Journal of Tropical Biodiversity and Biotechnology

The First Record of Snake Predation by an Invasive Species, Calotes versicolor (Daudin, 1802) in Indonesia: A Case Study on its Feeding Ecology

Rury Eprilurahman — 2025-07-11

Calotes versicolor (Daudin, 1802) is an agamid lizard originating from India, now widespread across Asia and invasive in certain regions, including parts of the Malay Archipelago. Here, we report its first recorded snake predation in Indonesia. A male C. versicolor was observed consuming an adult Painted Bronzeback Snake (Dendrelaphis pictus). The lizard began swallowing the snake headfirst and fled with it still wriggling in its mouth. This observation highlights the species’ capacity to prey on larger vertebrates, underscoring its potential ecological impact in invaded habitats. Further studies are needed to clarify its feeding ecology and implications for native fauna.

Fern Communities in Post-Gold Mining Sites of West Kalimantan, Indonesia

Adinda Octavia Syahsabilla — 2025-07-21

Understanding changes in plant communities in post-mining sites is important for managing a degraded landscape. Ferns have been known as species indicators for heavy metals-contaminated environments. However, research focusing on fern communities in post-mining environments is scarce. This study investigates fern communities in post-mining areas that have been abandoned for 1, 6, and 10 years in West Kalimantan, Indonesia. The results show that the composition and abundance of fern species differed among post-gold mining sites. Stenochlaena palustris, Pityrogramma calomelanos, Dicranopteris linearis, and Nephrolepis cordifolia are four species recognised as species indicators for post-mining sites aged six and ten years.

Elodea najas (Planch.) Casp. and Vallisneria natans (Lour.) H.Hara (Hydrocharitaceae): Two Recently Naturalized Aquascape Plants in Java, Indonesia

Arifin Surya Dwipa Irsyam — 2025-07-25

Aquatic ornamental plants are in high demand, driving market growth. The widespread importation of various aquascape species has led to the naturalisation of some taxa. During our field survey, we recorded two newly documented aquatic species in West and East Java from naturalized and cultivated populations: Elodea najas (Planch.) Casp. and Vallisneria natans (Lour.) H.Hara. Naturalized E. najas populations were found in Bogor and Sumedang, while V. natans proliferates along the Cilubang Tonggoh River in Bogor. The genus Elodea is often misidentified and sold as Hydrilla; thus, molecular analysis using the ITS sequence was conducted to confirm specimen identity.

Ethnobotany of Plants for Cleansing and Fragrancing in Jamasan Keris Used by Surakarta Community, Central Java, Indonesia

Joko Ariyanto — 2025-09-04

The Surakarta community practices the cultural tradition of caring for keris. This study documents traditional knowledge on plants used for cleansing and fragrance in keris care. Research was conducted from May to October 2023 through interviews, field observations, and literature reviews, with key informants selected purposively. Data were analysed thematically and quantitatively using the Relative Frequency of Citation (R.F.C.) index. Thirteen plant species, including Cocos nucifera L. and Citrus aurantiifolia (Christm.) Swingle, were essential for cleansing, while Santalum album L. was most recognized for fragrancing material. These findings highlight the importance of preserving ethnobotanical knowledge for cultural and plant sustainability.

Biodiversity and Seasonal Abundance of Dragonflies (Order: Odonata) in the Urban Areas of Makassar City and Gowa Regency, South Sulawesi, Indonesia

Moh. Ikram Mooduto — 2025-07-04

Dragonflies are insects belonging to the order Odonata; at the nymph stage, they act as bioindicators of water quality, and at the adult stage, they act as predators of small insects. Seasonal changes and environmental issues in urban areas can affect the existence of dragonfly populations. This study aims to identify species diversity, abundance, similarity, and the relationship between biotic vegetation characteristics and abiotic seasonal elements. The study was conducted in freshwater habitats, including running water and stagnant water habitats, in Makassar City and Gowa Regency during the dry and rainy seasons. Data collection was conducted using the Visual Encounter Survey (VES) method and specimen collection using insect nets. The results showed 12 species from 2 families, 11 species from Makassar City, and 6 species from Gowa Regency. The Shannon-Wiener diversity index showed that the dry season's diversity value is H' = 1.39 and the rainy season's value is H' = 1.72. The abundance of dragonflies showed that the species Agriocnemis pygmaea and Brachythemis contaminata were the most frequently observed species. Additionally, one particular research site shared the same species across six different aquatic environments. There was a correlation between the abundance of dragonflies in each research location and the variation of abiotic variables. Differences in vegetation composition also affected the structure of the dragonfly community.

