Displaying publications 41 - 60 of 148 in total

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  1. Fulltext Fusarium Species in Mangrove Soil in Northern Peninsular Malaysia and the Soil Physico-Chemical Properties
    Mohamed Zubi WS, Mohd MH, Mohamed Nor NMI, Zakaria L
    Microorganisms, 2021 Feb 26;9(3).
    PMID: 33652900 DOI: 10.3390/microorganisms9030497
    Fusarium genus comprises important saprophytic and phytopathogenic fungi and is widespread in nature. The present study reports the occurrence of Fusarium spp. in soils from two mangrove forests in northern Peninsular Malaysia and analyzed physico-chemical properties of the mangrove soil. Based on TEF-1α sequences, nine Fusarium species were identified: Fusarium solani species complex (FSSC) (n = 77), Fusarium verticillioides (n = 20), Fusarium incarnatum (n = 10), Fusarium proliferatum (n = 7), Fusarium lateritium (n = 4), Fusarium oxysporum (n = 3), Fusarium rigidiuscula (n = 2), Fusarium chlamydosporum (n = 1), and Fusarium camptoceras (n = 1); FSSC isolates were the most prevalent. Phylogenetic analysis of the combined TEF-1α and ITS sequences revealed diverse phylogenetic affinities among the FSSC isolates and potentially new phylogenetic clades of FSSC. Soil analysis showed varied carbon content, pH, soil moisture, and salinity, but not nitrogen content, between sampling locations. Regardless of the physico-chemical properties, various Fusarium species were recovered from the mangrove soils. These were likely saprophytes; however, some were well-known plant pathogens and opportunistic human pathogens. Thus, mangrove soils might serve as inoculum sources for plant and human pathogenic Fusarium species. The present study demonstrates the occurrence of various Fusarium species in the extreme environment of mangrove soil, thereby contributing to the knowledge on species diversity in Fusarium.
    Matched MeSH terms: Salinity
  2. Fulltext Water quality data in a shallow and narrow Setiu Lagoon
    Zainol Z, Akhir MF, Johari A, Ali A
    Data Brief, 2021 Apr;35:106866.
    PMID: 33816725 DOI: 10.1016/j.dib.2021.106866
    This article contains water quality data collected in a shallow and narrow Setiu Lagoon during the southwest monsoon, wet period of northeast monsoon and dry period of northeast monsoon. The surface water quality parameters, which include the temperature, salinity, chlorophyll-a and nutrients (ammonia, nitrate, phosphate, and silicate) were sampled twice per day (high and low tides) at a total of eight stations. Hourly current speed and direction was obtained from mooring of two units of current meters. Compared to the Malaysia Marine Water Quality Criteria and Standard (MWQCS), nutrients in Setiu Lagoon were in Class 2. Although limited, this dataset can provide insights on the changes of water quality condition in Setiu Lagoon under the presence of anthropogenic pressures.
    Matched MeSH terms: Salinity
  3. Fulltext Comparison of Pressure-Retarded Osmosis Performance between Pilot-Scale Cellulose Triacetate Hollow-fiber and Polyamide Spiral-Wound Membrane Modules
    Kakihana Y, Jullok N, Shibuya M, Ikebe Y, Higa M
    Membranes (Basel), 2021 Feb 28;11(3).
    PMID: 33671075 DOI: 10.3390/membranes11030177
    Pressure-retarded osmosis (PRO) has recently received attention because of its ability to generate power via an osmotic pressure gradient between two solutions with different salinities: high- and low-salinity water sources. In this study, PRO performance, using the two pilot-scale PRO membrane modules with different configurations-five-inch cellulose triacetate hollow-fiber membrane module (CTA-HF) and eight-inch polyamide spiral-wound membrane modules (PA-SW)-was evaluated by changing the draw solution (DS) concentration, applied hydrostatic pressure difference, and the flow rates of DS and feed solution (FS), to obtain the optimum operating conditions in PRO configuration. The maximum power density per unit membrane area of PA-SW at 0.6 M NaCl was 1.40 W/m2 and 2.03-fold higher than that of CTA-HF, due to the higher water permeability coefficient of PA-SW. In contrast, the maximum power density per unit volume of CTA-SW at 0.6 M NaCl was 4.67 kW/m3 and 6.87-fold higher than that of PA-SW. The value of CTA-HF increased to 13.61 kW/m3 at 1.2 M NaCl and was 12.0-fold higher than that of PA-SW because of the higher packing density of CTA-HF.
