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Carbon dioxide (CO2) biofixation by microalgae and its potential for biorefinery and biofuel production

Kassim MA, Meng TK

Sci Total Environ, 2017 Apr 15;584-585:1121-1129.
PMID: 28169025 DOI: 10.1016/j.scitotenv.2017.01.172

Carbon dioxide (CO2) using biological process is one of the promising approaches for CO2 capture and storage. Recently, biological sequestration using microalgae has gained many interest due to its capability to utilize CO2 as carbon source and biomass produced can be used as a feedstock for other value added product for instance biofuel and chemicals. In this study, the CO2 biofixation by two microalgae species, Chlorella sp. and Tetraselmis suecica was investigated using different elevated CO2 concentration. The effect of CO2 concentration on microalgae growth kinetic, biofixation and its chemical composition were determined using 0.04, 5, 15 and 30% CO2. The variation of initial pH value and its relationship on CO2 concentration toward cultivation medium was also investigated. The present study indicated that both microalgae displayed different tolerance toward CO2 concentration. The maximum biomass production and biofixation for Chlorella sp. of 0.64gL-1 and 96.89mgL-1d-1 was obtained when the cultivation was carried out using 5 and 15% CO2, respectively. In contrast, the maximum biomass production and CO2 biofixation for T. suecica of 0.72gL-1 and 111.26mgL-1d-1 were obtained from cultivation using 15 and 5% CO2. The pH value for the cultivation medium using CO2 was between 7.5 and 9, which is favorable for microalgal growth. The potential of biomass obtained from the cultivation as a biorefinery feedstock was also evaluated. An anaerobic fermentation of the microalgae biomass by bacteria Clostridium saccharoperbutylacenaticum N1-4 produced various type of value added product such as organic acid and solvent. Approximately 0.27 and 0.90gL-1 of organic acid, which corresponding to acetic and butyric acid were produced from the fermentation of Chlorella sp. and T. suecica biomass. Overall, this study suggests that Chlorella sp. and T. suecica are efficient microorganism that can be used for CO2 biofixation and as a feedstock for chemical production.
Analysis of microalgal growth kinetic model and carbohydrate biosynthesis cultivated using agro-industrial waste residuals as carbon source

Kassim MA, Ramli SH, Meng TK

Prep Biochem Biotechnol, 2021 Aug 28.
PMID: 34455938 DOI: 10.1080/10826068.2021.1969576

Microalgal carbohydrate is considered one of the potential feedstock for biofuel produced via the bioconversion process. However, the current cultivation process using commercial medium exhibited low biomass production and its carbohydrate productivity which become a bottleneck for sustainable microalgal-carbohydrate-based biofuel production. Thus, the objective of this study is to assess the utilization of industrial waste including molasses and glycerol on the Halochlorella rubescens and Tetraselmis suecica growth as well as its carbohydrate content under different cultivation modes such as autotrophic, heterotrophic and photoheterotrophic conditions. From this study, the highest maximum biomass of H. rubenscens and T. suecica of 0.653 ± 0.009 and 0.669 ± 0.01gL-1 were obtained when the cultivation was performed under photoheterotrophic using molasses. High carbohydrate content of H. rubescens and T. seucica of 56.81 ± 0.39% and 71.52 ± 0.03% with glucose represent the dominant sugar was observed under this condition. The growth kinetic model of the analysis indicated that Huang and Gompertz Models described well the growth of H. rubescens and T. suecica under photoheteroptroph condition with a high significant R2 of 0.99. The information generated could be beneficial for the future development of low-cost microalgal cultivation media formulation for future microalgal carbohydrate-based products such as bioethanol.
Green ultrasonication-assisted extraction of microalgae Chlorella sp. for polysaturated fatty acid (PUFA) rich lipid extract using alternative solvent mixture

Hui GT, Meng TK, Kassim MA

Bioprocess Biosyst Eng, 2023 Oct;46(10):1499-1512.
PMID: 37580470 DOI: 10.1007/s00449-023-02917-x

Conventionally, microalgal lipid extraction uses volatile organic compounds as an extraction solvent. However, these solvents are harmful to human and environmental health. Therefore, this study evaluated the feasibility of alternative green solvents, namely, ethanol, dimethyl carbonate (DMC), cyclopentyl methyl ether (CPME), and 2-methyltetrahydrofuran (2-MeTHF) in lipid extraction from Chlorella sp. via ultrasound-assisted extraction (UAE). This study indicated that extraction parameters, such as ethanol-to-2-MeTHF ratio, solvent-to-biomass ratio, temperature, and time, significantly affected the crude lipid yield (P
Removal of iron and manganese by artificial destratification in a tropical climate (Upper Layang Reservoir, Malaysia)

