Displaying publications 1 - 20 of 52 in total

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  1. Er CM, Sunar NM, Leman AM, Othman N
    MethodsX, 2015;2:340-4.
    PMID: 27077051 DOI: 10.1016/j.mex.2015.07.002
    Indoor air pollution by airborne fungi has risen to become a common issue all over the world and it is hazardous to indoor occupants' health as it is associated with a series of respiratory-related and skin-related diseases. Selected bioactive compounds from the food industry have been suggested to be effective against individual fungus isolated from indoor environment. However, the techniques used to evaluate these compounds were lengthy and unsuitable against total airborne fungi. Therefore, this paper describes an assay to assess the effectiveness of a bioactive compound to inhibit growth of total airborne fungi.•A combination and modification of previous methods and the NIOSH Manual Analytical Standard Method (NMAM 0800) is proposed.•This method concurrently samples the total airborne fungi and evaluates the ability of bioactive compounds (potassium sorbate in this paper), as a biocide, to treat these indoor airborne fungi.•The current method shortens the time of evaluation from 30 days to only 5 days and employs the counting of colony forming units (CFUs) to ease the measurement of the growth of fungi.
  2. Ramalakshmi S, Ooi CW, Ariff AB, Ramanan RN
    MethodsX, 2014;1:229-32.
    PMID: 26150957 DOI: 10.1016/j.mex.2014.09.006
    The use of biodegradable material such as simple carbohydrates and recyclable material such as thermo-sensitive polymers is in need to develop a sustainable aqueous two-phase system (ATPS) for the purification of biomolecules. Accurate determination of sucrose concentration is important in liquid-liquid equilibrium (LLE) study of carbohydrate-based ATPS. The well-established phenol-sulfuric acid method has been widely employed in the measurement of carbohydrate concentration. However, the presence of thermo-sensitive polymers, which has a lower critical solution temperature (LCST) below room temperature, in carbohydrate samples could hamper the precision of spectrophotometric analysis due to the formation of two phases or cloudiness in the sample. Thus, the following modifications were made in an attempt to eliminate the interference occurred during conventional phenol-sulfuric acid assay.•The modified assay for sucrose quantification was performed at an ice-cold temperature throughout the reaction in order to avoid the interference from thermo-sensitive polymers.•This method required a sample volume of 3 μL and hence the volume of other reagents employed was also considerably reduced.•The absorbance was measured at 520 nm which allowed a longer linearity range (0.05-7.5%, w/v).
  3. Khattak MA, Ali M, Rizvi SAR
    MethodsX, 2021;8:101198.
    PMID: 33425689 DOI: 10.1016/j.mex.2020.101198
    This research attempts to explore the total of 21 potential internal and external shocks to the European market during the Covid-19 Crisis. Using the time series of 1 Jan 2020 to 26 June 2020, I employ a machine learning technique, i.e. Least Absolute Shrinkage and Selection Operator (LASSO) to examine the research question for its benefits over the traditional regression methods. This further allows me to cater to the issue of limited data during the crisis and at the same time, allows both variable selection and regularization in the analysis. Additionally, LASSO is not susceptible to and sensitive to outliers and multi-collinearity. The European market is mostly affected by indices belonging to Singapore, Switzerland, Spain, France, Germany, and the S&P500 index. There is a significant difference in the predictors before and after the pandemic announcement by WHO. Before the Pandemic period announcement by WHO, Europe was hit by the gold market, EUR/USD exchange rate, Dow Jones index, Switzerland, Spain, France, Italy, Germany, and Turkey and after the announcement by WHO, only France and Germany were selected by the lasso approach. It is found that Germany and France are the most predictors in the European market.•A LASSO approach is used to predict the European stock market index during COVID-19•European market is mostly affected by the indices belonging to Singapore, Switzerland, Spain, France, Germany, and the S&P500 index.•There is a significant difference in the predictors before and after the pandemic announcement by WHO.
