http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/19538 Fri, 15 May 2026 23:56:58 GMT 2026-05-15T23:56:58Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21700 Title: The family Xeniidae (Octocorallia: Malacalcyonacea) of Vietnam with two new records. Authors: Hoang, Xuan Ben Abstract: Xeniidae is a soft coral family that has contributed to the diversity of tropical coral reef communities, including those found in Southeast Asia. From 50 soft coral samples of the family Xeniidae collected from coastal fringing reefs along the coast of central Vietnam, five species have been recorded belonging to two genera, Xenia (two species) and Heteroxenia (three species). Of five species, two were recorded for the first time in Vietnam are Xenia novaebritaniae Ashworth, 1900 and Heteroxenia elisabethae Kölliker, 1874. An identification key was provided based on colony forms and morphological characters of sclerites for five xeniid corals in Vietnam. Fri, 08 May 2026 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21700 2026-05-08T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21692 Title: Effects of IAA and kin on somatic embryogenesis and the effect of acadian marine plant extract powder content on micropropagule regeneration of the seaweed Kappaphycus striatus. Authors: Vu, Thi Mo; Nguyen, Ky Sanh; Le, Trong Nghia; Tran, Van Huynh; Tran, Mai Duc; Vo, Thanh Trung; Hoang, Nhat Uyen My; Nguyen, Thuy Phuong; Ho, Son Lam Abstract: The objective of this study was to perfect the callus culture method for propagatingKappaphycus striatus.Our research focuses on enhancing somatic embryo (SEs) induction from the callus and micropropaguleregeneration in SEs. In order to enhance the induction rate of SEs, the 16-week-old callus was transplantedinto a semi-solidified PES (0.4% agar) medium supplemented with 0.5–3.0 mg.L-1 3-indoleacetic acid (IAA) and 0.5–3.0 mg.L-1 kinetin (KIN), either alone or in combination. The results showed that the transplantationof the callus into a PES medium containing IAA and KIN (0.5–3.0 mg.L-1), both individually and in combination, significantly impacted the somatic embryogenesis of K. striatus. After 8 weeks of cultivation, the treatment with 1 mg.L-1 IAA + 2 mg.L-1 KIN exhibited the highest embryo induction rate (62.22 ± 5.09%)and the greatest number of SEs (182.00 ± 10.58 embryos/explant) compared to other treatments.Moreover, during the micropropagule regeneration stage, the commercial powdered extract of Ascophyllum nodosum(Acadian Marine Plant Extract Powder, AMPEP) at concentrations ranging from 5 ppm to 50 ppmwas found to enhance the rate of micropropagule regeneration from SEs of K. striatus. The optimalregeneration of SEs of K. striatus into complete micropropagules occurred in an AMPEP medium at a concentration of 20 ppm. Micropropagules cultured in this medium displayed the highest survival rate(75.6 ± 5.09%), number of branches (7.67 ± 0.58 branches/micropropagule), branch length (24.7 ± 1.53; 25 ± 1.00 mm), and fresh weight (173.7 ± 8.14 mg) compared to alternative treatments. Thu, 01 Jan 2026 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21692 2026-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21691 Title: Characteristics of composition, area and status of coral reefs at submerged banks and shoals on the continental shelf of Southern Vietnam. Authors: Nguyen, Van Long; Tran, Van Binh; Thai, Minh Quang; Nguyen, Le Thao My; Marina, Malyutina Abstract: The continental shelf off southern Vietnam, from Khanh Hoa to Ba Ria-Vung Tau provinces, containsnumerous submerged banks and shoals. These locations are considered to have significant potential, notonly for their distinctive landscapes but also for their valuable biodiversity and critical marine resources. Thisstudy was based on the compilation and analysis of data from U.S. Navy nautical charts, Vietnamese maps,and previously published reports from before 2001, combined with GIS techniques to build a 3D underwaterterrain model and calculate the area of 10 specific submerged banks and shoals on southern Vietnam’scontinental shelf. Additionally, coral reef conditions at these sites