Displaying publications 81 - 100 of 703 in total

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  1. Fulltext Recovery of glucose from residual starch of sago hampas for bioethanol production
    Awg-Adeni DS, Bujang KB, Hassan MA, Abd-Aziz S
    Biomed Res Int, 2013;2013:935852.
    PMID: 23509813 DOI: 10.1155/2013/935852
    Lower concentration of glucose was often obtained from enzymatic hydrolysis process of agricultural residue due to complexity of the biomass structure and properties. High substrate load feed into the hydrolysis system might solve this problem but has several other drawbacks such as low rate of reaction. In the present study, we have attempted to enhance glucose recovery from agricultural waste, namely, "sago hampas," through three cycles of enzymatic hydrolysis process. The substrate load at 7% (w/v) was seen to be suitable for the hydrolysis process with respect to the gelatinization reaction as well as sufficient mixture of the suspension for saccharification process. However, this study was focused on hydrolyzing starch of sago hampas, and thus to enhance concentration of glucose from 7% substrate load would be impossible. Thus, an alternative method termed as cycles I, II, and III which involved reusing the hydrolysate for subsequent enzymatic hydrolysis process was introduced. Greater improvement of glucose concentration (138.45 g/L) and better conversion yield (52.72%) were achieved with the completion of three cycles of hydrolysis. In comparison, cycle I and cycle II had glucose concentration of 27.79 g/L and 73.00 g/L, respectively. The glucose obtained was subsequently tested as substrate for bioethanol production using commercial baker's yeast. The fermentation process produced 40.30 g/L of ethanol after 16 h, which was equivalent to 93.29% of theoretical yield based on total glucose existing in fermentation media.
    Matched MeSH terms: Biomass
  2. Rhodovulum sulfidophilum in the treatment and utilization of sardine processing wastewater
    Azad SA, Vikineswary S, Chong VC, Ramachandran KB
    Lett Appl Microbiol, 2004;38(1):13-8.
    PMID: 14687209
    Rhodovulum sulfidophilum was grown in settled undiluted and nonsterilized sardine processing wastewater (SPW). The aims were to evaluate the effects of inoculum size and media on the biomass production with simultaneous reduction of chemical oxygen demand (COD).
    Matched MeSH terms: Biomass
  3. Growth and production of biomass of Rhodovulum sulfidophilum in sardine processing wastewater
    Azad SA, Vikineswary S, Ramachandran KB, Chong VC
    Lett Appl Microbiol, 2001 Oct;33(4):264-8.
    PMID: 11559398
    AIMS: Rhodovulum sulfidophilum was grown in sardine processing wastewater to assess growth characteristics for the production of bacterial biomass with simultaneous reduction of chemical oxygen demand.

    METHODS AND RESULTS: Growth characteristics were compared in diluted and undiluted, settled and non-settled wastewater growing in anaerobic light and aerobic dark conditions; and also at different agitation speeds. The highest biomass (8.75 g l(-1)) and a reduction in chemical oxygen demand of 71% were obtained in unsettled, undiluted wastewater after 120 h culture with 15% inoculum. In settled wastewater, highest biomass (7.64 g l(-1)) and a COD reduction of 77% was also obtained after 120 h. Total biomass was higher (4.34 g l(-1)) after 120 h culture in anaerobic light compared to (3.23 g l(-1)) in aerobic dark growth.

    CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: Better performance, mean of total biomass (6.97 g l(-1) after 96 h), total carotenoids (4.24 mg g(-1) dry cell from 24 h) and soluble protein (431 microg ml(-1) after 96 h) were obtained from aerobic dark culture at 300 rev min(-1). The COD reduction, however, was lower (69%) after 96 h culture. Thus, the benefits in the production of bacterial biomass in non-sterilized sardine processing wastewater with the reduction of chemical oxygen demand could be achieved.

    Matched MeSH terms: Biomass*
  4. Preparation and characterizations of oil palm fronds cellulose nanocrystal (OPF-CNC) as reinforcing filler in epoxy-Zn rich coating for mild steel corrosion protection
    Azani NFSM, Haafiz MKM, Zahari A, Poinsignon S, Brosse N, Hussin MH
    Int J Biol Macromol, 2020 Jun 15;153:385-398.
