International Research Symposium of UWU-2018

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An Accurate Multiple Sequence Alignment Algorithm for Biological Sequence Sets with High Length Variations
(Uva Wellassa University of Sri Lanka, 2018) Jayasingha, J.A.D.T.B.; Wannige, C.T.
Multiple sequence alignment (MSA) is used for many studies in modern biology. There are many algorithms available for the alignment of multiple sequences. Among them, progressive alignment algorithm is the most commonly used heuristic alignment strategy for MSA. It solves MSA with an economic complexity but does not provide accurate solutions, because there is a conflict between accuracy and complexity. The existing similarity score method in progressive alignment algorithm does not consider the lengths of the sequences in the considered sequence set. So, if the protein or DNA sequences are with high length variations, the initial alignment scores may not produce a correct measure of similarity between the sequences. This leads to less accurate initial alignment scores, and as a consequence, final multiple sequence alignment may produce inaccurate results. In this research, we present a modified progressive alignment algorithm especially for sequences with high length variations. We modify the latest version of ClustalW 2.1 by replacing the similarity distance measure in ClustalW algorithm with a novel distance measure. The new distance score method captures the distance between each sequence pairs in sequence set and the obtained distance measure is utilized to generate a better guide tree for progressive alignment. In order to determine the pairwise similarity distance measure, we used lengths of the shortest common super-sequence (SCS) and the Longest Common Sub-sequence (LCS). We assessed our algorithm with BALIBASE 3.0 protein benchmark and compared the obtained results to those obtained with ClustalW alignment algorithm using the Quality score (Q Score) and the Sum of Pairs Score (SPS). We obtained better Q scores and SP scores for the alignments from modified ClustalW algorithm over original ClustalW algorithm. Furthermore, the alignment speed of modified ClustalW algorithm is multiple times faster than the original ClustalW algorithm. Keywords
Adoption of Machinery in Tea Cultivation and Management by Tea Small Holders in Kalutara District
(Uva Wellassa University of Sri Lanka, 2018) Karunathilaka, U.M.; Dharmadasa, R.A.P.I.S.; Premathilaka, K.G.; Nakandala, D.M.J.
Use of machinery is a vital investment to enhance the productivity and overall performance of the tea industry. It is considered to be a better solution for the problems of labor shortage and high cost of production. The purpose of this study was to identify the factors affecting the adoption level of machinery. A sample of 154 tea small holders in Kalutara district was selected using multistage sampling technique. Data were collected using structured questionnaire and by interviewing the tea small holders at their residences. Data were analyzed using descriptive techniques as well as a Tobit regression model. According to the results of the descriptive analysis, overall adoption level of machineries is 12.73%. Small holders have higher adoption regarding pruning machine (29.22%) and TR1 selective tea harvester (20.13%) while lower adoption on Holing machine (7.14%), Fuel operated plucking machine (5.19%) and Battery operated plucking machine (1.95%).The Tobit regression analysis revealed that farming experience, gender, family labor, information by TRI, land ownership and yield positively affect the adoption level while educational level of the farmer, age of the farmer and time spending in the tea land negatively affect the adoption level of machinery. Therefore, more attention should be given on these significant variables to find the appropriate strategies for increasing the machinery usage by tea small holders in the study area. Awareness programs on machineries should be arranged frequently to improve the knowledge and awareness of the tea small holders in Kalutara district.
Agricultural, Economical and Ecological Importance of Phoenix pusilla (Ceylon Date Palm) and Its Future Research Perspectives
(Uva Wellassa University of Sri Lanka, 2018) Hapuarachchi, N.S.; Warnakula, L.; Cooray, R.; Dayarathne, D.A.R.K.; Safeena, M.I.S.
Phoenix pusilla, commonly known as Ceylon date palm (Indi) is a native palm species to Sri Lanka, belonging to the Family Arecaceae and Genus Phoenix. It is closely related but distinct from Phoenix dactylifera (date palm) by many morphological features. P.pusilla grows naturally in many parts of Northern and Eastern regions in Sri Lanka, and occasionally raised as an ornamental crop. It is considered as an underutilized fruit crop, and an untouched genetic resource, facing a severe genetic loss due to the negligence of the public and lack of scientific research. The aim of the review was to study the existing knowledge on agricultural, economical and ecological importance of P.pusilla. An extensive literature search was carried out in "Google scholar", "NCBI" and "AGRIS" databases using search terms "Ceylon date palm" and "P.pusilla" which resulted total of seven research articles. One study depicted that it is a multipurpose plant with many valuable traits, but with an inconsiderable attention within the country and globally. Three research papers showed the importance of its edible fruit in treating fever, hyperdipsia, consumption, cardiac and general debility, burning sensation, seminal weakness, and gasteropathy. Furthermore, leaflets have been used to weave mats, brooms and baskets. It is ecologically important as a nursing plant in improving degraded tropical dry evergreen forest landscapes, by conserving soil and maintaining favorable conditions for the growth of woody plants. It is highly drought tolerant and has been used to pollinate P.datylifera which has produced commercially valuable dwarf hybrids bearing seedless, edible fruits. In conclusion, further studies are essential to understand the physiology of P.pusilla to biotic and abiotic stresses, its ecological adaptations, nutritional and medicinal properties and phylogenetic relationships for the development as a cash crop and to improve other Phoenix species through interspecies hybridization.
