Journal of Tropical Biodiversity and Biotechnology

Nypa Palm Frond Degradation Utilizing Cellulolytic Lactic Acid Bacteria Isolated from Nypa Palm Worm (Namalycastis rhodochorde)

Rikhsan Kurniatuhadi, Tri Rima Setyawati, Ari Hepi Yanti, Albertus Williem — Tue, 08 Apr 2025 00:00:00 +0700

Cellulolytic lactic acid bacteria isolated from the gastrointestinal tract of nypa palm worms, namely NrLtC2, NrLtC4, and NrLtG2, exhibited cellulase enzyme activity in vitro. Cellulose degradation ability testing began on nipa palm frond fibers with variations in LAB type treatment and starter bacteria concentration (2%, 3.5%, and 5%) for 30 days. The results showed that the NrLtG2 bacterial isolate exhibited superior degradation ability compared to the other two isolates, resulting in a decrease in cellulose content of 20.14-26.39%. In contrast, the NrLtC2 and NrLtC4 isolates demonstrated lower degradation ability, with a range of 12.50-15.63%.

Protein Isolation and Purification of Sea Cucumber (Holothuria sp. and Stichopus sp.) from Sepanjang Beach, Yogyakarta

Budi Khoiri Ardiansyah, Tri Rini Nuringtyas — Fri, 25 Apr 2025 08:48:40 +0700

Holothuria sp. and Stichopus sp. at Sepanjang Beach, Yogyakarta were studied for protein isolation. The crude protein concentrations in the body wall and intestine of Holothuria sp. were 2.42% and 2.13%, while Stichopus sp. had 4.03% and 4.01%, respectively. Proteins identified through SDS-PAGE analysis included collagen, softenin, and actin. Purified protein concentrations in Holothuria sp. were 3.72 ± 0.04 μg mL⁻¹ (body wall) and 4.09 ± 0.05 μg mL⁻¹ (intestine), while Stichopus sp. had 3.98 ± 0.08 μg mL⁻¹ and 9.34 ± 0.48 μg mL⁻¹, respectively. This study supports nutraceutical development, identifying potential health-enhancing supplements and drugs.

Evaluation of Krusty/Homer and SPG1/SPG2 Primer Pairs in Identification of Six Begomoviruses Commonly Found in Indonesia

Mon, 28 Apr 2025 13:39:04 +0700

Fourteen symptomatic crops and weeds from Magelang, Klaten, Sleman, and Bantul Regencies were tested against begomoviruses using Krusty/Homer and SPG1/SPG2 primer pairs. The acquired nucleotide sequences were involved in phylogenetic analysis which clustered isolates into six species. Furthermore, three recombinant isolates were also identified. Protocol for molecular characterization of prevalent begomoviruses using both primer pairs was initiated in this report. Molecular data of the obtained 14 isolates added important information on the genetic diversity of Indonesian isolates.

Characteristics of Habitat and Diet of the Southern River Terrapin (Batagur borneoensis) in the Conservation Area on the Coast of Aceh, Indonesia

Abdul Latif Mawardi, Teuku Hadi Wibowo Atmaja, Muhammad Khalil — Fri, 02 May 2025 09:51:12 +0700

The Southern River Terrapin (Batagur borneoensis) is an endangered aquatic species with a critically low population, found only in specific habitats. Surveys revealed that it forages, basks, and mates in freshwater to brackish rivers, while nesting occurs in sandy coastal areas. Its diet consists of crustaceans (41 %), vegetation (41 %), and gastropods (18 %), indicating a primarily carnivorous diet that includes fruits, flowers, leaves, shoots, and aquatic vegetation. Various crustaceans and gastropods were also observed as food sources. Conservation efforts are essential to preserving its habitat and food supply, ensuring the survival of this endemic species.

