Molecular characterization of conjugative plasmids in pesticide tolerant and multi-resistant bacterial isolates from contaminated alluvial soil

A total of 35 bacteria from contaminated soil (cultivated fields) near pesticide industry from Chinhat, Lucknow, (India) were isolated and tested for their tolerance/resistance to pesticides, heavy metals and antibiotics. Bacterial isolates were identified by 16S rDNA sequencing. Gas Chromatography analysis of the soil samples revealed the presence of lindane at a concentration of 547 ng g⁻¹ and α-endosulfan and β-endosulfan of 422 ng g⁻¹ and 421 ng g⁻¹ respectively. Atomic Absorption Spectrophotometry analysis of the test sample was done and Cr, Zn, Ni, Fe, Cu and Cd were detected at concentrations of 36.2, 42.5, 43.2, 241, 13.3 and 11.20 mg kg⁻¹ respectively. Minimum inhibitory concentrations of all the isolates were determined for pesticides and heavy metals. All the multi-resistant/tolerant bacterial isolates were also tested for the presence of incompatibility (Inc) group IncP, IncN, IncW, IncQ plasmids and for rolling circle plasmids of the pMV158-family by PCR. Total community DNA was extracted from pesticide contaminated soil. PCR amplification of the bacterial isolates and soil DNA revealed the presence of IncP-specific sequences (trfA2 and oriT) which was confirmed by dot blot hybridization with RP4-derived DIG-labelled probes. Plasmids belonging to IncN, IncW and IncQ group were neither detected in the bacterial isolates nor in total soil DNA. The presence of conjugative or mobilizable IncP plasmids in the isolates indicate that these bacteria have gene transfer capacity with implications for dissemination of heavy metal and antibiotic resistance genes. We propose that IncP plasmids are mainly responsible for the spread of multi-resistant bacteria in the contaminated soils.     

Hybrid Composites Made from Oil Palm Empty Fruit Bunches/Jute Fibres: Water Absorption,Thickness Swelling and Density Behaviours

In this research, hybrid composite materials were prepared from combination of oil palm Empty fruit bunches (EFB) fibre and jute fibre as reinforcement, epoxy as polymer matrix. This study intended to investigate the effect of jute fiber hybridization and different layering pattern on the physical properties of oil palm EFB-Epoxy composites. Water absorption and thickness swelling test reveal that hybrid composite shows a moderate water absorption which is 11.20% for hybrid EFB/Jute/EFB composite and 6.08% for hybrid Jute/EFB/Jute composite. The thickness swelling and water absorption of the hybrid composites slightly increased as the layering pattern of hybrid composites changed. Hybrid composites are more water resistance and dimensional stable compare to the pure EFB composites. This is attributed to the more hydrophilic nature of EFB composites. Hybridization of oil palm EFB composites with jute fibres can improve the dimensional stability and density of pure EFB and Jute fibre reinforced composites has higher density of 1.2 g/cm³ compared to all other composites.     

Preparation and Fundamental Characterization of Cellulose Nanocrystal from Oil Palm Fronds Biomass

The objective of this work was to isolate cellulose nanocrystal (CNC) from oil palm fronds (Elaeis guineensis) and its subsequent characterization. Isolation involves sodium hydroxide/anthraquinone pulping with mechanical refining followed by total chlorine free bleaching (includes oxygen delignification, hydrogen peroxide oxidation and peracetic acid treatment) before acid hydrolysis. Bleaching significantly decreased kappa number and increased α-cellulose percentage of fibers as confirmed by Technical Association of the Pulp and Paper Industry standards. Transmission electron microscopy (TEM), X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis revealed that acid hydrolysis along with bleaching improved crystallinity index and thermal stability of the extracted nanocrystals. It was observed that CNC maintained its cellulose 1 polymorph despite hydrolysis treatment. Mean diameter as observed by TEM and average fiber aspect ratio of obtained CNC was 7.44 ± 0.17 nm and 16.53 ± 3.52, respectively making it suitable as a reinforcing material for nanocomposite.     