  4. Abd Manan TSB, Beddu S, Khan T, Wan Mohtar WHM, Sarwono A, Jusoh H, et al.
    MethodsX, 2019;6:1701-1705.
    PMID: 31388505 DOI: 10.1016/j.mex.2019.07.011
    Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic compounds, composed of two or more fused benzene rings and abundantly found in mixed-use areas. Mixed-use areas consist of dense population, urbanization, industrial and agricultural activities. River pollution are common in mixed-use areas and 98% of Malaysia's fresh water supply originates from surface water. The biological degradation, adsorption and advanced oxidation process were documented as the available PAHs treatment for water. To date, the application of the photo-Fenton oxidation process has been reported for the treatment of PAHs from contaminated soil (review paper), landfill leachate, municipal solid waste leachate, sanitary landfill leachate, aniline wastewater, ammunition wastewater and saline aqueous solutions. As for potable water, the application of Fenton reagent was aided with photo treatment or electrolysis not focusing on PAHs removal. •The presented MethodsX was conducted for PAHs degradation analysis in potable water samples using photo-Fenton oxidation process.•The designed reactor for batch experiment is presented.•The batch experiment consists of parameters like concentration of 17 USEPA-PAHs in the prepared aqueous solution (fixed variable), reaction time, pH and molarity ratio of hydrogen peroxide (H2O2): ferrous sulfate (FeSO4).
  5. Mohammed JN, Wan Dagang WRZ
    MethodsX, 2019;6:1467-1472.
    PMID: 31289724 DOI: 10.1016/j.mex.2019.06.002
    The economy of mass bioflocculant production and its industrial application is couple with the cost of production. The growth medium is the most significant factor that accounts for the production cost. In order to find a substitute for the expensive commercial media mostly the carbon and nitrogen sources used for bioflocculant production, we use chicken viscera as a sole source of nutrient for bioflocculant production. The culture conditions for Aspergillus flavus S44-1 growth and bioflocculant yield were optimized through one factor at a time (OFAT). The use of chicken viscera as a sole source to develop a culture medium seems to be more appropriate, simple, reduce cost of bioflocculant production and in addition offers a sustainable means of managing environmental pollution by the poultry waste. In this article, we focus on detailed description of the steps involve in developing an optimized culture medium using chicken viscera as a sole source for bioflocculant production. •A new media for bioflocculant production was developed from chicken viscera.•The culture conditions for bioflocculant production were determined and optimized.•The bioflocculant yield and efficiency were parallel to mycelial weight at log phase.
  6. Arifin MH, Kayode JS, Ismail MKI, Abdullah AM, Embrandiri A, Nazer NSM, et al.
    MethodsX, 2021;8:101182.
    PMID: 33365262 DOI: 10.1016/j.mex.2020.101182
    A novel methodological approach was developed to quantified the volume of industrial waste desposal (IWD) site, combined with municipal waste materials (MWM), through the integration of a non-invasive, fast, and less expenssive RES2-D Electrical Resistivity Technique (ERT), using Wenner-Schlumberger electrode array geophysical method with Oasis Montaj software. Underground water bearing structures, and the eco-system are being contaminated through seepage of the plumes emanating from the mixtures of the industrial waste materials (IWM), made of moist cemented soil with municipal solid wastes (MSW) dumped at the site. The distribution of the contiminant hazardous plumes emanating from the waste materials' mixtures within the subsurface structural lithological layers was clearly map and delineated within the near-surface structures, using the triplicate technique to collect samples of the soil with the waste mixtures, and the water analysis for the presence of dissolved ions. The deployed method helped to monitor the seepage of the contaminant leachate plumes to the groundwater aquifer units via the ground surface, through the subsurface stratum lithological layers, and hence, estimation of the waste materials' volume was possibly approximated to be 312,000 m3. In summary, the novel method adopted are as presented below:•The novel method is transferable, reproduce-able, and most importantly, it is unambiguous technique for the quantification of environmental, industrial and municipal waste materials.•It helps to map the distribution of the plumes emanating from the waste materials' mixtures within the subsurface structural lithological layers that was clearly delineated within the near-surface structures underlain the study site.•The procedure helped in the monitoring of leachate contaminants plumes seepages into the surface water bodies and the groundwater aquifer units, via the ground surface, through to the porous subsurface stratum lithological layers.