Metabarcoding of Freshwater Green Microalgae from Two Urban Streams in the Philippines

Tue, 13 May 2025 00:00:00 +0700

Green microalgae (Chlorophyta) are found worldwide in various environments. Currently, there are few studies on Philippine freshwater green microalgae and traditional identification methods using morphology and life cycle characters are time consuming and may be unreliable. This study used eDNA and Illumina sequencing to sample algal communities in two urban streams situated in a local university campus and found 39 chlorophyte genera. Three markers were used and each marker detected taxa not found by the other markers, suggesting that a multimarker approach might be best for future metabarcoding studies and that other gene markers should be tested for utility.

Whole-Genome Analysis and Tolerance Assessment on Bifidobacteria-like Bacteria Isolated from Breast Milk and Infant Fecal Samples in Indonesia

Fri, 11 Apr 2025 00:00:00 +0700

Probiotics are living microorganisms that can provide health benefits to the host when administered in sufficient quantities. To exert their health effects, probiotics must first be capable of surviving the harsh conditions of the gastrointestinal tract. We decided to sequence whole genomes of Bifidobacteria-like isolates (i.e., BS2-PS1, BS2-PS2, BS2-PB5, and BR2-12) and assess their abilities to resist low pH and bile salt. Molecular identification through whole genome sequencing indicated that the bacteria isolated from human breast milk were identified as Bifidobacterium breve (BS2-PS1 and BS2-PS2) and Lacticaseibacillus paracasei subspecies paracasei (BS2-PB5), whereas the bacteria isolated from infant feces was identified as Lactiplantibacillus plantarum (BR-12). All isolates exhibited resilience upon exposure to bile salts at concentrations of 0%, 0.3%, and 0.5%, with survival observed even at the highest concentration (0.5%) after three hours of incubation. The ability to withstand bile salt was presumably mediated by various genes that encode the resistance, e.g., bsh, cbh, dps, glf, cfa, or nagB, found in genomes of tested isolates. Upon exposure to pH 2 and 5 for three hours, BS2-PS1, BS2-PS2, and BR-12 exhibited acid resistance as well. The ability to withstand low pH could be mediated by the presence of relevant genes, e.g., argC, argH, dapA, pyk, pyrG, as well as genes that encode F₀F₁-ATPase enzyme, such as atpC, atpB, atpE, atpF, atpH, atpA, atpG, and atpD in their genomes. In summary, these results indicated the potential of all isolates to be further developed as probiotic candidates.

Assessing Indigenous Ureolytic Bacteria Isolated from Gua Damai Limestone for Microbially Induced Calcite Precipitation (MICP)

Mon, 14 Apr 2025 00:00:00 +0700

Low porosity and non-aggregated soil are significant global concerns, presenting substantial environmental hazards. This study determined the capacity of native ureolytic bacteria found in limestone to stabilise soil through the process of microbially induced calcite precipitation (MICP). Six pure bacterial isolates obtained from limestone in Gua Damai, Batu Caves, Selangor were qualitatively assessed for urease production. The isolate S4C4, identified as Bacillus tropicus strain NTF4, demonstrated the highest urease activity at 821.654 U mL^-1. This isolate precipitated 37.15 ± 9 mg mL^-1 of CaCO₃ after 96 hours of incubation and XRD analysis confirmed the biocementation of organic soils treated by B. tropicus strain NTF4, primarily forming calcite and vaterites. Significant calcite polymorph presence in soil samples is attributed to a longer treatment duration which promotes crystal development and stability. Harnessing indigenous limestone ureolytic bacteria with high urease activity presents a promising avenue for green soil bio-stabilisation. This approach potentially unlocks sustainable and scalable applications of microbial-induced calcite precipitation (MICP) in large-scale geo-engineering projects.