    PMID: 32145234 DOI: 10.1016/j.ijbiomac.2020.03.020
    Oil palm frond (OPF) is one of largest contributions to the biomass waste from oil palm plantation. In this work, OPF has been successfully utilized to prepare cellulose nanocrystal (OPF-CNC) by acid hydrolysis. OPF was initially treated with autohydrolysis treatment. The obtained OPF-CNC was characterized via complementary analyses. The produced OPF-CNC showed a high crystallinity index value (60%) and high BET surface area (26.10 m2 g-1) as compared to α-cellulose (crystallinity index: 54% and BET surface area:7.14 m2g-1). The surface analyses via scanning electron microscope (SEM) and transmission electron microscopy (TEM) demonstrated that the OPF-CNC has a smooth surface with a needle-like shape, where the average length and diameter are 95.09 nm and 6.81 nm, respectively. The corrosion analyses via electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PD) illustrate that the coated mild steel with the inclusion of 0.5 wt% OPF-CNC has managed to sharply reduce the corrosion (99%). The coated mild steel with the inclusion of 0.5 wt% OPF-CNC showed the highest hydrophobicity (100.5 ± 0.7°) and has lowest amount of O via water contact angle and energy dispersive X-ray spectroscopy (EDX) analyses respectively, indicating lowest corrosion rate.
    Matched MeSH terms: Biomass
  5. Vermiremoval of heavy metal in sewage sludge by utilising Lumbricus rubellus
    Azizi AB, Lim MP, Noor ZM, Abdullah N
    Ecotoxicol Environ Saf, 2013 Apr;90:13-20.
    PMID: 23294636 DOI: 10.1016/j.ecoenv.2012.12.006
    Experiments were conducted to remove heavy metals (Cr, Cd, Pb, Cu and Zn) from urban sewage sludge (SS) amended with spent mushroom compost (SMC) using worms, Lumbricus rubellus, for 105 days, after 21 days of pre-composting. Five combinations of SS/SMC treatments were prepared in triplicate along with a control for each treatment in microcosms. Analysis of the earthworms' multiplication and growth and laboratory analysis were conducted during the tenth and fifteenth week of vermicomposting. Our result showed that the final biomass of earthworms (mg) and final number of earthworms showed significant differences between treatments i.e. F=554.70, P=0.00 and F=729.10, P=0.00 respectively. The heavy metals Cr, Cd and Pb contained in vermicompost were lower than initial concentrations, with 90-98.7 percent removal on week ten. However, concentrations of Cu and Zn, that are considered as micronutrients, were higher than initial concentrations, but they were 10-200-fold lower than the EU and USA biosolid compost limits and Malaysian Recommended Site Screening Levels for Contaminated Land (SSLs). An increment of heavy metals were recorded in vermicompost for all treatments on week fifteen compared to week ten, while concentration of heavy metals in earthworms' tissue were lower compared to vermicompost. Hence, it is suggested that earthworms begin to discharge heavy metals into their surroundings and it was evident that the earthworms' heavy metals excretion period was within the interval of ten to fifteen weeks.
    Matched MeSH terms: Biomass
  6. Green bioprocessing of protein from Chlorella vulgaris microalgae towards circular bioeconomy
    Azmi AAB, Chew KW, Chia WY, Mubashir M, Sankaran R, Lam MK, et al.
    Bioresour Technol, 2021 Aug;333:125197.
    PMID: 33930672 DOI: 10.1016/j.biortech.2021.125197
    The work aimed to study the potential in producing a system with high microalgal protein recovery and separation by utilizing a one-step or integrated downstream process. This in turn enables green biorefinery of protein, contributing to circular bioeconomy whereby less energy, labor, and cost are required for the process. By utilizing electric three phase partitioning flotation system, high protein recovery yield, R of 99.42 ± 0.52% and high separation efficiency, E of 52.72 ± 0.40% system was developed. Scaling up also showed high protein recovery yield with R value of 89.13 ± 1.56%. Total processing duration (extraction, separation, and purification) was also significantly reduced to 10 min. This system showed remarkable potential in reducing processing time, alternatively cost of production, benefiting microalgal downstream processing. Concisely, through this system, microalgal bioprocessing will no longer be complex allowing a wide array of potentials for further studies in this field.
    Matched MeSH terms: Biomass
  7. Current application of electrical pre-treatment for enhanced microalgal biomolecules extraction
    Azmi AAB, Sankaran R, Show PL, Ling TC, Tao Y, Munawaroh HSH, et al.
    Bioresour Technol, 2020 Apr;302:122874.
