Rosmarinic acid production in cell suspension cultures of Ehretia asperula Zollinger & Moritz

Plant cell cultures provide an alternative means for producing secondary compounds in food, cosmetic and pharmaceutical industries. Ehretia asperula Zollinger & Moritzi is used as a traditional medicine for the treatment of liver detoxification, ulcers, tumors, inflammation and enhancing the body's resistance in Vietnam. The study was carried out to select suitable callus line for cell suspension cultures of E. asperula Zollinger & Moritzi and investigate the effects of inoculum size, rotation speed and naphthalene acetic acid (NAA) on the proliferation of cell suspension cultures. In addition, the influence of light intensity on the growth and rosmarinic acid (RA) biosynthesis of cell suspension was also surveyed. After 4 weeks of culture, the white to pale yellow friable callus expanded significantly with a fresh weight (FW) of 0.788 g and a high RA content of 2.062 mg/g FW. An appropriate medium for cell proliferation was the liquid B5 medium, which contained 30 g/l glucose, 0.1 mg/l benzyl adenine (BA) and 0.4 mg/l NAA. The results also demonstrated that a 1:20 ratio (w/v) inoculum size, darkness and rotation speed of 90 rpm were the optimal conditions for the proliferation and RA accumulation to 188.217 mg/l in 4 weeks of culture. These findings showed that E. asperula Zollinger & Moritzi cell suspension cultures could be a potential alternative approach for RA production in vitro

Isolation and determination of Vibrio spp. pathogen from Sciaenops ocellatus suffering from hemorrhagic disease under cage culture in Vietnam

This study was carried out to isolate and determine the Vibrio spp. from the Red drum fish (Sciaenops ocellatus) suffering from the hemorrhagic disease in Vietnam.  In this study, 18 strains of Vibrio bacteria were identified from 27 samples of Red drum fish. The isolated bacterial strains were identified with the 16S rRNA sequencing method and checked for morphological, physiological, and biochemical characteristics by using the API 20E KIT. Results of the study revealed the presence of twelve strains of V. alginolyticus, three strains of V. fluvialis, and three strains of V. orientalis. All Vibrio strains have gene similarities with those on the Genbank ranging from 98.05 to 100%. The biochemical characteristics of these 18 isolates were similar and these are susceptible to tetracycline and doxycycline and entirely resistant to ampicillin, amoxicillin, and erythromycin

Use of Inter – Sector Approach in Teaching Specialists in Social Science anh Human in Vietnam – From Historical View

In the current context, with the continuous development of digital technology 4.0 and AI, the social sciences and humanities majors need to change approaches in teaching, transformation and combine multi-method, interdisciplinary in teaching. Approaching from a historical perspective, the article analyzes the transformation and operation of the interdisciplinary approach in teaching and research in social sciences and humanities in Vietnamese universities. The above research results confirm that the interdisciplinary approach in teaching and research in the social sciences and humanities is an inevitable trend in the context of university autonomy in Vietnam and responds to the changing the world today

Development of a diagnostic scar marker for Vibrio shilonii caused acute hepatopancreatic necrosis disease in whiteleg shrimp

Background: In a previous report, we showed that Vibrio shilonii was found on whiteleg shrimp (Litopenaeus vannamei) with acute hepatopancreatic necrosis disease in Thua Thien Hue province, Vietnam. This study was performed to develop a diagnostic molecular marker generated by random amplified polymorphic DNA (RAPD) for V. shilonii rapid detection.Methods: Pathogen Vibrio spp. were isolated from shrimps and fishes, and were identified by 16S rRNA sequencing. Genetic diversity of Vibrio strains was analysis by RAPD technique. Specific PCR product for V. shilonii was cloned and sequenced. SCAR marker was developed from specific PCR product.Result: Twenty random primers were evaluated for RAPD to identify DNA polymorphisms between Vibrio species. The random primer OPN-06 generated a 468-bp DNA fragment specific for V. shilonii. This was then converted into a sequence-characterized amplified region (SCAR) marker designated N6-441.Conclusion: Specific primers (Vshi-441F/Vshi-441R) amplified a unique DNA fragment in all V. shilonii isolates but not in the other Vibrio spp. This PCR assay showed significantly sensitive to the target DNA and reliably for the amplification the V. shilonii genome.Keywords: AHPND; RAPD; SCAR; Vibrio shilonii; Vietna

Constituents from stem barks of Anacolosa poilanei Gagnep. (Olacaceae)