A Streamlined Plant DNA Extraction Method with Liquid Nitrogen-Free Approach

Fri, 18 Apr 2025 00:00:00 +0700

Molecular technique such as Polymerase Chain Reaction (PCR) is essential in various research fields. The amplification process of plant DNA can be challenging due to the presents of metabolites that can inhibit the polymerase eznyme, as well as expensive procedures or time-consuming laboratory work required. Most of the protocol involved liquid nitrogen, which is not always accessible, especially in laboratories with limited resources. Consequently, this study proposed an alternative protocol free from liquid-nitrogen usage, that was designed to be efficient in the DNA extraction from dry and fresh leaf samples across 40 plant species belonging to 27 different families. The DNA obtained from all the samples showed concentrations greater than 50 ng µL^-1, with the quality indexes in the acceptable range (A260/280: 1.50-2.21, A260/230:0.60-2.20). The efficacy of this method was demonstrated by successful PCR amplification using rbcL primer, validating the DNA suitability. This protocol can be considered a good option to be used both with fresh and dried plant leaves. Moreover, the absence of liquid nitrogen usage in the protocol could decrease the laboratory cost considerably and turning it into a more easily replicable method to be used in laboratories with limited resources.

Identification and Characterisation of Endophytic Bacteria in Rice Bean (Vigna umbellata)

Marjohn C. Niño, Jerome H. Ruiz, Maria Lima D. Pascual — Mon, 21 Apr 2025 00:00:00 +0700

Rice bean (Vigna umbellata) is an underutilised legume with unexplored endophytic microbiome. Identification and characterisation of these endophytes are critical in understanding their roles in plant’s growth, health, and productivity. In this study, twelve morphologically and biochemically distinct bacterial endophytes were isolated from rice bean roots. Sequence analysis of the 16S rDNA of the isolates revealed that members of Proteobacteria, including Stenotrophomonas sp., Shinella sp., Roseomonas sp., Pantoea dispersa, and Serratia marcescens dominated the root tissues of rice bean. The remaining isolates were found to be members of Actinobacteria, Bacteroidetes, and Firmicutes. The in vitro assays showed the potential abilities of the endophytic Stenoprophomonas sp., Shinella sp., Microbacterium gilvum, Serratia marcescens, and Bacillus qingshengii in indole acetic acid production, exopolysaccharide production, and phosphate solubilisation. Overall findings suggest diverse and potentially multifunctional endophytes in rice bean that can be incorporated into agricultural practices and crop improvement programs.

DNA Barcoding, Prey Spectrum Analysis, and Vegetative Propagation of Nepenthes mirabilis × rafflesiana, A Rarely Sighted Pitcher Plant Hybrid from Peninsular Malaysia

Mon, 05 May 2025 00:00:00 +0700

A solitary female Nepenthes hybrid (Nepenthes mirabilis × rafflesiana), bearing 20-cm tall reddish pitchers, was discovered in the last remaining peat swamp forest in Johor, Peninsular Malaysia. The nothospecies (natural hybrid) is considered a very rare occurrence and has been designated as a taxon of high ecological importance, underscoring the urgent need for in-depth study and targeted conservation initiatives. To confirm its genetic identity, DNA sequencing was conducted, and the phylogenetic analysis of the internal transcribed spacer region (ITS1-5.8S-ITS2) indicated a strong genetic relationship between the hybrid (accession no. OR741796) and N. rafflesiana. Consistent with this, the ITS1 secondary structure of the hybrid exhibited a conserved folding structure similar to that of N. rafflesiana. It was recorded that the nothospecies primarily preys on hymenopterans from the family Formicidae, including at least seven genera. Furthermore, mosquito larvae from the genus Toxorhynchites were observed in both upper and lower pitchers, highlighting the pitcher plant's importance as a crucial breeding site for the predatory elephant mosquito. Given that only one living specimen of the nothospecies was discovered, we optimised a shoot-based vegetative propagation method that allowed several clones to be produced, which will be vital for the success of future reintroduction efforts. This is the first report to simultaneously address the molecular, ecological, and horticultural aspects of a Nepenthes natural hybrid in Peninsular Malaysia.