Nanocatalyzed biodiesel synthesis from the oily contents of Marine brown alga Dictyota dichotoma

This research article demonstrates biodiesel synthesis through the methanolysis of the oily contents (4.02 ± 0.27% w/w on dried basis) of Dictyota dichotoma collected from the coast of Hawksbay, Pakistan. The metal oxides (CaO, MgO, ZnO, and TiO₂) used as nanocatalysts were refluxed (5% K₂SO₄), calcinated (850 °C) and characterized by Atomic Force Microscopy (AFM) which produced 93.2% w/w FAME (biodiesel) at relatively mild condition (5% catalyst, 65 °C, 3 h, 18:1 molar ratio) using CaO. Whereas, MgO, ZnO, and TiO₂ produced 92.4%, 72.5%, and 31.8% w/w FAME, respectively at elevated condition (225 °C). Thus, CaO was considered to be the best catalyst among the others. This tri-phase reaction require continuous fast mixing and the yield depends on the reaction parameters like catalyst amount, temperature, reaction time and molar ratio (methanol: oil). The reusability of these heterogeneous catalysts simplified the purification step, reduced the waste generation and make the final product technically and economically viable.     

Proposing of new building scheme and composite towards global warming mitigation for Malaysia

The building sector has been regarded as a potential sector where there is large capacity to reduce the climate change effect. This study has proposed solutions to mitigate environmental impacts and achieve low CO₂ emission from residential sector. Therefore, full life cycle assessment (LCA) has been run to assess the CO₂ emission and its effect on the atmosphere and climate change. Based on the result, timber scheme is the best choice due to releasing less CO₂ emissions to the atmosphere. However, house builders in Malaysia have almost completely neglected timber as a building material, with timber use as building components reduced to 5%. In this study, LCA Software was used to assess CO₂ emissions from different wall construction. The alternative building scheme has been made by reinforce steel stud, wooden beam and timber wall (S8) to improve the scheme deficiency while releasing less CO₂ emissions compared to other schemes. Therefore, S8 has a decreased CO₂ effect by 85% less than precast concrete frame and 90% less than brick over their lifetime. (S8) increased the load bearing compared to conventional timber beam. Thus, new scheme S8 could be replaced by current scheme and promote more adjustable scheme for Malaysian housing.     

Anti-oviposition activities of used sock media against a dengue vector: prospects of eco-friendly control and solutions to pollution

Yearly, huge amounts of sock refuse are discarded into the environment. Socks contain many molecules, and worn ones, which are rich in smell-causing bacteria, have a strong influence on animals’ behaviors. But the impacts of sock odor on the oviposition behavior of dengue vectors are unknown. We assessed whether Aedes albopictus changes its oviposition activity in response to the presence of used socks extract (USEx) in potential breeding grounds, using choice and no-choice bioassays (NCB). When furnished even chances to oviposit in two sites holding USEx and two others containing water (control), Ae. albopictus deposited significantly less eggs in USEx than in water sites. A similar pattern of oviposition preference was also observed when there were more oviposition options in water. When there were greater oviposition opportunities in USEx sites, Ae. albopictus oviposited preferentially in water. Females laid significantly more eggs during the NCB involving water than USEx. Also, significantly more mature eggs were retained by females in the NCB with USEx than in that with water. These observations strongly suggest the presence of molecules with either repellent or deterrent activities against Ae. albopictus females and provide an impetus to advocate the integration of used socks in dengue control programs. Such applications could be a realistic end-of-life recourse to reroute this waste from landfills.