Analysing Critical Factors Associated with Perceived Risk for Major Types of Cancers in Sri Lanka — using Data Mining Techniques
(Uva Wellassa University of Sri Lanka, 2018) Parakrama, M.L.; Kodikara, K.A.K.D.; Senanayake, S.H.D.
Cancer is one of the world recognized critical cause of morbidity and mortality. Identification of demographic, health and life style factors are significant to detect and prevent from the cancers. Since the Sri Lankan public has lack of knowledge about influence of those factors on cancer risk, the research has been conducted using data mining techniques to develop significant patterns in order to identify the critical factors towards the most recorded cancer types in Sri Lanka (Breast, Oral and Oesophagus cancers). Hence, the ultimate objective of the research is to increase the awareness among Sri Lankan public which will be helpful to take preventive approaches. The research was based on the patients' data within a fiveyear period of time, which was collected from the sources of Apeksha hospital, Maharagama. By following the Knowledge Discovery in Databases process, data collection and preprocessing were completed manually. Data was analysed through the data mining tool called Weka. The research was used Random Forest classification technique, k-mean clustering technique, and Apriori association rule mining. From the research it has been identified that the gender, number of children, breast feeding, menopause, weight, age at menarche as the critical factors towards the breast cancers. The gender, marital status, weight, smoking, consumption of alcohol, betel chewing were identified as critical factors towards the oral cancers. The gender, consumption of alcohol, occupation, weight and age were identified as critical factors towards the Oesophagus cancers. The patterns were obtained from the above identified critical factors with their approximate values.
Analysis of Chemical Composition and Oil Yield of Cymbopogon nardus and Cymbopogon winterianus in Thanamalwila Area
(Uva Wellassa University of Sri Lanka, 2018) Gamage, T.G.K.M.; Ariyasinghe, H.A.E.N.; Alakolanga, A.G.A.W.
Citronella (Cymbopogon nardusand Cymbopogon winterianus) plant is a perennial crop which is used to extract citronella oil as a commercial product. Citronella is cultivated in Southern coastal area of Sri Lanka, mostly in Matara and Hambantota districts. Citronella cultivation is recently started in Thanamalwila area. Variety, climatic and soil condition can affect the yield and chemical composition of citronella oil. Objective of this study was to analyze and compare the oil yield and chemical composition of two species cultivated in Thanamalwila area to select the best species for oil extraction. Steam distillation technique was used to extract the citronella oil and gas chromatography-mass spectrometry (GC-MS) was followed to analyze the chemical composition. It was found significantly (P < 0.05) higher percentages of Citronellol (7.14%), Citronella! (9.02%) and Geraniol (16.01%) in Cymbopogon nardusthan in Cymbopogon winterianus in which the respective values were 4.68%, 4.81% and 6.3%. There were no significant differences between two species with respect to their Camphene, Limonene and Borneol contents. The oil yield of Cymbopogon nardus was significantly (P < 0.05) higher than that of Cymbopogon winterianus. Therefore, as far as the oil yield and chemical composition of oil are concerned, Cymbopogon nardus is the best variety to cultivate in Thanamalwila area.
An Analysis of Factors Affecting on Tourism Receipts in Sri Lanka after the Liberalization of the Economy
(Uva Wellassa University of Sri Lanka, 2018) Gunarathne, G. S.P.; Perera, P.D.M. V.