  7. Sulandari W, Subanar S, Lee MH, Rodrigues PC
    MethodsX, 2020;7:101015.
    PMID: 32793431 DOI: 10.1016/j.mex.2020.101015
    Hybrid methodologies have become popular in many fields of research as they allow researchers to explore various methods, understand their strengths and weaknesses and combine them into new frameworks. Thus, the combination of different methods into a hybrid methodology allows to overcome the shortcomings of each singular method. This paper presents the methodology for two hybrid methods that can be used for time series forecasting. The first combines singular spectrum analysis with linear recurrent formula (SSA-LRF) and neural networks (NN), while the second combines the SSA-LRF and weighted fuzzy time series (WFTS). Some of the highlights of these proposed methodologies are:•The two hybrid methods proposed here are applicable to load data series and other time series data.•The two hybrid methods handle the deterministic and the nonlinear stochastic pattern in the data.•The two hybrid methods show a significant improvement to the single methods used separately and to other hybrid methods.
  8. Danish M, Akhtar MN, Hashim R, Saleh JM, Bakar EA
    MethodsX, 2020;7:100983.
    PMID: 32742942 DOI: 10.1016/j.mex.2020.100983
    This article encompasses the method related to image segmentation of the Field Emission Scanning Electron Microscope (FESEM) images of Acacia Mangium Wood derived Activated Carbons under different conditions. Image segmentation using Hue-Saturation-Value (HSV) thresholding method was adapted to identify the different pattern composition in the grayscale images by varying the intensity Value (V) and keeping Hue (H) and Saturation (S) to zero, and each pattern was considered as one type of element that constituted the Activated Carbon. The algorithm was developed to compute the percentage of each pattern using non-zero pixels, and on the basis of different patterns, different elements having certain percentage of composition were recorded. Later, these results were compared with the Energy Dispersive X-ray Spectroscopy (EDS) to cross check the difference in percentage of each element present at the surface of the Activated Carbon. Part of this result is published in the article [1], "Comparison of surface properties of wood biomass Activated Carbons and their application against rhodamine B and methylene blue dye" Surfaces and Interfaces vol. 11 (2018) pp1-13.•The methods involved will be useful for characterization of Activated Carbon materials.•Image segmentation using HSV thresholding will inspire other researchers to apply similar concept on other materials.•Different patterns obtained for FESEM images using HSV thresholding was able to determine the presence of multiple elements present in the prepared Activated Carbon samples.
  9. Elias MS, Ibrahim S, Samuding K, Rahman SA, Wo YM
    MethodsX, 2018;5:454-465.
    PMID: 30090704 DOI: 10.1016/j.mex.2018.05.001
    Fourteen sediment samples were collected along Linggi River, Malaysia. Neutron activation analysis (NAA) and inductively coupled plasma-mass spectrometry (ICP-MS) techniques were used in the determination of toxic element contents. The results showed that As, Cd and Sb concentrations were higher at all sampling stations, with enrichment factor values ranging from 17.7 to 75.0, 2.1 to 19.5 and 6.6 to 28.4, respectively. Elements of Pb and Zn) were also enriched at most of the sampling stations whilst Cu, Cr and Ni were shown as background levels. The sediment of Linggi River can be categorised as low (<8.0) to very high degree of contamination (>32.0). The mean concentrations of elements viz. Cd, Cr, Ni, Pb, Sb and Zn were lower than the threshold effect level (TEL) of FSQGs values except for As. The concentration of As (arsenic) was higher than PEL and PEC of FSQGs values.
