Browsing by Author "Kannangara, S."

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Aromatic hydrocarbon degrading Phyllosphere Fungi
(University of Sri Jayawardhanapura, 2013) Undugoda, L.J.S.; Kannangara, S.; Sirisena, D.M.
Aromatic hydrocarbon degrading phyllosphere microorganisms
(University of Kelaniya, 2013) Undugoda, L.J.S.; Kannangara, S.; Sirisena, D.M.
Pyrogenic nature of the most recalcitrant aromatic hydrocarbons elevates their persistency in the environment and rapid bioaccumulation in living organisms. Therefore, air pollution by aromatic hydrocarbons is one of the current concerns. It has been shown that utilization of phyllosphere microorganisms as bioremediators is an efficient means of remediating these air pollutants. This study was carried out to isolate aromatic hydrocarbon degrading phyllosphere fungi and bacteria from selected plants; Ixora sp., Hibiscus sp., Ervatamia sp., and Amaranth sp., which are highly abundant in roadsides around the oil refinery at Sapugaskanda and high traffic areas. Phenanthrene, naphthalene, xylene and toluene degradation ability of the isolated bacteria and fungi was then examined using plate assays and spectrophotometric analysis. The best degraders were selected for further identification and characterization. Phenanthrene, naphthalene, toluene and xylene utilization rates of identified phyllosphere fungi; Penicillium sp. Aspergillus sp. and Trichoderma sp. were comparatively higher than that of isolated phyllosphere bacterial species; Pseudomonas sp., Paracoccus sp., Klebsiella sp. and Alcaligenes sp. Penicillium janthinellum utilized more than 90% of polyaromatic hydrocarbons in the medium during seven days’ incubation, but Pseudomonas sp. required 14 days of incubation to achieve that level. Moreover, the best toluene degrader Aspergillus niger degraded toluene very efficiently compared to Pseudomonas sp. The best xylene degrader Aspergilus flavus utilized only 57.35% of xylene in the medium in seven days, but 90% degradation was observed in 14 days. Therefore, xylene degradation ability of fungi was comparatively less but significantly higher than that of bacteria. Bioremediation is a very economically and environmentally friendly strategy used in cleaning of AH contaminated sites. According to the results, Penicillium spp. and Aspergillus spp. could be considered as the best fungal candidates for bioremediation. Pseudomonas sp. was able to degrade all tested AHs at relatively high efficiencies. Therefore, it can be considered as a general AH degrader. Therefore, ability of these microorganisms to degrade AH while surviving under environmental stress makes them very suitable candidates for bioremediation.
Assessing the antioxidative potential of lactic acid bacteria inhabiting tender coconut water
(Faculty of Graduate Studies - University of Kelaniya, Sri Lanka, 2023) Pavalakumar, D.; Undugoda, L.J.S.; Manage, P.M.; Nugara, R.N.; Kannangara, S.
Probiotics are renowned for their beneficial impact on human health, including their antioxidative properties. Lactic acid bacteria (LAB), which constitute a major group within probiotics, have been recognized for their ability to act as potent antioxidants, providing relief from oxidative stress in the host. This study aims to evaluate the antioxidative activity of probiotic LAB inhabiting the tender coconut water samples collected from different regions of Sri Lanka. In a previous study, analysis of the collected tender coconut samples resulted in the identification of four potential probiotic strains at the species level: Lactiplantibacillus plantarum CWJ3, Lacticaseibacillus rhamnosus CWKu12, Lacticaseibacillus paracasei CWKu14, and Lacticaseibacillus casei CWM15. The antioxidative activities of these strains were evaluated using four different chemical antioxidant assays: the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay at 517 nm, the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay at 734 nm, the ferric reducing antioxidant power (FRAP) assay at 593 nm, and the total phenolic content (TPC) assay at 765 nm through spectrophotometric method. Three different concentrations of each bacterial strain (107, 108, and 109 CFU mL-1) were prepared using overnight grown cultures in deMan, Rogosa, and Sharpe broth at 37 °C, included in the study. The results indicate a significant increase (p < 0.05) in antioxidative activity for all four strains across all analyzed methods with an increase in cell concentration. Lactiplantibacillus plantarum CWJ3 exhibited the highest antioxidative potential at 109 CFU mL-1, with 88.85±0.84% radical scavenging activity in the DPPH assay, 84.0±0.14% radical scavenging activity in the ABTS assay, 0.029±0.004 mg mL-1 ascorbic acid equivalent in the FRAP assay, and 0.0052±0.0006 mg mL-1 gallic acid equivalent in the TPC assay. Conversely, Lacticaseibacillus paracasei CWKu14 demonstrated the lowest values for all antioxidative activities. Continued research on the antioxidative properties of probiotic LAB derived from tender coconut water holds promising prospects for the development of functional beverages.
