Aliphatic Hydrocarbons In Surface Sediments From South China Sea Off Kuching Division, Sarawak

Eighteen surface sediment samples collected from South China Sea off Kuching Division, Sarawak were analyzed for aliphatic hydrocarbons. These hydrocarbons were recovered from sediment by Soxhlet extraction method and then analyzed using gas chromatography equipped with mass spectrometer (GC/MS). Total concentrations of aliphatic hydrocarbons in surface sediments from South China Sea off Kuching division are ranged from 35.6 ug/g to 1466.1 ug/g dry weights. The sediments collected from Bako Bay, Kuching showed high concentrations of total aliphatic hydrocarbons. Several molecular indices were used to predict the predominant sources of hydrocarbons. Carbon preference index (CPI) value revealed widespread anthropogenic input in this study area (CPI= 0 to 4.1). The ratio of C31/C19and C29/C31indicated that major input of aliphatic hydrocarbon mostly transfer by lateral input to the marine environment than atmospheric movements. Generally, the concentrations of aliphatic hydrocarbons in sediment from South China Sea off Kuching division are generally higher compare to other area in the world

Vertical Profiles of Natural Uranium Isotopes in Sediment Cores from Kota Kinabalu and Labuan Ports, Malaysia

Sediment cores were collected from Kota Kinabalu and Labuan ports to determine the distribution of natural uranium isotopes, calcium (Ca), aluminium (Al) and total organic matter (TOM). A strong statistical correlation value between 234U/238U and Ca contents were shown at Kota Kinabalu (r2 = 0.811), and Labuan (r2 = 0.833) ports. Good statistical correlation r2 > 0.8 was also obtained between uranium isotopes and TOM at Kota Kinabalu port. Most activity ratio values of 234U/238U found in sediment cores from Kota Kinabalu port were more than 1.0; the major input of uranium at Kota Kinabalu port may be related to the sorptive process of authigenic uranium that occurs in the water column. In this case, the mobile U(VI) was reduced to immobile U(IV) by organic matter and scavenged to the sediment with co-precipitation of organic matter and calcium carbonate. On the other hand, a low activity ratio of 234U/238U (≤ 1) from Labuan was of detrital origin and also showed positive statistical correlation between calcium and aluminium

Optimization of extraction methods and detectors for heavy metal analysis in sediment

The optimization analysis, extractions of metals (Zinc, Cadmium, Lead, and Copper) content in Certified Reference Material, BCR ®-667 of estuarine sediment was carried out by different procedures of acid digestion such hydrochloric acid-nitric acid-hydrofluoric acid, nitric acid-perchloric acid, and sulphuric acid-hydrogen peroxide mixtures. These metals concentrations were determined by using Differential Pulse Stripping Voltammetry (DPSV) and Inductive Coupled Plasma-Mass Spectrometry (ICP-MS). The purpose was to determine these metals (Zn, Cd, Pb, Cu) concentration in sediment samples simultaneously in good precision and accuracy measurement. The results showed both have small standard deviation indicates good precision of metals determinations in both detectors. The accuracy for DPSV ranged from 18.85-154.38% and ICP-MS ranged from 75.28-90.13%. Zn, Cd, Pb, and Cu were simultaneously measured in BCR ®-667. When the optimized method was applied into real sediment samples, both determinations showed a good precision in analysis but ICP-MS was selected as the detector. It measured all the metals of interest (Zn, Cd, Pb, Cu) in the real sediment sample simultaneously

Geochemical Studies of Rare Earth Elements (REE) in Ion Adsorption Clays (IAC) in Gua Musang, Kelantan

Rare earth element (REE) become the ‘critical metals’ for green technology development that have been rapidly expanded worldwide in these days. REE is mainly originated from granitic rocks. REE in ion adsorption clay (IAC) is the product from weathering of granite. IAC are believed to store high concentration of heavy rare earth element (HREE) and light rare earth element (LREE). Gua Musang is selected for this study because it is located on the three longitudinal belts that composed of acid volcanic igneous rocks from Main Range, Senting and Boundary Range Granites. In this study, the characteristics of ion adsorption clays and REE distribution in Gua Musang have been studied by mineralogy and geochemical analyses. Rocks and soil samples were collected closed to the granite bodies and its surrounding to represent its weathering products. Polarised optical microscopy was used for petrography and mineralogy studies. From fieldwork observation, Gua Musang lithologies composed of carbonate facies, argillaceous facies and pyroclastic facies. X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Inductive Coupled Plasma Microspectrometry (ICP-MS) were used accordingly to characterise the composition of major and trace elements in IAC samples. REE value in Pulai are the highest concentration as iron nodule have been found in the sampling area. Sample from Boundary Range granite also reported store high concentration of REEs in this study

Comprehensive approaches for the detection of Burkholderia pseudomallei and diagnosis of melioidosis in human and environmental samples