Diversity of snails (Mollusca: Gastropoda) in the Mangrove Area of Karangsong, Indramayu Regency, West Java Province, Indonesia

Lailancika Ansyar — 2025-07-08

The Karangsong mangrove forest region has significantly advanced in the administration and exploitation of natural resources, transforming into an ecotourism hotspot and silvofishery area for fish aquaculture. The aim of this study is to analyse the composition of gastropod communities, essential for the stability of mangrove ecosystems and biodiversity management. The study was carried out during May-June 2024 in the Karangsong mangrove ecosystem of Indramayu Regency, Indonesia. Purposive sampling was used based on three different mangrove habitats in Karangsong. Mangrove density was measured using three random transect plots (10 x 10 m²) and five quadrants (1 x 1 m²) for gastropod collection. The present study identified two distinct species of mangroves, namely Avicennia marina and Rhizophora mucronata. The discovered snails consist of six families: Potamididae, Ellobiidae, Littorinidae, Terebridae, Nassariidae, and Onchidiidae. Gastropod diversity is moderate (H' = 1.62), with no species dominating any research site (C = 0.24). The prevalence of gastropods significantly correlates with the mangrove biodiversity (r = 0.671). The results indicate that the gastropod community within the Karangsong mangrove habitat is stable.

Pteridophyte Richness and Community Structure in the Tropical Lowland Habitats of Andanan Protected Landscape, Northeastern Mindanao, Philippines

Harold Jay A. Sumilhig — 2025-07-14

Pteridophytes are among the most diverse vascular plants in the Philippines, with significant conservation and economic value. This study documents the richness and community structure of pteridophytes in the tropical lowland habitats of the Andanan Protected Landscape (APL), North-eastern Mindanao, Philippines. A combination of quadrat sampling and transect walks was used for pteridophyte assessments. A total of 69 species were recorded, belonging to 19 families and 34 genera, representing about 6.3 % of the Philippine pteridophytes. Of these, 11.6 % are threatened, and 2.9 % are Philippine endemics. The Polypodiaceae was the most species-rich family, comprising 17 % of the total species. Forty-eight species were terrestrial, 12 were epiphytes, and six were lithophytes. Selaginella engleri Hieron. was the most important species in the area, with the highest importance value (12.77). The APL exhibited high pteridophyte diversity, with Shannon (H’=3.65) and Simpson (D=0.96) indices, and significant variation in species richness among sampling sites (p<0.05). Among the sampling sites, Mt. Ararat demonstrated the highest pteridophyte diversity (H'=3.4) and richness (n=56). Multivariate analysis revealed a high degree of community similarity (ANOSIM R=0.31, p<0.01), with overlapping compositions between Berseba and Calaitan, while Mt. Ararat showed a more distinct assemblage. The high pteridophyte diversity and the presence of conservation-priority species support the designation of APL as a critical forest landscape for preserving biological communities and their habitats. This study provides a preliminary checklist and distribution of pteridophyte flora to inform management and conservation efforts in the APL, North-eastern Mindanao, Philippines.