Ismail R, Kassim MA, Inman M, Baharim NH, Azman S

Water Sci Technol, 2002;46(9):179-83.
PMID: 12448467

Environmental monitoring was carried out at Upper Layang Reservoir situated in Masai, Johor, Malaysia. The study shows that thermal stratification and natural mixing of the water column do exist in the reservoir and the level of stratification varies at different times of the year. Artificial destratification via diffused air aeration techniques was employed at the reservoir for two months. The results show that thermal stratification was eliminated after a week of continuous aeration. The concentrations of iron and to a lesser extent manganese in the water column was also reduced during the aeration period.
Fulltext Monitoring the impact of Movement Control Order (MCO) in flattening the cummulative daily cases curve of Covid-19 in Malaysia: A generalized logistic growth modeling approach

Pang NTP, Kamu A, Mohd Kassim MA, Ho CM

Infect Dis Model, 2021;6:898-908.
PMID: 34377875 DOI: 10.1016/j.idm.2021.07.004

Introduction: COVID-19 has affected almost every country in the world, which causing many negative implications in terms of education, economy and mental health. Worryingly, the trend of second or third wave of the pandemic has been noted in multiple regions despite early success of flattening the curve, such as in the case of Malaysia, post Sabah state election in September 2020. Hence, it is imperative to predict ongoing trend of COVID-19 to assist crucial policymaking in curbing the transmission.
Method: Generalized logistic growth modelling (GLM) approach was adopted to make prediction of growth of cases according to each state in Malaysia. The data was obtained from official Ministry of Health Malaysia daily report, starting from 26 September 2020 until 1 January 2021.
Result: Sabah, Johor, Selangor and Kuala Lumpur are predicted to exceed 10,000 cumulative cases by 2 February 2021. Nationally, the growth factor has been shown to range between 0.25 to a peak of 3.1 throughout the current Movement Control Order (MCO). The growth factor range for Sabah ranged from 1.00 to 1.25, while Selangor, the state which has the highest case, has a mean growth factor ranging from 1.22 to 1.52. The highest growth rates reported were in WP Labuan for the time periods of 22 Nov - 5 Dec 2020 with growth rates of 4.77. States with higher population densities were predicted to have higher cases of COVID-19.
Conclusion: GLM is helpful to provide governments and policymakers with accurate and helpful forecasts on magnitude of epidemic and peak time. This forecast could assist government in devising short- and long-term plan to tackle the ongoing pandemic.
Conventional methods and emerging wastewater polishing technologies for palm oil mill effluent treatment: a review

Liew WL, Kassim MA, Muda K, Loh SK, Affam AC

J Environ Manage, 2015 Feb 1;149:222-35.
PMID: 25463585 DOI: 10.1016/j.jenvman.2014.10.016

The Malaysian palm oil industry is a major revenue earner and the country is ranked as one of the largest producers in the world. However, growth of the industry is synonymous with a massive production of agro-industrial wastewater. As an environmental protection and public health concern, the highly polluting palm oil mill effluent (POME) has become a major attention-grabber. Hence, the industry is targeting for POME pollution abatement in order to promote a greener image of palm oil and to achieve sustainability. At present, most palm oil mills have adopted the ponding system for treatment. Due to the successful POME pollution abatement experiences, Malaysia is currently planning to revise the effluent quality standards towards a more stringent discharge limits. Hence, the current trend of POME research focuses on developing tertiary treatment or polishing systems for better effluent management. Biotechnologically-advanced POME tertiary (polishing) technologies as well as other physicochemical methods are gaining much attention as these processes are the key players to push the industry towards the goal of environmental sustainability. There are still ongoing treatment technologies being researched and the outcomes maybe available in a while. However, the research completed so far are compiled herein and reported for the first time to acquire a better perspective and insight on the subject with a view of meeting the new standards. To this end, the most feasible technology could be the combination of advanced biological processes (bioreactor systems) with extended aeration, followed by solids separation prior to discharge. Chemical dosing is favoured only if effluent of higher quality is anticipated.
Fulltext Lipase-catalyzed Production and Purification of Palm Esters Using Stirred Tank Reactors (STR)

