Browsing by Author "Yapa, P. N."

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Development of sausages from immature jackfruit (Artocarpus heterophyllus) with rice bran fermented with Lactobacillus delbrueckii subsp. bulgaricus
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Tharaka, H. M. D.; Yapa, P. N.; Bamunuarachchige, C. T.
Jackfruit (Artocarpus heterophyllus) is used as a food and for primary healthcare in traditional medicine of Sri Lanka for a long time. A survey was carried out in Mihintale Divisional Secretariat, North Central Province in Sri Lanka with the aim of finding the use of young jackfruit for medicinal and nutritional purposes. Data was gathered from randomly selected 175 villagers and 25 traditional physicians, including ayurvedic doctors using key informant interviews. Results of the survey reveal that 85% of the respondents state that jackfruit has valuable pharmacological and nutritional properties and used for it for generations. Fifteen percent of respondents said that it used only as food and not for medicinal value. Ten percent of the above majority, being traditional physicians stated that immature jackfruit (polos) is used to enhance platelet count of the blood circulation system in the human body. The survey revealed, processing immature jackfruit into novel food was timely and useful. Therefore, sausages were developed with polos and rice bran fermented with Lactobacillus delbrueckii subsp. bulgaricus. Three types of rice bran, including brans of red rice, white rice and mix of both were fermented separately with L. delbrueckii was used to make sausages from polos. Similarly, above three types of rice bran, without fermentation, were also used in another set of treatments. A sensory evaluation was performed and statistical analysis revealed that fermented white bran included polos sausages has significantly higher consumer preference for taste (p = 0.002) than sausages with non-fermented white rice bran. The fermentation of rice bran did not significantly affect (p> 0.05) for overall appearance of the sausages irrespective of the type of rice bran. The aroma of sausages with the mixture of fermented rice bran showed a significantly higher consumer preference (p=0.01). Therefore, mixing immature jackfruit and fermented rice bran with L. delbrueckii can be used to produce an alternative food, sausages which have got nutritional and medicinal properties
Effect of phosphorus fertilizers and soil amendments on cadmium accumulation in maize (Zea mays L.) seeds
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Wanninayakea, P. C. U.; Yapa, P. N.; Malaviarachchi, M. A. P. W. K.; Hettiarachchi, R. P.
Phosphorus (P) is important for plant growth and metabolism. Higher percentage of phosphorus (up to 80%) is immobile or unavailable to uptake by plants because of adsorption, precipitation, leaching and conversion to organic forms. As a result, about 30 million tons of phosphorus fertilizer is used in agriculture worldwide every year. Phosphorus fertilizers contain cadmium (Cd) as a contaminant at different levels from trace amounts to high. Once accumulated in agricultural products, Cd can enter the human body resulting in severe health issues. Therefore, investigating the effect of different types of P fertilizers on Cd uptake and accumulation in maize seeds was the main focus of this study. A field trial was carried out at Field Crop Research and Development Institute in Mahailluppallama. Eppawela rock phosphate (ERP) and triple super phosphate (TSP) were separately applied as P fertilizers, with four amendments namely compost, biochar, dolomite and arbuscular mycorrhizal inoculants (AMF) in a randomized complete block design with three replicates. Amount of Cd in soil and accumulated in seeds were determined using Atomic Absorption Spectrophotometry and the data was analyzed using a two-factor factorial design. Available soil Cd and total seed Cd amount were significantly higher (p<0.05) in TSP treatments compared to ERP treatments, with and without the amendments. Addition of organic amendments compost, biochar and dolomite to the soil significantly reduced seed Cd level compared to treatments without the amendments. There was no colonization of AMF in TSP applied soil, while 25-60% colonization was recorded with ERP. Therefore, conclusion of the study was that ERP contribute to lower Cd accumulation in maize seeds and with the addition of compost and biochar with ERP, cadmium accumulation was further reduced
Evaluation of antibacterial potential of tea and different herbal plant extracts against Escherichia coli and Staphylococcus aureus
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Hansanee, K. P. N.; Yapa, P. N.
