International Conference on Sustainable Biotechnology [ICoSBi] 2025

Permanent URI for this collectionhttps://rda.sliit.lk/handle/123456789/4450

Browse

Now showing 1 - 20 of 25

Open Access
Biodegradation of Crystal Violet by Ascomycetous Fungi Isolated from Local Dump Sites: An Approach for Potential Mycoremediation of Textile Dyes
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Piyumali, S. K. K; Manamgoda,D. S.; Udayanga, D
Dyes are integral elements used to impart colours to textile materials. The wastewater effluent generated from textile industries during the processing and treatment of the dye contains inorganic and organic compounds that are hazardous, thereby posing a serious threat to ecosystems.This study focused on the assessment of the decolourization capability of textile dyes using eleven (11) ascomycetous fungal isolates, obtained from selected local dump site habitats in Sri Lanka.
Open Access
Biodegradation of Lignocellulosic Waste by Enriched Environmental Microbial Sources and Sequential Fermentation by Saccharomyces Cerevisiae
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Alahakoon, A. H. D.; Rizvi, E. M. J. M.
The increasing global demand for energy and the rapid depletion of fossil fuels have led to the search for alternative energy sources. Bioethanol is one option that can be produced from lignocellulose materials, which involves their biodegradation and fermentation. This study investigated the degradation of three lignocellulose waste materials by enriched microbial communities from three environmental sources andtheir sequential fermentation by Saccharomyces cerevisiae. The NaOH-pretreated lignocellulose substrates in a basal medium were inoculated with enriched microbial suspensions and incubated at room temperature. The extent of biodegradation was determined after 5 days of incubation by the gravimetric method. The bioethanol content was estimated by the solvent extraction & dichromate oxidation method after incubating another 3 days with S. cerevisiae. Both the extent of biodegradation and ethanol yield differed significantly among the different lignocellulose-microbial source combinations (p<0.05). The highest biodegradation (80.95%) was found in grass clippings by cow dung microbial consortium, while the lowest degradationwas in palmyra by compost consortium (19.46%). The ethanol yield ranged from 1.24 to 1.87% (V/V) substrate, which was comparable to reported values from similar studies, but it did not correlate with the extent of lignocellulose degradation (r = 0.0378 and P = 0.923). This could be either because microbial consortia, though they are good degraders they are poor saccharifiers, or the fermentation would have been limited by broth conditions. Microbial consortia with high lignocellulose-degrading potential may be formulated from natural microbial sources, but their contribution to ethanol production needs further studies.
Open Access
Characterisation of Acid Protease-Producing Bacterium Micrococcus luteus from the Pitcher Fluid of Nepenthes distillatoria L.
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Gunawardhana, P.; Manamgoda, D.; Udayanga, D.
Nepenthes distillatoria L., a carnivorous plant endemic to Sri Lanka, produces pitcher fluid, rich in digestive enzymes. Despite its apparently hostile conditions, the pitcher fluid harbours a diverse and unique microbial community. In this study, bacteria were isolated from the open pitcher fluid of N. distillatoria collected at two sites in distinct locations in Kalawana, Rathnapura district, in Sri Lanka. From twelve samples, twenty-four bacterial isolates were obtained and subjected to acid-protease enzyme assay using an agar plate method. Relative enzymatic activity was quantified for all the isolates that produced positive results. Notably, one isolate displaying significant acid protease activity was identified as Micrococcus luteus based on 16S rRNA sequence analysis. Therefore, this study revealed the pitcher fluid of N. distillatoria supports a distinct bacterial community with potential industrial applications, highlighting its value as a promising source for bioprospecting.
Open Access
Comparative Analysis of Starch Extracted from Banana (Musa spp.) Corms: Evaluation of Antioxidant Properties and Other Nutritional Properties
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Dahanayake, T. M. W.; Priyadarshani, S. V. G. N.; Gammanpila, H. W.