Brachyuran Crab Diversity in the Mangrove Rehabilitation Site of Misamis Oriental, Mindanao Island, Philippines

Cres Ferrie Vincent Aleman Borong — 2025-07-18

This study was conducted to determine the crab diversity of the mangrove rehabilitation site in Misamis Oriental, Mindanao, Philippines. Specifically, it aimed to (1) determine the species composition of crabs in the mangrove area; (2) assess the species richness, relative abundance, and density of crab species; (3) evaluate the species diversity of crabs, and; (4) compare the diversity of crab species found in the mangrove area. Three sampling sites were selected using a plot sampling technique. A total of 163 individuals in 12 species of brachyuran crabs from seven families were recorded at the site. In terms of relative abundance, station 3 (Eastward zone) had the highest abundance with 93 individuals, followed by station 1 (Landward zone) with 47 individuals, and station 2 (Middle zone) with 21 individuals. Mictyris longicarpus had the highest population density of 0.12 individuals/m², while Ptychognathus sp. and Portunus reticulatus had the lowest population density of 0.01 individuals/m². The Shannon-Weiner diversity index revealed that sampling station 3 (Eastward zone) had the highest diversity index of H’ = 1.77 compared to stations 1 (H’ = 1.70) and 2 (H’ = 1.42). The key finding of this study showed that brachyuran crab species were more abundant and diverse in the zonation of new-growth mangroves compared to the old-growth mangroves.

Variation and Phenetic Relationships of Sweet Potato Cultivars (Ipomoea batatas (L.) Lam) in Kutai and Karanganyar Based on Morphological and Molecular Characters

Maysavitrie Citra Wijayanti Kristianto — 2025-07-31

Ipomoea batatas (L.) Lam. has a diversity of morphological forms of tubers, leaves, flowers, and stems. Each cultivar has distinct characteristics that can be characterised and analysed using molecular markers to determine the phenetic relationships formed. The study aimed to determine the genetic variation of I. batatas in Kutai, East Kalimantan and Karanganyar. This study was conducted on 19 I. batatas samples. Morphological characters were used to observe variations in I. batatas cultivars and were strengthened using the ISSR (Inter Simple Sequence Repeat) molecular approach. A total of 31 morphological and micromorphological characters were observed, and seven ISSR primers were used to amplify I. batatas DNA from samples in Kutai and Karanganyar. The data obtained were analysed qualitatively and quantitatively. The similarity index between OTUs was determined using the Gower general similarity formula for morphological characters and Jaccard similarity for molecular characters, clustering using the UPGMA algorithm. The results showed variations in the colour of the tuber flesh, leaf shape, and tuber shape. At the molecular level, variations were indicated by the presence of polymorphic bands. Morphological characterisation resulted in three clusters based on tuber flesh colour, while molecular classification formed three clusters based on the region of origin

Frequency of ALDH2 Gene Polymorphism (rs671) in Dayak, Javanese, Minahasan, and Papuan Ethnic Populations

Jerry Ferry Langkun — 2025-08-04

The rs671 is a single nucleotide polymorphism in the ALDH2 gene which resulted in the ALDH2 enzyme inactive so that the acetaldehyde detoxification is disrupted. Individuals carrying the ALDH2*2 allele are at increased risk of diseases associated with alcohol consumption. The rs671 polymorphism is very common in East Asia and is strongly suspected to originate from the Han-Chinese ethnic group. Research in Indonesia shows that the frequency of ALDH2*2 alleles is quite wide and high (15.5 to 72.6%). This raises the question of why the prevalence of the ALDH2*2 allele in Indonesia is much higher than China. The aim of this study was to determine the genotypic and allele frequencies of rs671 of Indonesian with different ethnic background, namely the Dayak, Javanese, Minahasan and Papuan ethnic groups. SNP rs671 was detected by the Taqman SNP genotyping assay method using the QuantStudio 5 Applied Biosystems real-time PCR. The genotypic frequencies of typical homozygous, heterozygous, and atypical homozygous in the Minahasan ethnic group were 97.8%, 2.2% and 0%, respectively. The frequency of the ALDH2*2 allele is only 1.1%. The genotypic frequencies of the Dayak, Javanese and Papuan ethnic groups were 100% typical homozygotes (ALDH2*1/*1), the ALDH2*2 allele was not found. This study shows that rs671 is very rarely found among Indonesian with different ethnic background. The results of this study are in accordance with distribution patterns in East Asia, Southeast Asia and Oceania.

