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Isolation and Identification of IAA-Producing and Phosphate-Solubilizing Rhizobacteria from Sesuvium portulacastrum and In Vitro Growth-Promotion Effect on Vigna radiata L. Yuliana, Baiq Fadilla; Zulkifli, Lalu; Rasmi, Dewa Ayu Citra; Sedijani, Prapti
Jurnal Biologi Tropis Vol. 25 No. 4a (2025): Special Issue
Publisher : Biology Education Study Program, Faculty of Teacher Training and Education, University of Mataram, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jbt.v25i4a.10070

Abstract

Sesuvium portulacastrum is a coastal plant resistant to high salt content and drought. Exploration of rhizosphere bacteria is necessary to obtain potential isolates that can be developed as biofertilizers in the future. This study aims to isolate and identify rhizosphere bacteria from Sesuvium portulacastrum that are able to produce Indole Acetic Acid (IAA) and dissolve phosphate, and to test their effects in vitro on the germination of Vigna radiata L. Rhizosphere bacteria from the Bagek Kembar Mangrove Ecosystem Area, Sekotong, West Lombok Regency. A total of 14 bacterial isolates were successfully obtained and characterized based on morphological, physiological, and biochemical properties. All isolates produced IAA qualitatively and quantitatively (19.85–33.71 ppm) with isolate KT1 having the highest production (33.71 ppm). Qualitative phosphate solubilization test showed that 12 isolates were able to form a clear zone, while quantitatively it ranged from 7.86 to 16.18 ppm with isolate K8 having the highest value (16.18 ppm). Selected isolates KT1 (the highest IAA producer), K8 (the highest phosphate solubilizer), and K5 (both with high abilities) were tested for their effect on mung bean germination. Inoculation had a significant effect on plant height, root length, and dry weight (p<0.05). These results indicate that S. portulacastrum rhizosphere bacteria have the potential to be an environmentally friendly biofertilizer for plants in high-salinity soils.
Endophytic Bacteria of Mangrove Roots from the West Coast of Lombok Island with Phosphate-Solubilizing and IAA-Producing Abilities as Biofertilizer Candidates Zulkifli, Lalu; Sakaroni, Rubiyatna; Rasmi, Dewa Ayu Citra; Wirajagat, Gde Cahyadi
Jurnal Biologi Tropis Vol. 25 No. 4b (2025): Special Issue
Publisher : Biology Education Study Program, Faculty of Teacher Training and Education, University of Mataram, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jbt.v25i4b.11175

Abstract

Mangrove ecosystems are unique habitats with extreme environmental conditions that select for adaptive endophytic microorganisms, making them a potential source of plant growth-promoting bacteria (PGPB). Exploring the potential of endophytes as biofertilizers to reduce dependence on chemical fertilizers is crucial in the context of sustainable agriculture. This study aims to characterize the potential of mangrove root endophytic bacteria from the coast of Lombok as biofertilizer agents through the evaluation of Indole-3-Acetic Acid (IAA) hormone production and phosphate solubilization ability. Endophytic bacteria were isolated from roots, evaluated for IAA production using the Salkowski method, while phosphate solubilization ability was evaluated qualitatively on Pikovskaya agar and quantitatively in liquid culture using molybdenum blue spectrophotometry. Potential isolates were characterized morphologically to determine their bacterial genus. The results showed that all isolates produced IAA, with AV1 (51.52 ppm) and AV4 (42.86 ppm) categorized as high producers. Phosphate solubilization ability varied significantly, with AV1 showing the strongest activity (index 4.41), followed by M1 (1.93), while some isolates showed low to no activity. Quantitative tests showed a peak in dissolved phosphate on day 4, with M2 (18.20 ppm) and M1 (16.31 ppm) being the most efficient phosphate solubilizers. Phenotypic characterization identified all promising isolates (AV1, AV4, M1) as Gram-positive, rod-shaped bacteria belonging to the genus Bacillus sp. based on Bergey’s Manual of Systematic Bacteriology. Overall, AV1, AV4, and M1 were identified as the most promising candidates for further development as biofertilizers.
Japanese Papaya (Cnidoscolus aconitifolius): An Integrated Biological System with Mechanism-Based Utilization Sedijani, Prapti; Mahrus, Mahrus; Rasmi, Dewa Ayu Citra; Kusmiyati, Kusmiyati; Khaerudin, Khaerudin
Jurnal Biologi Tropis Vol. 25 No. 4a (2025): Special Issue
Publisher : Biology Education Study Program, Faculty of Teacher Training and Education, University of Mataram, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jbt.v25i4a.11234

Abstract

Cnidoscolus aconitifolius (Japanese papaya or chaya) is a tropical plant from the Euphorbiaceae family known for its high nutritional value and diverse biological activities. Several studies have reported antioxidant, antimicrobial, and other biological properties, suggesting the involvement of complex molecular systems. This article presents a conceptual literature review using a systems biology approach to understand Japanese papaya as an integrated biological system in which nutritional components, secondary metabolites, and enzymatic activities interact. By positioning hydrolytic enzyme systems as the central mechanism, this review discusses the potential utilization of Japanese papaya as a biological resource and as a basis for the development of functional derivative products, including biomolecular hydrolysates. Possible applications in mechanism-based bioconversion processes are also briefly addressed.
Association Between Dietary Patterns and Nutritional Status of Fifth-Grade Students in Kediri District Azizah, Baiq Nurul; Kusmiyati, Kusmiyati; Rasmi, Dewa Ayu Citra
Jurnal Biologi Tropis Vol. 26 No. 1 (2026): Januari-Maret
Publisher : Biology Education Study Program, Faculty of Teacher Training and Education, University of Mataram, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/jbt.v26i1.11502

Abstract

The quality of future human resources is closely linked to the current nutritional status of children. Unhealthy and irregular dietary patterns can lead to undernutrition or overnutrition, affecting overall health and brain development. This study aimed to examine the relationship between dietary patterns and the nutritional status of fifth-grade students in Kediri District. A correlational design with random sampling was conducted in eight schools, involving 221 respondents. Dietary patterns were classified as good (66.5%), fair (24.4%), very good (7.2%), and poor (1.8%). Nutritional status was predominantly normal (96.8%), with 3.2% categorized as overweight, and no cases of underweight. Chi-Square analysis indicated a significant association between dietary patterns and nutritional status (p = 0.009 < 0.05), with a low correlation coefficient (r = 0.224). These findings suggest that dietary patterns are not the sole determinant of nutritional status; factors such as health condition, physical activity, illness frequency, and environmental conditions also contribute. It is recommended to promote healthy eating habits among students and parents, ensure food hygiene in schools, and provide nutritious food options. Future research should consider nutritional education interventions to assess their impact on students’ dietary patterns and nutritional status.