    Matched MeSH terms: Salinity
  4. Regional suitability prediction of soil salinization based on remote-sensing derivatives and optimal spectral index
    Wang Z, Zhang F, Zhang X, Chan NW, Kung HT, Ariken M, et al.
    Sci Total Environ, 2021 Feb 12;775:145807.
    PMID: 33618298 DOI: 10.1016/j.scitotenv.2021.145807
    Soil salinization is an extremely serious land degradation problem in arid and semi-arid regions that hinders the sustainable development of agriculture and food security. Information and research on soil salinity using remote sensing (RS) technology provide a quick and accurate assessment and solutions to address this problem. This study aims to compare the capabilities of Landsat-8 OLI and Sentinel-2A MSI in RS prediction and exploration of the potential application of derivatives to RS prediction of salinized soils. It explores the ability of derivatives to be used in the Landsat-8 OLI and Sentinel-2A MSI multispectral data, and it was used as a data source as well as to address the adaptability of salinity prediction on a regional scale. The two-dimensional (2D) and three-dimensional (3D) optimal spectral indices are used to screen the bands that are most sensitive to soil salinity (0-10 cm), and RS data and topographic factors are combined with machine learning to construct a comprehensive soil salinity estimation model based on gray correlation analysis. The results are as follows: (1) The optimal spectral index (2D, 3D) can effectively consider possible combinations of the bands between the interaction effects and responding to sensitive bands of soil properties to circumvent the problem of applicability of spectral indices in different regions; (2) Both the Landsat-8 OLI and Sentinel-2A MSI multispectral RS data sources, after the first-order derivative techniques are all processed, show improvements in the prediction accuracy of the model; (3) The best performance/accuracy of the predictive model is for sentinel data under first-order derivatives. This study compared the capabilities of Landsat-8 OLI and Sentinel-2A MSI in RS prediction in finding the potential application of derivatives to RS prediction of salinized soils, with the results providing some theoretical basis and technical guidance for salinized soil prediction and environmental management planning.
    Matched MeSH terms: Salinity
  5. Fulltext A Review on Haematococcus pluvialis Bioprocess Optimization of Green and Red Stage Culture Conditions for the Production of Natural Astaxanthin
    Oslan SNH, Shoparwe NF, Yusoff AH, Rahim AA, Chang CS, Tan JS, et al.
    Biomolecules, 2021 02 10;11(2).
    PMID: 33578851 DOI: 10.3390/biom11020256
    As the most recognizable natural secondary carotenoid astaxanthin producer, the green microalga Haematococcus pluvialis cultivation is performed via a two-stage process. The first is dedicated to biomass accumulation under growth-favoring conditions (green stage), and the second stage is for astaxanthin evolution under various stress conditions (red stage). This mini-review discusses the further improvement made on astaxanthin production by providing an overview of recent works on H. pluvialis, including the valuable ideas for bioprocess optimization on cell growth, and the current stress-exerting strategies for astaxanthin pigment production. The effects of nutrient constituents, especially nitrogen and carbon sources, and illumination intensity are emphasized during the green stage. On the other hand, the significance of the nitrogen depletion strategy and other exogenous factors comprising salinity, illumination, and temperature are considered for the astaxanthin inducement during the red stage. In short, any factor that interferes with the cellular processes that limit the growth or photosynthesis in the green stage could trigger the encystment process and astaxanthin formation during the red stage. This review provides an insight regarding the parameters involved in bioprocess optimization for high-value astaxanthin biosynthesis from H. pluvialis.
    Matched MeSH terms: Salinity
  6. Fulltext mRNA profile provides novel insights into stress adaptation in mud crab megalopa, Scylla paramamosain after salinity stress
    Zhang Y, Wu Q, Fang S, Li S, Zheng H, Zhang Y, et al.
    BMC Genomics, 2020 Aug 14;21(1):559.