Escherichia coli is the most commonly found bacteria in the human intestinal tract. E. coli is non-pathogenic in normal conditions, but virulent strains such as Escherichia coli O157:H7 can cause gastroenteritis, urinary tract infections, neonatal meningitis etc. Staphylococcus aureus colonizes the human skin as a part of the normal flora and the most common pathogen causing bacterial infections in hospitalized patients. Further, S. aureus causes food borne infections in humans as well as pneumonia, bacteraemia, osteomyelitis, endocarditis, sepsis and toxic shock syndrome. The prevalence of methicillin resistant S. aureus (MRSA) and its ability to resist multiple drugs has posed a serious challenge for disease control. Tea is mainly an infusion of leaves of the plant Camellia sinensis consumed for centuries as a beverage and is valued for its medicinal properties. It was hypothesized that some herbal teas could also be useful in fighting against some bacteria especially enteropathogens. In the present study, C. sinensis tea leaves and plant parts frequently used in herbal tea production, were selected and their aqueous extracts were tested for antimicrobial activity against E. coli and S. aureus. C. sinensis black tea and green tea leaves, flower buds of Syzygium aromaticum, stems of Hemidesmus indicus, flowers of Senna auriculata, Aegle marmelos, plant of Aerva lanata, inner bark of Cinnamomum zeylanicum, and rhizome of Zingiber officinale were purchased from domestic markets and herbalists from Mihinthale, Kandy and Kalutara areas. They were air-dried, ground into powder and extracts were made using boiled distilled water, allow to cool at 370C and tested for its antimicrobial effect against E. coli and S. aureus, using standard agar-gel diffusion inhibition test. The test bacteria were introduced and uniformly spread on the surface of Mueller Hinton agar plates. After placing 20 μl of extracts into each well, plates were incubated at 370C for 24 hr and the diameter of the growth inhibition zone around the wells were measured. Comparisons were performed using one-way ANOVA followed by Duncan multiple-range test. Green tea was found to be most effective, followed by black tea, H. indicus and C. zeylanicum extracts, against S. aureus. The tested aqueous extracts did not show antibacterial activity against E. coli. It can be concluded that green and black teas as well as tea made by infusing specific parts of H. indicus and C. zeylanicum can be used to prevent and control diseases caused by S. aureus. Further, E. coli present in human gastrointestinal tract will not be affected by drinking the tested extracts.
Potential antibacterial activity of selected marine algae against foodborne bacteria
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Herath, H. M. B. M. M. D.; Yapa, P. N.; Sandaruwan, M. K. K. D.