Assessment of phytochemicals and antifungal effect of Croton aromaticus against postharvest fungal pathogens isolated from tropical fruits
(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Wijesundara, S.A.D.T.L.; Kannangara, S.; Abeywickrama, K.
Chemical control using synthetic chemical fungicides is still the most common method of controlling postharvest diseases of fruits. Plant extracts which are rich in antimicrobial secondary metabolites such as terpinoids, alkaloids, saponins and flavonoids could be possible alternatives for synthetic fungicides. Current study was focused on evaluating the antifungal effect of ethanolic extract of Croton aromaticus (Kappettiya) leaves in vitro against mycelial growth and the spore germination of postharvest fungal pathogens isolated from fruits of banana (Colletotrichum musae, Rhizopus sp., Lasiodiplodia theobromae) papaya (Rhizopus stolonifer, Colletotrichum gleosporioides, Lasiodiplodia theobromae) and mango (Alternaria alternata, Pestalotiopsis mangiferae, Lasiodiplodia theobromae). Surface sterilized diseased banana, papaya and mango fruit tissues were cultured on PDA plates in order to obtain pure cultures of possible fungi and they were identified by morphological and microscopic characteristics, using identification keys. Inhibitory effect of the ethanolic extract of C. aromaticus against test pathogens were investigated by well diffusion method using PDA medium, by incorporating crude extract dissolved in DMSO, ranging from 1 mg/ml up to 300 mg/ml concentrations along with the positive (Captan) and negative (DMSO) controls. Significant (P < 0.05) inhibitory effects were exhibited by the ethanolic extract of C. aromaticus leaves against all test pathogens except L. theobromae. The highest mycelial growth and spore germination inhibition of most of the pathogens were observed at 100 mg/ml. The lowest Minimum Inhibitory Concentration of the leaf extract (5 mg/ml) was observed for spore germination inhibition of C. gleosporioides and P. mangiferae. TLC analysis revealed four compounds having Rf values of 0.551, 0.672, 0.810 and 0.913. Phytochemical screening of ethanolic extract revealed the presence of alkaloids, terpenoids, quinones, phytosterols and flavonoids. Current findings indicate the potential use of ethanolic extract of C. aromaticus leaves in controlling banana, papaya and mango postharvest fungal pathogens in vitro.
Bioactivities of endolichenic fungi of the lichen Usnea barbata at Hakgala montane forest
(14th International Foresry and Environmental Symposium Proceedings Part I: Abstracts of Papers.University of Sri Jayewardenepura, 2009) Rajapaksha, C.; Paranagama, P.A.; Kannangara, S.
Biocontrol potential of endophytic fungi in tea (Camellia sinensis (L.) Kuntze) leaves against selected fungal phytopathogens
(Malaysian Journal of Microbiology, 2022) Thambugala, K.; Daranagama, D.; Kannangara, S.
Aims: Endophytic fungi are a diverse group of microorganisms that stay asymptomatically in the healthy tissues of the host. Many fungal endophytes are associated with the tea plant (Camellia sinensis) and the pathogens of the tea plant have the potential to grow as endophytes or act as latent pathogens during the initial growth of the plant. The present study aimed at screening tea endophytic fungi with the potential for control of a few critical phytopathogens, Fusarium sp., Lasiodiplodia theobromae, Pestalotiopsis sp. and Sclerotinia sclerotiorum while evaluating the efficiency of growth inhibition of these phytopathogens by the endophytic fungal isolates using in vitro assays. Methodology and results: Five endophytic fungal strains; Colletotrichum gloeosporioides, C. siamense, Daldinia eschscholtzii, Pseudopestalotiopsis chinensis and Phyllosticta capitalensis isolated from leaves of C. sinensis in Sri Lanka were evaluated for growth inhibition against plant pathogens; Fusarium sp., L. theobromae, Pestalotiopsis sp. and S. sclerotiorum using the dual culture assay and volatile compound-mediated inhibition assay. All the fungal endophytes used in this study exhibited antifungal activity against Fusarium sp., Pestalotiopsis sp. and S. sclerotiorum in the dual culture assay on PDA. Daldinia eschscholtzii (67.30%) and C. gloeosporioides (61.54%) showed strong antagonistic activity against S. sclerotiorum, while P. capitalensis (42.30%) demonstrated moderate activity. All the endophytic fungal strains showed moderate antifungal activities against Fusarium sp. The percentage growth inhibitions of Pestalotiopsis sp. by all the endophytic isolates tested were below 25.00%. In the volatile compound-mediated inhibition assay, none of the endophytic isolates showed visible inhibition against the phytopathogens used. Conclusion, significance and impact of study: In this study, the fungal endophytes which showed potential antagonistic activity against the tested phytopathogens can be used to develop commercialized products of fungal biocontrol agents (BCAs) for controlling plant fungal diseases.