    PMID: 32795331 DOI: 10.1186/s12864-020-06965-5
    BACKGROUND: Mud crab, Scylla paramamosain, a euryhaline crustacean species, mainly inhabits the Indo-Western Pacific region. Wild mud crab spawn in high-salt condition and the salinity reduced with the growth of the hatching larvae. When the larvae grow up to megalopa, they migrate back to estuaries and coasts in virtue of the flood tide, settle and recruit adult habitats and metamorphose into the crablet stage. Adult crab can even survive in a wide salinity of 0-35 ppt. To investigate the mRNA profile after salinity stress, S. paramamosain megalopa were exposed to different salinity seawater (low, 14 ppt; control, 25 ppt; high, 39 ppt).

    RESULTS: Firstly, from the expression profiles of Na+/K+/2Cl- cotransporter, chloride channel protein 2, and ABC transporter, it turned out that the 24 h might be the most influenced duration in the short-term stress. We collected megalopa under different salinity for 24 h and then submitted to mRNA profiling. Totally, 57.87 Gb Clean Data were obtained. The comparative genomic analysis detected 342 differentially expressed genes (DEGs). The most significantly DEGs include gamma-butyrobetaine dioxygenase-like, facilitated trehalose transporter Tret1, sodium/potassium-transporting ATPase subunit alpha, rhodanese 1-like protein, etc. And the significantly enriched pathways were lysine degradation, choline metabolism in cancer, phospholipase D signaling pathway, Fc gamma R-mediated phagocytosis, and sphingolipid signaling pathway. The results indicate that in the short-term salinity stress, the megalopa might regulate some mechanism such as metabolism, immunity responses, osmoregulation to adapt to the alteration of the environment.

    CONCLUSIONS: This study represents the first genome-wide transcriptome analysis of S. paramamosain megalopa for studying its stress adaption mechanisms under different salinity. The results reveal numbers of genes modified by salinity stress and some important pathways, which will provide valuable resources for discovering the molecular basis of salinity stress adaptation of S. paramamosain larvae and further boost the understanding of the potential molecular mechanisms of salinity stress adaptation for crustacean species.

    Matched MeSH terms: Salinity
  7. Fulltext Tides and Their Dynamics over the Sunda Shelf of the Southern South China Sea
    Daryabor F, Ooi SH, Abu Samah A, Akbari A
    PLoS One, 2016;11(9):e0162170.
    PMID: 27622552 DOI: 10.1371/journal.pone.0162170
    A three-dimensional Regional Ocean Modelling System is used to study the tidal characteristics and their dynamics in the Sunda Shelf of the southern South China Sea. In this model, the outer domain is set with a 25 km resolution and the inner one, with a 9 km resolution. Calculations are performed on the inner domain. The model is forced at the sea surface by climatological monthly mean wind stress, freshwater (evaporation minus precipitation), and heat fluxes. Momentum and tracers (such as temperature and salinity) are prescribed in addition to the tidal heights and currents extracted from the Oregon State University TOPEX/Poseidon Global Inverse Solution (TPXO7.2) at the open boundaries. The results are validated against observed tidal amplitudes and phases at 19 locations. Results show that the mean average power energy spectrum (in unit m2/s/cph) for diurnal tides at the southern end of the East Coast of Peninsular Malaysia is approximately 43% greater than that in the East Malaysia region located in northern Borneo. In contrast, for the region of northern Borneo the semidiurnal power energy spectrum is approximately 25% greater than that in the East Coast of Peninsular Malaysia. This implies that diurnal tides are dominant along the East Coast of Peninsular Malaysia while both diurnal and semidiurnal tides dominate almost equally in coastal East Malaysia. Furthermore, the diurnal tidal energy flux is found to be 60% greater than that of the semidiurnal tides in the southern South China Sea. Based on these model analyses, the significant tidal mixing frontal areas are located primarily off Sarawak coast as indicated by high chlorophyll-a concentrations in the area.
    Matched MeSH terms: Salinity
  8. Fulltext Effects of different environmental parameters on the respiratory metabolism of the larvae of Malaysian horseshoe crab, Tachypleus gigas (Müller)
    Suniza, A.M.S., Zaleha Kassim, Chatterji, Anil
    Pertanika Journal of Science & Technology, 2011;19(1):1-9.