Bacterial foodborne diseases are becoming a growing public health concern worldwide, increasing the demand of antibiotics. Considering the safety of using natural antimicrobials, the objective of the present study was to evaluate the antibacterial activity of selected marine algae extracts against foodborne bacteria. Whole marine algae samples of Chnoospora minima, Gracilaria foliifera, Gracilaria hikkaduwensis, Ulva prolifera, Sargassum polycystum, and Ulva lactuca were collected from west sea coast of Sri Lanka. Crude algal extracts of distilled water, methanol, acetone and diethyl ether were separately tested for antibacterial activity against Staphylococcus aureus NCTC 6571, Staphylococcus aureus ATCC 25923, Escherichia coli NCTC 10418, E. coli ATCC 25922 and Enterococcus faecalis. Antibacterial activity was evaluated by using the standard well-diffusion method. Each tested strain was suspended in 3 ml of sterile distilled water with a turbidity optically comparable to that of the 0.5 McFarland standard (1.5 × 108 CFU/ ml) and 100 μl aliquots of each suspension were inoculated and uniformly spread on the surface of Muller Hinton agar plates in triplicates separately. After placing 50 μl of extracts into each well, plates were incubated at 37 °C for 24 - 48 hours and the diameter of the growth inhibition zone around the wells were measured. Further, minimum inhibition concentrations of each extract were also evaluated. Comparisons were performed using one-way ANOVA followed by Tukey’s Pairwise Comparisons. It was revealed that the 0.75 g/ml of G. foliifera in distilled water and 0.05 g/ml methanol, acetone, diethyl ether extracts of G. foliifera exhibited antibacterial activity against Enterococcus faecalis. Further, 0.05 g/ml of acetone extracts of U. proliifera, G. hikkaduwensis, C. minima and U. lactuca showed inhibitory effect against Enterococcus faecalis. Acetone (0.05 g/ml), methanol (0.05 g/ml) and diethyl ether extracts (0.5 g/ml) of G. folifera, S. polycystum inhibited the growth of E. coli NCTC 10418 and E. coli ATCC 25922. Distilled water (0.05 g/ml) and methanol extracts (0.1 g/ml) of G. foliifera, S. polycystum showed inhibitory effect against S. aureus NCTC 6571 and S. aureus ATCC 25923. Further, all tested extracts of C. minima were shown antibacterial activity against S. aureus. Methanolic extracts (0.1 g/ml) of G. hikkaduwensis, U. prolifera and U. lactuca inhibited the growth of S. aureus. Results indicated that the potential of these marine algae to be used in isolation of bioactive compounds responsible for antibacterial activity
Role of the vetiver (Chrysopogon zizanioides L.) and arbuscular mycorrhizal fungi on soil quality improvement in Pinus plantation soil
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Lakmali, J. P. D.; Yapa, P. N.; Sandaruwan, M. K. K. D
Abundant public lands and deforested areas of South-West wet zone region of Sri Lanka has subjected to reforested by Pinus caribaea exotic species during 1970’s and 1980s. Yet, several environmental problems such as groundwater extraction, forest fire, soil erosion, effects on natural regeneration were recognized due to this reforestation. The strategies are needed to improve soil quality in Pinus plantation soil, which mitigates negative impacts and restores soil biological functions while increasing the ecosystem processes, services, and productivity. Vetiver (Chrysopogon zizanioides L.) belongs to family Poaceae with arbuscular mycorrhizal fungi (AMF) can be used in soil quality improvement. Therefore, this study was carried out for evaluating the ability of vetiver with AMF to enhance the soil quality in Pinus plantations. A pot experiment was carried out at Panwila, Central Province of Sri Lanka, in a randomized complete block design with four replicates. Soil collected randomly from two different depths of 0-10 cm and 15- 25 cm, from Pinus plantation at Panwila was used as respective controls. The four treatments were soil with 5% biochar, soil with 5% organic manure, soil with native AMF and soil with 2.5% biochar and native AMF. Vetiver plants of approximately similar size and age were selected and one plant was transplanted in each pot. Soil chemical, biological and plant growth parameters were determined initially and after three months of growing vetiver. The soil from the forest patch of the Knuckles mountain range which is subjected to similar climatic conditions as Panwila, was tested for the above soil parameters and used as the reference of the healthy soil in statistical analysis. Analysis was carried out as a three-factor factorial design. It was revealed that different treatments were significantly different (p< 0.05) for soil pH, electrical conductivity, soil microbial activity, bacterial count, fungal count, plant dry root and shoot biomass, yield and percentage AMF colonization (p= 0.001). It can be concluded that the application of vetiver with or without tested amendments improved the soil chemical and biological properties in disturbed Pinus plantation soil towards the healthy soil of Knuckles mountain region. Furthermore, with the amendments of AMF, biochar and organic manure, some soil biological properties of disturbed soil in tested vegetation type, was improved more than the reference soil. Hence the application of vetiver with the AMF, biochar and organic manure is an effective strategy to be used in soil quality improvement in disturbed vegetation