    PMID: 32007308 DOI: 10.1016/j.biortech.2020.122874
    Pretreatment of microalgal biomass possessing rigid cell wall is a critical step for enhancing the efficiency of microalgal biorefinery. However, the conventional pretreatment processes suffer the drawbacks of complex processing steps, long processing time, low conversion efficiency and high processing costs. This significantly hinders the industrial applicability of microalgal biorefinery. The innovative electricity-aid pretreatment techniques serve as a promising processing tool to extensively enhance the release of intracellular substances from microalgae. In this review, application of electric field-based techniques and recent advances of using electrical pretreatments on microalgae cell focusing on pulsed electric field, electrolysis, high voltage electrical discharges and moderate electric field are reviewed. In addition, the emerging techniques integrating electrolysis with liquid biphasic flotation process as promising downstream approach is discussed. This review delivers broad knowledge of the present significance of the application of these methods focusing on the development of electric assisted biomolecules extraction from microalgae.
    Matched MeSH terms: Biomass
  8. Ultrasonic technology for value added products from feather keratin
    Azmi NA, Idris A, Yusof NSM
    Ultrason Sonochem, 2018 Oct;47:99-107.
    PMID: 29908610 DOI: 10.1016/j.ultsonch.2018.04.016
    Feather keratin is a biomass generated in excess from various livestock industries. With appropriate processing, it holds potential as a green source for degradable biopolymer that could potentially replace current fossil fuel based materials. Several processing methods have been developed, but the use of ultrasonication has not been explored. In this study, we focus on (i) comparing and optimizing the dissolution process of turkey feather keratin through sonication and conventional processes, and (ii) generating a biodegradable polymer material, as a value added product, from the dissolved keratin that could be used in packaging and other applications. Sonication of feather keratin in pure ionic liquids (ILs) and a mixture containing ILs and different co-solvents was conducted under different applied acoustic power levels. It was found that ultrasonic irradiation significantly improved the rate of dissolution of feather keratin as compared to the conventional method, from about 2 h to less than 20 min. The amount of ILs needed was also reduced by introducing a suitable co-solvent. The keratin was then regenerated, analyzed and characterized using various methods. This material holds the potential to be reused in various appliances.
    Matched MeSH terms: Biomass
  9. Trend and status of air quality at three different monitoring stations in the Klang Valley, Malaysia
    Azmi SZ, Latif MT, Ismail AS, Juneng L, Jemain AA
    Air Qual Atmos Health, 2010 Mar;3(1):53-64.
    PMID: 20376168
    Over the last decades, the development of the Klang Valley (Malaysia), as an urban commercial and industrial area, has elevated the risk of atmospheric pollutions. There are several significant sources of air pollutants which vary depending on the background of the location they originate from. The aim of this study is to determine the trend and status of air quality and their correlation with the meteorological factors at different air quality monitoring stations in the Klang Valley. The data of five major air pollutants (PM(10), CO, SO(2), O(3), NO(2)) were recorded at the Alam Sekitar Sdn Bhd (ASMA) monitoring stations in the Klang Valley, namely Petaling Jaya (S1), Shah Alam (S2) and Gombak (S3). The data from these three stations were compared with the data recorded at Jerantut, Pahang (B), a background station established by the Malaysian Department of Environment. Results show that the concentrations of CO, NO(2) and SO(2) are higher at Petaling Jaya (S1) which is due to influence of heavy traffic. The concentrations of PM(10) and O(3,) however, are predominantly related to regional tropical factors, such as the influence of biomass burning and of ultra violet radiation from sunlight. They can, though, also be influenced by local sources. There are relatively stronger inter-pollutant correlations at the stations of Gombak and Shah Alam, and the results also suggest that heavy traffic flow induces high concentrations of PM(10), CO, NO(2) and SO(2) at the three sampling stations. Additionally, meteorological factors, particularly the ambient temperature and wind speed, may influence the concentration of PM(10) in the atmosphere.
    Matched MeSH terms: Biomass
  10. Microalgae bio-oil production by pyrolysis and hydrothermal liquefaction: Mechanism and characteristics
    Ağbulut Ü, Sirohi R, Lichtfouse E, Chen WH, Len C, Show PL, et al.
    Bioresour Technol, 2023 May;376:128860.