    MyJurnal
    Respiratory metabolism of the larvae of Malaysian horseshoe crab Tachypleus gigas (Müller) was studied under different salinities, pH, and temperature. The trend in oxygen consumption was uniform at all salinities, ranging from 10-40 ppt, indicating insignificant influence on the oxygen consumption by the larvae. Similarly, the correlation coefficient values showed that the relationship between oxygen consumption and salinity was not significant (P > 0.05; r = 0.245). During the first three hours, the oxygen consumption was 8.89, 10.72, 17.4, and 12.06% at 10, 20, 30, and 40 ppt salinities, respectively. Meanwhile, the maximum oxygen consumption was recorded after 12 hrs, i.e. at salinity 20 ppt. A sudden drop in oxygen consumption was recorded during 3-6 hours of the experiment. This was followed by a gradual increase in the consumption of oxygen up to 12 hours of experiment. A similar trend in the oxygen consumption was observed in different pH levels, ranging from 5 to 9. At pH 6 and 9, during the first six hour, a moderate consumption of oxygen was observed. However, at pH 6, 7 and 8, the rates of oxygen consumption were found to be relatively greater after six hours, indicating unfavourable conditions. The data were statistically tested and it was found that a high degree of correlations existed between pH and oxygen consumption (r = 0.97). The analysis of covariance showed a significant relationship between oxygen consumption and pH (P < 0.05). Meanwhile, minimal variation in oxygen consumption was recorded between 30 and 40oC, with a
    gradual decrease in dissolved oxygen concentration up to 12 hours of experimental time. At 50oC,
    almost all dissolved oxygen was consumed by the larvae. The rate of oxygen consumption between
    30 and 40oC was low during the first 9 hours of the experiment but it was significantly increased at later hours. A sudden increase in the oxygen consumption was recorded at 50oC, suggesting that it
    might be the most unfavourable temperature condition. Meanwhile, a significant relationship was
    observed between temperature and oxygen consumption (P < 0.05; r = 0.98).
    Matched MeSH terms: Salinity
  9. Fulltext Preliminary investigation on electrochemical parameters of lake waters in and around miri city, Malaysia
    M. V. Prasanna, R. Nagarajan, A. Elayaraja, S. Chidambaram
    Pertanika Journal of Science & Technology, 2014;22(1):329-335.
    MyJurnal
    Surface water samples were collected from 16 Lakes in and around Miri City to assess the electrochemical parameters includes pH, Electrical conductivity (EC), Total dissolved solid (TDS), redox potential (Eh), resistivity and salinity. Sampling locations for monitoring were selected in the vicinity of major roads, industries, settlements and agricultural region. Interpretation of data shows that the surface water in the central region of the study area is polluted by various anthropogenic activities, while in the southern part is within the limits of guideline values. This kind of investigation is essential in the study area to save the resources for future perspective. Further detailed studies are also needed to get a clear picture of the surface water quality in Miri city and for future sustainable management of this resource.
    Matched MeSH terms: Salinity
  10. Fulltext Distribution of Recent Ostracoda in offshore sediment of the South China Sea
    Ramlan, O., Noraswana, N. F.
    Pertanika Journal of Science & Technology, 2014;22(2):433-444.
    MyJurnal
    A study on the distribution of Recent Ostracoda in offshore sediment was carried out around the South China Sea. A total of 30 sediment samples were taken from the sampling stations between latitude 1°48’ and 7°25’N and longitude 102°09’ and 105°16’E. From this study, 79 species of ostracods belonging to 16 families and 44 genera were identified. The dominant species was Foveoleberis cypraeoides with 937 individuals obtained. There were 13 to 43 species in total. Diversity Index, H(s), was in the range of 2.1 to 3.3, whereas the dominance values were between 4.4 and 14.7%. Several environmental parameters were measured including depth, temperature and salinity. The range values for each of these parameters are 13-72 m, 25.24-30.06o C and 27.74-34.91 ppt, respectively. The sediment texture in this study area can be categorized as sand, sandy mud, clayey mud, silty mud, silty clay, clayey sand, clayey silt and silty sand. The observations revealed that abundance and diversity of ostracod appeared to be principally controlled by depth. Two faunal assemblages were identified in terms of faunal composition, namely, shallow water (Hemikrithe orientalis, Neomonoceratina iniqua, Stigmatocythere indica, Cytherelloidea leroyi and Neocytheretta snellii) and deep water (Paracypris sp., Alataconcha pterogona, Bythocytheropteron alatum, Keijella paucipunctata and Actinocythereis scutigera). A comparative analysis showed a high degree resemblance between the study area and south-eastern Malay Peninsula (the South China Sea).