Depolymerization of polyaromatic hydrocarbons by Penicillium spp. inhabit the phyllosphere of urban ornamental plants
(Environmental Quality Management, 2022) Dharmasiri, R. B. N.; Undugoda, L. J. S.; Nilmini, A. H. L.; Pathmalal, M. M.; Nugara, N. N. R. N.; Udayanga, D.; Kannangara, S.
A variety of anthropogenic sources release hazardous polyaromatic hydrocarbons (PAHs) into the phyllosphere which is an excellent niche for diverse fungi, and some of them have PAHs degradation capabilities. Therefore, this research attempted to determine the PAHs (phenanthrene, anthracene, naphthalene, and pyrene) degradation capability of phyllosphere inhabited Penicillium species. The leaf samples were collected from highly polluted urban areas (Panchikawatta, Pettah, Orugodawatta, Maradana, Sapugaskanda, and Colombo Fort) in Sri Lanka to isolate fungal species inhabiting the phyllosphere. Furthermore, their distribution patterns among the leaf tissue layers were studied using bright-field microscopic observations. Moreover, the best PAHdegraders were screened out using plate assays and confirmed throughHigh Performance Liquid Chromatography (HPLC) analysis. Further, their enzymatic activities during the PAHs degradation were analyzed. As per the microscopic observations, the highest fungal distribution was in the upper epidermis of the leaves followed by the fungal distribution in the interspaces of palisade mesophyll layers. Out of isolated fungal species, two Penicillium spp. (Penicillium citrinum P23B-91 and Penicillium griseofulvum P9B - 30) showed the highest PAHs (phenanthrene, anthracene, naphthalene, and pyrene) degradation capabilities. Manganese peroxidase (MnP) enzyme dominated phenanthrene degradation in P. griseofulvum P9B - 30, which showed the highest phenanthrene degradation ability (61%). In addition, P. citrinum P23B-91 was good at degrading anthracene (88%) and also displayed a higher MnP activity during the anthracene degradation than laccase and lignin peroxidase activities. The discoveries from the toxicity assay during the PAHs degradation processes revealed that the produced byproducts had no toxic effects on the fungal growth cycle and the phyllosphere. Therefore this phyllosphere Penicillium spp. are ideal for the bioremediation of polluted air in urbanized areas.
Disease control strategies for extending storage life of papaya (Carica papaya), cultivars ‘Red Lady’ and ‘Rathna’
(2012) Abeywickrama, K.P.; Wijerathna, C.; Rajapaksha, N.; Sarananda, K.; Kannangara, S.