    PMID: 36907228 DOI: 10.1016/j.biortech.2023.128860
    Microalgae have great potential in producing energy-dense and valuable products via thermochemical processes. Therefore, producing alternative bio-oil to fossil fuel from microalgae has rapidly gained popularity due to its environmentally friendly process and elevated productivity. This current work aims to review comprehensively the microalgae bio-oil production using pyrolysis and hydrothermal liquefaction. In addition, core mechanisms of pyrolysis and hydrothermal liquefaction process for microalgae were scrutinized, showing that the presence of lipids and proteins could contribute to forming a large amount of compounds containing O and N elements in bio-oil. However, applying proper catalysts and advanced technologies for the two aforementioned approaches could improve the quality, heating value, and yield of microalgae bio-oil. In general, microalgae bio-oil produced under optimal conditions could have 46 MJ/kg heating value and 60% yield, indicating that microalgae bio-oil could become a promising alternative fuel for transportation and power generation.
    Matched MeSH terms: Biomass
  11. Elucidating the effect of process parameters on the production of hydrogen-rich syngas by biomass and coal Co-gasification techniques: A multi-criteria modeling approach
    Bahadar A, Kanthasamy R, Sait HH, Zwawi M, Algarni M, Ayodele BV, et al.
    Chemosphere, 2022 Jan;287(Pt 1):132052.
    PMID: 34478965 DOI: 10.1016/j.chemosphere.2021.132052
    The thermochemical processes such as gasification and co-gasification of biomass and coal are promising route for producing hydrogen-rich syngas. However, the process is characterized with complex reactions that pose a tremendous challenge in terms of controlling the process variables. This challenge can be overcome using appropriate machine learning algorithm to model the nonlinear complex relationship between the predictors and the targeted response. Hence, this study aimed to employ various machine learning algorithms such as regression models, support vector machine regression (SVM), gaussian processing regression (GPR), and artificial neural networks (ANN) for modeling hydrogen-rich syngas production by gasification and co-gasification of biomass and coal. A total of 12 machine learning algorithms which comprises the regression models, SVM, GPR, and ANN were configured, trained using 124 datasets. The performances of the algorithms were evaluated using the coefficient of determination (R2), root mean square error (RMSE), mean square error (MSE), and mean absolute error (MAE). In all cases, the ANN algorithms offer superior performances and displayed robust predictions of the hydrogen-rich syngas from the co-gasification processes. The R2 of both the Levenberg-Marquardt- and Bayesian Regularization-trained ANN obtained from the prediction of the hydrogen-rich syngas was found to be within 0.857-0.998 with low prediction errors. The sensitivity analysis to determine the effect of the process parameters on the model output revealed that all the parameters showed a varying level of influence. In most of the processes, the gasification temperature was found to have the most significant influence on the model output.
    Matched MeSH terms: Biomass
  12. Substrate docking and molecular dynamic simulation for prediction of fungal enzymes from Trichoderma species-assisted extraction of nanocellulose from oil palm leaves
    Bahaman AH, Abdul Wahab R, Hamid AAA, Halim KBA, Kaya Y, Edbeib MF
    J Biomol Struct Dyn, 2020 Sep;38(14):4246-4258.
    PMID: 31608812 DOI: 10.1080/07391102.2019.1679667
    Fungi of the Trichoderma species are valued industrial enzymes in support of the 'zero-waste' technology to convert agro-industrial biomass into valuable products, i.e. nanocellulose (NC). In this study, an in silico approach using substrate docking and molecular dynamic (MD) simulation was used to predict the order of which the multilayers of cellulosic polymers, i.e. lignin, hemicellulose and cellulose in oil palm leaves (OPL) are degraded by fungal enzymes, endocellulase and exocellulase. The study aimed to establish the catalytic tendencies of the enzymes to optimally degrade the cellulosic components of OPL for high yield production of NC. Energy minimized endocellulase and exocellulase models revealed satisfactory scores of PROCHECK (90.0% and 91.2%), Verify3D (97.23% and 98.85%) and ERRAT (95.24% and 91.00%) assessments. Active site prediction by blind docking, COACH meta-server and multiple sequence alignment indicated the catalytic triads for endocellulase and exocellulase were Ser116-His205-Glu249 and Ser382-Arg124-Asp385, respectively. Binding energy of endocellulase docked with hemicellulose (-6.0   kcal mol-1) was the most favourable followed by lignin (-5.6   kcal mol-1) and cellulose (-4.4   kcal mol-1). Exocellulase, contrarily, bonded favorably with lignin (-8.7   kcal mol-1), closely followed by cellulose (-8.5   kcal mol-1) and hemicellulose (-8.4   kcal mol-1). MDs simulations showed that interactions of complexes, endocellulase-hemicellulose and the exocellulase-cellulose being the most stable. Thus, the findings of the study successfully identified the specific actions of sugar-acting enzymes for NC production. Communicated by Ramaswamy H. Sarma.