Tourism can be primarily defined as travel for pleasure or business that provides many employment opportunities, income & other benefits. It is evident in literature that tourism industry positively contributes to economic growth of developing countries. It is more important to identify the factors that affect the growth of performances (tourist receipts) of tourism industry. Based on this background, the general objective of this study is to estimate the contribution of factors affecting tourist receipts in Sri Lanka. Existing literature suggests that tourist arrivals, excursionist arrivals, tourist nights, accommodation capacity & annual occupancy rate etc. affect tourist receipts. The secondary data from 1977 to 2016 were extracted from Central Bank annual reports & time series analysis was used to analyse the data. Prior to analysis, optimal number of lag value was identified as 3 by using Akaike Information Criteria. Augmented Dickey Fuller test indicated that all the variables become stationary at their 1st deference while excursionist arrivals become stationary at 2nd deference. There is a long run relationship among all the variables due to Johansen test of cointegration which implied as 5 cointegrating equations. Presence of long run relationship lead to run Vector Error Correction Model to identify the short run impact. Among the factors, there is a significant positive impact of tourist arrivals & excursionist arrivals on tourist receipts in the short run although accommodation capacity, annual occupancy rate have a significant negative impact. In addition, tourist nights do not indicate any significant short run impact on tourist receipts. Hence, it can be concluded that there is a positive impact of tourist arrivals & excursionist arrivals on tourist receipts in short run based on the Sri Lankan context. Keywords
Analysis of Organizational and Environmental Benefits from Sustainable Waste Management Practices in Hotels (with special reference to Kandy District, Sri Lanka)
(Uva Wellassa University of Sri Lanka, 2018) Wijesinghe, W.A.D.S.; Damunupola, A.K.A.; Femando, P.I.N.
Kandy district is a reputed tourists' destination which records the second largest waste generation next to the Colombo district in Sri Lanka. Today the highest business competition has made sustainable waste management as a trend in hospitality organizations' environment. According to the main purpose the study analyzed the organizational & environmental benefits from sustainable hotel waste management practices in Kandy district, Sri Lanka. The study was adopted a descriptive survey research design. Convenience sampling method was used to select the respondents. Data collection instruments included questionnaires targeting the hotel general manager, departmental managers and junior staff. The collected data were coded tabulated and edited with the aid of SPSS electronic statistical package then presented using table, graphs and pie charts to enhance a meaningful description. The data were analyzed using the mixed method including frequencies distribution percentages and means to explain the variable characteristics, while inferential statistics including correlation to determine the variable relationship. As per the research findings, hotels in Kandy have to overcome many challenges to gain organizational and environmental benefits from sustainable waste management practice. Assistance from local government authorities improves the awareness among working staff innovative working environment an appropriate policy framework for hotels are essential to improve the waste management confidently face to critical challenges in order to the growth of sustainability in the hotel industry in Kandy district.
Analysis of Pesticide Residues in Fruits and Vegetables exported to the European Union and determining the effect of Chlorine Treatment on Diazinon Residues
(Uva Wellassa University of Sri Lanka, 2018) Mallikaarachchi, M.A.S. K.; Magamage, M.C.; Premathilake, K.G.; Weerawansha, A.N.R.
Presence of pesticide residues in agricultural commodities can cause acute and chronic toxicities on humans.The objective of this study was to develop a monitoring programme to regulate the pesticide usage of farmers and to determine the effect of chlorine treatment on diazinon residues of tomato and bean samples. Two surveys were conducted to identify the malpractices of the farmers and exporters who cultivate and process the commodities, which are exported to the EU. A total of 98 samples of fresh fruits and vegetables were analysed for the presence of 66 active ingredients of pesticides. The quick easy cheap effective rugged and safe multi-residue extraction method was followed, using gas chromatography mass spectrometry. There were no malpractices were identified at farmer level while three malpractices were identified at exporter level. Analytical results revealed that only 26% of the samples were positive for pesticide residues. Pesticide residues above the European Union Maximum Residue Limit (MRL) were detected in 65% of samples among the contaminated. Multiple residues (2-3) were present in 11% of contaminated samples. Eleven pesticides were detected, of which 7 were insecticides, 4 were fungicides and no weedicides. Mostly detected active ingredients were profenophos and etofenphox, both of which were insecticides and carbendezim, a fungicide. The chlorine treatment had a significant effect on reduction of Diazinon residues in tomato (p = 0.024) and bean (p = 0.005) samples. The results confirmed the presence of pesticide residues in fruits and vegetables exported to the EU. Chlorine treatment at 150 ppm dosage could effectively reduce the residues of diazinon in tomato and beans.
Analysis of Slope Stability on Road Cut Slopes; a Case Study at Badulla- Bibile Road and a Cost-Effective Proposal for Future Road Cut Slope Studies
(Uva Wellassa University of Sri Lanka, 2018) Rifkhan, M.N.M.; Jayasinghe, P.; Christopher, W.A.P.