Enhancing Somatic Embryogenesis in Dendrobium discolor Lindl. through Optimized PGRs Addition: A Promising Approach for Mass Propagation

Zozy Aneloi Noli — 2025-08-08

Somatic embryogenesis in orchids offers a fast and reliable way to grow new plants from cells, aiding propagation efforts. The present study evaluated the technique for SE production and plantlet regeneration of Dendrobium discolor. Thin cell layer (TCL) explants were treated with concentrations of 2.4-Dichlorophenoxyacetic acid (2.4-D) (1;2;3; and 4 mg/L) to induce callus formation of Den. discolor. The application of 2 mg/L 2.4-D effectively promoted the callus emergence rate of Den. discolor. During the proliferation and regeneration stage of SE, the induction of shoots and roots depends on a synergistic combination of auxin and cytokinin PGRs. Two-week-old culture of primary callus were transferred to proliferation media (1/2 MS) supplemented with thidiazuron (TDZ) and 1-Naphthaleneacetic acid (NAA) (0 mg/L TDZ+0 mg/L NAA, 0.15 mg/L TDZ+0.05 mg/L NAA, 0.3 mg/L TDZ+0.1 mg/L NAA, 0.6 mg/L TDZ+0.2 mg/L NAA, 0.9 mg/L TDZ+0.3 mg/L NAA). The best response observed was 0.6% coleoptilar embryo production from TCL’s embryonic callus on 0.15 mg/L TDZ+0.05 mg/L NAA. Plantlet was developed from SE in regeneration media (1/2 MS) supplemented with various combinations of 6-Benzylaminopurine (BAP) and NAA (0 mg/L BAP+0 mg/L NAA, 0.5 mg/L BAP+0.5 mg/L NAA, 1 mg/L BAP+1 mg/L NAA, 1.5 mg/L BAP+1, 5 mg/L NAA, 2 mg/L BAP + 2 mg/L NAA). The best response for plantlet regeneration was observed on 0.5 mg/L BAP+0.5 mg/L NAA. This study showed that the TCL embryogenesis protocol is promising for in vitro multiplication of Den. discolor.

Edamame (Glycine max (L.) Merr) Seedling Growth Promotion by Streptomyces sp. RT52 and Analysis of Its phoD Gene

Ira Erdiandini — 2025-08-12

The excessive use of synthetic fertilisers in edamame (Glycine max (L.) Merr) cultivation has raised environmental and health concerns, necessitating sustainable alternatives. This study aimed to characterise the plant growth-promoting properties of RT52 strain, an isolate from acidic peat soil, by assessing its indole acetic acid production, phosphate solubilisation activity, nitrogenase activity, in vivo seedling growth-promotion and analysis of phoD partial sequences. Based on the results of molecular identification of the 16S rRNA gene, strain RT52 was closely related to the genus Streptomyces. Interestingly, seedling growth-promotion revealed that Streptomyces sp. RT52 could significantly increase primary root length 104.64 %, shoot length 29.69 %, number of lateral roots 63.35 % and dry weight 18.75 % of edamame sprouts. Colorimetric assays confirmed that Streptomyces sp. RT52 produced 30.73 µg mL⁻¹ IAA. Its phosphate solubilisation reached 153.50 ± 23.57 µg mL⁻¹, while nitrogenase activity, determined via acetylene reduction assay, was 21.29 ± 1.04 nmol C₂H₄ h⁻¹ tube⁻¹. Nonetheless, partial sequence of PhoD Streptomyces sp. RT52 reached 99.19 % similarity with alkaline phosphatase from Streptomyces. Superposition analysis of this sequence confirmed its structural similarity to alkaline phosphatase D from Bacillus subtilis (2YEQ), supporting its role in phosphate solubilisation under acidic conditions. These findings demonstrate the potential of Streptomyces sp. RT52 as a biofertiliser candidate for promoting edamame growth.