    Matched MeSH terms: Biomass
  13. Fulltext Isolation of Industrial Important Bioactive Compounds from Microalgae
    Balasubramaniam V, Gunasegavan RD, Mustar S, Lee JC, Mohd Noh MF
    Molecules, 2021 Feb 10;26(4).
    PMID: 33579001 DOI: 10.3390/molecules26040943
    Microalgae are known as a rich source of bioactive compounds which exhibit different biological activities. Increased demand for sustainable biomass for production of important bioactive components with various potential especially therapeutic applications has resulted in noticeable interest in algae. Utilisation of microalgae in multiple scopes has been growing in various industries ranging from harnessing renewable energy to exploitation of high-value products. The focuses of this review are on production and the use of value-added components obtained from microalgae with current and potential application in the pharmaceutical, nutraceutical, cosmeceutical, energy and agri-food industries, as well as for bioremediation. Moreover, this work discusses the advantage, potential new beneficial strains, applications, limitations, research gaps and future prospect of microalgae in industry.
    Matched MeSH terms: Biomass*
  14. Seasonal variations of zooplankton biomass and size-fractionated abundance in relation to environmental changes in a tropical mangrove estuary in the Straits of Malacca
    Balqis ARS, Yusoff FM, Arshad A, Nishikawa J
    J Environ Biol, 2016 Jul;37(4 Spec No):685-95.
    PMID: 28779727
    Seasonal variations of zooplankton community in terms of biomass and size-fractionated densities were studied in a tropical Sangga Kechil river, Matang, Perak from June 2010 to April 2011. Zooplankton and jellyfish (hydromedusae, siphonophores and ctenophores) samples were collected bimonthly from four sampling stations by horizontal towing of a 140-?m plankton net and 500 ?m bongo net, respectively. A total of 12 zooplankton groups consisting of six groups each of mesozooplankon (0.2 mm-2.0 mm) and macrozooplankton (2.0 mm-20.0 cm) were recorded. The total zooplankton density (12375?3339 ind m(-3)) and biomass (35.32?14.56 mg m(-3)) were highest during the northeast (NE) monsoon and southwest (SW) monsoon, respectively, indicating the presence of bigger individuals in the latter season. Mesozooplankton predominated (94%) over the macrozooplankton (6%) during all the seasons, and copepods contributed 84% of the total mesozooplankton abundance. Macrozooplankton was dominated by appendicularians during most of the seasons (43%-97%), except during the NE monsoon (December) when chaetognaths became the most abundant (89% of the total macrozooplankton). BIO-ENV analysis showed that total zooplankton density was correlated with turbidity, total nitrogen and total phosphorus, which in turn was positively correlated to chlorophyll a. Cluster analysis of the zooplankton community showed no significant temporal difference between the SW and NE monsoon season during the study period (> 90% similarity). The present study revealed that the zooplankton community in the tropical mangrove estuary in the Straits of Malacca was dominated by mesoplankton, especially copepods.
    Matched MeSH terms: Biomass*
  15. Fulltext Rainfall seasonality and pest pressure as determinants of tropical tree species' distributions
    Baltzer JL, Davies SJ
    Ecol Evol, 2012 Nov;2(11):2682-94.
    PMID: 23170205 DOI: 10.1002/ece3.383
    Drought and pests are primary abiotic and biotic factors proposed as selective filters acting on species distributions along rainfall gradients in tropical forests and may contribute importantly to species distributional limits, performance, and diversity gradients. Recent research demonstrates linkages between species distributions along rainfall gradients and physiological drought tolerance; corresponding experimental examinations of the contribution of pest pressure to distributional limits and potential interactions between drought and herbivory are limited. This study aims to quantitate differential performance and herbivory as a function of species range limits across a climatic and floristic transition in Southeast Asia. Khao Chong Botanical Garden, Thailand and Pasoh Forest Reserve, Malaysia straddle the Kangar-Pattani Line. A reciprocal transplantation across a seasonality gradient was established using two groups of species ("widespread" taxa whose distributions include seasonally dry forests and "aseasonal" taxa whose distributions are limited to aseasonal forests). Growth, biomass allocation, survival, and herbivory were monitored for 19 months. Systematic differences in performance were a function of species distribution in relation to rainfall seasonality. In aseasonal Pasoh, aseasonal species had both greater growth and survivorship than widespread species. These differences were not a function of differential herbivory as widespread and aseasonal species experienced similar damage in the aseasonal forest. In seasonally dry Khao Chong, widespread species showed higher survivorship than aseasonal species, but these differences were only apparent during drought. We link this differential performance to physiological mechanisms as well as differential tolerance of biotic pressure during drought stress. Systematic decreases in seedling survival in aseasonal taxa during drought corresponded with previously documented physiological differences and may be exacerbated by herbivore damage. These results have important implications for tropical diversity and community composition in light of predicted increases in the frequency and severity of drought in hyperdiverse tropical forests.
