https://bestjournal.untad.ac.id/index.php/ejurnalfmipa/issue/feed 2024-06-28T13:58:00+00:00 F Fahri fahribadjeber11@gmail.com Open Journal Systems <p><a title="Link Sinta" href="https://sinta.kemdikbud.go.id/journals/profile/288" target="_blank" rel="noopener"><strong>Natural Sciences: Jurnal of Science and Technology</strong> [eISSN : 2541-1969 | pISSN : 2338-0950]</a> is an open access journal from Tadulako University, Indonesia. Natural Sciences: Journal of Science and Technology (hence JST) is an international journal providing an authoritative source of scientific information for researchers in academia, research institutions and government agencies, and industries. We publish original research papers, review articles and case studies on the scientific works in the field of life science in tropical area including biodiversity and environment, ecology, biotechnology, bioinformatics, molecular biology, biochemistry, ethnobiology, herbal medicine, zoology and botany as well as related topics. JST does not accept papers related to the topic of material science, education, economy, social and humanities and other issues outside the topic of life science. All papers are peer-reviewed by at least two referees. Other topics are welcome if it discusses biodiversity or biotechnology. Natural Sciences: Journal of Science and Technology is published and imprinted by Faculty of Science, Tadulako University (UNTAD) and managed to be issued twice in every volume. For further information, please visit https://bestjournal.untad.ac.id/index.php/ejurnalfmipa.</p> <p><strong>Natural Sciences: Journal of Science and Technology</strong> <span class="fontstyle0">officially published three times a year. But, starting on January 1, 2021 Journal of Science and Technology will be published twice a year.</span></p> https://bestjournal.untad.ac.id/index.php/ejurnalfmipa/article/view/17057 2024-06-28T13:57:59+00:00 Pasjan Satrimafitrah pasjan82@gmail.com Nov Irmawati Inda nov_chemuh@yahoo.co.id Navalia Mahensiska navaliamahensiska@gmail.com Indasari indasarichem12@gmail.com

<p>A stability study of previously isolated and selected crude amylase PL-16 has been performed. The purpose of this study was to determine the effect of pH and temperature alterations on the stability of crude amylase enzymes PL-16 produced by thermophilic bacteria found in Pulu hot springs in Central Sulawesi. Stability characterization was carried out by storing and incubating crude amylase for 24 hours and at elevated heat prior to activity assay at varied pH and temperatures. Enzyme activity following characterization was determined by the DNS method and UV-VIS spectrophotometry at a wavelength of 540 nm, using maltose as the standard. The results showed that at storage for 24 hours with pH varied from 5-12, the crude amylase enzyme activity was able to maintain its 85-95% stability in the pH range of 7-9, then decreased in stability at pH of 10-12. While at 2 hours storage in elevated temperature, it maintained 84-85% stability against heat at 70-80 °C, then decreased at higher temperatures. Our results suggested that crude amylase PL-16 is a promising candidate for industrial enzyme application due to its capability to maintain stability in high temperatures and acidic to neutral pH.</p>

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