Bioremediation and Detoxification of the Textile Dye Methyl Blue by Trichoderma asperellum LBKURCC1 with Laccase Activity

Fri, 16 May 2025 15:36:28 +0700

Textile production generates effluent contaminated by 10-15 % dyes used. Fungal-mediated remediation presents an ecologically acceptable and inexpensive method for treating dye effluents. Trichoderma asperellum LBKURCC1 isolated from Riau cacao rhizosphere produces laccase. Laccase can catalyse the degradation of several textile dyes. This study aims to investigate T. asperellum LBKURCC1 ability to bioremediate and to detoxify the textile triphenylmethane dye, methyl blue (MB). T. asperellum LBKURCC1 cultures in minimal media with pHs of 4.5, 5.5 and 6.5 were incubated (24 hours, room temperature) with 50-ppm MB solutions. MB decolorisation analysis was conducted by examining the UV-Vis absorption spectra of MB after 24 hours treatment. It was also determined if the degradation was contributed by enzymatic biodegradation or by biosorption processes. The contribution of laccase activity to the bioremediation process was assessed by monitoring laccase activity in fungal treated MB solution. Acute toxicity of MB to Artemia salina larvae was determined pre- and post-fungal treatment. The results showed that decolorisation of MB by T. asperellum LBKURCC1 occurred at all tested pH levels, but at different rates for different pH. The highest decolorisation rate was at pH 4.5 (85 % per 24 hours). Enzymatic biodegradation was the higher contributor to the decolorisation, compared to mycelia biosorption. Laccase activity was induced by MB and the highest activity was found at pH 4.5. MB toxicity to A. salina larvae was eliminated by the fungal biodegradation. This study confirms the potential of T. asperellum LBKURCC1 life cultures in the degradation of MB, eliminating its toxicity.

Bioactivity of Volatile Compounds Present in Crinum zeylanicum Leaf Extracts Identified by GC-MS for the Control of Cercospora malayensis Isolates of Okra (Abelmoschus esculentus L.) In Vitro

Mon, 19 May 2025 14:30:29 +0700

Cercospora malayensis induced leaf spot is a dangerous okra disease that reduces crop yields. The aim of this study is to use leaf extract from Crinum zeylanicum to regulate the growth of Cercospora malayensis in vitro. The pathogen was isolated from okra leaves from the Meyomessala and Akonolinga localities that had typical disease symptoms. Phytochemical screening and GC-MS analysis of C. zeylanicum leaf extracts were carried out. The mycelial growth and germination of C. malayensis isolates 1 and 2 were evaluated with concentrations of 15, 30, 60, and 120 μL mL^-1, fungicide (3.33 g L^-1), and control. Minimum inhibition concentrations (MIC50 and MIC90) were evaluated. The results showed the presence of alkaloids, phenols, terpenoids and sterols in the leaf extracts. In acetone (AcE), methanol (ME) and aqueous (AqE) extracts, 32; 39 and 10 chemical compounds, respectively were found by GC-MS analysis. The most prevalent biochemically active compounds were n-Hexadecanoic acid (35.04 %), Cis-Vaccenic acid (31.76 %), Quinoline-7-carboxylic acid, 2-phenyl-, methyl ester (26.63 %), 9,12-Octadecadienoic acid (Z,Z)- methyl ester (16.89 %) and 9,12-Octadecadienoic acid (Z,Z) (10.83 %). AqE, AcE and ME extracts at 120 μL mL^-1 inhibited 100 % of mycelial growth and conidial germination of isolates 1 and 2 compared to the control. The lowest MICs (MIC50 and MIC90) were 6.79 and 10.98 μL mL^-1 for isolate 1 and 7.48 and 11.22 μL mL^-1 for isolate 2, respectively. C. zeylanicum it is possible to use extracts for their volatile biochemical substances in a C. malayensis control program.