Banana corms are frequently regarded as agricultural waste globally, in contrast to the other parts of the banana plant. This study focuses on developing an optimal procedure for extracting starch from the banana corm and evaluating its antioxidant activity and nutritional composition to determine whether it has the potential to be used in food products. Starch was extracted from the banana corm using the wet milling method, and 1% Ascorbic acid was used to prevent browning. Three Sri Lankan banana varieties, Embul, Ambun, and Alukesel were used in the study. The starch yield ranged between 2.11% to 7.2%, with the highest obtained from Ascorbic acid-treated Embul (Embul-As). Ascorbic acid treatment significantly improved both starch yield and color (p < 0.05). The highest DPPH radical scavenging activity for Ascorbic free samples was given by Embul, which is 1.96 mg AAE/g. Nutritional profiling of Embul-As revealed favorable macronutrient content, including carbohydrate 82.2% and an energy value of 337 kcal/100g. These findings highlight banana corm-starch as a sustainable, underutilized resource with strong potential for innovative applications in food product development.
Open Access
Detection of Polymorphism in Ethyl Methyl Sulfonate Treated Cordyline fruticosa (L.) A.Chev. mutants using RAPD markers
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Kondapperuma, C.; Hewagamage, H.; Pieris, S. E.
Cordyline fruticosa (L.) A. Chev. is an ornamental plant with significant horticultural value but limited genetic diversity, which constrains breeding for improved traits. This study aimed to generate and evaluate genetic and morphological variation in C. fruticosa using Ethyl Methyl Sulfonate (EMS) mutagenesis. In-vitro plantlets were exposed to EMS at concentrations of 1%, 2%, 3%, and 4%, for 10 minutes and their growth was monitored over nine weeks. Key morphological parameters, includingplant height, leaf number, and leaf pigmentation, were recorded to assess the impact of EMS treatment. Genomic DNA was extracted from treated and control plants, and genetic variation was evaluated using Random Amplified Polymorphic DNA (RAPD) markers. The results demonstrated that EMS induced concentration-dependent changes in plant morphology, with 1% EMS producing the greatest reduction in plant height and leaf number, as well as lighter leaf pigmentation. RAPD analysis revealed increasedgenetic polymorphism in EMS-treated groups compared to the control, with the highest level observed in the 1% EMS treatment. Cluster analysis further confirmed the genetic divergence between treated and control plants. These findings indicate that EMS mutagenesis, particularly at lower concentrations, is effective in generating both morphological and genetic diversity in C. fruticosa. The study provides a foundation for future breeding programs aiming to enhance the ornamental and adaptive traits of thisspecies through targeted mutation breeding.
Open Access
Development of a Proteinous Composite Flour for the Bakery Industry
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Divyanjalee, S.; Mathangadeera, R.; Jayasinghe, M.
Bakery products are commonly prepared using refined wheat flour, which lacks nutrients such as highquality proteins and minerals. The incorporation of plant-based ingredients into composite flours has emerged as a promising approach to improve the nutritional quality of bakery products. This study was focused to develop a nutritionally enhanced composite flour by blending exudate soy flour, pumpkin seed powder, and spinach powder with wheat flour and assess its functional suitability in muffin production. Four flour combinations were formulated: T1 (100% wheat as control), T2 (60% wheat + 36% soy + 2% pumpkin + 2% spinach), T3 (65% wheat + 31% soy + 2% pumpkin + 2% spinach), and T4 (70% wheat + 26% soy + 2% pumpkin + 2% spinach). Muffins prepared from these blends were subjected to a series of analyses, including proximate composition (protein, fat, ash, moisture), mineral content (Mg, Zn, Fe, Ca), antioxidant activity (DPPH assay), and sensory evaluation using a 5-point hedonic scale. Results revealed that the T2 formulation demonstrated the highest protein content (26.5%), strong antioxidant activity, and the most favourable sensory acceptance among all variations. These improvements were achieved without compromising taste, texture, or shelf-life stability. The findings confirm that replacing a portion of wheatflour with locally available, nutrient-rich ingredients can significantly improve the nutritional value of bakery products. Therefore, the study supports the practical potential of composite flours in addressing protein deficiency and promoting healthier bakery alternatives.
Open Access
Development of Plant-Based Yogurt Analogue from Coconut Milk
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Senevirathna, R.M.H.D.; Gunathilaka, R.M.S.; Abeysiriwardana, D.D.S.D.Z.