    Matched MeSH terms: Salinity
  11. Fulltext Serum cortisol level and survival rate of juvenile Epinephelus fuscoguttatus following exposure to different salinities
    Tahir D, Shariff M, Syukri F, Yusoff FM
    Vet World, 2018 Mar;11(3):327-331.
    PMID: 29657425 DOI: 10.14202/vetworld.2018.327-331
    Background and Aim: Brown-marbled grouper Epinephelus fuscoguttatus is a premium marine food fish with high demand in Asia. In fish, stress due to environmental changes such as fluctuations in the salinity can result in increased cortisol level. Stress in fish increases susceptibility to diseases ultimately resulting in death. Therefore, the aim of this study was to investigate the salinity tolerance of E. fuscoguttatus and their survival in lower salinities.

    Materials and Methods: In this study, grouper juveniles (92.43±standard error of the mean 0.51 mm) maintained in 31 ppt seawater were transferred into five tanks with seawater diluted to 25, 20, 15, 10, and 5 ppt. The salinity of the control group was not changed and was maintained at 31 ppt. Serum cortisol was measured using ELISA at 0, 30, 60, and 120 min after the fish were transferred to the different concentrations of salinity.

    Results: The survival percentage was recorded for 14 days following the transfer and the results revealed that serum cortisol of fish in a high change in salinity (15, 10, and 5 ppt) was significantly higher than the control group immediately after exposure. At the high salinity change, the cortisol levels gradually decrease at 30 min and 60 min, until no difference in cortisol concentration was observed at 120 min. No mortality was observed in fish exposed to low salinity change (25 and 20 ppt) while in higher salinity change (5 ppt), the survival percentage was 50%.

    Conclusion: The study revealed that the serum cortisol concentration was high initially and continues to decrease to resting cortisol level at 120 min indicating that cortisol hormone is released following acute stress as a primary response in grouper juveniles.

    Matched MeSH terms: Salinity
  12. Effect of aquaculture salinity on nitrification and microbial community in moving bed bioreactors with immobilized microbial granules
    Gao Y, Wang X, Li J, Lee CT, Ong PY, Zhang Z, et al.
    Bioresour Technol, 2020 Feb;297:122427.
    PMID: 31784249 DOI: 10.1016/j.biortech.2019.122427
    The novel immobilized microbial granules (IMG) shows a significant effect of nitrification for freshwater aquaculture. However, there is lack of evaluation study on the performance of nitrification at high salinity due to the concentration of recycled water or seawater utilization. A laboratory scale moving bed bioreactor (MBBR) with IMG was tested on recycled synthetic aquaculture wastewater for the nitrification at 2.5 mg/L NH3-N daily. The results indicated that IMG showed a high salinity tolerance and effectively converted ammonia to nitrate up to 92% at high salinity of 35.0 g/L NaCl. As salinity increased from near zero to 35.0 g/L, the microbial activity of nitrite oxidation bacteria (NOB) in the IMG decreased by 86.32%. The microbial community analysis indicated that salinity significantly influenced the community structure. It was found that Nitrosomonas sp. and Nitrospira sp. were the dominant genera for ammonia oxidation bacteria (AOB) and NOB respectively at different salinity levels.
    Matched MeSH terms: Salinity
  13. Currents simulation in the Malacca Straits by using three-dimensional numerical model
    Rizal S, Setiawan I, Ilhamsyah Y, Musman M, Iskandar T, Wahid MA
    Sains Malaysiana, 2010;39.
