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• Study onin vitroApplication of Silver Nanoparticles inLeaf Propagation of Globe Amaranth(Gomphrena globosaL.)

  Bui Thi Thu Huong, Dong Huy Gioi

  Date Received: 10-06-2020 / Date Accepted: 19-08-2020

   Abstract PDF (VIETNAMESE)

  Globe amaranth(Gomphrena globosaL.) is one of the beautiful flowers and is popularly grown in Vietnam and many worldwide countries. The objective of this study was to assess the effect of nano silver on the in vitropropagation of Globe Amaranthfrom leaves. The different concentrations of silver nanoparticles (2, 4, 6, 8 and 10ppm) were added to the culture medium at all stages of the tissue culture. The results showed that the callus induction mediumsupplemented with 4-6ppm of nano silver gave the callus formation rate to reach 100%, callus were ivory white, soft and spread across of sample surface after 4 weeks of culturing; the callus of Globe Amaranthwas cultured in shoot regeneration medium supplemented with 4ppm of nano silver for the best shoot generation effect, the shooting rate reached 100%, the average number of shoots was 5.32 shoots/callus, the average height of shoots reached 2.36cm; the highest number of shoots per explant (8.36) was found onshoot multiplication medium supplemented with 6 ppm of nano silver; the root induction mediumadded with 8 ppm of nano silver gave rooting rate of 100%,the average number of roots was 4.08 roots/shoots, the root length reached 4.16cm after 4 weeks of culturing.

• Selecting Suitable Disinfection Method for Tissue Culture of Seaweed (Kappaphycus alvarezii)

  Pham Thi Mat, Le Thanh Tung, Nguyen Thi Duyet, Nguyen Van Nguyen

  Date Received: 08-02-2025 / Date Published: 21-02-2025

   Abstract PDF (VIETNAMESE)

  This study evaluated the effective method of disinfecting the sample surfaces at varying concentrations of bactericidal agents to produce axenic materials for Kappaphycus alvarezii micropropagation. The experiment was conducted with 3 types of bactericidal agents including (1) sodium hypochlorite solution at concentration of 0.25% for 5 seconds, (2) pure Sigma antibiotics at concentrations of 0.5%, 1% and 1.5% for 48 hours, (3) nano silver solution at concentrations from 100 to 1000 ppm for 5 minutes. The research results showed that using sodium hypochlorite solution to prevent bacterial contamination in K. alvarezii was the best disinfection method. The samples treated by sodium hypochlorite solution produced high rate of axenic explants (86.67%), highest rate of callus induction (94.44%) and good callus quality. For treatment of pure antibiotics and nano silver solution, when the concentration was higher, the axenic sample rate was higher but the survival rate and the callus induction rate were lower. The antibiotics with a concentration of 1.5% gave lowest callus rate (41.11%) and highest (54.44%) at a concentration of 0.5%. The concentration of nano silver solution at 1000 ppm gave the lowest callus rate (45.56%), while the 100 ppm formula had the highest callus rate (71.11%) but the lowest clean sample rate (only 12.22%).

  DOI: https://doi.org/10.1234/3vhwm882

• Testing the Antiprotozoal Potential of Nanosilver Against Ichthyophthirius multifiliis on Snakehead Fish (Channa argus)

  Le Viet Dung

  Date Received: 25-08-2020 / Date Accepted: 01-10-2022

   Abstract PDF (VIETNAMESE)

  This study evaluated the efficacy of nano-silver (NS) for treatment of disease caused by I.multifiliisin snakehead fish (Channa argus) both vitroand vivoexperiments. A series of NS concentrations (0, 0.1, 0.5, 1, and 1.5 ppm) was tested on the parasitic stage (Trophont) and reproductive stage (Tomont). In vitrotesting results showed that NS was effective in killing germs in both trophont and tomont stages. The pathogen mortality was highest at 1.5 ppm NS; after 12h the mortality rate was 95.45 and 98.15% for trophont and tomont, respectively. All snakehead fish (3g) in the 7-day in vivoexperiment died at treatments of 1.5, 1 and 0 ppm NS on the 1st, 1st, and 6thday, respectively. The survival of fish in the 0.1 and 0.5 ppm treatments was 63.3% and 33.3%, respectively, on the 7thday. Hence, the NS might have killing effects on trophont and tomont but also toxic effects on 3-g snakehead fish.

