Browsing by Author "Udayanga, D."
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Item Application of Newly Develop Bacterial Consortium for Decolorization of Structurally Different Textile Dyes(Uva Wellassa University of Sri Lanka, 2019-02) Ekanayake, E. M. M. S.; Udayanga, D.; Manage, P. M.Sri Lanka, niche of high quality supplier of apparel to the world, produce heavy load of textile wastewater every day. Such textile dye contained wastewater is to be treated prior discharge to the environment to maintain the pollution standards. The existing physical and chemical treatments methods are highly expensive. Therefore, the present study was focused on develop a novel bacterial consortium isolated and characterized previously as textile dye decolorizing bacteria which were isolated from textile wastewater effluent sites. Selected bacterial strains were starved overnight in 0.01 M sodium chloride, equalized the suspension at A590 = 0.35 and 5% (v/v) of suspension was introduced into sterile CI Direct Blue 201 (DB) textile dye at final concentration of 50 mg L-1. Standard spectrophotometric method was followed to determine the decolorization percentage. Three individual bacteria; Alcaligenes faecalis, Micrococcus luteus, and Staphylococcus warneri acquired 60, 64 and 72 h respectively for complete decolorization of DB dye, were selected to prepare the bacterial consortium. Decolorization of the DB dye by the bacterial consortium was completed within 48 h. It was found that the complementary interactions among three strains for rapid decolorization of DB dye than their individual effect. Decolorization of DB dye by the consortium was further enhanced under static conditions with the presence of yeast extract and glucose in the medium. Repetitive addition of DB dye to the same initial biomass showed a complete decolorization up to four cycles and descending decolorization trend was observed afterward. Further, the bacterial consortium was able to complete decolorization of selected structurally different textile dyes (Vat green FFB, Cibracorn blue, Moxillon blue) confirming their application on treatment of wide range of textile dyes by providing a greener approach to Sri Lankan textile dyeing industry to fulfill 2030 Green Environment Concept.Item Domestication of Two Edible Wild Mushrooms, Lentinus squarrosulus and Lentinus tuber-regium from Sri Lanka(Uva Wellassa University of Sri Lanka, 2019) Miriyagalla, S.D.; Silva, E.I.P.; Udayanga, D.; Manamgoda, D.S.Tropical ecosystems are rich in species diversity of wild edible mushrooms but very few domestication attempts were recorded in Sri Lanka. The objective of this study was to domesticate two wild mushroom species, L. squarrosulus and L. tuber-regium freshly collected from Sri Lanka and to evaluate suitable growth conditions for both strains. L. squarrosulus (M013) and L. tuber-regium (LSK005) were collected from Ragama and Matale respectively. Species were morphologically identified initially and to confirm the identification Internal Transcribed Spacer (ITS) region was sequenced. Sequences were verified with available sequences in GenBank and a phylogenetic analysis was performed with reference Lentinus sequences. Growth rates of the isolates were determined in four different culture media. Rice grains with 0.5% CaSO4 and corn grains with 1.2% CaSO4 and 0.3% CaCO3 were tested as mother spawn media while rubber and mango saw dust were utilized as the carbon source of the growth media. A commercially available Pleurotus ostreatus mushroom strain was used in parallel as a control in each of the above experiments. Results confirmed that the highest growth rates of both wild mushroom cultures were observed on Potato Dextrose Agar. Both the isolates colonized corn based mother spawn medium with a higher mycelial density rate. Out of the two saw dust culture media, both isolates showed a better colonization with mango. L. tuber-regium produced fruiting bodies after 70 days of inoculation of culture media whereas L. squarrosulus and commercially grown Pleurotus produced fruiting bodies after 66 and 63 days, respectively. When two culture media are compared rubber saw dust produced higher yield than mango saw dust based media. In conclusion, both wild mushroom strains, L. squarrosulus and L. tuber-regium can be successfully domesticated and are potential candidates to introduce to the consumers and commercial mushroom growers in Sri Lanka.Item Effect of Different Marinades with Bee Honey and Pineapple on Quality Attributes of Smoked Chicken Jerky(Uva Wellassa University of Sri Lanka, 2020) Edema, W.N.; Jayarathne, G.G.N.; Udayanga, D.; Senevirathne, T.A.S.M.; Jayasena, D.D.This study was carried out to investigate the effect of different marinades made with bee honey, pineapple, and their combination of physicochemical and sensory attributes of smoked chicken jerky (SCJ). As the marinade solution, different levels of bee honey (5%, 10%, 15%) and pineapple (5, 10, and 15%), and combinations of bee honey and pineapple (2.5%+2.5%, 5%+5%, 7.5%+7.5%) and for the control sample water (20%) with spice mixture was used. Preliminary trials were conducted to