Basri M, Rahman NFA, Kassim MA, Shahruzzaman RMHR, Mokles MSN

J Oleo Sci, 2019 Apr 01;68(4):329-337.
PMID: 30867390 DOI: 10.5650/jos.ess18197

Lipase-catalyzed production of palm esters was performed via alcoholysis of palm oil and oleyl alcohol in solvent and solvent-free systems using a 2 L stirred tank reactor (STR). Two immobilized lipases were tested and Lipozyme RM IM exhibited superior performance in both reaction systems. Reusability studies of the enzymes in a solvent-free system also demonstrated the high stability of Lipozyme RM IM as shown by its ability to yield more than 70% palm esters with up to 19 cycles of reusing the same enzymes. Modification of the enzyme washing process improved the stability of Lipozyme TL IM in a solvent system as demonstrated by maintaining 65% yield after 5 times of repeated enzyme use. The scale up process for both lipases was conducted in the presence of solvents by using the impeller tip speed approach. Lipozyme RM IM-catalyzed reaction in a 15 L STR produced 85.7% yield and there was a significant drop to 60.7% in the 300 L STR, whereas Lipozyme TL IM had a lower yield (65%) when the reaction volume was increased to 15 L. The low yields could be due to the accumulation of enzymes at the bottom of the vessel. Purification of palm esters via solvent-solvent extraction revealed that more than 90% of oleyl alcohol was extracted after the third extraction cycle at 150 rpm impeller speed with reduced palm esters: ethanol ratio (v/v) from 1:4 to 1:3.
Microwave-assisted extraction of polysaccharide from Cinnamomum cassia with anti-hyperpigmentation properties: Optimization and characterization studies

Al-Ajalein AAS, Shafie MH, Yap PG, Kassim MA, Naharudin I, Wong TW, et al.

Int J Biol Macromol, 2023 Jan 31;226:321-335.
PMID: 36502951 DOI: 10.1016/j.ijbiomac.2022.12.023

The anti-hyperpigmentation effect and tyrosinase inhibitory mechanism of cinnamon polysaccharides have not been reported. The current study focused on the extraction of polysaccharides from Cinnamomum cassia bark using microwave-assisted approach and optimization of the extraction process (i.e., microwave power, irradiation time and buffer-to-sample ratio) by Box-Behnken design to obtain a high yield of polysaccharides with high sun protection factor (SPF), anti-hyperpigmentation and antioxidant activities. The extracted pectic-polysaccharides had low molecular weight and degree of esterification. The optimal extraction process had polysaccharides characterized by (a) monophenolase inhibitory activity = 97.5 %; (b) diphenolase inhibitory activity = 99.4 %; (c) ferric reducing antioxidant power = 4.4 mM; (d) SPF = 6.1; (e) yield = 13.7 %. The SPF, tyrosinase inhibitory and antioxidant activities were primarily contributed by the polysaccharides. In conclusion, the polysaccharides from C. cassia could be an alternative therapeutic source for skin hyperpigmentation treatment.
Fulltext Efficacy of a single-session online ACT-based mindfulness intervention among undergraduates in lockdown during the COVID-19 pandemic

Pang NTP, Tio VCS, Singh ASB, Tseu MWL, Shoesmith WD, Abd Rahim MA, et al.

Trends Psychiatry Psychother, 2023 Feb 17;44:e20200172.
PMID: 34392668 DOI: 10.47626/2237-6089-2020-0172

INTRODUCTION: COVID-19 has trickle-down psychological effects on multiple strata of society, particularly university students. Apart from the worry of contracting or spreading COVID-19, Malaysian university students were also locked down on their campuses, suffering significant psychological distress. Hence, an online mindfulness intervention was proposed to alleviate psychological distress and improve psychological flexibility and mindfulness.
METHODS: This was a quasi-experimental study with university students as participants. Intervention group participants were instructed to complete online questionnaires which covered basic demographics and instruments assessing depression, anxiety, stress, mindfulness, psychological flexibility, and fear of COVID-19 before and after the one-hour intervention. The control group also completed before and after questionnaires and were subsequently crossed over to the intervention group. Repeated measures ANOVA was conducted to assess time*group effects.
RESULTS: 118 participants were involved in this study. There were significant differences in anxiety (F(1,116) = 34.361, p < 0.001, partial eta-squared = 0.229) and psychological flexibility between the two groups (F(1,116) = 11.010, p = 0.001, partial eta-squared = 0.087), while there were no differences in depression, stress, mindfulness, or fear of COVID-19.
CONCLUSION: The results of this study corroborate the efficacy of online single-session mindfulness therapy as a viable short-term psychological intervention under financial and time constraints. Since university students are in the age group with the highest incidence of depressive and anxiety disorders, it is crucial to utilize resources to address as many students as possible to ensure maximum benefit.
Fulltext Malay Version of the Fear of COVID-19 Scale: Validity and Reliability