Anthracnose (Colletotrichum gloeosporioides), stem-end rot (Lasiodiplodia theobromae) and Phomopsis rot (Phomopsis caricae-papayae) are major post-harvest diseases in papaya resulting in relatively high postharvest losses, up to 45%, in Sri Lanka. The current consumer preference is for tropical fruits free of synthetic pesticides. The objectives of the present investigation were to identify major post-harvest pathogens in papaya fruits, test in vitro fungitoxic effect of basil oil (Ocimum basillicum) and alum (sodium aluminium sulphate) on major fungal pathogens of papaya fruit and develop a relatively safe, disease control strategy. Alum (1% w/v) and basil oil (0.12– 0.16% v/v) in a liquid bioassay, indicated fungistatic and fungicidal efficacy on C. gloeosporioides, L. theobromae and P. caricae-papayae isolated from „Red Lady‟ and „Rathna‟ cultivars of papaya. In vivo investigation of fruits of both papaya cultivars harvested from fruit plantations in Sri Lanka („Red Lady‟–Yatawarawatta plantation, Kurunegala, „Rathna‟ – CIC plantation, Kekirawa and the Agricultural farm, Polonnaruwa) at 25% maturity level indicated that papaya washed in 1% (w/v) alum and subsequently sprayed with an emulsion solution of 0.16% (v/v) basil oil and enclosed in styrofoam sleeves could be stored for 14 days at 12–14 oC. The visual quality rating (VQR) was high (11–13), shriveling and „green islands‟ were low on fruits with zero disease severity where results were statistically similar to 500 mg/L Bavistin treatment. Physicochemical properties assessed were unaffected by the treatments and were comparable to the controls washed only in water. The organoleptic properties were slightly low in fruits subjected to cold temperature compared to fruits subjected to ambient temperature. No residues of basil oil could be detected on fruit peel by gas chromatography at the end of the experimental period of 14 days. The treatment strategy developed could be adopted for sea shipment or temperature-regulated supermarket storage of papaya fruits where storage life could be lengthened up to 14 days.
Effect of alum in combination with vacuum packaging in extending the shelf life of Embul banana
(Faculty of Graduate Studies, University of Kelaniya, 2015) Siriwardana, H.L.S.; Abeywickrama, K.P.; Kannangara, S.; Jayawardena, B.
Crown rot disease is the major post harvest disease in Embul banana causing severe post harvest loss both in terms of quality and quantity. Due to hazardous effects of fungicides, use of eco-friendly methods of controlling crown rot disease are being investigated throughout the world. In this study, efficacy of alum (sodium aluminium sulphate) in combination with vacuum packaging was investigated in extending the shelf life of Embul banana at cold temperature. Approximately 85-day mature Embul banana hands were washed with 1% alum (w/v) solution and control was washed only in water. Treated and control fruits were packed in Low density polyethylene bags, air inside bags were removed using a vacuum and placed in fibre board cartons and stored in a cold room at 12-14 ºC. Each treatment comprised 8 replicate boxes each with 5 hands. In-package gases were analysed on initial day and every seven days thereafter up to 28 days of storage. Physicochemical and sensory properties and crown rot disease severity (CRS) were determined in ripened fruits after each storage period. Medium (50 kg) and large scale (100 kg) test marketing trials were conducted at fruit outlets in Dambulla and Kiribathgoda, Sri lanka by providing treated Embul banana samples to consumers and staff to obtain feedback on the quality of treated banana. Crown rot disease severity was low (CRS index < 1) in alum treated samples compared to control after 28 days. Physicochemical and sensory properties were unaffected by alum+vacuum packaging treatment. Oxygen within packages was maintained between 3.3 - 4.4 % while CO2 % varied between 3.9 - 4.0 %. In medium and large scale test marketing trials, treatment controlled crown rot disease to a fair extent and obtained higher score values from the customers and staff of fruit outlets for the sensory properties compared to control. Therefore, this eco-friendly treatment method could be adopted for effective control of crown rot disease and to extend shelf life of Embul banana up to one month.
Effect of Croton aromaticus leaf extracts in controlling Crown Rot disease of Embul banana.
(International Research Symposium on Pure and Applied Sciences, 2017 Faculty of Science, University of Kelaniya, Sri Lanka., 2017) Dilhani, S.; Wimalasiri, S.; Abeywickrama, K.; Kannangara, S.