Plant-based “yogurt” products are ideal alternatives to milk for ethical and health concerns. A coconut milk-based “yogurt” was developed in this study, and its physicochemical properties, microbial stability, and sensory attributes were analysed. Changes of coconut milk into “yogurt” involved major changes, such as a reduction of pH from 6.45 to 4.66 and an increase of acidity from 0.17% to 0.68, which suggests asuccessful fermentation. Moisture content was reduced from 83.79% to 70.20%; this improved the texture and consistency of the “yogurt”; total solids increased from 16.21% to 29.80%; these results contribute to a rich flavour profile. As a result, 100% coconut milk “yogurt” and vanilla-flavoured variants were identified as the most preferred by panellists through sensory evaluation. Over four-week shelf-life testing on proof batches revealed no microbial contamination, indicating the absence of yeast, mold, and coliform bacteria. Acidity of increased steadily with storage, necessitating fermentation optimization to strike an appropriate flavour stability and consumer acceptability. Comparative analysis with existing literature proved that coconut milk “yogurt” is nutritious and sensory beneficial but also revealed limitations like its low protein content and difficulty in maintaining consistent flavour over time. Optimization of fermentation processes, further study into alternative plant-based protein and functional additive formulations, as well as adoption of sustainable packaging solutions, are some of the recommendations mentioned. This study provides significant insights into the feasibility of coconut milk “yogurt” as a plant-based dairy alternative, which caters to consumer needs for healthy, low lactose, and more environmentally friendly dairy products.
Open Access
Effects of Green Synthesized Copper-Derived Nano Particles extracted from Piper betel to Eliminate Contaminations in tissue culture of Dracaena sanderiana Sander ex Mast. cv ‘Gold’
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Gunawardana, R.; Peiris, S. E.; Peiris, C. N.; Jayasinghe, S.
Micropropagation is often hindered by contamination from endophytic microbes. While antibiotics are used to eliminate these without harming plant tissues, they risk promoting antibiotic resistance. This study explores a green alternative by synthesizing copper nanoparticles (Cu-NPs) using antimicrobial-rich Piper betel leaf extract. The eco-friendly method uses plant biomolecules as natural reducing and stabilizingagents. The aim was to (i) produce Cu-NPs via eco-friendly plant-based synthesis, (ii) evaluate their antibacterial activity against Escherichia coli and S. aureus, and (iii) assess their effectiveness in reducing microbial contamination in plant tissue culture. Cu-NPs were produced by reacting leaf extract with cupric sulphate under controlled heating and stirring. Their antibacterial activity was tested against E. coli and Staphylococcus aureus via time-kill assays, and their efficacy in reducing contamination was assessed by applying them to Dracaena sanderiana explants in vitro. 200 ppm was identified as the optimal concentration for the antibacterial activity in in vitro establishment trials of Dracaena sanderiana, 50 ppm Cu-NPs proved to be the most effective concentration, resulting in 100% survival when used both for surface sterilization and as a supplement in the culture medium, and 80% survival when used only for surface sterilization. Thefindings suggest that green-synthesised Cu-NPs from P. betel show potential as an alternative to antibiotics in plant tissue culture, with promising effects on contamination control and reduced risk of antibiotic resistance.
Open Access
Establishment of Micropropagation System for Mulberry (Morus alba L.)
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Munasinghe, S.; Priyadarshani, S. V. G. N.; Chithramali, J.
Mulberry (Morus alba L.) is an economically and ecologically significant woody perennial widely cultivated for sericulture, pharmaceuticals, and nutraceutical applications. However, conventional propagation methods are limited by low multiplication rates, genetic heterogeneity, and vulnerability to pests and diseases. This study aimed to develop a standardised and efficient micropropagation protocol for M. alba to support large-scale, uniform plant production. Explants (nodes, stems, and leaves) from healthy threeyear- old mother plants were subjected to ten surface sterilisation treatments using combinations of Clorox (10%), AgNO₃ (0.1 g/L), Tween 20, fungicides, and antibiotics. The optimised sterilisation method achieved a contamination rate of <5% and a survival rate >90%. Murashige and Skoog (MS) medium supplemented with 5.0 mg/L 6-Benzylaminopurine (BAP) and 0.2 mg/L Naphthalene Acetic Acid (NAA) yielded the highest shoot induction and shoot biomass across nodal and leaf explants. Significant callus formation was observed in nodal and stem explants, while browning -particularly in leaf cultures was mitigated using Woody Plant Medium and citric acid.
