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Journal of Natural Sciences
Published by Mahesa Research Center
ISSN : -     EISSN : 27215571     DOI : 10.34007
Core Subject : Agriculture, Social,
Agriculture, Biological Sciences & Forestry Environmental Science
The Journal of Natural Sciences is a scientific publication media in the study and development of Science in the fields of science and Education (Biology, Chemistry, and Physics). The Journal of Natural Sciences includes scientific writings in the form of conceptual, research results as well as relevant issues in the fields of science and education. The Journal of Natural Sciences is published three times a year.
Arjuna Subject : Ilmu Lingkungan (semua ketegori) - Ilmu Lingkungan (Lain-Lain)
Articles 117 Documents
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Karakterisasi Proksimat Tepung Colocasia esculenta Sebagai Pangan Lokal Alternatif di Kabupaten Kubu Raya Alang, Hasria
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.1016

Abstract

Taro flour is a form of diversification of taro tubers, and can be used as an alternative to replace the use of wheat flour. The purpose of this study was to determine the proximate characteristics of taro flour that has been processed simply as a basis for information for handling processed taro flour products. This study was conducted at the Fisheries Cultivation Laboratory of Pontianak State Polytechnic. The method used was the simple production of taro flour. The resulting flour was then analyzed for its proximate content. Determination of protein content was carried out using the kjeldahl method, determination of ash and water content was carried out using the thermogravimetric method, determination of fat content using a Soxhlet apparatus, and determination of carbohydrate content using the by difference method. The results of the study showed that the ash content in taro tubers was 2.57%, water content 11.90%, fat 1.95%, carbohydrate 77.58%, and protein 4.5%. Based on the research results, it was concluded that the high carbohydrate content indicates that this flour can be used as a substitute for wheat flour, the low water content indicates that processed products made from this flour can last a long time, the lowfat content indicates that processed products made from this flour are very suitable for a low-fat diet.
Aktivitas Antibakteri Isolat Jamur Endofit Kitolod (Hippobroma longiflora (L.) G. Don.) terhadap Bakteri Escherichia coli dan Staphylococcus aureus Pramesta, Carerina Oktavia; Syaifudin, Andang; Kusumarini, Niken
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.1031

Abstract

Endophytic fungi are microorganisms that inhabit plant tissues without causing harm to their hosts. Hippobroma longiflora (L.) G. Don (kitolod) is known to contain secondary metabolites with antibacterial potential. This study aimed to isolate and evaluate the antibacterial activity of endophytic fungi from the leaves and flowers of kitolod against Escherichia coli and Staphylococcus aureus. Isolation was performed by surface sterilization using 1% NaOCl, 70% ethanol, and sterile water, followed by cultivation on PDA medium. Nine isolates were obtained, consisting of four from flowers and five from leaves. Extracts from PDB cultures were tested using the disc diffusion method (30 µL/disc). Results showed that isolate BK1 exhibited strong antibacterial activity against S. aureus (11.16 mm) and moderate activity against E. coli (9.71 mm). Isolates BK3 and DK3 also displayed strong inhibition zones. The positive control (chloramphenicol) produced very strong inhibition, while the negative control (sterile water) showed none. The antibacterial activity is presumed to originate from secondary metabolites of endophytic fungi, indicating their potential as natural antibacterial sources. Further studies are needed to determine MIC values and conduct molecular identification of the selected isolates.
Analisis Metode Penyelesaian Relasi Rekursif dalam Matematika Diskrit serta Implikasinya terhadap Pembelajaran Siregar, Fadilla Sri Utami; Rambe, Arjuna Yahdil Fauza; Amir, Almira
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.1025

Abstract

Recursive relations are an important concept in discrete mathematics used to define sequences, functions, and computational models. This study aims to analyze various methods for solving recursive relations and their implications for mathematics learning. The study used a library research approach to 15 articles published in SINTA-accredited national journals (1–5) and Scopus-indexed international journals during the 2020–2025 period. Articles were selected through identification, screening, eligibility, and inclusion stages based on topic relevance and full-text availability. The results of the study indicate that each method has its own characteristics: substitution and iteration are suitable for basic cases, characteristic equations are effective in homogeneous linear relations, generating functions excel in combinatorics contexts, and numerical approaches are relevant for complex dynamic systems. From a learning perspective, the application of recursive relations contributes to improving students' critical, logical, and creative thinking skills through discovery learning strategies, blended learning, and the use of concrete media. This study emphasizes the importance of integrating recursive relations in the discrete mathematics curriculum to equip students with higher-order thinking skills that are appropriate to the demands of the 21st century.
Kinetika Hidrolisis Selulosa Menjadi Glukosa Pada Limbah Kulit Nanas (Ananas comosus) Menggunakan Enzim Selulase Annidya, Putri Azmi; Rachmanto, Tuhu Agung; Novembrianto, Rizka
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.1033