Pang NTP, Kamu A, Hambali NLB, Mun HC, Kassim MA, Mohamed NH, et al.

Int J Ment Health Addict, 2022;20(1):263-272.
PMID: 32837437 DOI: 10.1007/s11469-020-00355-4

The newly developed Persian Fear of COVID-19 Scale (FCV-19S) is a seven-item uni-dimensional scale that assesses the severity of fear of COVID-19. A translation and validation of the FCV-19S in the Malay language was expedited due to the severe psychological sequelae of COVID-19 in Malaysia. Formal WHO forward and backward translation sequences were employed in translating the English version into Malay. Malaysian university participants were recruited via convenience sampling online using snowball methods. The reliability and validity properties of the Malay FCV-19S were rigorously psychometrically evaluated (utilising both confirmatory factor analysis and Rasch analysis) in relation to socio-demographic variables and response to the depression, anxiety and stress subscales of the Malay validation of the DASS-21. The sample comprised 228 Malaysian participants. The Cronbach α value for the Malay FCV-19S was 0.893 indicating very good internal reliability. The results of the confirmatory factor analysis showed that the uni-dimensional factor structure of the FCV19S fitted well with the data. The FCV-19S-M was significantly correlated with anxiety (r = 0.481, p
Fulltext Correction to: Malay Version of the Fear of COVID-19 Scale: Validity and Reliability

Pang NTP, Kamu A, Hambali NLB, Mun HC, Kassim MA, Mohamed NH, et al.

Int J Ment Health Addict, 2023;21(1):684.
PMID: 32840246 DOI: 10.1007/s11469-020-00373-2

[This corrects the article DOI: 10.1007/s11469-020-00355-4.].
Fulltext Fear of COVID-19 and COVID-19 Stress and Association with Sociodemographic and Psychological Process Factors in Cases under Surveillance in a Frontline Worker Population in Borneo

Pang NTP, Nold Imon G, Johoniki E, Mohd Kassim MA, Omar A, Syed Abdul Rahim SS, et al.

Int J Environ Res Public Health, 2021 Jul 05;18(13).
PMID: 34281147 DOI: 10.3390/ijerph18137210

COVID-19 stress and fear of COVID-19 is an increasingly researched construct in the general population. However, its prevalence and association with sociodemographic factors and psychological process variables has not been explored in frontline workers under surveillance in a Bornean population. This study was a cross-sectional study using a sociodemographic questionnaire incorporating two specific epidemiological risk variables, namely specific questions about COVID-19 surveillance status (persons under investigation (PUI), persons under surveillance (PUS), and positive cases) and the nature of frontline worker status. Furthermore, five other instruments were used, with three measuring psychopathology (namely depression, anxiety and stress, fear of COVID-19, and stress due to COVID-19) and two psychological process variables (namely psychological flexibility and mindfulness). Kruskal-Wallis and Mann-Whitney tests were performed to assess if there were significant differences in psychopathology and psychological process variables between sociodemographic and epidemiological risk variables. Hierarchical multiple regression was further performed, with depression, anxiety, and stress as dependent variables. There were significant differences in the fear of COVID-19 between positive cases, PUI, and PUS. The fear of COVID-19 scores were higher in positive cases compared to in PUS and PUI groups. Upon hierarchical multiple regression, mindfulness and psychological flexibility were significant predictors of depression, anxiety, and stress after controlling for sociodemographic and epidemiological risk factors. This study demonstrates that exposure to COVID-19 as persons under investigation or surveillance significantly increases the fear of COVID-19, and brief psychological interventions that can positively influence mindfulness and psychological flexibility should be prioritized for these at-risk groups to prevent undue psychological morbidity in the long run.

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