Physico-chemical Properties and Fatty Acid Profile of Black Rice Bran Oil Extract (Oryza sativa L. ‘Sembada Hitam’)

Fifiola Aditya Ponkiyawati — 2025-08-15

The current study highlights black rice as a nutrient-rich grain with functional properties, emphasising its relevance in advancing dietary strategies for health improvement. As a functional food, black rice contains various bioactive compounds, including anthocyanins, tocopherols, oryzanol, and essential oils, which are primarily concentrated in the bran layer of the grain. Black rice bran can be utilized as a source of rice bran oil (RBO), which enriched with nutrients, essential oils and antioxidant compounds. However, the RBO industry in Indonesia remains limited, partly due to a lack of comprehensive information on the properties of black RBO. This research aims to characterise the physico-chemical properties and fatty acid profile of black rice bran oil (Oryza sativa L. 'Black Sembada'), a local black rice cultivars widely cultivated in Sleman, Yogyakarta. The characterisation of RBO includes measurement of density, yield, water content, acid value, saponification value and peroxide value. Fatty acid profiles were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The results showed that the yield of Sembada Hitam RBO ranged from 11.537-28.887 % with a water content 0.017-0.49 %, density between 0.920-1.027 g mL^-1, acid value 79.203-86.427 mgKOH g^-1, saponification value 167.450-199.723 mg KOH g^-1 and peroxide value 5.953-118.233 mEq kg^-1. The fatty acid profile was dominated by palmitic acid (14.58 %), oleic acid (43.44 %), linoleic acid (37.52 %), and stearic acid (2.08 %).

Virtual Tracing of DFR mRNA and Protein Variabilities Trace the Ancestral Origin of Vitis vinifera Grapevine Cultivars Across Geographic Regions

Fatchiyah Fatchiyah — 2025-08-22

Various grape cultivars are genetically diverse with challenging genetic variations. However, traditional markers such as SSR and SNP in identifying genetic polymorphism between cultivars are less sensitive for detecting variability between grape plant cultivars. This study aimed to determine the DFR mRNA phylogenetic, protein heatmap, mRNA SNPs, and haplotype network of Vitis vinifera grape cultivars by in silico analysis. DFR mRNA and protein databases of grape cultivars Vitis vinifera and Vitis bellula as outgroups were collected from the NCBI database nuccore. The DFR nucleotide sequences were aligned using the ClustalW method in MEGA-X with default parameters. Heatmaps and SNPs were analyzed by calculating p distances to all taxa aligned on MEGA-X and aligned sequences of Vitis vinifera DFR were analysed with DNASP6 to identify haplotype distribution among cultivars. Based on full-length DFR mRNA sequences, Lambrusco f.f. from Italy followed by three cultivars from France as the initial lineage of the DFR is the most likely ancestor of grapevines, besides Sylvestris as a known grapevine wild-type. The DFR mRNA heat map of sixteen Vitis cultivars shows genetic variants of Lambrusco f.f. from Italy and V. bellula from China which are differences in their respective SNPs. The haplotypes of these two cultivars have adaptive properties that affect trait variation and organism fitness as genetic markers of the genetic diversity of Vitis species. This finding highlighted that Vitis vinifera DFR mRNA and protein sequence variability is highly influenced by gene recombinants, mutations, and environmental factors across plant breeding sites and geographic regions.

Genetic Relationship of 22 Pigmented Rice from Central Java and East Java Based on Simple Sequence Repeat (SSR)

Yeni Avidhatul Husnah — 2025-08-25

Pigmented rice contains distinct bioactive compounds compared to regular white rice. The study aimed to determine the genetic diversity of 22 pigmented local rice varieties originating from East Java and Central Java Province, Indonesia. This research used a PCR-based molecular marker approach utilizing plant pigment marker genes, namely Simple Sequence Repeat (SSR). The research commenced with planting and maintaining the rice plants, DNA isolation according to the cetyltrimethylammonium bromide (CTAB) method, DNA amplification, and PCR visualization, followed by phylogenetic tree construction using PAST 4.0 software. Based on the allele structure analysis, four main clusters of pigmented rice were identified. The identified polymorphisms and clustering patterns provide valuable insights for future plant evolution, breeding, and conservation research. In addition, genetic differentiation suggests a high level within the population. Based on allele structure analysis, black rice shares genetic characteristics with other rice colours, including red, brown, and white. In conclusion, black rice shows the most complex allele structure for colour-related genes among all rice colours.