Open Access
Foliar and Postharvest Application of Phosphite Promotes Postharvest Resistance of Potato Tubers to Late Blight Caused by Phytophthora infestans
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Mohammadi, M. A; Wang-Pruski, G.
Postharvest losses due to late blight, caused by Phytophthora infestans, remain a significant challenge for sustainable potato production. This study evaluated the effectiveness of potassium phosphite (KPhi) applications during the growing season and postharvest in enhancing tuber resistance to late blight in three potato cultivars (Cv. Xinjia No. 2, Cv. Zhongshu No. 3, and Cv. Minshu No. 3). Whole tuber assays were conducted on four-month stored tubers inoculated with ASO and 1-12-25 isolates of P. infestans, revealing that foliar KPhi treatments significantly reduced the disease severity in tubers. Five foliar applications during the growth season provided more protection than three applications. Cv. Xinjia No. 2 displayed higher resistance, Cv. Zhongshu No. 3 has moderate resistance, and Cv. Minshu No. 3 is moderately susceptible. Half-tuber and slice assays confirmed these findings, demonstrating markedly reduced late blight development in KPhi-treated samples compared to the controls, particularly when challenged with the more aggressive ASO isolates versus the 1-12-25 isolates of P. infestans. The most pronounced protection against the 1-12-25 isolates was observed in Cv. Xinjia No. 2. While KPhi did not entirely inhibit rot development at all treatments, it consistently delayed symptom progression and reduced lesion size across all three cultivars. These results support the application of KPhi as an effective, cultivar-dependent strategy for managing late blight development in potato tubers, with the degree of protection positively correlated with the application frequency. Postharvest KPhi application is a promising strategy to reduce tuber late blight, prolong storage life, and limit disease spread.
Open Access
Formulation and Sensory Evaluation of a Herbal Tea Using Pomegranate Peel
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Perera, S.; Kasturiarachchi, J; Mathangadeera, R.
This study evaluates the sensory attributes and physicochemical properties of pomegranate peel-based herbal tea formulations to determine the most acceptable blend. Sensory evaluation was conducted with a semi-trained panel (n=36) using a 9-point hedonic scale to assess aroma, brew colour, taste, astringency, aftertaste, and overall acceptability across five formulations. Statistical analysis using the Friedman test indicated significant differences in sensory acceptability among formulations (p < 0.001). Formulation 567, containing a blend of pomegranate peel powder (PPP), lemongrass powder (LP), ginger powder (GP), and cinnamon powder (CP), exhibited the highest acceptability. In addition, a comparison was made between herbal teas prepared using pomegranate peel powder and those made with coarse pomegranate peel to identify the differences and determine which is most preferred. The findings suggest that formulation 567 offers an optimal balance of sensory qualities, supporting its potential for commercial herbal tea development. This study contributes valuable insights into the utilisation of pomegranate peel waste in functional beverage formulations.
Open Access
Genome-Based Analysis of Mutations Driving Ciprofloxacin Resistance in Klebsiella pneumoniae
(Department of Applied Sciences, Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Akram, A.; Kawshalya, I.
Klebsiella pneumoniae functions as a major pathogenic microorganism that causes pneumonia infections, urinary tract infections, and bloodstream infections. The advanced resistance of K. pneumoniae against ciprofloxacin presents medical professionals with significant management issues for treatment strategies.This research examined ciprofloxacin resistance-related genetic mutations and alterations in K. pneumoniae through detailed analysis of essential DNA gyrase and topoisomerase IV genes: gyrA, gyrB, parC, and parE. The research analysed alterations between resistant and susceptible microbial strains through bioinformatics methodology. The scientific confirmation established that ciprofloxacin resistance exhibits a strong relationship with gyrA mutations at Ser83, along with Asp87 positions. Research confirms thatenzyme structure changes caused by these alterations lead to decreased ciprofloxacin binding effectiveness. The mutation of Ser359Ala and Ser367Thr in gyrB increased bacterial resistance slightly when compared to gyrA mutations. Ser80Ile and Glu84Val parC mutations showed a reduction in ciprofloxacin binding ability, thus causing an increase in resistance. The drug-binding site of ciprofloxacin became stronger through parE mutations that included Ile529Leu and Ser458Ala, which reinforced ciprofloxacin resistance. Genomic surveillance must remain active because these research results verify the contribution of these mutations to ciprofloxacin resistance. Research into K. pneumoniae resistance molecular pathways becomes vital for developing antimicrobial strategies as well as for stopping resistance strain proliferation.