    The Malacca Straits is located between Peninsula Malaysia and Sumatra Island. This investigation used equation of motion (Navier-Stokes equation) with the following driving forces: tides, wind of National Centers for Environmental Prediction (NCEP) for year of 2007, salinity and temperature. The equation of motion was solved by means of Hamburg Shelf Ocean Model (HAMSOM). The results for both southwest and northeast monsoon were explained and discussed. The simulation results both for February and August 2007 were relatively similar. Current surface simulation in the Malacca Straits agrees well with the current pattern of previous works. The magnitude of current was between 10-70 cm/s to the northwest. While at the layer 30-50 m in the Malacca Straits, the currents have the magnitude of 10-30 cm/s towards northwest. For the bottom current, the current speed was 0-20 cm/s towards northwest. For the surface and 30-50 m layer, generally the current magnitudes were greater in February compared to those in August. While for the bottom layer, the current magnitudes between February and August were relatively the same.
    Matched MeSH terms: Salinity
  14. Factors influencing the distribution of chl-a along coastal waters of east peninsular Malaysia
    F. Shaari, Mustapha MA
    Sains Malaysiana, 2017;46:1191-1200.
    Determination of chlorophyll-a (Chl-a) distribution in the coastal waters is important to understand the coastal environmental conditions. This study was conducted to understand the spatial and temporal distribution of Chl-a along coastal waters of east Peninsular Malaysia and factors influencing its variability using Chl-a data derived from Aqua MODIS satellite (1 km spatial resolution) from January 2006 to December 2012. Chl-a variability was described using empirical orthogonal function (EOF) analysis. In-situ data (temperature, salinity, density and nitrate) and rainfall data from the Department of Meteorology were analyzed using spatial interpolation to determine factors influencing the distribution of Chl-a. The seasonal progressions of Chl-a showed high value during northeast monsoon along the coast. This variability was described by four modes of the EOF analysis. The first mode (72.08% of total variance) indicated seasonal cycle with high variability along the coast. Second mode (17.03% of variance) explained the northeast monsoon with high variability from river mouth to the south. Third mode (2.39% of variance) indicated variability during southwest monsoon along the coast and much higher to the south. Mode 4 (1.93% of variance) explained the inter-monsoon period observed along the northern and southern coastline. Concentration and distribution of Chl-a were related to availability of nutrient influenced by rainfall. The thermohaline front was also observed to play an important role in accumulation of phytoplankton biomass during northeast and southwest monsoon.
    Matched MeSH terms: Salinity
  15. Fulltext Experimental dataset on the dispersion stability of natural polymer non-covalently functionalized graphene nanoplatelets in high salinity brines
    Hamdi SS, Al-Kayiem HH, Muhsan AS, Magaril E
    Data Brief, 2020 Aug;31:105702.
    PMID: 32462067 DOI: 10.1016/j.dib.2020.105702
    The data in this article present the effective parameters of experimental ultrasonication process on the dispersion stability of graphene nanoplatelets (GNPs) grafted with a natural polymer of Gum Arabic (GA). These datasets are supporting the article "Natural Polymer Non-Covalently Grafted Graphene Nanoplatelets for Improved Oil Recovery Process: A Micromodel Evaluation" [1]. The datasets were gained during experiments conducted at various dwell time (30, 60, 90 and 120 min) at constant power amplitude (60%) of sonication for preparing the stable GA-GNP/brine solutions aiming cost-effective and green agent solution for chemical enhanced oil recovery (C-EOR). The GA-GNPs dispersion data was verified using particle size analyser and UV-Vis measurements. The optimized time and power amplitude parameters of the sonication process were utilized for preparing stabilized samples of GA grafted GNPs in regarding to research work on Natural Polymer Non-Covalently Grafted Graphene Nanoplatelets for EOR. The dispersion stability of GA-GNPs nanofluids at reservoir conditions of high salinity and high temperatures (HSHT) was further demonstrated in the measured data through the sedimentation of nanoparticles.
    Matched MeSH terms: Salinity
  16. Construction of microbial electrodialysis cells equipped with internal proton migration pathways: Enhancement of wastewater treatment, desalination, and hydrogen production
    Salehmin MNI, Hil Me MF, Daud WRW, Mohd Yasin NH, Abu Bakar MH, Sulong AB, et al.