Diversity of Butterfly in The Segenter Waterfall Eco-Tourism Area, Lombok Island Forest Park, Indonesia

Mohammad Liwa Ilhamdi — 2025-09-01

Segenter Waterfall (SWF) is one of the ecotourism spots in the Nuraksa Forest Park, Lombok, Indonesia that requires conservation efforts to be optimally and sustainably utilised. This necessitates data related to the synecology of important ecosystem components, namely butterflies. Butterflies play an important role in pollinating plants for ecosystem sustainability. This research aims to analyse the diversity of Lepidoptera suborder Rhopalocera at SWF. The research was conducted during January-June 2024 using direct survey techniques with sweeping net. Sampling locations included the downstream watercourse, around the SWF, and the upstream watercourse. The collected data consisted of species richness and the number of individuals per butterfly species. The data obtained were analysed using the Shannon-Wiener diversity index, Evenness index, and Simpson's dominance index. During the observations, we found a total of 24 butterfly species represented by 5 families. The total number of specimens successfully collected was 84 individuals, with Jamides celeno being the most predominant species. The ecological index analysis results showed that H’ = 3.115, E = 0.980, and C = 0.047. This indicated that the diversity of Lepidoptera from the suborder Rhopalocera is considered high. SWF has important value for the community as a source of clean water, tourist destination, conservation centre, cultural ritual site, and environmental education facility. This needs to be maintained so that the SWF area can become a sustainable ecotourism area.

The Biodiversity Assessment of Sediment Community in Balekambang Lake, Dieng Plateau, Indonesia, using Environmental DNA (eDNA) Metabarcoding Approach

Ni Kadek Dita Cahyani — 2025-09-08

A sediment community is vital for the health of the surrounding community. Microbes play an essential role in chemical cycling. Meanwhile, diatoms, unicellular photosynthetic algae found in the water bodies and sediments, are used as water bioindicators for their fast responses to changes in water quality. Assessing the sediment community is crucial to understanding ecosystem dynamic. With the newest technology in DNA identification, this research aims to identify the community in the Balekambang Lake, Dieng Plateau, Central Java, Indonesia. This preliminary study tested the Environmental DNA (eDNA) Metabarcoding method to determine the eukaryotes in the sediment community. This study utilized the High-Throughput Sequencing method to massively identify the organism communities in the sediment, targeting the 18S rRNA gene. This study captured millions of sequences, including Eukaryota, Excavata, Amoebozoa, Opisthokonta, Rhizaria, and Alveolata supergroups. This method identified 14 genera and 13 species of multicellular and unicellular organisms from the Balekambang Lake sediment samples. Although this study could not identify more organism taxa due to a high number of "unidentified" groups in the sampling area, the results show the importance of the eDNA Metabarcoding technique for biodiversity assessment in the sediments.

Optimization of Celullase Production by Molecular Identification Bacterial Isolated, PUA 18 by Using Response Simulation Modelling

Feskaharny Alamsjah — 2025-09-15

Cellulase enzymes are essential for converting cellulose into glucose, enabling sustainable industrial processes. Optimising cellulase production at an industrial scale requires refining microbial strains, growth medium components, and operating conditions. Traditional One-Factor-At-A-Time (OFAT) approaches are limited in efficiency, whereas Response Surface Methodology (RSM) provides a robust statistical tool for evaluating multiple variables simultaneously. This study improved cellulase production from Bacillus subtilis PUA-18, identified through 16S rRNA sequencing, using a combined Design of Experiment (DoE) approach. Screening and optimising were applied by using Plackett Burman Design (PBD) and Box-Behnken Design (BBD), respectively. Temperature was the most influential factor, followed by KNO₃, FeSO₄, and CaCl₂. The predicted maximum cellulase activity of 0.574 U mL⁻¹ was achieved at 40 °C, 1.45 g L⁻¹ KNO₃, 20 mg L⁻¹ FeSO₄, and 50 mg L⁻¹ CaCl₂. The DoE approach yielded a 293 % improvement in cellulase activity, demonstrating its superiority over traditional methods. These findings highlight Bacillus subtilis PUA-18 as a promising cellulase producer and emphasise the critical role of advanced optimisation strategies for enhancing enzyme production, paving the way for broader industrial applications.