  10. Yusup Y, Kayode JS, Alkarkhi AFM
    MethodsX, 2018;5:448-453.
    PMID: 30090703 DOI: 10.1016/j.mex.2018.05.003
    The southern South China coastal oceans within the South East Asian region are much lacking in the perception of the surface energy budget and evaporation over the ocean waters in response to climatic changes. The eddy covariance method was used to measure the energy fluxes, microclimate variables, and surface water temperature from November 2015 to October 2017 at the Straits of Malacca, South China Sea; Pulau Pinang, Malaysia, situated at latitude 5°28'06″N, and longitude 100°12'01″E. This work focused on the methodological approach to the air-sea energy fluxes data collection and analysis. In this regard, the method applied for the direct measurements and analysis of energy fluxes and other meteorological parameters in the site is considered and reported. •The paper summarizes the analysis of energy fluxes, microclimate variables, and surface water temperature data in a tropical coastal ocean station using the eddy covariance method.•The methodological approach illustrates the method of analysis applied in this study which can be compared and used for similar studies in other places.•The reproducible data analysis technique matches similar comparative methods such as Matlab and Python.
  11. Agatonovic-Kustrin S, Morton DW
    MethodsX, 2018;5:797-802.
    PMID: 30101083 DOI: 10.1016/j.mex.2018.07.013
    A high-performance thin-layer chromatography (HPTLC) method was developed for quantification of α-amylase inhibitory activity and stigmasterol content in ant plant extracts. An improved HPTLC method for the determination of total free radical scavenging activity in samples using DPPH• is also reported. For quantification of α-amylase inhibitory activity, the developed HPTLC plate is dipped into an α-amylase solution, and the bioautogram is then incubated at 25 °C for 30 min under humid conditions. For visualization of enzyme inhibitory activity, the starch test with an iodine indicator solution is used. The blue zone observed comes from the starch-iodine complex formed from starch that was not hydrolyzed by the amylase due to enzyme inhibition by the compound(s) present in the sample. The area of the blue zones was used to compare and quantify relative α-amylase inhibitory activity in different extracts. Location of the blue zones (hRF) on the plate was used to detect compounds that are responsible for the α-amylase inhibitory activity. Relative α-amylase activity was not related to the antioxidant activity, but was highly correlated with the stigmasterol content in the sample extracts (R = 0.95). Therefore, plant sterols present in the extracts might be responsible for α-amylase inhibitory activities in the extracts. •The developed method for quantification of α-amylase inhibitory activity provides an efficient and effective tool that can be used to screen, detect and quantify α-amylase inhibitory activity in plant extracts.•The proposed protocol is easy to run, involves minimal sample preparation, with multiple samples able to be analyzed in parallel on the same chromatographic plate, in a short time.•There were significant differences in α-amylase inhibitory activity, stigmasterol content, and total free radical scavenging activity between methanol, ethanol, dichloromethane, and ethyl acetate ant plant extracts.
  12. Husain MAA, Hashim S, Zakaria N, Mohamed Zin MR
    MethodsX, 2018;5:1346-1363.
    PMID: 30416978 DOI: 10.1016/j.mex.2018.10.011
    This paper describes the development of a custom-designed underwater scanner to support the experimental works for characterizing irradiated fuel stored in the TRIGA PUSPATI pool by means of radiography technique. Materials used to build the scanner are aluminum 6061, lead and teflon. Three main units that make up the scanner are rig structure, arm block and collimator. Collimator is designed to control radiation exposure by opening and closing the shutter. The experimental works were conducted underwater at 5-m depth hence water tightness is one of the main design criteria. Radiation in terms of gamma energy is captured by radiography film which after development and processing revealed the image of the radiation impact in terms of pixel and gray value. The film size used is 4in x 8in which was slot in the collimator. To validate the scanner, fuel element containing 8.5 wt% and 12 wt% enriched Uranium 235 were used. It was found that the experimental output is consistent with the fuel type and confirmed that the scanner is viable for fuel characterization study.