Sri Lanka is frequently affected by hydro meteorological disasters, one of which is slope failure triggered by unusual intense rainfall. Post-disaster inspections reveal the lack of preliminary investigations being carried out on cut slope failures. The first objective, which was a slope stability analysis on proposed cut slopes of Badulla-Bibile road was designed in a three-fold methodology including Preliminary Study, Field Investigation and Laboratory Investigations. Laboratory investigation consisted of Sieve analysis, Liquid limit, Direct Shear and simple pour pile method. The data were interpreted with reference to slope geometry and soil strength. Geometrical interpretation identified that 32.5% of natural and 73.3% of cut slope failures were possible. The soil analysis interpreted using Unified Soil Classification System reveals that silty gravel, Lean Clay, Silt, Silty Sand, Clayey Sand soil types were present. All these soils were known to be cohesion-less and changing the slope angle was identified to be the ideal mitigation. The second objective was to understand the importance of preliminary study in future road cut slope. This proposed method includes geometrical and soil study. Geometrical study is done with three criteria considering the slope angle, slip angle, friction angle, strike of slip and strike slope. The soil analyses are performed using Unified soil classification system considering the Sieve analysis and Liquid limit test. Identified properties of the soil were modeled in Slope W software to check the factor of safety. This method to find the soil properties is cost effective and less time consuming than direct Shear method. This study has considered direct shear as a conventional method and interpreted for a location. Both results were coinciding, and a conclusion can be drawn that the proposed cost effective basic method is economical which can be used as a preliminary study in future road projects in Sri Lanka.
Analysis of the Contemporary Situation of Illicit Alcohol Consumption in Sri Lanka
(Uva Wellassa University of Sri Lanka, 2018) Guruge, G.N.D.; Young, S.M.; Kithalawaarachchi, S.K.
Illicit alcohol “Kassippu” consumption is a serious threat in Sri Lankan community causing many deaths, especially in low-income families and common among both male and females. Excessive use of illicit alcohol can lead to physical, psychological and social harm since it contains methanol, a lethal substance in the brew in varying proportions. There are more than 200,000 illicit alcohol outlets operating in the country and about 5,000 manufacturers. Thus, an investigation was carried out by the President’s Task Force to see whether the consumption has decreased or increased between 2015 to 2017. Two methods have been followed where the President's Task Force (a) collected information from 228 out of 332 divisional secretariats through the respective divisional secretary (b) and collected information from 438 police stations in all nine provinces from the Officer in Charge of the relevant police station. A questionnaire was used to collect information to see whether the illicit alcohol consumption is low, moderate or high. The relevant highest officer in charge has certified the data collection. The results clearly show that the consumption of illicit alcohol in all provinces, percent mean for low, moderate and high was 51.5, 30.5, and 18.0 respectively. In the divisional secretariats, percent mean for low, moderate and high was 54.1, 33.6, and 12.3 respectively. Both methods show comparable results and a drastic decrease in 2017 since 2015. Especially high consumption category shows a 47.8% decrease (p < 0.0001, CI 95%). Eastern, Northern and Uva provinces show high percentages of low consumption in both cases while the Western province shows a high percentage for high consumption as for police data. The study concluded that there is a decrease in illicit alcohol consumption between 2015 and 2017 in Sri Lanka in almost all provinces where North, East and Uva provinces show a dramatic decrease.
Analysis of the Effect of the Working Environment to the Job Satisfaction of the Air Hostesses (with special reference to Sri Lankan Airlines)
(Uva Wellassa University of Sri Lanka, 2018) Wijerathna, W.G.N.S.C.D.; Herath, H.M.W.M.
The research was done to analyze the job satisfaction of Air hostesses in respect to their working environmental factors and with a special reference to Sri Lankan Airlines. Airhostesses make the first impression of the country. They need to serve food and beverages to the passengers while taking care of the safety and security of all on board. Even if lots of benefits come with air hostess positions, there are difficulties to do the job too. Mostly the working environment factors are affecting the job dissatisfaction. Young ladies are selected to work on the air with strange people, work being far away from beloved ones, tough roster, long hours, odd working times, sleepless nights, routine work and etc. Objectives of the research are, identifying the effect and the major critical factors of working environment that effect to the job satisfaction of the Air Hostesses. Population was all currently working Sri Lankan Airlines airhostesses and a sample was 50 of them. The simple random sampling method was used and with questionnaires and Google forms the data was collected. In the analysis Air hostesses' job satisfaction was the dependent variable and their working environment was the dependent variable including three factors such as Job It Self, Job Environment and Organizational Characteristics. For the analysis, Descriptive statistics was used the Demographic factor analysis and correlation and Regression were used for relationship analysis. With the 0.813 overall Pearson correlation, it proved that there is a strong positive correlation in between independent and dependent variables at the significant level 0.01. Coefficient table of the regression analysis of this study showed all the independent variables had been negatively reacted upon the dependent variable with an unstandardized beta coefficient for the constant -0.059. The major affecting factor for the job satisfaction is the job environment with 0.658 unstandardized coefficient beta value. As the suggestions flexible time schedules for flying, fare duty rosters, provide comfortable garments and the accessories, minimize the injurious and the heavy equipments from ladies and having altered solutions for them, and minimize the monotonous working pattern can be given.