Anti-Vibrio Compounds from Digestive Symbiont Bacteria of Whiteleg Shrimp (Litopenaeus vannamei) from Traditional Ponds in Kaur, Bengkulu, Indonesia as Probiotic Candidates for Shrimp Aquaculture

Risky Hadi Wibowo — 2025-08-29

Kaur Regency is one of the areas with high potential for whiteleg shrimp pond cultivation, but it often faces shrimp deaths and crop failure due to infection with pathogenic Vibrio spp. and antibiotic resistance. One alternative preventive is to utilise potential symbiotic bacteria from the digestive tract that can produce anti-Vibrio and enzymatic activities. This study aimed to select potential digestive symbiont bacteria based on their anti-Vibrio ability through isolation, purification, identification, biochemical tests, and anti-Vibrio tests. Candidates showing activity were further tested for toxicity, hemolysin, effectiveness, enzymatic, and molecular identification. Out of 40 digestive symbiont isolates, two Bacillus isolates of the γ-hemolytic type, namely ALF 3 and ALF 6, showed the most potential against seven pathogenic Vibrio spp. isolates (OALF 1, OALF 2, OALF 3, OALF 5, WALF 7, WALF 8, and WALF 10) from the digestive tract and infected whiteleg shrimp pond water, with toxicity percentage of 86.67-100 %, α and β-hemolytic type pathogenicity in BA. Based on their anti-Vibrio activity, amylolytic and proteolytic abilities, ALF 3 and ALF 6 were identified as Bacillus stercoris and Bacillus amyloliquefaciens, respectively, with effectiveness percentages of 89.7-100 % for B.stercoris, 87.7-100 % for B.amyloliquefaciens, and 97.7-100 % for the consortium compared to the treatment without co-culture with potential bacteria against the Vibrio spp. population growth in TCBSA media. This study highlights the potential of whiteleg shrimp digestive symbiont bacteria to enhance immunity against vibriosis while providing safe digestive enzymatic potential for whiteleg shrimp and humans as a potential probiotic candidate.

Diversity of Thermophilic Bacteria Isolated from Extreme Environments in Indonesia: A Perspective in Biotechnology Applications

Dyah Wulandari — 2025-09-12

Indonesia, located along the Pacific Ring of Fire, hosts abundant geothermal sites and hot springs, creating ideal environments for thermophilic bacteria, which are microorganisms capable of thriving at elevated temperatures. These bacteria are recognized for producing thermostable enzymes, including amylases, proteases, cellulases, xylanases, and lipases, which are highly valuable for various industrial applications. This review compiles and analyses the diversity of thermophilic bacteria isolated from 13 geothermal locations across Indonesia, highlighting their enzymatic capabilities and potential applications in biotechnology. Notable genera include Bacillus, Geobacillus, Pseudomonas, Anoxybacillus, and Thermoanaerobacterium. These isolates demonstrate promising roles in bioenergy production, waste treatment, environmental bioremediation, food processing, agriculture, and pharmaceuticals. Additionally, several strains exhibit the capacity to produce bioactive compounds such as antimicrobial agents and natural pigments. The review also details standardized screening methods using selective solid media and outlines molecular identification techniques, including 16S rRNA gene sequencing and whole genome sequencing. Furthermore, it explores recombinant enzyme technologies applied to thermophiles, enabling enhanced expression, activity, and thermal stability of enzymes for industrial processes. Despite Indonesia's extensive geothermal resources, its microbial biodiversity remains largely untapped. This review not only serves as a scientific inventory of thermophilic strains but also emphasizes their relevance for biotechnological innovations. It aims to support future research, bioprospecting strategies, and industrial applications based on Indonesia’s unique thermophilic microbial diversity, ultimately contributing to sustainable technological advancement and resource utilisation.