    Matched MeSH terms: Biomass
  16. Fulltext Effects of Aging on Parasite Biomass, Inflammation, Endothelial Activation, Microvascular Dysfunction and Disease Severity in Plasmodium knowlesi and Plasmodium falciparum Malaria
    Barber BE, Grigg MJ, William T, Piera KA, Boyle MJ, Yeo TW, et al.
    J Infect Dis, 2017 06 15;215(12):1908-1917.
    PMID: 28863470 DOI: 10.1093/infdis/jix193
    Background: In populations pauci-immune to malaria, risk of severe malaria increases with age. This is particularly apparent in Plasmodium knowlesi malaria. However, pathophysiological mechanisms underlying knowlesi malaria, and of the age-related increase in risk of severe malaria in general, are poorly understood.

    Methods: In Malaysian patients aged ≥12 years with severe (n = 47) and nonsevere (n = 99) knowlesi malaria, severe (n = 21) and nonsevere (n = 109) falciparum malaria, and healthy controls (n = 50), we measured parasite biomass, systemic inflammation (interleukin 6 [IL-6]), endothelial activation (angiopoietin-2), and microvascular function, and evaluated the effects of age.

    Results: Plasmodium knowlesi parasitemia correlated with age (Spearman's correlation coefficient [rs] = 0.36; P < .0001). In knowlesi malaria, IL-6, angiopoietin-2, and microvascular dysfunction were increased in severe compared to nonsevere disease, and all correlated with age, independent of parasitemia. In falciparum malaria, angiopoietin-2 increased with age, independent of parasite biomass (histidine-rich protein 2 [HRP2]). Independent risk factors for severe malaria included parasitemia and angiopoietin-2 in knowlesi malaria, and HRP2, angiopoietin-2, and microvascular dysfunction in falciparum malaria.

    Conclusions: Parasite biomass, endothelial activation, and microvascular dysfunction are associated with severe disease in knowlesi malaria and likely contribute to pathogenesis. The association of each of these processes with aging may account for the greater severity of malaria observed in older adults in low-endemic regions.

    Matched MeSH terms: Biomass
  17. Fulltext Long-term trends in calcifying plankton and pH in the North Sea
    Beare D, McQuatters-Gollop A, van der Hammen T, Machiels M, Teoh SJ, Hall-Spencer JM
    PLoS One, 2013;8(5):e61175.
    PMID: 23658686 DOI: 10.1371/journal.pone.0061175
    Relationships between six calcifying plankton groups and pH are explored in a highly biologically productive and data-rich area of the central North Sea using time-series datasets. The long-term trends show that abundances of foraminiferans, coccolithophores, and echinoderm larvae have risen over the last few decades while the abundances of bivalves and pteropods have declined. Despite good coverage of pH data for the study area there is uncertainty over the quality of this historical dataset; pH appears to have been declining since the mid 1990s but there was no statistical connection between the abundance of the calcifying plankton and the pH trends. If there are any effects of pH on calcifying plankton in the North Sea they appear to be masked by the combined effects of other climatic (e.g. temperature), chemical (nutrient concentrations) and biotic (predation) drivers. Certain calcified plankton have proliferated in the central North Sea, and are tolerant of changes in pH that have occurred since the 1950s but bivalve larvae and pteropods have declined. An improved monitoring programme is required as ocean acidification may be occurring at a rate that will exceed the environmental niches of numerous planktonic taxa, testing their capacities for acclimation and genetic adaptation.
    Matched MeSH terms: Biomass
  18. Integrated catalytic insights into methanol production: Sustainable framework for CO2 conversion
    Bhardwaj R, Sharma T, Nguyen DD, Cheng CK, Lam SS, Xia C, et al.