Embul banana (Musa acuminata-AAB) is one of the major dessert fruits in Sri Lanka, widely consumed by all economic groups due to its small size and characteristic flavour. Although Embul banana has high potential for export market storage and export of this commodity over long distances is difficult in consequence of postharvest fungal diseases. The most common and serious postharvest disease that affect Embul banana is Crown Rot (CR). Use of synthetic fungicides is the widely used method in controlling postharvest diseases of fruits worldwide. The interest of finding natural bioactive components has increased due to the harmful effects of synthetic fungicides on environment and health. In the present study, antifungal activity of aqueous, hot water and ethanolic leaf extracts of Croton aromaticus in controlling CR disease of Embul banana was investigated in vivo. Embul banana hands (85-days mature) were treated with C. aromaticus aqueous, hot water 100% (v/v) and ethanolic leaf extracts (400 mg/ml) alone or in combination with alum (1%) or distilled water (control) were stored in modified atmosphere packaging at 12-14 0C for 14 days. Each treatment comprised of 4 replicates. In-package gases were analysed on initial day and thereafter up to 14 days. Physicochemical properties (pH, firmness, TSS, TA), sensory properties (peel colour, flesh colour, aroma, flavour, taste, overall acceptability), and Crown Rot disease severity were determined in ripening induced fruits after 7 and 14 days of storage period. Statistical analysis was done using the MINITAB 16 statistical package. Oxygen levels measured were observed to be amaintained at 2.2-4.4% while CO2 levels were maintained at 5.5-8.4% in all packages at the end of 14 day storage period. C. aromaticus ethanolic leaf extract (400 mg/mL) was the most effective extract in controlling crown rot disease of Embul banana compared to aqueous and hot water leaf extracts. Physicochemical properties of Embul banana treated with C. aromaticus leaf extract alone and in combination with alum were not significantly different compared to control except for TSS and TA. Most of the sensory properties were preferred by sensory panelists with score values of above 6 indicating the good quality of samples. C. aromaticus ethanolic leaf extract + alum in combination with modified atmosphere packaging and cold storage could be used as a potential safe way of controlling Crown Rot disease of Embul banana.
Effect of Ocimum basilicum oil plus modified atmosphere packaging of quality of Embul banana
(2016) Abeywickrama, K.; Siriwardana, H.; Kannangara, S.; Jayawardena, B.
Effect of pretreatments on quality of minimally processed cooking banana variety Alukesel (Musa acuminata * Musa balbisiana, ABB Group)
(Sabaragamuwa University of Sri Lanka, 2015) Siriwardana, H.; Abeywickrama, K.P.; Kannangara, S.
Cooking banana is a vegetable which can be stored for longer periods in intact form but undergoes browning soon after slicing. A study was undertaken to evaluate the effect of selected pretreatments in maintaining quality of minimally processed cooking banana variety Alukesel. Minimally processed Alukesel was subjected to pretreatments of ascorbic acid (3%), citric acid (3%), ascorbic acid (2%), citric acid (2%), citric acid + ascorbic acid (1.5% each), sodium metabisulphite (2%) and distilled water (control), packed in polystyrene packages and stored at 5-70 C for a week. The effects of pretreatments on sensory and physicochemical properties (percentage weight loss, changes in firmness, pH, Total Soluble Solids (TSS) and Titratable Acidity (TA)) were evaluated on day 0 and day 7, while browning was assessed using a spectrophotometric method. Pretreatments had a significant effect on physicochemical and sensory attributes of minimally processed cooking banana compared to control. Ascorbic acid (3%), citric acid (3%) and citric acid + ascorbic acid (1.5% each) pretreated cooking banana obtained higher ranking values for sensory properties (appearance, colour, odour, flavour, taste and overall acceptability) while the same three pretreatments and sodium metabisulphite (2%) pretreatment effectively controlled enzymatic browning. This research revealed that pretreatments of ascorbic acid (3%), citric acid (3%) and citric acid + ascorbic acid (1.5% each) were more successful in retaining quality of minimally processed cooking banana for one week in cold storage. It could be concluded that Alukesel treated as above can be considered as a potential value added sale item at local supermarkets where cold storage facility is available.
Efficacy of Alum Treatment and Vacuum Packaging in Controlling Crown Rot Disease of Cavendish Banana
(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Siriwardana, H.; Abeywickrama, K.; Kannangara, S.; Jayawardana, B.