Genetic and Morphometric Variation of the Genus Nyctixalus in Indonesia Based on mtDNA 16S rRNA Gene

Fri, 23 May 2025 09:25:21 +0700

The genus Nyctixalus was first described by Boulenger in 1882. Previous systematic studies of this group primarily focused on its relationships with other rhacophorid frogs and did not explore inter- and intraspecific variation in detail. This study aimed to determine the position of Indonesian species within their genus. We used DNA barcoding of the mitochondrial 16S rRNA gene and conducted a morphological analysis. Mitochondrial genealogies were constructed based on NJ, ML, and BI analyses, while uncorrected p-distance was also calculated. The Mann-Whitney U-test and PCA were used to analyse variations among species for each character component. Dissimilarity may contribute to measurable group structure. DNA barcoding revealed that Nyctixalus forms a monophyletic group. The PCA analysis revealed that N. margaritifer population from Java formed a group, while N. pictus could not be separated on the scatter plot. DNA barcoding revealed that Nyctixalus forms a monophyletic group. The genetic distance within the population of N. margaritifer (0–1.52 %) and N. spinosus (0–0.2 %) showed a variation of intraspecific genetic distance. However, in the two allopatric populations of N. pictus Kalimantan and Sumatra (p-distance = 4.3–4.6 %), there are high variations (6.9–9 %) between populations from Sumatra and Malaysia. These findings suggest that N. anodon van Kampen, 1907, from Kayu Tanam, Sumatra Barat, Indonesia, represents a distinct species from N. pictus Peters, 1871, originally described from Sarawak, Malaysia.

Mandibular Characteristics to Determine Quaternary Proboscideans of Indonesia

Arkanniti Dibyawedha Adisajjana, Donan Satria Yudha — Mon, 26 May 2025 08:42:32 +0700

Proboscideans (order Proboscidea) are a group of mammals known for theirdistinctive proboscis or trunk. During the Pleistocene Epoch, proboscideansthrived globally, including the Indonesian Archipelago. Most taxonomic determination for proboscidean fossils have primarily relied on molar analysis. Mandible analysis to determine Quaternary proboscidean taxa in Indonesia was still rarely utilized, despite their high potentiality. Therefore, this research aims to identify the diagnostic characters of Quaternary proboscideans found in Indonesia based on their mandibular characteristics. Quantitative morphometrical analysis and qualitative morphological observations were conducted in determining the diagnostic characters of each taxon. Mandible specimens of modern Asian elephant (Elephas maximus) were also used as a comparison to fossil specimens. The values obtained by morphometric measurements were then analyzed using the Principal Component Analysis (PCA) method using PAST 4.12b software. In addition, qualitative morphological characters obtained were described to further support the PCA results. The results showed that the mandibles of each taxon observed have their own distinguishable characteristics, thus it can be used to determine the taxa of Quaternary proboscideans found in Indonesia.

Tree Architecture Models of the Syzigium Genus Collection at the Purwodadi Botanical Gardens

Farhani Nurshafa Rahmania, Bayu Agung Prahardika, Rony Irawanto — Mon, 02 Jun 2025 08:56:32 +0700

There are many species of plants in the genus Syzygium. This genus is distinguished by its strong root system, evergreen, sprawling and complex tree crowns and a powerful branching system on the trunk. The vertical structure of Syzygium trees is distinguished by branching a large crown. Based on its characteristics, the genus Syzygium has a great potential in supporting the sustainability of ecosystem balance. The diversity of tree architecture possessed by the genus Syzygium allows Syzygium species to play an active role in soil and water conservation efforts. The aim of this study is to identify various architectural models of trees Syzygium species in the collection of Purwodadi Botanical Garden in order to assess their role in the ecosystem. The method used in this study was to measure the physical characteristics of trees, such as tree height, trunk diameter, and crown area, and to observe the shape of trees, such as stem growth patterns, branching patterns, and direction of branch development. As the result, of the 17 Syzygium tree species selected and in accordance with the research criteria, 7 of them have the Stone model, 3 species have the Scarrone model, 2 species have the Attims model, 2 species have the Petit model, and 1 species each has the Koriba, Massart, and Troll models. Each variation of tree architecture model has different functions to the ecosystem.