• Experimental Study on Combining Nanosilver and Florfenicol in the Treatment of Aeromonas veroniiDisease on Channel Catfish (Ictalurus punctatus)

  Nguyen Thi Dung, Le Viet Dung, Kim Van Van, Truong Dinh Hoai

  Date Received: 17-12-2020 / Date Accepted: 01-03-2022

   Abstract PDF (VIETNAMESE)

  This study aimed to evaluate the antibacterial potential of florfenicol and nanosilver combination for the treatment of bacterial infection caused by Aeromonas veronii in channel catfish. The susceptibility of A. veroniito nanosilver and the antibiotic florfenicol was evaluated in vitrovia measurement of inhibited zone based on the diffusion methods. The in vivoexperimental treatment was performed by challenging healthy Channel catfish at LD50 and by feeding with the supplement with different formulations of florfenicol and nanosilver. The results of in vitroexperiments showed that the combination of 10ppm florfenicol and 5ppm nanosilver resulted in the inhibited zone comparable to that of conventional use of antibioticflorfenicol (15ppm). After 7 days of treatment, the combination of florfenicol and nanosilver antibiotics had a similar therapeutic effect compared to those using antibiotics alone.

• Evaluation of the Inhibitory Effect of Plasma Silver Nanoparticles on Streptococcus agalactiae Caused Disease in Tilapia and the Disinfection Efficiency in Experimental Treatment Protocols

  Truong Đình Hoài, Dang Thi Hoa, Tran Thi Trinh, Nguyen Duc Chinh, Dang Huu Anh, Nguyen Thị Hương Giang, Vu Thi Hao, Le Thi Hau, Do Hoang Tung

  Date Received: 07-02-2025 / Date Published: 21-02-2025

   Abstract PDF (VIETNAMESE)

  Nanosilver plasma, a new material created through the electrochemical silver plasma method, is believed for its higher potent antimicrobial activity against different types of bacteria. However, its application in aquaculture has yet to be extensively researched. This study evaluated the efficacy of nanosilver plasma in eliminating pathogenic bacteria Streptococcus agalactiae in tilapia, aiming to lay the groundwork for its practical use in disease prevention and treatment in aquaculture. Nanosilver plasma was examined for its capacity to inhibit bacterial growth under in vitro conditions, its safety on fish and its disinfection capability in experimental treatments. The research results demonstrate that nanosilver plasma at concentrations of 0.25, 0.5, and 1 ppm inhibited 97.8%, 99.9%, and 100% of S. agalactiae, respectively, under in vitro conditions and was entirely safe for tilapia when used for soaking and sterilization. Nanosilver plasma at 0.5ppm exhibits antiseptic capabilities comparable to BKC (0.5ppm) and Glutandehyl (0.05ppm) in treating diseases caused by S. agalactiae in tilapia, alongside the antibiotic amoxicillin(40 mg/kg fish) under experimental conditions.

  DOI: https://doi.org/10.1234/be7xzt07

• Identification of Fungi and Bacteria Causing Postharvest Decay on Litchi Fruit and Development of Control Measures

  Ha Viet Cuong, Tran Thi Dinh

  Date Received: 10-03-2016 / Date Accepted: 16-05-2016

   Abstract PDF (VIETNAMESE)

  Litchi (Litchi chinensis Sonn), a specialty fruit, has an appealing natural red color, high nutritional value, and pleasant flavour. However, it is highly perishable and has a very short postharvest life due to microbial decay. This study aimed to identify the microorganisms causing postharvest decay on litchi fruit and to develop the control measures to inactivate them in vitro. Results on artificial infection and DNA sequencing demonstrated that Gluconobacter oxydans and Lasiodiplodia pseudotheobromae are the major cause of post-harvest diseases on litchi. Results on development of control measure showed that carbendazim inhibited Gluconobacter oxydans better than Lasiodiplodia pseudotheobromae. Nano silver could completely inhibit Gluconobacter oxydans and Lasiodiplodia pseudotheobromae at 10 ppm and 15 ppm, respectively. In conclusion, nano-silver effectively controlled the growth of pathogens on litchi after harvest.