    Sci Total Environ, 2023 Jan 10;855:158527.
    PMID: 36096221 DOI: 10.1016/j.scitotenv.2022.158527
    Microbial electrodialysis cells (MEDCs) offer simultaneous wastewater treatment, water desalination, and hydrogen production. In a conventional design of MEDCs, the overall performance is retarded by the accumulation of protons on the anode due to the integration of an anion exchange membrane (AEM). The accumulation of protons reduces the anolyte pH to become acidic, affecting the microbial viability and thus limiting the charge carrier needed for the cathodic reaction. This study has modified the conventional MEDC with an internal proton migration pathway, known as the internal proton migration pathway-MEDC (IP-MEDC). Simulation tests under abiotic conditions demonstrated that the pH changes in the anolyte and catholyte of IP-MEDC were smaller than the pH changes in the anolyte and catholyte without the proton pathways. Under biotic conditions, the performance of the IP-MEDC agreed well with the simulation test, showing a significantly higher chemical oxygen demand (COD) removal rate, desalination rate, and hydrogen production than without the migration pathway. This result is supported by the lowest charge transfer resistance shown by EIS analysis and the abundance of microbes on the bioanode through field emission scanning electron microscopy (FESEM) observation. However, hydrogen production was diminished in the second-fed batch cycle, presumably due to the active diffusion of high Cl¯ concentrations from desalination to the anode chamber, which was detrimental to microbial growth. Enlarging the anode volume by threefold improved the COD removal rate and hydrogen production rate by 1.7- and 3.4-fold, respectively, owing to the dilution effect of Cl¯ in the anode. This implied that the dilution effect satisfies both the microbial viability and conductivity. This study also suggests that the anolyte and catholyte replacement frequencies can be reduced, typically at a prolonged hydraulic retention time, thus minimizing the operating cost (e.g., solution pumping). The use of a high concentration of NaCl (35 g L-1) in the desalination chamber and catholyte provides a condition that is close to practicality.
    Matched MeSH terms: Salinity
  17. Fulltext Diversity, distribution and different habitat use among the tropical freshwater eels of genus Anguilla
    Arai T, Abdul Kadir SR
    Sci Rep, 2017 08 08;7(1):7593.
    PMID: 28790355 DOI: 10.1038/s41598-017-07837-x
    Along with the mysteries of their ecology, freshwater eels have fascinated biologists for centuries. However, information concerning species diversity, geographic distribution, and life histories of the tropical anguillid eels in the Indo-Pacific region are highly limited. Comprehensive research on the species composition, distribution and habitat use among tropical anguillid eels in the Peninsular Malaysia were conducted for four years. A total of 463 specimens were collected in the northwestern peninsular area. The dominant species was A. bicolor bicolor constituting of 88.1% of the total eels, the second one was A. bengalensis bengalensis at 11.7%, while A. marmorata was the least abundant at 0.2%. A. bicolor bicolor was widely distributed from upstream to downstream areas of the rivers. In comparison, A. bengalensis bengalensis preferred to reside from the upstream to midstream areas with no tidal zones, cooler water temperatures and higher elevation areas. The habitat preference might be different between sites due to inter-species interactions and intra-specific plasticity to local environmental conditions. These results suggest that habitat use in the tropical anguillid eels might be more influenced by ambient environmental factors, such as salinity, temperature, elevation, river size and carrying capacity, than ecological competition, such as interspecific competition.
    Matched MeSH terms: Salinity
  18. The long-term impacts of anthropogenic and natural processes on groundwater deterioration in a multilayered aquifer
    Sheikhy Narany T, Sefie A, Aris AZ
    Sci Total Environ, 2018 Jul 15;630:931-942.