Cavendish is the widely grown banana cultivar in the world today and the most prominent cultivar in the international trade. Crown rot, one of the most drastic postharvest diseases of Cavendish banana can cause severe postharvest loss both in the local and export markets. In the industry, cut crowns of banana are treated with fungicides to control this disease. Due to hazardous effects of fungicides, finding suitable alternatives in the management of crown rot of banana is essential. In this study, effect of alum (potassium aluminium sulphate) in combination with vacuum packaging was investigated in controlling crown rot disease and extending the shelf life of Cavendish banana at cold storage. Twelve week mature Cavendish banana (Musa acuminata, AAA, Grande Naine cultivar) hands were treated with 1% (w/v) alum or distilled water (controlled). Treated and control fruits were packed in Low density polyethylene bags, air inside bags were removed using vacuum and placed in fiber board cartons and stored in a cold room at 12-14 ºC. Each treatment comprised 10 replicate boxes each with 5 hands. In-package gases were analyzed after 14 days of cold storage. Physicochemical properties (pH, TSS, TA and firmness), sensory properties (peel colour, flesh colour, aroma, flavour, taste and overall acceptability) and crown rot disease severity were determined in ripening induced fruits. Test marketing trials were conducted at CIC fruit outlet in Dambulla, Sri Lanka where treated fruits were provided to consumers and staff to obtain feedback on the quality of treated banana. At the end of 14 days, O2 in packages remained between 5.0 to 5.8% while CO2% ranged from 4.9% to 5.8%. Alum in combination with vacuum packaging significantly controlled crown rot disease of Cavendish banana compared to the control. Physicochemical and sensory properties were unaffected by alum + vacuum packaging treatment when compared to control. Treated banana obtained higher score values from the customers and staff of fruit outlets for the sensory properties compared to the control. Therefore, this eco-friendly treatment strategy could be recommended in preparing Cavendish banana for local market as well as commercial scale export to various destinations which require a transit time of two weeks.
Efficacy of basil oil and alum in controlling crown rot disease of Cavendish banana (Musa acuminata, AAA) during cold storage
(2016) Siriwardana, H.; Abeywickrama, K.; Kannangara, S.; Attanayake, S.
Effect of Ocimum basilicum (basil) oil spray treatment, alum in combination with modified atmosphere packaging (MAP) was investigated in extending the shelf life of Cavendish banana (Musa acuminata, AAA - Grand Naine cultivar) at 12-14 0C. Twelve week mature Cavendish banana fruits were treated with 1% (w/v) alum (Potassium aluminium sulphate), 1% (w/v) alum + 0.4% (v/v) basil oil, 0.5 g/L carbendazim and distilled water (control). Treated banana samples were packed in Low Density Polyethylene bags and stored at 12-14 0C. In-package gases were analysed every seven days up to 28 days of storage. Physicochemical properties (pH, firmness, TSS, TA), sensory properties (peel colour, flesh colour, aroma, flavour, taste, overall acceptability) and crown rot disease severity were determined in ripening induced fruits after each storage period. At the end of 28 days of storage O2 in all packages remained between 5.0- 5.4% while CO2 varied from 5.1 to 5.6%. Further, treatment of 1% alum+0.4% basil oil effectively controlled crown rot disease of Cavendish banana completely up to 21 days. Most of physicochemical and sensory properties of treated banana were not adversely affected by the treatment.
Evaluation of antifungal effect of Croton aromaticus on storage life extension of banana
(2016) Dilhani, S.; Wimalasiri, S.; Abeywickrama, K.; Kannangara, S.
Effect of Croton aromaticus aqueous, hot water and ethanolic leaf extracts alone and in combination with alum against banana crown rot causing fungal pathogens were investigated using 96 well plate bioassay and liquid bioassay in vitro. According to the results of 96 well plate assay, C. aromaticus aqueous extract successfully inhibited conidial germination of C. musae up to 96.9%. Percentage germination inhibition of F. proliferatum is less than that of C. musae. Hot water extract expressed higher conidial germination inhibition of F. proliferatum. Conidial germination of C. musae was 100% inhibited at the concentration of 600 (%w/v) of ethanoic extract and at the same concentration F. proliferatum was inhibited by 90.4 %. Alum was fungicidal against C. musae and L. theobromae. C. aromaticus leaf extract in combination with alum controlled F. proliferatum more effectively compared to leaf extract alone. During liquid bioassay, ethanolic leaf extract totally inhibited the mycelial growth of test pathogens at the concentration of 800 (%w/v). Among three tested extracts, ethanolic extract was most effective in inhibiting both spore germination and mycelial growth of crown rot causing fungal pathogens.
Fungal pretreatment to enhance the yield of phytochemicals and evaluation of α-amylase and α-glucosidase inhibition using Cinnamomum zeylanicum (L.) quills pressurized water extracts
(Blackwell Scientific Publications, 2021) Wariyapperuma, W.A.N.M.; Kannangara, S.; Wijayasinghe, Y.S.; Subramanium, S.; Jayawardena, B.