Exploring Bivalve Community on the Southern Beaches of Bangkalan Madura Regency, Indonesia

Nadila Nur Rahma Windari, Reni Ambarwati — Thu, 05 Jun 2025 14:11:58 +0700

The southern beaches of Bangkalan Madura Regency are located in the Madura Strait, near the harbour of Surabaya. The areas have various substrates and mangrove vegetation, rich in invertebrates’ diversity such as bivalve. This study aimed to identify the species, to analyse the diversity, and the importance value index of bivalve, as well as to describe the ecological characteristics on the southern beaches of Bangkalan Madura Regency, Indonesia. The sampling was conducted in the intertidal zone of the southern beaches of Bangkalan, namely Rongkang Beach, Kwanyar Beach, and Modung Beach. The quadrant transect method was applied for the sampling process using 270 plots of 1 x 1 m², located at upper intertidal, middle intertidal, and lower intertidal of beaches. Furthermore, samples were identified based on morphological characters and diversity was analysed using the Shannon-Wiener diversity index. The importance value index of each species was calculated and the ecological characteristics of the habitat were analysed by using Principal Component Analysis (PCA). The results showed that the South Beach of Bangkalan Madura Regency had 19 bivalve species from 10 families and 7 orders. Bivalve in this area were diverse, with a diversity index of 2.16. The highest importance value index was Solen sp. at 58.87 % followed by Tegillarca granosa at 30.34 %. Additionally, the PCA results showed that substrate pH, water pH, salinity, temperature, sand of substrate, and clay of substrate affected bivalve community. This showed that the southern beaches of Bangkalan were favourable for bivalve habitat.

Foraminifera Abundance in the Southern Waters of Sumbawa, Senunu Canyon, West Sumbawa, Sumbawa, West Nusa Tenggara

Tue, 10 Jun 2025 00:00:00 +0700

The Southern Waters of Sumbawa, Senunu Canyon, West Nusa Tenggara, is influenced by the Indonesian Throughflow (ITF), crucial for regional marine dynamics. This area also faces impacts from mining tailings discharged into the seabed, raising concerns about their effects on meiobenthic fauna, including foraminifera. This study examined changes in foraminiferal assemblages, abundance, and diversity using 20 gravity core samples from sites NM.021 and NM.023. The results revealed a diverse and abundant presence of foraminifera, with planktonic foraminifera dominating in terms of abundance compared to benthic foraminifera, as indicated by an average P/B ratio exceeding 90 %. Twelve species of planktonic foraminifera and 17 species of benthic foraminifera were identified, with distinct compositions across the sites. At site NM.021, the most abundant benthic foraminifera were Bulimina sp. (23.5 %), Ceratobulimina pacifica (18.7 %), and Hoeglundina elegans (13.3 %), while dominant planktonic foraminiferal taxa consist of Hastigerina pelagica (21.6 %), Pulleniatina obliquiloculata (17.8 %), and Neogloboquadrina dutertrei (17.4 %). At site NM.023, the most abundant benthic foraminifera were Bolivinita quadrilateral (22.3 %) and Ceratobulimina pacifica (21.8 %), while the planktonic foraminiferal taxa showed similar dominance, with Pulleniatina obliquiloculata (20.8 %), Hastigerina pelagica (15 %), and Neogloboquadrina dutertrei (13.3 %) being the most abundant. The study highlights warm, eutrophic conditions with potential upwelling, indicated by planktonic species Pulleniatina obliquiloculata and Neogloboquadrina dutertrei. Additionally, these waters also have low oxygen levels (dysoxic), as evidenced by the presence of benthic species Bulimina sp. and Ceratobulimina pacifica.