Analyzing Seasonal Variation of Water Quality Parameters of Kelani River
(Uva Wellassa University of Sri Lanka, 2018) Ranathissa, N.P.K.; Sampath, J.K.H.; Attanayake, A.N.B.; Amarakoon, H.A.K.
Raw water quality of a surface water body directly affects the purification process and the final water quality of drinking water. When considering Sri Lanka, the Kelani River plays a vital role in fulfilling people's water necessities, as it provides water for more than 80% of the population of the capital city, Colombo. The current study focuses on the Kelani River in order to identify the models of variation of raw water quality parameters and to investigate patterns and trends of parameter variation. The main objective was to forecast the variation of water quality parameters with special reference to the Kelani River. The water quality was analyzed with different parameters including pH, Turbidity, Electrical Conductivity, Total Colifortn and Escherichia coli, and data gathered for five years (2012 - 2017) at five different intakes. Analysis was carried out by R studio software. Time Series techniques were used to perform the tests, and all decisions were made under p-value of 0.05. ARIMA and SARIMA models were used to identify the best fitting model for the variation of quality parameters with time. Results were forecasted for a 6 month time period using the above fitted models. Based on obtained results, the seasonality of the water quality parameters changed from one intake to another. When analyzing the pH, Ambathale and Biyagama showed seasonality while other three intakes showed non seasonality. Electrical Conductivity had a seasonal variation at Biyagama and Pugoda intakes, while Escherichia colishowed seasonality for Ambathale intake only. Frequent long-term monitoring of physicochemical parameters of surface water resources is vital for the better management of water resources as well as aquatic habitats and the environment. Based on the results of this study, a better prior understanding about the behavior of raw water quality parameters can be obtained, and this prior understanding can be used to manage the water purification process and final water quality.
Anti-oxidant Activities of Bioactive Compounds Extracted from Pterygoplichthys pardalis (Scavenger Fish) Harvested at Digana, Central Province, Sri Lanka
(Uva Wellassa University of Sri Lanka, 2018) Perera, B.B.A.N.S.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Pterygoplichthys pardalis (Scavenger fish) survive by competing with native biota. This species is an omnivore whichthreat to endemic fish species and inland aquaculture industry. However, these fishes contain compounds which autolysis proteins under low temperatures. Objective of this study was to check the difference in the water soluble proteins which can be used as bioactive compounds separated from scavenger fish after slaughtering stored at 4 °C for 24 hrs. Female fish (n = 3) were collected from local reservoir and slaughtered in the field. Slaughtered fish which stored at 4 °C were separated in to 4 main components as flesh, GI tract, mucus and other gonads in 0, 3, 6, 9, 12 and 24 hrs of storing. Separated parts were homogenized with distilled water (1:4) and centrifuged to collect the supernatant. Level of separation was observed using SDS-PAGE gel electrophoresis. Then samples were lyophilized and used for further analysis. Antioxidant activity was measured using TBARS inhibitory assay and DPPH scavenging activities. SDSPAGE images confirmed that there were no differences in the extracted compounds after 03 hrs of slaughtering. According to the TBARS assay, three extractions from flesh, mucus and other organs had stronger antioxidant properties compared to the control (p < 0.05). While DPPH scavenging results showed over 75% activity (other organs-91.26±8.28%, flesh- 87.07±4.49%, GI-86.20±3.94%, mucus- 75.20±4.09%) but no difference was observed among the extracted compounds (p > 0.05). Concluding water extracted in 0-3 hrs after slaughtering of female scavenger fish showed strong antioxidant activities and this can be used as natural anti-oxidant agent in food industry.
Antibacterial Activities of Endophytic Fungi of Cyperus iria Collected from Matale Distric
(Uva Wellassa University of Sri Lanka, 2018) Jayasundara, J.M.N.M.; Ratnaweera, P.B.; de Silva, E.D.