  13. Adewoyin OO, Omeje M, Joel ES, Akinwumi SA, Ehi-Eromoseled CO, Embong Z
    MethodsX, 2018;5:1419-1426.
    PMID: 30456176 DOI: 10.1016/j.mex.2018.10.023
    The activity levels of 238U, 232Th and 40K in soil surrounding major office complexes in Covenant University were analyzed for radiological hazards to determine the safety of the residents in such environment. Sixteen (16) soil samples were collected, prepared and sent to Acme laboratory in Canada for analysis with the use of high purity germanium detector. The mean activity concentrations of 238U, 232Th and 40K were found to be 45 ± 10, 135 ± 8 and 195 ± 20 respectively. The concentrations of 238U and 232Th were found to be higher than the world recommended standard of 35 and 30, while the result for 40K was noted to be lower than the world safe limit. The average values of Raeq, D, AED, Iyr, Hex and ELCR in this study were estimated to be 252.33 Bq/kg, 110.15 nGy/h, 0.13 mSv/y, 1.78, 0.68 and 0.47 × 10-3 respectively. It was noticed that none of the measured parameters was higher than the internationally recommended safe limits. 232Th was found to be the major contributor to the environmental radionuclides in the area of study. Therefore, the inhabitants of the office complexes whose environment was assessed are considered not be exposed to any radiological hazards.
  14. Khasawneh OFS, Palaniandy P, Teng LP
    MethodsX, 2019;6:2735-2743.
    PMID: 31788439 DOI: 10.1016/j.mex.2019.11.016
    Heterogeneous photocatalysis is a promising advanced oxidation process for the degradation of emerging contaminants. In this regard, Hematite (α-Fe2O3) doped TiO2 nanocomposite catalyst was synthesized via sol-gel method. The catalyst was prepared in large quantities (225 g) comparatively with other studies and characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy-dispersive X-ray (EDX), and nitrogen gas physisorption studies. The bandgap of the synthesized catalyst was determined using UV-vis diffused reflectance spectroscopy (DRS), and the point of zero charge (PZC) was identified by measuring the zeta potential (ζ-potential) of the nanoparticles. A large-scale study was conducted using a modified Compound Parabolic Collector Reactor (CPCR) for the degradation of paracetamol under natural sunlight irradiations. The operating parameters including the initial concentration of paracetamol, initial pH of the solution, and catalyst loading were optimized using face-centered central composite design (FCCD) based on response surface method (RSM) to obtain the maximum degradation efficiency of paracetamol. •The simplified and direct sol-gel method described helps in the synthesis of a novel nanocomposite catalyst (Fe2O3/TiO2) in large quantities while maintaining good characteristics compared to other methods.•The described treatment method using the modified CPCR will allow the degradation of paracetamol in a more sustainable and green manner.•Optimizing the operating parameters that have a significant influence on the degradation of paracetamol will contribute towards higher degradation rates.
  15. Kassem MM, Mohamed Nazri F, Noroozinejad Farsangi E
    MethodsX, 2019;6:199-211.
