Category Archives: Publications

Kakunawela Pathirana Amaya Imanthi, Fathima Sumaiya Idroos and Marakkala Manage Pathmalal

published in Songklanakarin J. Sci. Technol.

Microbial Fuel Cell (MFC) is an environmentally friendly and sustainable technology where microbial degradation on organic substrates generates electricity, with potential application to wastewater treatment. This study mainly focused on investigating the effects of wastewater source on efficient electricity generation using a bio-cathode. Carbon cloth (2 × 4 cm2) were used as anode and cathode electrodes with 0.33Ω external resistor. Anode medium was leachate (setup 01) and rice wash water (setup 02) and cathode medium was Chroococcus sp. culture. Control setup was maintained by adding distilled water in cathode. Landfill leachate and rice wash water were used as the wastewater sources, all other conditions were the same in both setups. Highest electricity generation and wastewater treatment were recorded in setup 02 with rice wash water. The maximum voltage was 1,111 mV with current 3,366.67 mA and 467.55 mW m-2 power density. The wastewater treatment efficiencies reported as reductions in COD, Nitrate, Nitrite and Orthophosphate were 61.94%, 61.01%, 55.14%, and 26.01% in setup 02. These study outcomes disclose that dual chamber MFC with rice wash water as the wastewater source has potential for simultaneous power generation and wastewater treatment.

Madhava Meegaskumbura; Gajaba Ellepola; Gayani Senevirathne; Kelum Manamendra-Arachchi; Nayana Wijayathillaka; Marcio Pie; Dan Sun; Rohan Pethiyagoda; Christopher J. Schneider

published in bioRxiv

Ecomorphs result from divergent natural selection, leading to species-rich adaptive radiations. Identifying ecomorphs and the resulting adaptive radiations in frogs is challenging due to conserved morphology and high species diversity. In this study, we demonstrate the ecological and climate specializations that have driven the diversification of shrub frogs of the genus Pseudophilautus in Sri Lanka, a tropical continental island. We use a time-calibrated phylogeny, morphometric analyses, and climate-niche evolution, and identify five ecomorphological categories, including Tree-shrub, Rock-boulder, Leaf-litter, Habitat Generalists, and Canopy forms, and describe their evolution. Body size is the primary factor separating species, and specific body features correlate with habitat type. Ecomorphs likely evolved multiple times in disparate lineages, and in different regions and altitudes, during cold climatic periods owing to monsoon cycles resulting from the Himalayan-Tibetan orogeny. The common ancestor was a medium-sized, wet-adapted, tree-shrub habitat specialist which originated in the late Oligocene. Extreme size classes (diminutive leaf litter forms and large canopy forms) evolved recently and suggest that morphological disparity arose late in diversification, possibly aided by favorable climates. This work will facilitate understanding of adaptive radiations in frogs, which possibly will help uncover the prevalence of subtle adaptive radiations in frogs, just as in tailed-vertebrates.

A. K. C. Wijerathna, K. P. P. Udayagee, F. S. Idroos & Pathmalal M. Manage

Book chapter published in Sustainable Valorization of Agriculture & Food Waste Biomass

There has been a significant increase in global waste generation owing to rapid urbanization and industrialization. Anthropogenic activities associated with exploiting natural resources pose severe threats to the long-term resilience of ecosystems. The buildup of waste biomass in ecosystems causes various adverse environmental conditions, such as greenhouse gas emissions, global warming, bioaccumulation and biomagnification of hazardous chemicals, surface and groundwater pollution, and acid rains suppress and lessen biological diversity. According to the World Bank predictions, 3.4 billion tons of municipal solid waste will have been generated by 2050. Thus, effective waste biomass management through valorization is critical in circular bio-economy and meeting environmental feasibility. Due to its abundance and renewability, lignocellulosic waste biomass can be a beneficial substrate to produce many high-value goods such as biofuels, biofertilizers, composts, biochar, pharmaceuticals, bioplastics, and food additives. This chapter summarizes the potential of hydrothermal conversion processes, including hydrothermal carbonization, hydrothermal liquefaction, and hydrothermal gasification, in producing a range of value-added products from solid waste substances. Moreover, the future trends of biological conversions that use microbial bioconversion generate a number of eco-friendly valorized products like biopesticides, biohydrogen, organic acids, antibiotics, enzymes, food colors, amino acids, and single-cell proteins were discussed. Further, this chapter highlights the multidisciplinary approaches for waste biomass valorization combined with advanced bio-nanotechnology, enzymatic sequent biomass hydrolysis treatments that are becoming popular and research gaps to overcome the challenges of waste biomass valorization by enhancing the process efficiency.

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Sashini U. Kuruppuarachchi, Uthpala A. Jayawardena and Varuni K. Gunathilake

published in Alternatives to Laboratory Animals

Marine sponge extracts are known to contain potentially toxic compounds that have biological activities of possible pharmacological interest. Thus, it is vital that biological models are used for the preliminary toxicity screening of such extracts. The present study reports the use of Allium cepa, a low-cost plant-based in vivo model, to assess the cytotoxicity and genotoxicity of Luffariella herdmani marine sponge crude extract (SCE). Pre-germinated onion bulbs, exposed for 96 hours to different concentrations of SCE (ranging from 0.3125 to 20 μg/ml), were used to determine general cytotoxicity. Root length as well as morphological abnormalities were recorded. Genotoxicity was assessed by exposing the root tips to SCE (0.3125–20 μg/ml) and the appropriate controls for 48 hours, and then staining with acetocarmine. The
Mitotic Index (MI), Mitotic Phase Indices (MPIs) and chromosomal aberrations were evaluated and recorded. SCE inhibited A. cepa root growth (EC50 = 10.34 μg/ml) and elicited a mitodepressive effect (LC50 = 1.95 μg/ml) in a dose-dependent and significant manner. In addition, macroscopic alterations as well as chromosomal aberrations were detected. Overall, our findings indicate that L. herdmani crude extract exhibits cytotoxic and genotoxic activity, suggesting that it might contain substances with anti-proliferative/anticancer potential that could be subject to further characterisation.

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