SLIIT Journal of Humanities and Sciences [SJHS]

Permanent URI for this communityhttps://rda.sliit.lk/handle/123456789/2238

Browse

Filters

2022 - 20242

Advanced Search

Filter by

Settings

Author: search.filters.author.Peiris, S. E.

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    PublicationOpen Access
    In Vitro Evaluation of Antibacterial Activity of Copper and Sulfur Nanoparticles for Controlling Bacterial Blight Caused by Xanthomonas sp. in Anthurium andraeanum Lind.
    (Faculty of Humanities and Sciences, SLIIT, 2022-10-20) Peiris, S. E.; Seneviratne, K. L.; Shashikala, R. P. A.; Peiris, Colin N.; Imalka, M. I.; Piumika, Y. P
    Bacterial blight in Anthurium andraeanum Lind. which is caused by Xanthomonas sp. is regarded as the most threatening disease in the anthurium industry worldwide. Therefore, the current study was carried out to determine whether the application of copper nano particles (CuNPs) and sulfur nanoparticles (SNPs) is a possible solution to control the bacterial blight in anthurium. The bacterium Xanthomonas sp. was isolated using standard methods and a single bacterial colony was grown in nutrient agar (NA). The colonies produced in cultures were identified as Xanthomonas sp. as they were Gram-negative, motile rods with yellow colour due to production of xanthin. The symptoms appeared in the pathogenicity test which was carried out by injecting purified Xanthomonas sp. into disease free anthurium plants confirmed the identification of the bacterial strain. Concentrations of 5, 15 and 25mg/100ml CuNPs and 50, 75 and 1000 mg in 100ml SNPs were mixed separately with isolated Xanthomonas sp. to investigate the behavior of two types of nano particles in destroying the bacterium. All three concentrations (5, 15 and 25 mg/100ml) of copper nanoparticles used in suspensions of the bacterium Xanthomonas sp. did not support any bacterial growth. In contrast, all three concentrations of SNPs in Xanthomonas sp. showed bacterial growth though it was less in 1000 mg /in 100ml compared to the control treatment. Hence it can be concluded that 5 mg/100 ml CuNPs is capable of destroying in vitro growth of Xanthomonas sp. bacterium which causes bacterial blight in Anthurium andraeanum.
  • Thumbnail Image
    PublicationOpen Access
    Microbial Pigment Isolation, Culturing, and Extraction to Use as Textile Dyes
    (Faculty of Humanities and Sciences, SLIIT, 2024-07-26) Hewagama, H. L; Somarathna, G. M. T. K.; Herath, L.; Peiris, S. E.
    The textile industry is one of the largest worldwide polluters of clean water due to the heavy use of synthetic dyes. These chemicals negatively affect the environment, especially aquatic life due to their toxic and mutagenic properties. Synthetic dyes cause harm to human health such as skin allergies and respiratory sensitization. Several advantages such as ease of extraction, availability, high yields and no seasonal variation make microbial pigments the most ideal source of natural pigments. This study was done to isolate colour pigment producing bacteria and fungi from soil collected from organic farms from various locations in Sri Lanka. Out of 7 soil samples, 3 yielded pigment producing bacteria and fungi. In total, 9 pigment producing bacteria and 3 pigment producing fungi were isolated. Gause’s synthetic agar yielded the most pigmented isolates. Isolates were inoculated in broths and pigment production was observed. Extracellular pigments produced by 5 of the bacterial isolates were extracted by a water-based method. The antibacterial activity of the pigments in their crude and concentrated forms was tested using the well diffusion method against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538P. Inhibition zone against S. aureus was observed for both crude (12.33±0.58mm) and concentrated pigments (9.67±0.58mm) extracted from purple pigment producing bacterial isolate (BPU). This pigment has the potential to be used in antibacterial textile preparation. Extracted pigments were used to dye scoured cotton fabric with the use of 3% alum as mordant. Pigment from BPU isolate resulted in better coloured fabric.