Antibiotic resistance of bacteria has become an ongoing severe human health concern which requires extensive research priority. Endophytic fungi of Cyperaceae family plants are considered as a potential source for isolating bioactive compounds. Hence, the objective of the current study was to isolate endophytic fungi of Cyperus iria and investigate the antibacterial activities of the crude fungal extracts. Healthy C. iria plants were collected from Weragama in Matale district and endophytic fungi were isolated from the surface sterilized roots and aerial parts using five types of media (SYP, YPD, ME, PDA and MEA) enriched with antibiotics. Each pure fungal culture was sub cultured in ten PDA dishes, incubated close to sporulation, extracted into ethyl acetate, filtered and resulting crude extracts were obtained. The crude extracts were tested for antibacterial activity using agar disc diffusion assay against four bacteria, Staphylococcus aureus (ATCC 25928), Bacillus cereus (ATCC 11718), Pseudomonas aeruginosa (ATCC 9027) and Escherichia coli (ATCC 35218) at 400 ug disc-1 concentration where Gentamycin (10 ug disc-1) and methanol (10 IA disc') were used as the positive and negative controls, respectively. Total 34 morphologically distinct putative endophytic fungi, 23 from aerial parts and 11 from roots, were isolated. Thirteen fungal extracts exhibited antibacterial activity against S. aureus, 24 against B. cereus, 12 against P. aeruginosa and one against E. coli. Among all, 29 fungi were active against at least one bacterium tested while five fungi were inactive to all. Activity of three extracts against B. cereus, 12 against P. aeruginosa, and one against E. coli was similar to the activity of the positive control. Fifteen extracts against B. cereus, 27 against P. aeruginosa, 33 against E. coli and 21 against S. aureus showed significant (p < 0.05) antibacterial activities compared to the negative control. In conclusion, C. iria from Matale harbors a lot of endophytic fungi, where several are capable of producing bioactive secondary metabolites with selective antibacterial properties.
Antibacterial Activity of Silver Deposited Vein Graphite against Waterborne Pathogenic Escherichia coil
(Uva Wellassa University of Sri Lanka, 2018) Kumar, K.K.A.D.; Amaraweera, T.H.N.G.; Premetilake, M.M.S.N.; Wijayasinghe, H.W.M.A.C.
The microbial contamination of drinking water is a major health problem in the world which requires an effective treatment. Silver ion (Ag+2) is used as nonspecific antibacterial factor and it acts against a very broad spectrum of bacterial species. In this study, antibacterial efficiency of Ag deposited vein graphite were studied using Escherichia coli strain. Ag was deposited on the graphite surface by reduction of Ag+2 in silver nitrate solution using reducing agent. Scanning electron microphotographs of the Ag deposited graphite reveal that the deposited silver particles are highly agglomerated or spongy voids. Although the size of silver particle agglomerates are relatively coarse, the average size of individual silver nanoparticle is around 75 nm. Antibacterial efficacy of the synthesized sample was investigated using waterborne pathogenic E. coli strain. The antibacterial test was done using prepared composite samples and samples of E. coli, using shake flask method. A commercial antibiotic (Ofloxin-200 mg) was used as the positive control. The samples were drawn periodically (1, 1.5, 2, 2.5 and 3 hours) from the flask and tested against E. coli by plate count method using standard procedures. There was a significant E. coli removal efficiency by the synthesized Ag Graphite composite compared to purified graphite and positive control (One-way ANOVA, p-value=0.00). Therefore, this study suggests that Ag- vein graphite composite could be used as an effective material in water purification, especially in removing of E. coli.
Antifungal Activity of Bacillus amyloliquefaciens Ethyl Acetate Extract and Fractions Against the Fungus Khuskia oryzae
(Uva Wellassa University of Sri Lanka, 2018) Lohanathen, G.P.; Jayasundara, J.M.N.M.; Ratnaweera, P.B.; de Silva, E.D.