Investigation on Nutritional Values of Three Different Ananas comosus (L.) Merr. Species Planted in Vietnam

Son L. Hoang, Thanh N.K. Le, Ngan B. Huynh — Mon, 30 Jun 2025 16:31:58 +0700

This study aimed to evaluate the nutritional values, phytochemicals, antioxidant activity, and anti-nutritional factors of three different pineapple cultivars (Cayenne, Queen, and MD2) cultivated in various provinces of Vietnam. The pineapple samples were collected from many farms ranging from the Central to the South of Vietnam. The analyses were performed as per standard test methods (the European standard and Association of Official Agricultural Chemists - AOAC methods). In general, there were no significant differences in energy-yielding nutrients (carbohydrates, fats, and protein). However, significant differences were observed in vitamin and mineral content. The MD2 cultivar had a high level of vitamin B5 and a low concentration of calcium, whereas both Cayenne and Queen were rich in vitamin C and chlorine. All three studied pineapple varieties exhibited moderate levels of phenolics and flavonoids, low concentrations of bromelain, and weak antioxidants. All three pineapple species studied contained low concentrations of oxalates and a void of tannins. These findings scientifically contribute valuable information to the food database system and can be considered in diet planning.

Partially Purified L-asparaginase with Low Glutaminase and Urease Co-Activities of Bacteria from the Rancabuaya Coast, Indonesia

Fri, 13 Jun 2025 00:00:00 +0700

L-asparaginase, enzyme that can hydrolyses L-asparagine into L-aspartate and ammonia is used as a therapeutic enzyme in treating Acute Lymphoblastic Leukemia (ALL). The use of this enzyme is restricted by the presence of dual substrate specificity towards asparagine and glutamine, which causes side effects. The objectives of this research are to isolate and to identify marine bacteria from Rancabuaya Coast that generate L-asparaginase with low glutaminase and urease co-activity and to produce and to measure the asparaginase activity using the Nessler reagent. Bacteria were isolated from seawater, and screened using Zobell Marine media containing either L-asparagine, glutamine or urea, with phenol red as an indicator. The bacterial isolate with the highest asparaginase activity and relatively lower glutaminase and urease activity, was identified by 16S rRNA gene sequence. This bacterial isolate, RB3, was identified as Pseudoalteromonas tetraodonis GFC with greater than 99 % homology. Enzyme specific activity of crude extracellular and intracellular enzyme were 72.30 U mg^-1 and 67.18 U mg^-1 respectively, while the highest enzyme specific activity from ammonium sulphate fractionation was found at 40-60% saturation (F3), which was 136.03 U mg^-1. SDS-PAGE of the enzyme solutions showed the presence of a 35 kDa band suspected to be the L-asparaginase protein.

Early Event at In Vitro Propagation of PGL-15 Tea Clone

Ratna Dewi Eskundari, Taryono, Taufan Alam, Desty Oktavianingtyas — Mon, 16 Jun 2025 00:00:00 +0700

In vitro propagation is one solution to maintain or even to increase tea’s productivity in Indonesia. This study aimed to obtain early-event information related to in vitro tea propagation using embryo axis and cotyledon of PGL-15 clone. This research was carried out by culturing the explants on MS medium with half strength (½ MS) (A medium); ½ MS + BAP 2 mg L^-1 (B medium); ½ MS + BAP 2 mg L^-1+ GA3 0.5 mg L^-1 (C medium); and ½ MS + BAP 2 mg L^-1 + GA3 0.5 mg L^-1 + eco enzyme 0.1 % v v^-1 (D medium), with five explants per bottle and each treatment was repeated three times. The result showed that the D medium was the best medium in inducing further development of embryo axis and cotyledon explants. Morphological analysis showed that embryo axis explants cultured on the B, C, and D medium seemed better vigour, indicated by the increasing size and blooming of leaf primordial(s). Surface ultrastructure analysis showed that speed development of leaf primordial(s) on embryo axis explant varied among tested explants, depending on the type of the culture medium. For cotyledon in vitro propagation, it showed that at 7 days after culture (7-DACs), the D medium gave the best results in inducing explants for further development. This successful induction of further development of these explants is expected to open possibility of its multiplication in large quantity and its application for further research on tea plant.