    PMID: 29499548 DOI: 10.1016/j.scitotenv.2018.02.190
    In many regions around the world, there are issues associated with groundwater resources due to human and natural factors. However, the relation between these factors is difficult to determine due to the large number of parameters and complex processes required. In order to understand the relation between land use allocations, the intrinsic factors of the aquifer, climate change data and groundwater chemistry in the multilayered aquifer system in Malaysia's Northern Kelantan Basin, twenty-two years hydrogeochemical data set was used in this research. The groundwater salinisation in the intermediate aquifer, which mainly extends along the coastal line, was revealed through the hydrogeochemical investigation. Even so, there had been no significant trend detected on groundwater salinity from 1989 to 2011. In contrast to salinity, as seen from the nitrate contaminations there had been significantly increasing trends in the shallow aquifer, particularly in the central part of the study area. Additionally, a strong association between high nitrate values and the areas covered with palm oil cultivations and mixed agricultural have been detected by a multiple correspondence analysis (MCA), which implies that the increasing nitrate concentrations are associated with nitrate loading from the application of N-fertilisers. From the process of groundwater salinisation in the intermediate aquifer, could be seen that it has a strong correlation the aquifer lithology, specifically marine sediments which are influenced by the ancient seawater trapped within the sediments.
    Matched MeSH terms: Salinity
  19. Phosphorus starvation response genes and function coupling: A mechanism to regulate phosphorus availability in a subtropical estuary
    Lin L, Xiong J, Yue T, Xu W, Liu L, Wang F, et al.
    Sci Total Environ, 2024 Jun 10;928:172575.
    PMID: 38641105 DOI: 10.1016/j.scitotenv.2024.172575
    Phosphorus (P) plays an important role in regulating primary production in estuarine environments. However, knowledge of the P-functional gene composition of microbial communities and the mechanisms of microbial adaptation to changes in available P in estuaries remain limited. This study coupling 16 s rDNA and metagenomics sequencing was conducted to reveal the relationship between P cycling functional genes, microbial interactions, and P availability in the Jiulong River Estuary. The results showed that the relative abundance of P cycling functions genes was highest in winter, and lowest in summer. Spatially, the total relative abundance of P cycling functions genes was higher in the riverward than that in the seaward. P cycling functional microbial interactions and P cycling gene coupling were strongest in summer and in the seaward. Changes in both temperature and salinity had significant direct and indirect effects on P cycling function, and the influence of salinity on P cycling function was greater than that on the microbial community in the estuary. Salinity had significant direct negative effects on inorganic P-solubilization (IP), organic P-mineralization (OP), and P uptake and transport functions (PT). Whereas, salinity had a significant positive effect on P-starvation response regulation (PR) function. Thus, salinity and microbial communities regulate the soluble reactive phosphate concentrations in estuarine environments by strengthening internal coupling among P cycling functions, promoting PR function, and facilitating PT gene expression. PR is the most important predictors, PR, PT, and PR-PT together explained 38.56 % of the overall soluble reactive phosphorus (SRP) variation. Over 66 % of the explained SRP variations can be predicted by the PR, PT, and PR-PT functional genes. This finding improves the knowledge base of the microbial processes for P cycling and provides a foundation for eutrophication management strategies in the estuary.
    Matched MeSH terms: Salinity
  20. The effect of salinity on chlorophyll, proline and mineral nutrients in common weeds of coastal rice fields in Malaysia
    Hakim MA, Juraimi AS, Hanafi MM, Ismail MR, Rafii MY, Aslani F, et al.
    J Environ Biol, 2014 Sep;35(5):855-64.
    PMID: 25204059
    Six weed species (Leptochola chinensis, Echinochloa crus-galli, Echinochloa colona, Jussiaea linifolia, Oryza sativa (weedy rice) and Cyperus iria) were tested for their salt tolerant traits in terms of chlorophyll, proline and mineral nutrients accumulation against different salinity levels (0, 4, 8, 16, 24, 32, and 40 dS m(-1)). Chlorophyll a, b and total chlorophyll content, proline and mineral nutrients accumulation were determined. Salt stress showed prominent effect on all the parameters investigated and there were significant variations between the all weed species. Chlorophyll content, K+, Ca(2+) and Mg(2+) ions in both shoots and roots significantly decreased; while proline and Na+ accumulation significantly increased with increasing salinity up to 40 dS m(-1). In terms of overall performance, Cyperus iria and E. crus-galliwere relatively more tolerant; E. colona and J. linifolia were tolerant; L. chinensis and O. sativa L were salt sensitive, respectively.
    Matched MeSH terms: Salinity*
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