Fungal infections are common among plants and animals which result in economic losses. Finding new antifungal agents from alternative sources may help to solve the above issue. It was observed that, in culture Bacillus amyloliquefaciens isolated from a contamination shows antifungal activity against the fungus Khuskia oryzae. Therefore, the objective of the current study is to determine the antifungal activity of the crude ethyl acetate extract and the fractions of crude extract of B. amyloliquefaciens against the fungus K oryzae. B. amyloliquefaciens was grown on Luria-Bertani Agar (LBA), extracted into ethyl acetate after an incubation period of three days and the antifungal activity of the crude extract was tested against K. oryzae at 400 lig disc-1 using agar disc diffusion method. Crude extract of 1.5 g was first fractionated by Kupchan solvent-solvent partitioning scheme, sequentially using hexane, methanol/water (9:1); chloroform, methanol/water (6:4) and ethyl acetate, water. Antifungal activity of the three fractions hexane, chloroform and ethyl acetate was determined and the chloroform fraction was active against K. oryzae. The active fraction was further purified using Sephadex LH2O size exclusion chromatography using methanol as the eluent. Fractions were combined according to the thin layer chromatography (TLC) profiles and the antifungal activity was tested for the combined fractions (A-F). Flucanozole and methanol was used as the positive and negative controls respectively. Fraction C (32.8 mg) resulted from size exclusion chromatography of the chloroform fraction exhibited 18 mm radius inhibition zone against K. oryzae while none of the other fractions showed any activity. Activity of fraction C was similar (p > 0.05) to the activity of the positive control. However, TLC profile of the fraction C showed the presence of more than one compound. Thus, further purification of fraction C is necessary in order to isolate the active compound/s which may lead to a potential antifungal agent.
Antimicrobial Activity of Turmeric (Curcurna longa) Against Salmonella Spp and E. coli Spp
(Uva Wellassa University of Sri Lanka, 2018) Lakmina, D.L.L.; Ranasinghe, M.K.; Abeyrathne, E.D.N.S.; Jayasena, D.K.D.D.
The active components of natural herbs and spices contribute to the self-defense against mechanisms infectious organisms and also getting the attention as alternatives for synthetic chemicals due to their inherent antimicrobial nature, which is primarily used in food preparation. Turmeric is a tropical herb, which use to obtain aromatic powder from its mature rhizomes used for various purposes. The research was conducted to evaluate the Turmeric Methanolic Extraction (TME) and Turmeric Powder (TP) against Salmonella spp and E. coil spp. Dilution series of TME and TP were prepared according to 0.4%, 0.8%, 1.2%, and 1.6% and well diffusion method was conducted. Distilled water served as the negative control while Augmentin® (0.625ppm) served as the positive control. Antimicrobial activity was measured using the diameter of bacterial inhibition zone (DBIZ). TME inhibition for E-coli spp were shown significant difference (P<0.05) between treatments while 1.2% dilution series (DBIZ of 9.6910.54 mm) was closely related to positive control (DBIZ of 9.98±1.57 mm). However, TME inhibition for Salmonella spp did not show significant difference (P>0.05) between treatments. Inhibition of TP inhibition for E-coli spp showed significant difference (P<0.05) between treatments and the best treatment was 0.8% (DBIZ of 1.84±0.10 mm). Moreover, TP inhibition for Salmonella spp showed significant difference (P<0.05) between treatments and the best treatment was 1.2% (DBIZ of 2.31±0.08 mm). In conclusion, 1.2% concentration in both TME and TP samples can be selected as the suitable treatment for antimicrobial property by considering the cost effectiveness.
Antioxidant Activity of Selected Ten Underutilized Fruit Species
(Uva Wellassa University of Sri Lanka, 2018) Dilani, V.J.; Singhalage, I.D.
The study was conducted to assess the antioxidant potential of ten underutilized fruit species namely Phyllanthus emblica L,Flacourtia sp.,Elaeocarpus serratus L., Phyllanthus acidus (L.) Skeels , Averrhoa carambola L., Averrhoa bilimbi L., Cynometra cauliflora L., Morus sp., Spondias sp. and Manilkara zapota (L.) P.Royen grown in Sri Lanka. Fruit extracts were prepared by centrifuging (4500 rpm) finely ground fresh fruit samples (20 g) with distilled water (40 ml) for 90 minutes. The extraction was repeated twice and the supernatants were used for analysis. Total Ascorbic Acid Content (TAsC) was determined using an iodomatric titration technique, calculated as mol per gram of fresh weight. Antioxidant potential was determined using DPPH• and ABTS•+ radical scavenging assays. The DPPH• Radical Scavenging Activity (RSA) of the extracts was expressed as IC50 values. The ABTS•+ activity (RSA) was calculated as percentage of discoloration. This experiment was conducted by following complete randomized design with 3 replicates. Ascorbic acid was used as a positive control and distilled water was used as a negative control. The TAsC varied among the species from 0.125x10-3 ± 0.000025 mol g- of fresh fruit of C. cauliflora L. to 4.608 x 10-3 ± 0.0001665 mol g - of fresh fruit of P. emblica L. The TAsC and antioxidant activity (DPPH• and ABTS•+ assays) were found in order to, C. cauliflora L.< Spondias sp.