Open Access
Identification of Antibiotic-Resistant Bacteria in Processed Meat Products Available in Local Markets from Five Selected Localities in Sri Lanka
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Jayakody, U; Vithanage, D
This study focused on identifying antibiotic-resistant bacteria in processed meat products available in Sri Lankan local markets, considering the potential risks caused by inappropriate packaging and storage conditions. Five processed meat samples were purchased from five localities in Sri Lanka and examined on Luria-Bertani (LB) agar medium using both homogenised and direct culture techniques. The Kirby-Bauerdisc diffusion method was used in the Antibiotic Sensitivity Test (ABST) to determine how bacteria responded to various antibiotics. Samples that were improperly packaged revealed the presence of antibiotic-resistant bacterial strains, exhibiting resistance to both ampicillin and amoxicillin, while ciprofloxacin sensitivity was observed in every tested bacterium. DNA was extracted from the antibioticresistant bacteria. Escherichia coli and Staphylococcus sp. were confirmed using Polymerase Chain Reaction(PCR) and agarose gel electrophoresis. Although PCR identified many isolates, it was unable to confirm two bacterial species; after additional DNA sequencing analysis, these two unidentified organisms were determined as Enterobacter sp. and Psychrobacter piechaudii. These results demonstrate the significance of appropriate packaging in avoiding the foodborne transmission of bacteria that are resistant to antibiotics.The study additionally indicates that to improve food safety and decrease antibiotic overuse, public awareness and stronger regulations are required. This study improves the understanding of how antibiotic resistance can spread through regularly consumed food products, which helps protect public health.
Open Access
Identification of Antibiotic-Resistant Bacteria in Ready-to-Eat Salads Available in Supermarkets in Thalawathugoda Area, Sri Lanka
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Wanninayaka, P.; Wijeratne, B.
The increasing demand for ready-to-eat (RTE) salads has raised concerns about food safety due to the potential for contamination by antibiotic-resistant bacteria. This study focused on the identification of antibiotic-resistant bacteria and their resistance profiles to discover resistant bacterial strains prevalent in RTE salads sold in supermarkets in Thalawathugoda area, Sri Lanka. To confirm the presence of pathogens, five different types of RTE salads were sampled and put through molecular analysis. These included Antibiotic Sensitivity Testing (ABST), DNA extraction, Polymerase Chain Reaction (PCR), Agarose gel electrophoresis, and Sanger sequencing. Antibiotic-resistant bacteria were found in S1 – Greek salad (GS),S3 – Potato salad (PS), S4 – Fresh Mix salad (FS), and S5 – Chicken potatoes and pineapple salad (CS), out of the five samples, according to the results. Amoxicillin displayed the strongest resistance in several samples, while ciprofloxacin was the most effective antibiotic according to ABST sensitivity patterns.Bacteria isolated from S2 - Apple salad (AS) showed sensitivity to each of the three tested antibiotics, suggesting that it is a high-quality sample with little chance of contamination by antibiotic resistant pathogenic bacteria. Staphylococcus spp. and Escherichia coli were detected in tested samples using PCR and agarose gel electrophoresis. Klebsiella quasipneumoniae was identified in S4 through Sanger sequencing,indicating the need for careful handling. The research highlights the significance of maintaining proper hygiene and implementing monitoring practices across the entire food supply chain, from production to retail, to minimize the risk of contamination in RTE salads. Further research and regular microbiological testing are recommended to ensure food safety and protect the health of customers.
Open Access
Impact of geographical variation on proximate composition of Sesbania grandiflora L. in Sri Lanka
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Dahanayaka, L. W.; Mapa, M. S. T.; Kadigamuwa,C. C.; Udayanga, D.
