http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/4 2026-07-18T02:13:01Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21789 Title: The biomass characteristics of Hydropuntiaeucheumatoides (Harvey) in the tidal beach of Hon Rua Island, Nha Trang Bay: potential source for exploitation, culture, and food processing. Authors: Vo, Thanh Trung; Tran, Mai Duc; Vu, Thi Mo; Dang, Xuan Cuong,; Le, Trong Nghia; Tran, Van Huynh Abstract: The study of biomass characteristics of Hydropuntia eucheumatoides (Harvey) (local name in Vietnam, Rong Cau chan vit) in Hon Rua - Nha Trang bay is a comprehensive study of its resources. The results of the study have described in detail the morphological characteristics, reproductive organs, weight and coverage of its in quadrat and habitats. As a result, other has successfully stored seaweed algae under laboratory condition for 30 days. The results can be shown that determined the appropriate harvesting time and direction to exploit and conserve resources and propagate this seaweed. In addition, the main chemical and carbohydrate components of this seaweed have also been identified which has shown great potential for their application in the processing of high value food and medicine products in Vietnam in the future. 2026-07-16T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21788 Title: Endophytic actinomycetes from mangrove plant Avicennia marina in Quang Ninh province, Vietnam: distribution, cytotoxicity, and antioxidant activities Authors: Quach, NgocTung; Bui, Thi Lien; Vu, Thi Hanh Nguyen; Nguyen, Thi Thu An; Chu, Hoang Ha; Phi, Quyet Tien Abstract: Mangrove endophytes have recently gained considerable attention due to their diversity and abundance of novel bioactive secondary metabolites. Despite the fact that Streptomyces species are producers of more than 75% of commercialized antibiotics, Streptomyces associated with the extremely widespread mangrove plant Avicennia marina remain poorly characterized. In this study, nine actinomycetes were isolated from A. marina growing in a mangrove forest, as yet unexplored, of Quang Ninh province, Vietnam. Phylogenetic analysis of actinomycetes-specific 16S rRNA sequences indicated that they were subjected to five Streptomyces species including Streptomyces cacaoi, Streptomyces californicus, Streptomyces enissocaesillis, Streptomyces coelicoflavus, and Streptomyces variabilis, which have not been previously reported in mangrove plants. Among them, S. cacaoi AM1 showed strong inhibition effects against six tested pathogenic bacteria with inhibitory zones ranging from 7.5−22.3 mm. Using standard 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, 100 µg/mL ethyl acetate extract of AM1 showed potent cytotoxicity against breast cancer MCF-7 and lung cancer A549 cell lines with cell viability of 16.5 ± 1.28% and 17.69 ± 2.3%, respectively. As for antioxidant activities, AM1 extract exhibited strong antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical (92.4 ± 0.004%) and superoxide anion radical (42.4 ± 0.019%), which were positively correlated to high polyphenol (84.3 ± 3.4 µg GAE/g FW) and flavonoid (34.9 ± 4.8 µg QE/g FW) contents. These findings indicated that S. cacaoi AM1 could be a promising reservoir of antibacterial, anticancer, and antioxidant agents. This is the first report of mangrove endophytic Streptomyces derived from A. marina. 2026-07-16T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21787 Title: The myriapod fauna (Chilopoda, Diplopoda) of the Truong Sa (Spratly) archipelago, Vietnam. Authors: Le, Xuan Son; Le, Xuan Dac; Ngo, Trung Dung; Dinh, The Dung; Nguyen, Duc Hung; Nguyen, Duc Anh Abstract: This paper provides the first data on myriapods in the Truong Sa archipelago (Vietnam). A total of 292 myriapod specimens identified 9 species in 7 genera, 6 families, 5 orders of two classes Chilopoda and Diplopoda were collected from 10 islands in the Spratly archipelago of Khanh Hoa province in Vietnam including Southwest Cay (Song Tu Tay), Sand Cay (Son Ca), Namyit island (Nam Yet), Grierson Reef (Sinh Ton Dong), Sin Cowe island (Sinh Ton), Pearson Reef (Phan Vinh), Central Reef (Truong Sa Dong), Spratly island (Truong Sa), West Reef (Da Tay), and Amboyna Cay (An Bang), , , during two surveys in October–November 2020 and May–June 2021. The class Chilopoda has 276 specimens of seven species, 6 genera, 5 families in three orders (Scolopendromorpha, Geophilomorpha, and Lithobiomorpha); The class Diplopoda has 16 specimens of 2 species, 2 genera, and 2 families in two orders (Polydesmida and Spirobolida). Among the recorded species, Rhysida longipes (Newport, 1845) were commonly recorded on all islands. 2026-07-15T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21783 Title: Optimization of brine shrimp lethality test for in vivo toxicity evaluation of poisonous plant species collected from Quang Tri province. Authors: Nguyen, Chi Mai; Nguyen, Tuong Van; Pham, Thi Hoe; Vu, Huong Giang; Ninh, Khac Ban; Tran, My Linh 2026-07-15T00:00:00Z http://tvhdh.vnio.org.vn:8080/dspace/handle/123456789/21773 Title: Effect of culture densities on maturation and spawning of the Portuguese oyster (Crassostrea angulata). Authors: Vu, Van Sang; Le, Tat Thanh; Cao, Truong Giang; Vu, Van In Abstract: The Portuguese oyster(Crassostrea angulata) is a mollusc species with many advantages forculture such as fast growth, and high economic importance. However, spat quality and quantityhave not met the needs of farmers, leading to unstable annual oyster yield. To improve thespawning efficiency of oyster, we carried out an experiment to evaluate the effect of rearingdensities on the maturation and spawning capacities of the Portuguese oyster broodstock,C. angulata. The experiment was evaluated with three rearing densities of 50, 80 and 100 individuals/m3. The results showed that there were no significant changes in the parameters of theenvironmental factors among three rearing densities (P > 0.05). At a density of 50–80 individuals/m3, survival after 30 days was > 84% and the percentage of oyster matured andspawned was 76−78%. Therefore, this is an essential reference basis for commercial spatproduction or mass selection program of C. angulatawhere there are more males and femalesinvolved in mating. 2025-01-01T00:00:00Z