ABSTRACT: Bioactive compounds entrapped in plant materials can be effectively recovered using fungal enzymes. Cinnamomum zeylanicum Sri Wijaya (SW) and Sri Gemunu (SG) accessions and commercially available C. zeylanicum (CC) were subjected to fungal pretreatment and extracted with pressured water (PWE, 0·098 MPa). Thirteen fungal species were isolated and the substrate utilization ability of the species was tested using cellulose, pectin and lignin (indirectly). Total phenolic content (TPC, Folin-Ciocalteu method), proanthocyanidin content (PC, vanillin method) and α-amylase and α-glucosidase inhibitory potential of the extracts were evaluated. The anti-diabetic drug, Acarbose was used as the positive control. Trichoderma harzianum (MH298760) showed the highest cell lysis ability and hence was used for the microbial pretreatment process. Extracts of SW treated with T. harzianum species (Pre-SW) gave the highest percentage yield (4·08% ± 0·15%), significantly potent inhibition (P < 0·05) of α-amylase and α-glucosidase activities (IC50 57 ± 8 and 36 ± 8 μg ml-1 respectively), TPC (2·24 ± 0·02 mg gallic acid equivalent g-1 ), and PC (48·2 ± 0·4 mg of catechin equivalent g-1 ) compared to Pre-SG, Pre-CC and nontreated samples. Trichoderma harzianum treatment can enhance the hypoglycaemic properties, PC and TPC of Cinnamon extracts and provide new insights into the recovery of phytochemicals. KEYWORDS: Cinnamomum zeylanicum; Trichoderma harzianum; pressured water extraction; α-amylase; α-glucosidase.
Fungal pretreatment to enhance the yield ofphytochemicals and evaluation of α-amylase and α-glucosidase inhibition using Cinnamomum zeylanicum (L.)quills pressurized water extracts
(Letters in Applied Microbiology, 2020) Wariyapperuma, W.A.N. Madushika; Kannangara, S.; Wijayasinghe, Y.S.; Subramanium, S.; Jayawardena, B.
Bioactive compounds entrapped in plant materials can be effectively recovered using fungal enzymes. Cinnamomum zeylanicum Sri Wijaya (SW) and Sri Gemunu (SG) accessions and commercially available C. zeylanicum (CC) were subjected to fungal pretreatment and extracted with pressured water (PWE, 0 098 MPa). Thirteen fungal species were isolated and the substrate utilization ability of the species was tested using cellulose, pectin and lignin (indirectly). Total phenolic content (TPC, Folin–Ciocalteu method), proanthocyanidin content (PC, vanillin method) and α-amylase and α-glucosidase inhibitory potential of the extracts were evaluated. The anti-diabetic drug, Acarbose was used as the positive control. Trichoderma harzianum (MH298760) showed the highest cell lysis ability and hence was used for the microbial pretreatment process. Extracts of SW treated with T. harzianum species (Pre-SW) gave the highest percentage yield (4 08% 0 15%), significantly potent inhibition (P < 0 05) of α-amylase and α-glucosidase activities (IC50 57 8 and 36 8 μg ml−1 respectively), TPC (2 24 0 02 mg gallic acid equivalent g−1), and PC (48 2 0 4 mg of catechin equivalent g−1) compared to Pre-SG, Pre- CC and nontreated samples. Trichoderma harzianum treatment can enhance the hypoglycaemic properties, PC and TPC of Cinnamon extracts and provide new insights into the recovery of phytochemicals.
In vitro anti-diabetic effects and phytochemical profiling of novel varieties of Cinnamomum zeylanicum (L.) extracts
(Corte Madera, 2020) Niroshani, W.A.; Wariyapperuma, M.; Kannangara, S.; Wijayasinghe, Y.S.; Subramanium, S.; Jayawardena, B.