Antioxidant Activity of the Crude Extract of Ulva lactuca (Sea Lettuce) Collected from the South Coast of Sri Lanka
(Uva Wellassa University of Sri Lanka, 2018) Rumeshani, K.L.G.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Ulva lactuca is one of the famous edible seaweeds around the world. It is a rich source of many nutrients and bioactive compounds. Solvent extraction method is commonly used in extracting bioactive compounds in seaweeds which may be nonfood grade. The objective of this study was to develop a simple, food grade extraction method to extract bioactive compounds from Ulva lactuca and identify the antioxidant activity of the crude water soluble extract and compare with a commonly used solvent extraction method. Four types of seaweed treatments (05 g) namely Fresh, Air-dried (AD), Oven-dried (OD) and Freeze-dried (FD) were used for the water extraction using three different ratios as 1:10, 1:20 and 1:30 and Airdried sample using Methanol as the control. The crude extracts derived from different extraction methods were used for analyzing the antioxidant activity by Thiobarbituric Reactive Substance (TSARS) assay and 2,2-dipheny1-1- picrylhydrazyl (DPPH) free radical scavenging assay. All the trials were done in triplicates. Data were analyzed using the Minitab 18. In TBARS assay, methanol extracts showed the lowest TEARS value (-1.10±0.08) and AD (1:30) and OD (1:10, 1:20, 1:30) showed no significant difference (p > 0.05) compared to antioxidant activity of the methanol extracts. Almost all the samples showed antioxidant activity except Fresh (1:10, 1:20) and AD (1:10). However, In DPPH scavenging assay, DPPH scavenging activity of Fresh (1:10, 1:20, 1:30), AD (1:10, 1:20, 1:30), OD (1:10. 1:30) and FD (1:30) showed no significant difference (p > 0.05) compared to that of methanol extracts. AD (1:10) showed the highest DPPH scavenging activity (89.54±4.56%) which is higher than methanol (87.75±2.87) and Ascorbic acid (85.73±0.19). Therefore it can be concluded that considering the time of production, simplicity, toxicity and cost; water extraction of Fresh (1:10) or AD (1:10) can be used as a best extraction for producing antioxidant agents in food industry.
Antioxidant and Metal Chelation Activities of Fish Protein Hydrolysates Produced from (Scomber japonicus) Pacific Mackerel Canned Fish Processing Fin Wastage
(Uva Wellassa University of Sri Lanka, 2018) Ediriweera, T.K.; Aruppala, A.L.Y.H.; Abeyrathne, E.D.N.S.
Pacific chub mackerel (Scomber japonicus) is a salience fish species which highly utilized in canned fish processing. In production, around 30% of raw fishes are discarded as wastes which lead to economic losses and environmental pollution. Hence, production of Fish Protein Hydrolysates (FPH) utilizing fish wastes, which contains bioactive compounds may be an ideal remedy. In this study Scomber japonicus canned fish processing fin wastage was collected and blended. Aqueous extracts of Fish Protein Concentrates (FPC) were produced with 04 different ratios as sample: distilled water, 1:1, 1:2, 1:3 and 1:4. Crude extraction was observed using 10% SDS-PAGE. Extracted FPCs were hydrolyzed using Papain, Pepsin, Trypsin and Protease enzymes (1:100) under 370C with their optimum pH conditions for 0, 3, 6, 9, 12 and 24 hours followed by heat inactivation at 1000C for 15 minutes. Hydrolyzed samples were lyophilized and observed for antioxidant activities by TBARS and DPPH scavenging assay and metal chelation activity by Fe (II) chelating activity. According to the observations there was no significant difference between the 04 ratios in yield (p > 0.05). So 1:1 ratio was selected with periods as Papain-24 h, Pepsin3 h, Trypsin-3 h, Protease-0 h for further experiments. According to the results obtained from TBARS assay, none of the FPHs showed antioxidant properties (p < 0.05), instead all showed high oxidative activity. However DPPH scavenging assay showed significance difference among the treatments (p < 0.05). Results obtained by Fe (II) chelation activity analysis revealed that the produced FPHs show Fe(II) releasing activity instead of chelation (1.84, 13.99, 16.48, 1.84%,), while FPHs produced according to standard protocol showed a slight chelating activity (0.73%). This concludes the FPHs produced using aqueous extracts of Scomber japonicus do not contain strong antioxidant activity and they have iron releasing properties. Keywords

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