Abstract

Pineapple peel waste (Ananas comosus) is a source of organic waste with high lignocellulose content that has the potential to be utilized through a bioconversion process into glucose. This study aims to determine the Michaelis–Menten kinetic equation of cellulose hydrolysis into glucose using cellulase enzymes and analyze the effect of substrate concentration (1–5% w/v) and hydrolysis time (60–180 minutes) on the reaction rate. The research stages include delignification using 5% NaOH at 80ºC and enzymatic hydrolysis with 10% cellulase at pH 5 and 50ºC. Glucose levels were measured using a Brix refractometer through a standard glucose solution calibration method. The results showed an increase in glucose concentration over time and substrate concentration, with the highest conversion of 91.5% at 5% substrate. Kinetic analysis using the Michaelis–Menten equation yielded an average reaction rate constant (k) of 0.3328 min⁻¹, with the highest k of 0.3828 min⁻¹ and the highest Michaelis–Menten constant ( ) of 2.357 mg·L⁻¹ at a substrate concentration of 5%. A significant increase in  from 0.2403 (1%) to 2.357 (5%) indicates a decrease in enzyme affinity due to substrate saturation. Therefore, a concentration of 5% is considered the optimal condition for the cellulose hydrolysis process, confirming the potential of pineapple peel waste as an efficient substrate source.
Analisis Kebutuhan Media Pembelajaran IPA Berbasis 4C untuk Penguatan Keterampilan Abad 21 di SMP Negeri 20 Lebong Astuti, Asmi; Fitriani, Apriza
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.1036

Abstract

The demands of 21st-century education emphasize the development of 4C skills (Critical Thinking, Creativity, Communication, Collaboration). However, science learning at SMP Negeri 20 Lebong has not been optimal in implementing innovative digital media that support these skills. Therefore, this study aims to analyze the need for developing 4C-based science learning media to improve students' 21st-century skills at the school. The method used was a descriptive quantitative survey-based method, involving 105 students in grades VII, VIII, and IX. Data were analyzed using descriptive statistics. The results indicate an urgent need for innovation. 87.1% of students require alternative learning methods, and 58.1% of students still have difficulty understanding abstract science material, especially the Coordination, Reproduction, and Pressure Systems, triggered by the many formulas and concepts. The majority of students (76.3%) consider the available media inadequate, and 82.8% require additional media, with 96.8% wanting digital technology-based media (computers/laptops/smartphones). Only 49.5% of students feel that teachers have encouraged critical thinking in learning. These findings provide a strong foundation for the development of 4C-based interactive science learning media that is digitally and collaboratively oriented, which concretely contributes to visualizing abstract concepts, increasing engagement, and strengthening students' 21st-century competencies.
Etnobotani Tumbuhan Pangan Tradisional Masyarakat Batak di Kabupaten Toba Sumatera Utara Amrul, Hanifah Mutia Zaida Ningrum
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.1017

Abstract

This study examines the diversity of plant species utilized as traditional food sources by the Batak community in Toba Regency, North Sumatra. The research aims to document traditional knowledge related to local food resources, including staple foods, vegetables, fruits, and cooking spices. Data were collected through field observations and semi-structured interviews, while the data analysis was conducted using a qualitative descriptive approach. The results revealed that the Batak people utilize 125 plant species, consisting of 13 carbohydrate sources, 37 vegetable species, 42 fruit species, and 34 plant species used as spices. The dominance of cultivated plants indicates an adaptation of the community to modern agricultural systems, while the continued use of wild plants reflects the preservation of local wisdom. This study is expected to contribute to the development of sustainable, locally based food security and to serve as a potential reference for the development of functional food products.
Pengaruh Model Pembelajaran Problem based learning (PBL) Terhadap Hasil Belajar Siswa Kelas VIII Pada Materi Sistem Pernapasan Manusia Kesumawati, Diah; Parinduri, Wina Mariana; Saraan, Zahra Khumayrah
Journal of Natural Sciences Vol 6, No 3 (2025): Journal of Natural Sciences November
Publisher : Mahesa Research Center

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34007/jonas.v6i3.990

Abstract

This study focuses on the effect of the problem-based learning (PBL) model on the learning outcomes of eighth-grade students on the subject of the human respiratory system at Mts Al-Washliyah Stabat. The purpose of this study is to determine how the Problem-Based Learning (PBL) model affects the learning outcomes of eighth-grade students at MTS Al-Washliyah Stabat on this subject. The research method used was a quasi-experimental design with a pre-test post-test control group design. This study involved all 132 eighth-grade students. The research sample was determined using purposive sampling, namely class VIII-C as the experimental class (PBL model) and class VIII-D as the control class (lecture method), with a 30-question multiple-choice test instrument, which was analyzed through normality, homogeneity, and independent t-test. The results showed a significant effect on the experimental class with a post-test average score of 84,81 compared to the control class with an average score of 72,09. The hypothesis test obtained a significance value of 0.000 0.05, which means that Ha is accepted, so it can be concluded that the Problem-Based Learning (PBL) model has a positive and significant effect on the learning outcomes of eighth-grade students on the material of the human respiratory system at Mts Al-Washliyah Stabat.

Page 12 of 12 | Total Record : 117

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