determine the best recipe for SCJ. A sensory evaluation was conducted by using 30 untrained panelists according to the 7- point hedonic scale to select the best treatments for further analysis. Selected SCJ treatments were tested for marinade uptake, cooking loss, proximate composition, pH, colour, water holding capacity, texture, microbiological analysis, and TBARS value for 4 weeks of storage. Based on sensory evaluation, SCJ with 5% and 15% bee honey were selected as the best treatments (p<0.05). Results further revealed that 15% of bee honey had the highest amount of protein and lower ash. The highest moisture (66.87%) content and cooking loss (54.55%) have resulted in SCJ with 5% bee honey. During the storage, pH was decreased and TBARS values increased within the permitted levels. There is no significant difference in the hardness and fat content between the samples (p>0.05). However, the highest gumminess and chewiness values have resulted in SCJ with 15% bee honey (p<0.05). Total plate count increased during the refrigerated (0-4 oC) storage within the permitted levels. The treatments kept under refrigerated (0-4 oC) condition extended the shelf life up to 4 weeks while the shelf life of those kept at room temperature (27-28oC) was limited to 2 weeks. Salmonella and Escherichia coli were absent in all treatments. In conclusion, bee honey enhanced the physicochemical and sensory attributes of SCJ at a 15% level at refrigerated (0-4 oC) storage. Keywords: Bee honey, Marination, TBARS value, Jerky, ChewinessItem Foliar Pathogenic Colletotrichum species Associated with Cultivated Rubber Trees in Sri Lanka(Uva Wellassa University of Sri Lanka, 2019) Herath, I.H.M.I.S.; Manamgoda, D.S.; Udayanga, D.Colletotrichum leaf disease (CLD) is regarded as one of the major threats on rubber trees worldwide. Due to recent revolutionary changes in species numbers in the genus Colleotrichum based on molecular data, it is essential to re-assess the Colletotrichum species associated with rubber trees in Sri Lanka. The objective of this study is to identify Colletotrichum species associated with rubber plants in Sri Lanka using morphology and DNA barcoding. Samples with leaf spots were collected randomly from rubber trees at selected sites in Colombo and Matale. Single spore isolation technique was followed to obtain five pure cultures of Colletotrichum spp. and their morphological characteristics were observed. Internal transcribed spacer (ITS) loci of all isolates were sequenced. Sequences were initially identified based on similarity search at NCBI and phylogenetic analysis was performed to further confirm the relative phylogenetic placement of Colletotrichum species. Pathogenicity tests were carried out to confirm the pathogenicity of the species and the Koch’s postulates were proven for potential pathogens. According to the morphological and molecular data, those isolates belong to C. gloeosporioides, C. gigasporium and C. truncatum species complexes. Two different species grouped within C. gloeosporioides complex showed highest growth rates in Potato Dextrose Agar (PDA) and Malt Extract Agar (MEA) whereas C. gigasporium and C. truncatum showed the highest growth rate in PDA and MEA respectively. Typical CLD symptoms were observed with C. gloeosporioides complex species after pathogenicity testing whereas C. gigasporium and C. truncatum were also able to colonize and produce spore masses on rubber leaves. According to our knowledge this is the first record of C. gigasporium and C. truncatum associated with rubber plants in Sri Lanka. Therefore, this study reveals the unknown diversity of Colletotrichum pathogens associated with cultivated rubber trees.Item Phenanthrene Degradation Ability of Bacillus sp. Phyllosphere Bacteria Inhabiting the Urban Areas in Sri Lanka(Uva Wellassa University of Sri Lanka, 2020) Dharmasiri, R.B.N.; Nilmini, A.H.L.; Undugoda, L.J.S.; Nugara, N.N.R.N.; Udayanga, D.; Pathmalal, M.M.Remediation of phenanthrene from the environment is essential since its toxic effect. Out of many remediation methods, bioremediation is the most eco-friendly and effective method which can be used to convert toxic substances to nontoxic. There are many phyllosphere microorganisms which have the capability in phenanthrene like polyaromatic air pollutant degradation. This attempt is to isolate, select, and identify the efficient phenanthrene degrading bacteria. Bacteria were isolated using specific leaf samples collected from Panchikawatta, Orugodawatta, Pettah, Maradana, Colombo Fort, and Sapugaskanda in Sri Lanka. Phenanthrene degradation ability of isolated bacteria was screened using plate assay. Phenanthrene degradation ability of each bacterial species was analysed using the UV-Vis spectrophotometer and HPLC. The selected bacterial isolates were identified up to species level by PCR amplification of a fragment of 16S rRNA gene and sequencing the amplified fragments using the primers 1492R and 27F. Four Bacillus species Bacillus sp. P2B-02, Bacillus velezensis, Bacillus sp.1, and Bacillus megaterium were able to degrade more than 40% of phenanthrene. Out of these bacteria, Bacillus sp.1 (MN190173) was