    PMID: 30766800 DOI: 10.1016/j.mex.2019.01.006
    This paper presents a simplified method in the seismic vulnerability assessment of reinforced concrete (RC) buildings based on proposed seismic vulnerability index (SVI) methodology. The employed procedure is derived with some modifications from the Italian GNDT and the European Macro-seismic approaches. Eight parameters were modeled in three distinct vulnerability classes to estimate the vulnerability indices of RC structures. The vulnerability classes were categorized based on the earthquake resistant design (ERD) defined as; (Low, Moderate, and High)-ERDs. Nonlinear time history analysis (NL-THA) and nonlinear static analysis (NL-SA) were carried out to define the weight of each parameter in order to calculate the seismic vulnerability index in a specific intensity (PGA) of an earthquake event. Knowing that it ranges from 0 to 1 from less vulnerable to most vulnerable with respect to the seismic intensity. In addition, the engineering demand parameter (EDP) used to determine the vulnerability index as the maximum top displacement of the structure. After determining the (SVI), The mean damage states were developed to evaluate the estimated physical damage of buildings in distinct seismic intensities. •This simplified methodology helps to manage and implements strategies for the safety of the communities before earthquake takes place by investigating the vulnerability classes for each building type.•Modeling the parameters that have an influence on the structural behavior without considering the past-damages observations through an analytical approach.•Developing the seismic vulnerability index can reduce or limit the role of the rapid visual screening methods, which is based on expert opinion decisions, and depends on observations of damages caused by earthquakes, and can be a useful framework criterion in earthquake filed.
  16. Jawad MS, Chandran P, Ramli AAB, Mahdin HB, Abdullah ZB, Rejab MBM
    MethodsX, 2022;9:101920.
    PMID: 36420313 DOI: 10.1016/j.mex.2022.101920
    To achieve the maximum return-of-investment for the adoption of Digital-Twin in manufacturing, organizations should be totally aware about the challenges that limit the widely adoption as well as opportunities that may create real-added values to their businesses at operational and strategic management. In this context, determining the most influential factors for successful adoption must be clear even at the early stages of planning towards high effective digital-transformation journey for business's sustainability. The beneficial achievements and outcome towards such successful planning and adoption of the industrial digital-twin are significant in terms of optimized processes, reduced costs and downtown of the operations, flexibility in product design and processes' adaptation to satisfy future markets demands The main purpose of this paper is to propose adoption modelling of digital-twin for optimized products and production processes. The methodology of the proposed modelling can be considered unique in the following aspects of:•Determining the expected added-values of adopting digital-twin to the manufacturing business according to certain business's operational criticality, budget and size.•Allowing processes' optimization at three levels of plant (factory) physical layout, Machines' operational fault tolerance and final products' design and quality.•Allowing strategic-planning achievement for sustainable Production-Product and future demands.
  17. Ismail MM, Fawzi M, Taweekun J, Leevijit T
    MethodsX, 2021;8:101583.
    PMID: 35004216 DOI: 10.1016/j.mex.2021.101583
    Engine knock is an obstacle for maximizing CNG fuel utilization on a Diesel-CNG Dual Fuel engine. Prolong experience of this phenomenon may lead to severe engine damage. The low intensity of this phenomenon is difficult to recognize due to other noises from the engine. Thus, improper engine tuning techniques may make this phenomenon unnoticeable until the engine damages. Knock phenomena on such engines may not be detected in the combustion analysis graph. Its random occurrence in consecutive engine cycles makes it difficult to be seen using visual data. This knowledge gap, if closed, can lead to an opportunity for knock avoidance on the multifuel engine. This work proposed a method to quantify the knock occurrence based on engine block vibration using a single piezoelectric knock sensor. The knock occurrence was detected by comparing the calculated knock index with the knock threshold, determined using a statistical three-sigma rule analysis. This method can index the knock intensity, detect the engine knock occurrence, and visualize the knock phenomenon.•This paper describes an alternative engine knock detection technique based on engine block vibration.•This method proposes the knock threshold determination based on statistical three-sigma rule analysis.•This method is capable of visualizing the knock phenomenon in consecutive and at each engine cycle.
  18. Abu Bakar N, Mat Salleh M, Ali Umar A, Shapter JG
    MethodsX, 2017;4:486-491.
