Identification of water and sediment bacteria isolated from Las-Piñas-Parañaque lagoon using 16S rDNA

• Main Authors: Layco, Margarita B., Sisayan, Phoebe Kanelle, Tagle, Maria Reena Beatrice V.
• Format: text
• Language: English
• Published: Animo Repository 2011
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/12104
• Institution: De La Salle University

Fifty-nine (59) bacterial isolates were obtained from the water and sediment of the Las Piñas-Parañaque lagoon. Only 33 (85%) isolates from sediments were identified. These samples were observed in the area to raise awareness to the people about their health since some of the organisms identified were pathogenic and may pose transfer of disease to the community. Twenty- eight (85%) of these isolates were Bacillus spp., two (6%) were Brevibacillus spp., two (6%) were Pseudomonas spp., and one (3%) was Staphylococcus sp. Seventeen out of twenty isolates (85%) from water were also identified. Three (17%) of them were Bacillus spp., one (6%) Chryseobacterium sp., two (12%) were Comamonas sp., one (6%) was Klebsiella sp., one (6%) was Maricaulis sp., two (12%) were Methylobacterium sp., one (6%) was Sphingomonas sp., two (10%) were Staphylococcus spp., and four (23%) were Pseudomonas spp. Greater diversity of species can be observed from the water samples due to the presence of different bacteria found in the samples provided. Screening for the presence of MDH gene was also done using polymerase chain reaction amplification process. Out of the thirty-nine (39) sediment isolates, three (3) tested out to be positive for the MDH gene while among the twenty (20) water isolates, six (6) tested to be positive for the corresponding gene. These were Bacillus cereus (DLSULPL- 26s), Bacillus cereus (DLSULPL-29s), Pseudomonas stutzeri (DLSULPL-38s). Among the 20 water isolates, six (6) tested to be positive for the corresponding gene namely, Comamonas aquatica (DLSULPL-02w), Pseudomonas mendocina (DLSULPL-03w), Comamonas aquatica (DLSULPL-06w), Pseudomonas fluorescens (DLSULPL-10w), Methylobacterium hispanicum (DLSULPL-13w), and an unidentified isolate (DLSULPL-18w). With this knowledge, these microorganisms that were identified may be capable of bioremediation thus they can facilitate in the treatment of the Las Piñas-Parañaque lagoon. We suggested that the presence of mdh gene in Gram-negative Pseudomonas sp., Comamonas and Methylobacterium sp. was due to horizontal gene transfer either by plasmid or tansposons since it was noted that mdh BLAST results revealed mdh genes from bacterial isolates which didn’t support their identity based on 16s rDNA data. The bacterial isolates in the water was found to be more varied since more genera of bacteria was identified compared to the bacterial isolates in sediment.