Melioidosis is endemic in Southeast Asia and northern Australia. The causative agent of melioidosis is a Gram-negative bacterium, Burkholderia pseudomallei. Its invasion can be fatal if melioidosis is not treated promptly. It is intrinsically resistant to a variety of antibiotics. In this paper, we present a comprehensive overview of the current trends on melioidosis cases, treatments, B. pseudomallei virulence factors, and molecular techniques to detect the bacterium from different samples. The clinical and microbial diagnosis methods of identification and detection of B. pseudomallei are commonly used for the rapid diagnosis and typing of strains, such as polymerase chain reaction or multi-locus sequence typing. The genotyping strategies and techniques have been constantly evolving to identify genomic loci linked to or associated with this human disease. More research strategies for detecting and controlling melioidosis should be encouraged and conducted to understand the current situation. In conclusion, we review existing diagnostic methodologies for melioidosis detection and provide insights on prospective diagnostic methods for the bacterium

Distribution of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of Langkawi Island, Malaysia

The individual compounds and sources of polycyclic aromatic hydrocarbon (PAHs) were studied in the surface sediments at 32 locations in the tourism area of Langkawi Island. A total of 15 PAHs were determined and quantified by gas chromatography coupled with mass spectrometry (GC-MS). The total PAH concentrations of surface sediments from Langkawi Island ranged from 228.13 to 990.25 ng/g and they were classified as being in the low to moderate pollution range. All sampling stations were dominated by high molecular weight PAHs with 4 rings (31.59%) and 5-6 rings (42.73%). The diagnostic ratio results showed that in most cases, the sampling stations have pyrogenic input. Further analysis using principal component analysis (PCA) combined with absolute principal component score (APCS) and multiple linear regression (MLR) showed that the natural gas emissions contributed to 57% of the total PAH concentration, 22% from the incomplete combustion and pyrolysis of fuel, 15% from pyrogenic and petrogenic sources and 6% from an undefined source

Bioprocess Strategy of Haematococcus lacustris for Biomass and Astaxanthin Production Keys to Commercialization: Perspective and Future Direction

Haematococcus lacustris (formerly called Haematococcus pluvialis) is regarded as the most promising microalgae for the production of natural astaxanthin, which is secondary metabolism used as a dietary supplement, also for cosmetic applications, due to its high antioxidant activity. Astaxanthin has a wide range of biological activities and high economic potential, and currently dominates the market in its synthetic form. Furthermore, because of the difficulty of bioprocess and the high cost of cultivation, astaxanthin extracted from this microalga is still expensive due to its low biomass and pigment productivities. Large-scale biomass production in biotechnological production necessitates the processing of a large number of cultures as well as the use of both indoor and outdoor systems, such as open pond raceway systems and photo-bioreactors (PBR). The photo-bioreactors systems are suitable for mass production because growth conditions can be controlled, and the risk of contamination can be reduced to a certain extent and under specific culture parameters. This review discusses current technologies being developed to improve cultivation and operation efficiency and profitability, as well as the effect of parameter factors associated with H. lacustris cultivation on biomass and astaxanthin bioproduction, and even strategies for increasing bioproduction and market potential for H. lacustris astaxanthin

Evolution of green space under rapid urban expansion in Southeast Asian cities

Globally, rapid urban expansion has caused green spaces in urban areas to decline considerably. In this study, the rapid expansion of three Southeast Asia cities were considered, namely, Kuala Lumpur City, Malaysia; Jakarta, Indonesia; and Metro Manila, Philippines. This study evaluates the changes in spatial and temporal patterns of urban areas and green space structure in the three cities over the last two decades. Land use land cover (LULC) maps of the cities (1988/1989, 1999 and 2014) were developed based on 30-m resolution satellite images. The changes in the landscape and spatial structure were analysed using change detection, landscape metrics and statistical analysis. The percentage of green space in the three cities reduced in size from 45% to 20% with the rapid expansion of urban areas over the 25-year period. In Metro Manila and Jakarta, the proportion of green space converted to urban areas was higher in the initial 1989 to 1999 period than over the latter 1999 to 2014 period. Significant changes in green space structure were observed in Jakarta and Metro Manila. Green space gradually fragmented and became less connected and more unevenly distributed. These changes were not seen in Kuala Lumpur City. Overall, the impact of spatial structure of urban areas and population density on green space is higher in Jakarta and Metro Manila when this is compared to Kuala Lumpur. Thus, the results have the potential to clarify the relative contribution of green space structure especially for cities in Southeast Asia where only a few studies in urban areas have taken place

Pasteurellosis vaccine commercialization: Physiochemical factors for optimum production

Pasteurella spp. are Gram-negative facultative bacteria that cause severe economic and animal losses. Pasteurella-based vaccines are the most promising solution for controlling Pasteurella spp. outbreaks. Remarkably, insufficient biomass cultivation (low cell viability and productivity) and lack of knowledge about the cultivation process have impacted the bulk production of animal vaccines. Bioprocess optimization in the shake flask and bioreactor is required to improve process efficiency while lowering production costs. However, its state of the art is limited in providing insights on its biomass upscaling, preventing a cost-effective vaccine with mass-produced bacteria from being developed. In general, in the optimum cultivation of Pasteurella spp., production factors such as pH (6.0–8.2), agitation speed (90–500 rpm), and temperature (35–40 °C) are used to improve production yield. Hence, this review discusses the production strategy of Pasteurella and Mannheimia species that can potentially be used in the vaccines for controlling pasteurellosis. The physicochemical factors related to operational parameter process conditions from a bioprocess engineering perspective that maximize yields with minimized production cost are also covered, with the expectation of facilitating the commercialization process