    J Environ Manage, 2021 Jul 01;289:112468.
    PMID: 33823414 DOI: 10.1016/j.jenvman.2021.112468
    A continuous increase in the amount of greenhouse gases (GHGs) is causing serious threats to the environment and life on the earth, and CO2 is one of the major candidates. Reducing the excess CO2 by converting into industrial products could be beneficial for the environment and also boost up industrial growth. In particular, the conversion of CO2 into methanol is very beneficial as it is cheaper to produce from biomass, less inflammable, and advantageous to many industries. Application of various plants, algae, and microbial enzymes to recycle the CO2 and using these enzymes separately along with CO2-phillic materials and chemicals can be a sustainable solution to reduce the global carbon footprint. Materials such as MOFs, porphyrins, and nanomaterials are also used widely for CO2 absorption and conversion into methanol. Thus, a combination of enzymes and materials which convert the CO2 into methanol could energize the CO2 utilization. The CO2 to methanol conversion utilizes carbon better than the conventional syngas and the reaction yields fewer by-products. The methanol produced can further be utilized as a clean-burning fuel, in pharmaceuticals, automobiles and as a general solvent in various industries etc. This makes methanol an ideal fuel in comparison to the conventional petroleum-based ones and it is advantageous for a safer and cleaner environment. In this review article, various aspects of the circular economy with the present scenario of environmental crisis will also be considered for large-scale sustainable biorefinery of methanol production from atmospheric CO2.
    Matched MeSH terms: Biomass
  19. Modeling and simulation of an enzymatic reactor for hydrolysis of palm oil
    Bhatia S, Naidu AD, Kamaruddin AH
    Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):435-40.
    PMID: 10595445
    Hydrolysis of palm oil has become an important process in Oleochemical industries. Therefore, an investigation was carried out for hydrolysis of palm oil to fatty acid and glycerol using immobilized lipase in packed bed reactor. The conversion vs. residence time data were used in Michaelis-Menten rate equation to evaluate the kinetic parameters. A mathematical model for the rate of palm oil hydrolysis was proposed incorporating role of external mass transfer and pore diffusion. The model was simulated for steady-state isothermal operation of immobilized lipase packed bed reactor. The experimental data were compared with the simulated results. External mass transfer was found to affect the rate of palm oil hydrolysis at higher residence time.
    Matched MeSH terms: Biomass
  20. A study on the effects of increment and decrement repeated fed-batch feeding of glucose on the production of poly(3-hydroxybutyrate) [P(3HB)] by a newly engineered Cupriavidus necator NSDG-GG mutant in batch fill-and-draw fermentation
    Biglari N, Orita I, Fukui T, Sudesh K
    J Biotechnol, 2020 Jan 10;307:77-86.
    PMID: 31669355 DOI: 10.1016/j.jbiotec.2019.10.013
    This study investigates the effect of strategies on poly(3-hydroxybutyrate) [P(3HB)] production in bioreactor. In the production of P(3HB), urea and glucose feeding streams were developed to characterize the fed-batch culture conditions for new Cupriavidus necator NSDG-GG mutant. Feeding urea in repeated fed-batch stage (RFB-I) at 6, and 12 h in cultivation led to insignificant kinetic effect on the cell dry mass (CDM) and P(3HB) accumulation. Feeding glucose in repeated fed-batch stage (RFB-II) demonstrated that the incremental feeding approach of glucose after urea in fill-and-draw (F/D) mode at 24, 30, 36, 42, and 48 h in fermentation increased CDM and P(3HB) concentration. In the 1st cycle in RFB-II, the cumulative CDM reached the value of 26.22 g/L and then it increased with the successive repeated fed-batches to attain biomass of 145 g/L at the end of 5th cycle of RFB-II. The final cumulative P(3HB) concentration at the end of 5th cycle of RFB-II reached 111 g/L with the overall yield of 0.50 g P(3HB) g gluc- 1; the CDM productivity from the RFB-II cycles was in the range of 0.84-1.3 g/(L·h). The RFB-II of glucose in an increment mode produced nearly 2.2 times more increase in CDM and P(3HB) productivities compared to the decrement RFB-II mode. Repeated cultivation had also the advantage of avoiding extra time required for innoculum preparation, and sterilization of bioreactor during batch, thereby it increased the overall industrial importance of the process.
    Matched MeSH terms: Biomass
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