    PMID: 29201649 DOI: 10.1016/j.mex.2017.11.008
    Silver nanoparticles deposited on quartz substrates are widely used as SERS substrates. The nanoparticles can be deposited directly from colloidal solution by dipping technique. However, the adhesion of the particles on the quartz surface is very poor. Normally the substrate is pre-treated with hydroxylation or silanisation process. In this paper, we have demonstrated that the application of the sequence pre-treatment hydroxylation and silanisation have improved the density of silver nanoplates desposited on the quartz surface. •Sequence hydroxylation and silanisation pre-treatment assists the deposition of the nanoplate on the surface.•Various immersion times of the quartz surface into the colloidal nanoplates determined size distributions and density surface of the nanoplates on the surface.
  19. Joel ES, Maxwell O, Adewoyin OO, Ehi-Eromosele CO, Embong Z, Oyawoye F
    MethodsX, 2018;5:8-19.
    PMID: 29387568 DOI: 10.1016/j.mex.2017.12.002
    In this study, we evaluated the activity concentration of natural radionuclides (226Ra, 232Th and 40K) for fifteen (15) different brands of tile samples used for building purposes in Nigeria. The tile samples were analyzed using High purity Germanium gamma detector. The mean activity concentrations of 226Ra, 232Th, and 40K were observed to be 61.1 ± 5.5 Bq/kg, 70.2 ± 6.08 Bq/kg and 514.7 ± 59.8 Bq/kg respectively. Various hazard indices such as absorbed dose rate, external and internal hazard index, annual effective dose rate, Gamma activity Index (Iγ) and Alpha Index (Iα) were calculated. The obtained results showed that the mean radium equivalent activity (Raeq), the absorbed dose rate (D), external and internal hazard index, the annual effective dose (AEDR) equivalent, Gamma activity Index (Iγ) and Alpha Index (Iα) were: 204.42 Bq/kg, 177.61 nGyh-1, 0.55, 0.77, 0.96 mSvyr-1, 0.74 and 0.32 respectively. The average value of radium equivalent obtained in this study is less than that of the recommended value of 370 Bq/kg but the average values of the other radiological hazards for some samples are found to be slightly above international recommended values except Hex, Hin and AEDE which are within the international reference value of unity. The measured concentrations of these radioactive materials were correlated with other previous result obtained from similar tile materials used in other countries and found to be in good agreement with the international standard, however, the tiles are recommended for decoration purposes in Nigeria.
  20. Umar ZD, Aziz NA, Zulkifli SZ, Mustafa M
    MethodsX, 2017;4:104-117.
    PMID: 28280689 DOI: 10.1016/j.mex.2017.02.003
    Polycyclic Aromatic Hydrocarbons (PAHs) are complex and widely distributed environmental pollutants that can affect living ecosystems. This study was conducted to rapidly degrade phenanthrene and pyrene representing low and high molecular weight of PAHs, respectively. Cronobacter sakazakii MM045 (KT933253) was identified from used engine oil of contaminated soil. PAHs biodegradation was carried out using 2,6-dichlorophenol indophenol (DCPIP) assay. Biodegradation influencing factors including agitation, temperature, pH, inoculums volume and salinity were enhanced using Response Surface Methodology (RSM) by Central Composite Design (CCD). Phenanthrene and pyrene biodegrading metabolites were identified using gas chromatography mass spectrophotometer (GCMS). •Initial biodegradation indicated 75.2% and 54.3% phenanthrene and pyrene degraded by C. sakazakii MM045 within 24 h. After CCD optimisation, 100% degradation was achieved for each of the phenanthrene and pyrene, resulting in the formation of intermediate metabolites.•The identified phenanthrene metabolites were 3,4-dihydroxyphenathrene, phthalic acid, pyruvic acid, acetic acid and oxalic acid. Pyrene intermediates comprised pyrene cis-4,5-dihydrodiol, 3,4-dihydroxyphenanthrene, phthalic acid, pyruvic acid, acetic acid and lactic acid.•Cronbacter sakazakii MM045 was proven to be rapid and effective in degrading PAHs within 24 h despite the unavailability of existing literatures on PAHs biodegradation.
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