Sesbania grandiflora L. is a widely consumed green leafy vegetable in Sri Lanka, valued for its nutritional and therapeutic benefits. The nutrient composition can vary depending on many factors, including the geographical location. This study investigated the variation in proximate composition of S. grandiflora L. leaves collected from 16 locations across diverse agro-climatic zones in Sri Lanka, focusing on moisture,ash, protein, fat, carbohydrate, and fibre content. Samples were collected, cultivated under organic farming practices, and analysed using standard AOAC methods, methods of analysis established by the AOAC International (formerly the Association of Official Analytical Chemists). One-way ANOVA followed by Tukey post hoc test revealed significant differences (p < 0.05) in nutrient composition among the locations. Moisture content ranged from 64.13% to 82.79%, with both extremes recorded within the low-country wet zone, indicating substantial micro-environmental influence. Ash content varied from 1.89% to 5.68%, reflecting differences in mineral availability across soils. The highest protein content was recorded in the low-country dry zone (16.38%). Carbohydrate and fibre content were notably high in the low-country wet zone, with values reaching 18.33% and 11.79%, respectively. The findings highlight the influence of geographical location on the nutritional quality of S. grandiflora L. This study provides valuable insights for optimising the cultivation of S. grandiflora, contributing to improved dietary planning and region-specific agricultural practices in Sri Lanka.
Open Access
In silico Analysis of Clinically Significant TP53 Mutations: Implications for Sustainable Cancer Diagnostics
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Senarath, W. C. S.; Nandasena, R. M. I. M.
The TP53 tumour suppressor gene is one of the most frequently altered genes in human cancers. Several of its missense variants display distinct clinical relevance. This study aimed to characterise the structural and functional consequences of three well-documented TP53 mutations (R175H, R248Q, and R273H). These mutations remain underexplored in terms of computational evaluation. Variant pathogenicity wasassessed using SIFT and PolyPhen-2, while protein stability changes were predicted with I-Mutant 3.0. Homology models were generated through Swiss-Model, and structural perturbations were analysed and visualised using PyMOL. All three variants were predicted to be deleterious (SIFT ≤ 0.01; PolyPhen-2 ≥ 0.999) and destabilising, with ΔΔG values of −2.11 kcal/mol (R175H), −1.45 kcal/mol (R248Q), and −1.22 kcal/mol (R273H). Structural modelling revealed notable disruptions in the DNA-binding region, with R175H causing the most pronounced conformational alteration. The integrative in silico pipeline effectively revealed potential pathogenic mechanisms of these TP53 variants. This underscores the role of computational approaches in sustainable cancer diagnostics while reducing reliance on resource-intensiveexperimental studies.
Open Access
Influence of Climatic Factors on Dengue Transmission and Larval indices: A Comparative Analysis between Colombo and Nuwara Eliya districts, Sri Lanka
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Selvaratnam, S.; Kawshalya, I.; Jayawardena, T.
Dengue fever remains a major public health threat in Sri Lanka, with significant geographic and seasonal variability in incidence rates. This study investigated the impact of climatic variables - temperature, rainfall, and humidity- on dengue transmission dynamics in two ecologically contrasting districts: Colombo, alowland urban tropical zone, and Nuwara Eliya, a high-altitude, cooler region. Using a mixed-methods approach, the study analysed quantitative data from 2017 to 2023 sourced from the Dengue Control Unit and the Department of Meteorology, including monthly dengue cases, precipitation, temperature, relative humidity, and vector indices such as the House Index (HI) and Breteau Index (BI). Qualitative insights were gathered through expert interviews. Findings revealed consistently higher dengue incidence in Colombo, with peak outbreaks aligning with the Yala monsoon season (May–August). In contrast, Nuwara Eliya exhibited lower overall transmission, with occasional peaks during the Maha season (September– December). Elevated HI and BI values in Colombo (HI = 16.6; BI = 25.3 in May 2022) reflect more favourable conditions for Ae. aegypti breeding, while cooler temperatures in Nuwara Eliya generally suppressed vector development, though a notable rise in indices in late 2023 suggested emerging risks due to climaticanomalies. A statistical analysis between dengue incidence and climatic variables, particularly temperature and rainfall were conducted. The study underscores the importance of integrating climate-sensitive entomological surveillance into public health strategies. Tailored vector control efforts, especially in highrisk urban zones like Colombo, and continuous monitoring in emerging-risk areas such as Nuwara Eliya,are essential for early warning and prevention.
Open Access
Investigating Nicotine’s Role in In vitro Seed Germination and Seedling Growth of Tomato
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Perera, R.; Priyadarshani, S. V. G. N.