were assessed alongside biodiversityassessments during May-June 2023. The calculations show that the total area of the 10 submerged banksand shoals was approximately 19,144 hectares. Of these, 9 locations, including Grand Bank, De Thuy TrieuBank, Phan Rang Bay Shoal, Breda Shoal, Hollandias Bank, De Britto Bank, De L Astrolabe Bank, Bishop Bank,and Catwick Bank, had coral reefs distributed over 17,257 hectares. However, coral reefs were absent in thesoutheastern shoal group near La Gan Cape. Overall, coral reefs in these regions were severely degraded,with live coral cover ranging from 5–30%, except for Phan Rang Bay Bank, which had slightly higher coverage(31–50%). Macroalgal coverage was notably high, ranging from 5% to 75% per site. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21691 2025-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21690 Title: Evaluation of heavy metals in green algae Caulerpa lentillifera from Van Phong Bay and the bioaccumulation of copper in different concentrations in the laboratory. Authors: Nguyen, Thi Xuan Thuy; Nguyen, Nhat Nhu Thuy; Le, Trong Dung; Nguyen, Thi My Ngan; Le, Ho Khanh Hy; Dao, Viet Ha; Nguyen, Xuan Vy Abstract: In this study, morphological observation and genetic marker were applied to compare two clones, including natural Vietnamese and introduced clones. 11 elements of heavy metals in the algae collected from three different farms in Van Phong Bay were analyzed. In the laboratory, Caulerpa lentillifera was cultivated in different levels of Cu concentrations to evaluate the ability of Cu bioaccumulation and phytochelatin production of the algae. The results show that the morphological traits of erect frond and stalk between natural Vietnamese clones and introduced clones from Japan revealed significant differences but not ramuli diameter. Based on thetufA gene, there is no genetic differentiation between two clones, and Caulerpa lentillifera, C. germinata, C. cactoides, and C. bartoniae are sister species. The concentrations of Cd, Hg, and Pb from algae in Van Phong Bay were 0.10 (±0.017), 0.12 (±0.015), and 0.58 (±0.02) μg.g-1, repectively. In the seawater with 10 μM, algae showed the highest accumulation with 29.02 μg.g–1 in day 6, indicating the potential impact of the findings on understanding of heavy metal accumulation in marine algae. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21690 2025-01-01T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21689 Title: Heterologous expression and functional characterization of the homologous fucoidanase from Formosa haliotis. Authors: Vo, Thi Dieu Trang; Huynh, Hoang Nhu Khanh; Cao, Thi Thuy Hang; Le, Dinh Hung; Dinh, Thanh Trung; Phan, Thi Hoai Trinh; Ngo, Thi Duy Ngoc; Le, Thi Hoa; Pham, Duc Thinh; Maria, Dalgaard Mikkelsen; Anne, S. Meyer Abstract: Fucoidanases, enzymes that catalyze the degradation of fucoidan—a sulfated polysaccharide from brown algae—have garnered increasing attention for their potential in biomedical, pharmaceutical, and food applications. In this study, we report the heterologous expression and functional characterization of Fhf3ΔSPNW, a homologous fucoidanase derived from the marine bacterium Formosa haliotis. A truncated version of the gene was amplified and successfully cloned into the pET31b(+) vector, followed by transformation into Escherichia coli BL21(DE3) for protein expression. The recombinant protein, with a molecular weight of ~52 kDa, was confirmed using SDS-PAGE and Western blot analysis. Purification using Ni-NTA affinity chromatography yielded high-purity enzyme fractions. Functional assays demonstrated that Fhf3ΔSPNW exhibited specific activity against fucoidan from brown seaweedFucus evanescens, suggesting a preference for substrates with alternating α(1→3)/α(1→4) linkages and moderate sulfation. These findings highlight Fhf3ΔSPNW as a promising candidate for the selective production of bioactive oligo-fucoidans, and contribute to the growing toolbox of homologous fucoidanases for tailored enzymatic applications. Wed, 01 Jan 2025 00:00:00 GMT http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21689 2025-01-01T00:00:00Z