BACKGROUND: Diabetes mellitus type 2 (DMT2) is a leading metabolic disorder in the world. Anti-diabetic actions of phytochemicals from various medicinal herbs have been explored as an alternative therapy in the management of DMT2 due to adverse effects of synthetic drugs used in allopathic medicine. α-amylase and α-glucosidase inhibitory potential and phytochemical profiling were investigated in aqueous extracts of two new Cinnamomum zeylanicum accessions, namely C. zeylanicum Sri Wijaya (SW), C. zeylanicum Sri Gemunu (SG) and commercially available C. zeylanicum (CC). METHODS: Microwave Digestion (MD), Pressurized Water Extraction (PWE), Steam Distillation (SD), Solvent Extraction (SE), Decoction Water Extraction (DWE) and Infusion Water Extraction (IWE) methods were used to prepare Cinnamon quill extracts. Total phenolic content (TPC, Folin-Ciocalteu method) and Proanthocyanidin content (PC, vanillin assay), α-amylase and α-glucosidase inhibition of Cinnamon extracts were determined spectrophotometrically. The α-amylase and α-glucosidase inhibition were reported in terms of IC50 value. The phytochemical profiling was accomplished by GC-MS technique. RESULTS AND DISCUSSION: Lowest IC50 values were observed in PWE and DWE of SW. The highest PC and TPC were also observed in PWE and DWE of SW. Pressured water and decoctions are promising methods for the extraction of antidiabetic constituents from cinnamon. Benzoic acid, cinnamyl alcohol, benzyl alcohol, and 4-Allyl-2,6-dimethoxyphenol were identified as major compounds in SW extracts. These compounds are believed to be responsible for strong enzyme inhibitory activity of the extracts. CONCLUSIONS: This is the first study to explore the use of pressured and decoctions water to extract anti-diabetic phytochemicals from cinnamon. The extensive metabolite profiling of novel SW and SG extracts and comparison of that with commercially available CC are reported for the first time in this study. The C. zeylanicum, SW accession holds some promise in the management of diabetes. KEYWORDS: Cinnamomum zeylanicum; Decoction water extraction; Diabetes mellitus type 2; GC-MS; Pressurized Water Extraction; Sri Wijaya; α-amylase; α-glucosidase.
Isolation and identification of litter decomposing fungi in Nagacholai Forest Reserve, Mullaitivu, Sri Lanka
(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Bopitiya, B. D. S. S.; Dewangani, H. G. N.; Perera, H. W. K.; Premachandra, J. A. H. P.; Senevirathna, M. A. T. M.; Kalpani, N. N.; Kodituwakku, T. D.; Kannangara, S.
Nagacholai Forest Reserve, which was disturbed by local terrorism before 2009, is located in Mullaitivu District in the Northern Province of Sri Lanka. It is a tropical dry zone forest, administrated by the Department of Forest Conservation, Sri Lanka. Litter-fall and subsequent nutrient release from decomposing litter are crucial processes that regulate the nutrient availability and the nutrient cycling in soil, as well as the plant growth in forest ecosystems. Litter decomposition rates of forest ecosystems are governed by both biotic and abiotic factors. Therefore, the present study was conducted to study soil characteristics such as pH and electrical conductivity and to isolate and identify the litter decomposing fungi of the Nagacholai forest. Soil and litter were collected randomly by placing 0.5 m X 0.5 m size quadrats on the forest floor. The pH and electrical conductivity of each soil sample were determined by following standard methods. Litter decomposing fungi were isolated from leaf discs (1 mm X 1 mm) obtained from the collected litter following washing and plating method using sterilized distilled water. Pure cultures of isolated fungi were maintained at 28 °C in PDA and morphologically identified using identification keys. The low moisture content in the soil was reflected by brown colour, sandy-podzolic soil. The high proportion of less decomposed, dense litter layer reflected the low decomposition rate due to decelerated soil microbial activity and low water availability. Soil pH was within the range of 6.34 – 6.80 and electrical conductivity at 30 °C varied between 1.23 – 1.57 mS cm-1. Five different fungal species were isolated in high frequencies (50%>) from leaf litter, while four of them were identified up to the genus level based on their vegetative and reproductive morphology (i.e. Mucor sp., Aspergillus sp., Candida sp. and Pestalotiopsis sp.). The remaining unidentified species produced white colour colonies and branched, hyaline, septate hyphae without showing any sexual reproductive structure. Mucor, Aspergillus and Pestalotiopsis are some of the common fungal decomposers found in most of the forests of different climatic zones. However, Candida is a filamentous yeast, which is not frequently reported as a decomposer in terrestrial ecosystems, but found to be a member of the normal soil microflora in forests as secondary sugar fungi. Therefore, Mucor, Aspergillus and Pestalotiopsis could be identified as the most prominent genera of litter decomposing fungi in the Nagacholai forest. Nevertheless, this preliminary study needs to be elaborated further to confirm their identity up to species level using molecular techniques
Isolation of aromatic hydrocarbon degrading phyllosphere bacteria
(Sri Lanka Association for the Advancement of Science, 2013) Undugoda, L.J.S.; Kannangara, S.; Sirisena, D.M.