Nicotine is an addictive alkaloid found primarily in tobacco plants. Nicotine can be leached out into the soil through discarded tobacco products and can be taken up through the roots of plants and accumulated within them. Tomato (Solanum lycopersicum) is one of the major crops in the world that also contributes to the Sri Lankan economy. To study the effect of nicotine on plant growth and development, crude nicotine was extracted from dried tobacco leaves using the solvent extraction method. The study was conducted in vitro conditions. Tomato seeds were exposed to 20 μL/L, 50 μL/L, 100 μL/L, and 200 μL/L of crude nicotine (CN) in two types of media (media supplemented with 0.1 mg/L IAA and 2 mg/L BAP, and the other media without hormones). The seed germination rate and the growth and development of the seedlings were observed over a period of 8 weeks. The seed sprouting rate was highest in 100 μL/L CN in the media supplemented with hormones. The seed sprouting rate was highest in 50 μL/L CN in the hormone-free media. In the hormone-supplemented media, CN inhibited the growth of seedlings, especially in the 200 μL/L CN, where even the root growth was severely stunted. In the hormone-free media, some seedlings that were exposed to CN showed nutrient deficiency symptoms, and adventitious roots were observed coming from the leaves of some seedlings. This study provides insight into how nicotine from tobacco and nicotine products can affect seed germination and seedling growth.
Open Access
Molecular and Morphological Identification of Ustilaginoidea Virens, the Causal Agent of Rice False Smut in Sri Lanka
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Sewwandi, E. D. S.; Manamgoda, D. S.; Udayanga, D.
Seed-borne fungal pathogens significantly impact on both the quality and quantity of rice production of rice. Among these, Ustilaginoidea virens, the causal agent of rice false smut, directly impacts grain yield and quality by partially or completely replacing kernels with spore masses. Historically considered a minor issue, false smut has recently emerged as a major rice disease of concern. Accurate identification andconfirmation of U. virens are thus critical for developing effective disease management strategies. In this study, rice panicles with characteristic false smut symptoms were collected from the wet zone of Sri Lanka. The associated fungal pathogen was isolated on potato sucrose agar (PSA) and designated as isolateWC2.04. Colony and micro-morphological features of the isolate obtained were documented, followed by DNA extraction, Polymerase chain reaction and bidirectional Sanger sequencing of the internal transcribed spacer (ITS) region. Sequence data were analyzed using the Basic Local Alignment Search Tool (BLAST) against the NCBI database, and phylogenetic analyses were performed. The results confirmed the identity of WC2.04 as U. virens. This study presents the first molecular confirmation of the occurrence of U. virens in Sri Lanka, highlighting the importance of integrating morphological and molecular approaches for the accurate identification of rice seed-borne fungi. Accurate identification is crucial for developing and implementing effective disease management strategies to mitigate the impact of rice false smut in the region.
Open Access
Phenanthrene and Naphthalene Biodegradation by Soil Fungi in Agricultural Fields using Mycoremediation Techniques
(Department of Applied Sciences. Faculty of Humanities and Sciences,SLIIT, 2025-10-10) Dayawansha, I. P. S. S. M.; Dharmasiri, R. B. N.; Warnakula, S. T.; Prince, F. T.; Akber, F. A. A.; Rathnayaka, R. M. G. B. A.; Madanayaka, K. H.
Mycoremediation is a sustainable and environmentally friendly biotechnological approach used to remediate the environment by eliminating organic contaminants such as polycyclic aromatic hydrocarbons (PAHs), pesticides, and heavy metals. This strategy promotes soil health while improving crop productivity. The goal of this study is to identify the soil fungi that have the ability to degrade PAHs, particularly phenanthrene and naphthalene, and to evaluate the degradation efficacy and associated toxicity of identified fungi for sustainable food production. Soil samples were collected from Galle, Matara, Colombo, and Jaffna, among other urbanised areas of Sri Lanka. To isolate fungal colonies, the collected soil samples were serially diluted and plated using the spread plate method on potato dextrose agar (PDA)medium. The isolated colonies were subjected to primary screening in Bushnell Hass (BBH) medium to assess their degradation capacity. After demonstrating positive activity, colonies were selected to assess their capacity to degrade particular PAHs. Fungal strains that showed efficient degradation were identified at the molecular level. Ten morphologically different strains of fungi were identified in the first step. Nine strains showed better PAH degradation in primary screening.