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Identification and Mercury Sensitivity Test of Rhizosphere Bacteria From Ageratum conyzoides Plants Growing In Ratatotok Gold Mine, North Sulawesi Rania Nur Farida; Anna Rakhmawati; Tien Aminatun; Sri Atun
Indonesian Journal of Bioscience (IJOBI) Vol. 2 No. 2 (2024): Indonesian Journal of Bioscience (IJOBI)
Publisher : Department of Biology Education FMIPA Universitas Negeri Yogyakarta in collaboration with Perhimpunan Biologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/ijobi.v2i2.933

Abstract

Indonesia is known for its abundant natural resources, such as gold. However, the mercury-based amalgamation method in illegal gold mining causes environmental pollution. This research explores the potential of utilizing mercury-resistant rhizosphere bacteria from Ageratum conyzoides, a gold hyperaccumulator plant, to develop an effective bioremediation strategy for contaminated gold mining areas. This descriptive-exploratory study aims to identify and determine the sensitivity of mercury in five rhizosphere bacteria isolates from previous research. Bacteria were isolated from the roots of Ageratum conyzoides growing in the Ratatotok gold mining area of North Sulawesi. Bacteria identification was determined using profile-matching methods based on microscopic, macroscopic, physiological, and biochemical features. Similarity Indexes were determined using dendrogram visualization with MVSP software. Mercury sensitivity was analyzed using the cup-plate technique, varying mercury concentrations from 0 ppm to concentrations where clear zones appeared, indicating bacterial growth inhibition. The result indicated that the five isolates were bacteria from the genera Alcaligenes, Pseudomonas, Enterococcus, Streptococcus, and Micrococcus. Notably, Pseudomonas showed the highest potential for mercury resistance, being mercury sensitive at a concentration of 470 ppm, followed by Alcaligenes (110 ppm), Enterococcus (30 ppm), and both Streptococcus and Micrococcus (20 ppm).
Characterization And Identification of Halophilic Bacteria (Rastrelliger sp.) Extracellular Lipase Generator in Beringharjo Market Octavia, Bernadetta; Rakhmawati, Anna
Indonesian Journal of Bioscience (IJOBI) Vol. 2 No. 2 (2024): Indonesian Journal of Bioscience (IJOBI)
Publisher : Department of Biology Education FMIPA Universitas Negeri Yogyakarta in collaboration with Perhimpunan Biologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/ijobi.v2i2.1056

Abstract

Advances in biotechnology have allowed for the widespread use of lipase enzymes. One of the producers of lipase enzymes is halophilic bacteria. This study aims to determine the characteristics and genus, as well as the kinship relationship between lipase-producing halophilic bacterial isolates from salted fish (Rastrelliger sp.) in Beringharjo Market, Yogyakarta. Salted fish samples were isolated on Nutrient Agar + 3% NaCl + Tween 80 + 0.1% Rhodamine-B selective media to grow lipase-producing halophilic bacteria. Identification was carried out by the matching profile method based on Bergey's Manual of Determinative Bacteriology. The kinship relationship between bacterial isolates was classified using MVSP 3.1 software with the UPGMA clustering algorithm and constructed in the form of a dendogram.
Exploration and Identification of Lichen in the Temon, Depok, and Tegalrejo Hafizh Adyatma; Anna Rakhmawati; Bernadetta Octavia
Indonesian Journal of Bioscience (IJOBI) Vol. 3 No. 2 (2025): Indonesian Journal of Bioscience (IJOBI)
Publisher : Department of Biology Education FMIPA Universitas Negeri Yogyakarta in collaboration with Perhimpunan Biologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21831/ijobi.v3i2.2484

