Gambierdiscus and their habitat preferences were investigated. Field sampling was undertaken at Pulau Rawa, Terengganu and Pulau Sibu, Johor. Single cells of Gambierdiscus were isolated and clonal cultures were established. Morphology of Gambierdiscus was examined by using light and scanning electron microscopes. …

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Full-Text Articles in Environmental Microbiology and Microbial Ecology

Isolated Bacillus Licheniformis Sp01 From Daqing Oilfield In Reducing Chromium(Iii) Crosslinked Polymer Residue And Enhancing Oil Recovery, Xiao Hui

Student Works (2020-2029)

Assessment Of Bacterial Community Structure And Characterisation Of Novel Bacterial Species In Weaver Ants Oecophylla Smaragdina, Chua Kah Ooi

Student Works (2020-2029)

Evaluation Of Anti-Cancer Function In Natural Killer Cells Generated From Rat Hematopoietic Stem Cells, Alireza Pirahmadian

Student Works (2020-2029)

Graphene-Based Electrochemical Aptasensor For The Detection Of Salmonella Typhimurium, Shalini Muniandy

Student Works (2020-2029)

Molecular Characterisation Of Hsp70 Gene Expression, Histopathology And Immune System Of Snakehead Fish, Channa Striata, Under Temperature And Bacterial Stress, Eid Elhussein Ihlam Ibrahim

Student Works (2020-2029)

Optimisation Of Biomass And Lipid Production Of A Tropical Thraustochytrid Aurantiochytrium Sp. Umacc-T023 In Submerged-Liquid Fermentation For Large-Scale Biodiesel Production, Sohedein Mohamad Nor Azzimi

Student Works (2020-2029)

Abundance And Distribution Of Microplastics And Phthalic Acid Esters In Selected Mangrove Areas In Peninsular Malaysia, Anuar Norkhairah

Student Works (2020-2029)

Polyhydroxyalkanoates For Innovative Electrodes And Proton Exchange Membrane Modification In Microbial Fuel Cell, Abdul Azeez Olayiwola Sirajudeen

Student Works (2020-2029)

Isolation Of Plastic-Degrading Fungi From Landfill And Determining The Selected Plastics Biodegradation Capability, Mohan Priya

Student Works (2020-2029)

Comparison Of Three Analytical Techniques For General Characterisation Of Selected Algae And Cyanobacteria, Mohamed Iqbal Suhaina Nashath

Student Works (2020-2029)

Abundance And Distribution Of Microplastics And Persistent Organic Pollutants In Selected Rivers Of Peninsular Malaysia, Anuar Norkhairiyah

Student Works (2020-2029)

Hydrolysis Of Palm Oil Mill Effluent Using Enzymes From Spent Mushroom Substrate Of Pleurotus Pulmonarius (Fr.) Quel, Mat Yunan Nurul Anisa

Student Works (2020-2029)

Genomic And Taxonomic Studies Of An Antarctic Psychrotolerant Quorum Quenching Bacterium, Planococcus Versutus L10.15t, See-Too Wah Seng

Student Works (2020-2029)

Morphology, Molecular Characterization And Habitat Preference Of Harmful Benthic Dinoflagellate Gambierdiscus (Dinophyceae) In Malaysia, Nurin Izzati Mustapa

Student Works (2020-2029)