     

Development and characterization of cell line from the gill tissue of Catla catla (Hamilton, 1822) for toxicological studies

Catla gill cell line (ICG) was established from gill tissue of Indian major carp (Catla catla), a freshwater fish cultivated in India. The cell line was maintained in Leibovitz’s L-15 supplemented with 10% fetal bovine serum. These cells have been sub-cultured more than 55 passages over a period of 2 years. The ICG cell line consists predominantly of epithelial-like cells. The cells were able to grow at a wide range of temperatures from 24 °C to 32 °C with an optimum temperature of 28 °C. The growth rate of gill cells increased as the fetal bovine serum (FBS) proportion increased from 2% to 20% at 28 °C with optimum growth at the concentrations of 10% or 15% FBS. Amplification of mitochondrial gene 12s rRNA using primers specific to C. catla confirmed the origin of this cell line from C. catla. The cells were successfully cryopreserved and revived at passage numbers 25, 35, 45 and 55. The cytotoxicity of three metal salts (ZnCl₂, CuSO₄ and CdCl₂) was assessed in ICG cell line using multiple endpoints such as MTT, Neutral Red assay, Alamar Blue assay and Coomassie Blue protein assay. Acute toxicity assay on fish were conducted by exposing C. catla for 96 h to three metal salts under static conditions. Statistical analysis revealed good correlation with r² = 0.908–0.985 for all combinations between endpoints employed. Linear correlations between each in vitro EC₅₀ and the in vivo LC₅₀ data were highly significant.     

The potentials of internalising social banking among the Malaysian Islamic banks

Islamic banking has established for the last 40 years, yet only recently researchers acknowledge social failures of Islamic banking and finance. This has led to a proposition of forming new forms of banking and non-banking institutions that include social banking. It is argued that in considering the developmentalist needs of the Muslim societies in Malaysia, there is a need to go back to fundamentals of Islamic finance in realising the aspirational Islamic moral economy that emphasises on the social good, capacity development at the individual and social levels. This paper aims to explore the concept of social banking and search for the possibilities for internalisation in Malaysian Islamic banking. To gain understanding on this pertinent issue, an empirical investigation was conducted at 17 Islamic banks in Malaysia. A mixed method was employed. For the primary data collection, 477 respondents of Islamic banks clients and employees participated in a self-administrated survey, and 11 respondents from the executive and managerial level of eight Islamic banks involved in a semi-structured interview survey. The integrated analysis implies that Islamic banking significantly contributes to socio-economic development. On the contrary, financial and economic practices in everyday life do not reflect the social economic justice. The result further illustrates that the Islamic banks lack social contributions as they prone to practice efficiency-oriented institutions. Hence, a social banking model is needed to solve the lack of socio-economic development issue in the current practice of Islamic bank.     

Arsenic in shallow aquifer in the eastern region of Bangladesh: insights from principal component analysis of groundwater compositions

Probable sources and mechanisms of arsenic (As) release in shallow aquifer in eastern Bangladesh are evaluated using statistical analysis of groundwater compositions. Dissolved As in 39 samples ranged from 8.05 to 341.5 μg/L with an average of 95.14 μg/L. Ninety seven percent of wells exceed the WHO limit (10 μg/L) for safe drinking water. Principal component analysis is applied to reduce 16 measured compositional variables to five significant components (principal components—PCs) that explain 86.63% of the geochemical variance. Two component loadings, namely PC 1 and PC 2 (45.31% and 23.05%) indicate the natural processes within the aquifers in which organic matter is a key reactant in the weathering reactions. Four groups of wells are defined by the PCA and each group of wells represents distinct physicochemical characteristics. Among them, group III groundwater shows higher As concentration together with high concentrations of Fe, Mn, dissolved organic carbon, $\text{PO}_{4}^{3-}$ and $\text{HCO}_{3}^{-}$ than groups I and II. Speciation calculations suggest that only wells of group III are saturated with respect to siderite, and all groups of samples are supersaturated with respect of rhodochrosite. The relationship of As with these parameters in the different groups of wells of the study area suggests that reductive dissolution of Fe–Mn oxyhydroxides with microbially mediated degradation of organic matter is considered to be the dominant processes to release As in groundwater.