Four compounds were isolated from the stem barks of Anacolosa poilanei Gagnep. Theirs structures were established by spectroscopic analysis including MS and NMR. Accordingly, the isolates were identified as trichadenic acid B (1), trichadonic acid (2), amentoflavone (3) and β-sitosterol (4)

Optimization of culture conditions of Streptomyces antibioticus strain 1083 to improve the antimicrobial activity against Aeromonas hydrophila

Fish is a healthy, high protein and low fat food that encourages the health and growth of people, especially children. However, in fact fish is very sensitive to many diseases which affects the productivity and quality of fish. Therefore, identifying the cause of the diseases and finding preventive measures become an urgent task today. In the previous study, we isolated Streptomyces antibioticus strain 1083 that has the ability to antagonize Aeromonas hydrophila - a pathogenic bacterium in fish. Based on the obtained results, we continue to perform this study to determine optimal conditions for the culture of S. antibioticus strain 1083 in order to produce antimicrobial compounds against A. hydrophila. The production of antagonists by the strain 1083 was optimized by controlling the condition of different inoculations such as media, pH, temperature and incubation period. The results indicated that International Streptomyces Project 2 (ISP2) was the best medium for S. antibioticus strain 1083 to produce the highest antimicrobial activity against A. hydrophila with 32 mm in diameter of inhibited zone. The actinomycete strain 1083 could express the maximum antimicrobial activity when they were incubated in shaker incubator (200rpm) at 40oC with pH8 in 8 days. The ability of the actinomycete strain in antagonism against A. hydrophila was evaluated by adding different culture medium volume of S. antibioticus strain 1083. With adding 10% cultured solution volume of S. antibioticus strain 1083 into the culture medium of A. hydrophila, after 1 day of inoculation the number of pathogenic bacteria cells were completely eliminated

COMPARISON EFFICACY OF ITS AND 18S rDNA PRIMERS FOR DETECTION OF FUNGAL DIVERSITY IN COMPOST MATERIAL BY PCR-DGGE TECHNIQUE

Through composting process, biosolid wastes are gradually transformed into compost material which can be used as soil fertilizer. Among microorganisms involved in composting process, fungi play important roles because they break down complex substrates, such as ligno-cellulose. Recently, PCR-DGGE technique has been considered as a useful tool for analysis of fungal diversity in environmental samples. Among other factors, primer set selection is necessary for successful of the PCR-DGGE analysis. There are several PCR primer sets targeting fungal variable regions of 18S ribosomal DNA (rDNA) and internal transcribed spacer (ITS) for the use in community analyses, however there exist just few reports on efficacy of these primers in studying fungal communities in compost materials. In this study, four different primer sets were tested, including EF4/Fung5 (followed by EF4/NS2-GC), EF4/ITS4 (followed by ITS1F-GC/ITS2), NS1/GC-Fung, and FF390/FR1-GC. Extracted DNA from compost materials often contains co-extracted humic substances and other PCR inhibitors. Therefore, the primers were tested for (i) tolerance to the PCR inhibitors presenting in the DNA extracted from compost materials, and (ii) efficacy and specificity of the PCR. The results showed that of the four primer sets, only FF390/FR1-GC achieved both criteria tested whereas the other three did not, i.e. primer EF4/ITS4 had low tolerance to PCR inhibitors, primers EF4/Fung5 was low in PCR amplification efficacy, whereas primers EF4/ITS4 created unspecific products. DGGE analyses of PCR products amplified with the primer set FF390/FR1-GC showed single bands for reference pure cultures Penicillium sp., Aspergillus sp., and Trichoderma sp., as well as distinctly separated bands for the fungal communities of three different composting materials. Thus, the primer set FF390/FR1-GC could be suitable for studying structure and dynamic of fungal communities in compost materials

Prospects of Blended Learning Implementation at FPT University Can Tho, Vietnam

Drawing on the evaluations of students’ attitudes toward learning aspects the mixed-method research aims to examine the prospects of Blended Learning at FPT University in Can Tho. Four hundred sixty-seven students partook in the study by providing answers for a 30-item questionnaire with open-ended questions. The results showed that most students have positive attitudes towards factors constructing their Blended Learning adaptability, including (1) Study Management and Online Learning, (2) Classroom Learning, and (3) Learning Flexibility. The results of Binary Logistic Regression also clarified the good promise of Blended Learning implementation and the discovery of other concerns that hindered informants’ willingness, namely Worriment about Learning Effectiveness, Online Learning Barriers, and Learners’ Ego. The research findings served as a reference for FPT University and other higher institutions to better grasp how students perceive Blended Learning to develop strategies for successful practices