Abstract

This research aims to identify the diversity of lichen species in three different areas: Temon, Kulon Progo; Depok, Sleman; and Tegalrejo, Magelang. Besides that to analyze their ecological role as environmental bioindicators. The method used was direct field observation with visual documentation using a mobile phone camera, followed by morphological identification. The results of the study successfully identified nine lichen species: Flavoparmelia caperata, Physcia atrostriata, Dirinaria applanata, Phlyctis argena, Acarospora socialis, Ropalospora viridis, Pyxine sorediata, Cryptothecia striata, and Graphis sp.. These species exhibited unique adaptations to various substrates (tree bark, rocks, and urban environments) and showed sensitivity to environmental changes, particularly air pollution. The mutualistic symbiosis between fungi and photobionts (algae/cyanobacteria) is key to the resilience of lichens in marginal habitats. These findings strengthen the potential of lichens as natural bioindicators and ecological pioneers, while also highlighting the need for further research to map the distribution and applications of lichens in Indonesia.
Development of Discovery-Based Outdoor Learning Integrated with Papua Local Wisdom to Improve Cooperation and Understanding of the Biodiversity Concept of Students of Phase E of Sman Khas Papua Evi Linda; Anna Rakhmawati; Paidi
Jurnal Penelitian Pendidikan IPA Vol 11 No 8 (2025): August
Publisher : Postgraduate, University of Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jppipa.v11i8.12140

Abstract

This study aims to develop a discovery-based outdoor learning model integrated with Papuan local wisdom to improve the collaboration skills and understanding of biodiversity concepts of phase E students at SMAN Khas Papua. The background of this study is based on the low context of science learning regarding the local environment and culture, even though Papua has very high ecological and cultural potential to be used as a learning resource. The method used is the Design-Based Research (DBR) Plomp model which consists of three stages: introduction, development/prototyping, and summative assessment. The results of expert validation show that the model and learning tools have very good validity values (Average Validator Agreement > 3.5). Practicality tests through observation and questionnaires on teachers and students show that the model is easy to implement and helps make learning meaningful. The effectiveness of the model is proven by a significant increase in student learning outcomes (t-test; p < 0.05) as well as the development of collaboration skills through outdoor learning. The integration of Papuan local wisdom, such as forest conservation practices and traditional medicine, encourages emotional engagement and contextual scientific understanding. This model also supports the implementation of the Independent Curriculum and the strengthening of the Pancasila Student Profile. This research makes an important contribution to the development of innovative and adaptive local culture-based science learning in the 3T context. Further, large-scale studies are needed to test the model's sustainability and replicability in various regions with similar characteristics.
BACTERIAL CELLULOSE FROM RICE WASTE WATER AND ITS COMPOSITE WHICH ARE DEPOSITED NANOPARTICLE AS AN ANTIMICROBIAL MATERIAL Eli Rohaeti; Endang W Laksono; Anna Rakhmawati
ALCHEMY Jurnal Penelitian Kimia Vol 12, No 1 (2016): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.12.1.946.70-87

Abstract

Bacterial cellulose (C) and its composites were synthesized from rice waste water with addition of glycerol (G) and chitosan (Ch).Antibacterial activity of the C, the bacterial cellulose-chitosan composite (CCh), and the bacterial  cellulose – glycerol - chitosan composite (CGCh) which were deposited silver nanoparticles against S. aureus, E. coli,  and yeast C. albicans has been conducted. Silver nanoparticles was prepared by chemical reduction of a silver nitrate solution, a trisodium citrate as a reductor, and a PVA as a stabilizer. The UV-Vis spectroscopy is used to determine the formation of silver nanoparticles. The characterization was conducted on the bacterial celluloses and those composites including the functional groups by the FTIR, the mechanical properties by Tensile Tester, photos surfaces by SEM, and the test of the antibacterial activity against S. aureus, E. coli, and C. albicans by diffusion method. The silver nanoparticle characterization indicates that the silver nanoparticles are formed at a wavelength of 418.80 nm. The antibacterial test showed an inhibitory effect of the C, the CCh, and the CGCh which are deposited  the silver nanoparticles against of S. aureus, E. coli,  and C.albicans. The CGChs which are deposited silver nanoparticles has the highest antimicrobial activity against the Staphylococcus aureus ATCC 25923. The CGs which are deposited silver nanoparticles provide the highest antimicrobial activity against the E. coli ATCC 25922 and the yeast Candida albicans ATCC 10231.