the most efficient bacterial species which was highly capable of degradation of phenanthrene. The Bacillus sp. could be useful as a potential biological agent in bioremediation for polluted environments with phenanthrene like polyaromatic hydrocarbons. Keywords: Phyllosphere, Aromatic hydrocarbon, Bioremediation, PhenanthreneItem Phytochemical Screening, Quantitative Analysis and In Vitro Cytotoxic Potential of Justicia adhathoda Leaf Extracts(Uva Wellassa University of Sri Lanka, 2021) Silva, A.B.W.R.; Nugara, N.N.R.N.; Manage, P.M.; Undugoda, L.J.S.; Udayanga, D.; Nilmini, A.H.L.R.Justicia adhathoda L., also known as “Adhathoda” is one of the widely used medicinal plants in indigenous medicinal systems in Sri Lanka and India. Previous studies have found several beneficial effects of different solvent extracts of this plant. However, the best solvent to extract much of the phytoconstituents has not been studied. Therefore, the present study was focused on identification, quantification of phytoconstituents in different crude extracts and in vitro cytotoxic effect of J. adhathoda. Plant leaves were collected from Ambilipitiya, Sri Lanka. Ethanol (EE), hexane (HE) and water (WE) extracts were prepared by adding 1 g of powdered leaf samples to 25 mL of ethanol (99.9%), n-hexane and distilled water, separately in triplicates. Preliminary phytochemical screening was performed according to the Harborne method. Total phenolic content (TPC) was measured spectrophotometrically by Folin-Ciocalteu assay and total flavonoid content (TFC) was determined using aluminum chloride colorimetric assay. To identify the toxicity level of J. adhathoda, different concentration of the WE were exposed to 3T3-L1 cells, a well-established cell culture model that is extensively used to study adipogenesis. The treatment was carried out for 8 days and performed MTS assay to determine the suitability of the WE consumption. Phytochemical screening results showed the availability of flavonoids, terpenoids, steroids, anthocyanins, alkaloids and coumarins in the WE. In contrast, tannin and alkaloids were abundant in the EE. TPC in the WE was 8-fold higher than the EE. The TFC in the EE was 20-fold higher than HE, and marked the highest. Collectively, the best solvent to extract the maximum amount of phytoconstituents was found as distilled water. The WE showed no toxicity below 500 μg/mL against 3T3-L1 adipocytes. The presence of high content of different phytoconstituents in WE of J. adhathoda is a great advantage to gain the health benefits as herbal tea or herbal porridges. These results provide referential information to identify the medicinal value of J. adhathoda and to be utilized in screening novel target compounds to treat various diseases. Keywords: Justicia adhathoda; phytochemical analysis; Medicinal plant; TFC; TPC; 3T3-L1Item Species Limits in Curvularia: Updated Backbone Phylogeny and Fresh Collections from Sri Lanka(Uva Wellassa University of Sri Lanka, 2019-02) Ferdinandez, R.S.K.H.S.; Udayanga, D.; Deshappriya, N.; Munasinghe, M.L.A.M.S.; Manamgoda, D. S.The genus Curvularia comprises of fungal species frequently encountered as saprophytes, endophytes and pathogens. Both living and dead weeds as well as crops are well known for the survival and completion of life cycles of Curvularia in nature. Molecular phylogenetic assessments are leading to precise identification of species in this genus from closely related taxa since morphological identification alone is often insufficient for species discrimination. Updated molecular phylogeny with all the existing Curvularia species is essential in order to infer phylogenetic relationships for freshly collected strains. The major objective of this study is to assess the evolutionary relationships of species of Curvularia collected from Poaceous crops and related weed hosts in Sri Lanka incorporating them in an updated backbone phylogeny with all of the available ex-type Curvularia sequences. Fresh collections were made from selected Poaceous weeds, rice and maize crops and morphological characters were assessed based on microscopic imaging and culture based studies. An updated backbone phylogenetic tree was constructed based on ribosomal Internal Transcribed Spacer region and partial Glyceraldehyde 3-Phosphate Dehydrogenase using maximum parsimony, was used to place the fresh collections within the genus. In addition, Phylogenetic Informativeness (PI) profiling test was performed to evaluate the informativeness of loci at species level phylogenetic discrimination. The PI profiling proved that the GPDH is the highest informative locus among the loci compared for this genus. The fresh collections of Curvularia from local study sites which were incorporated in the current phylogeny were grouped within several different clades such as geniculata-clade, hominis-clade and lunata-clade, emphasizing the existence of diverse array of species among fresh collections. Therefore, it is vital to collect more samples from both crops and weed residues in order to establish impact on these pathogens on crops and to understand their host range and shifting patterns of life modes.