TURBIDITY REMOVAL BY MUCILAGE FROM BASELLA ALBA

Coagulation and flocculation are preliminary used in water treatment processes for turbidity removal, using popularily synthetic chemicals with health and environmental concerns. The use of natural flocculants has known to be a promising alteratives for chemical ones due to their environmental friendly behavior. This research investigated turbidity removal efficiency of mucilage extracted from Basella alba - an indigenous species in Vietnam - in the role of a flocculant. The removal efficiency of mucilage was investigated in combination with PAC or Alum on To Lich river water by mean of Jar tests. PAC or Alum alone can remove maximum 97% and 90% turbidity of To Lich river water at its original pH for the sedimentation time of 30 minutes. The combination of mucilage and PAC or Alum increased the efficiencies of turbidity removal and reduced the amount of chemicals needed. The corresponding increases were maximum 7% and 18%, respectively; while the reduction of PAC/Alum used was 75-80%

Drought stress - related functional characterization of transcription factor GmNAC085 in soybean

Studies on soybean GmNAC085 transcription factor revealed that the gene expression in plants was induced by water shortage treatments and its overexpression in the model plant Arabidopsis displayed improved plant tolerance characteristics towards drought stress. In this study, we continued analyzing the biological functions of GmNAC085 using transgenic soybean system overexpressing GmNAC085 gene, by targeting at a number of plant physiological features and biochemical activities in response to limited water growing condition. Compared to the wild-type, the transgenic line demonstrated that it possessed stress tolerance characters, including enhanced elongation of taproot, minimized reduction of shoot growth, lower intracellular H2O2 content and stronger peroxidase enzyme activity under drought condition. The results of this study therefore suggest the transgenic plants had better drought tolerance and the GmNAC085 plays important role in aiding plants to cope with water deficit condition, probably via regulating the growth of roots and shoots, and activities of reactive-oxygen-species- scavenging enzymes

Role of GmNAC019 transcription factor in salinity and drought tolerance of transgenic Arabidopsis thaliana

Increasingly severe drought and salinity stress due to global climate change have made these stresses bigger threats to ecosystem and agriculture. Previous studies reported that GmNAC019, a soybean NAC transcription factor - encoding gene, displayed induced expression upon drought treatment in wild-type cultivars. In this study, drought and salinity stresses were applied on GmNAC019-overexpressing Arabidopsis plants to verify the contribution of GmNAC019 in regulating plant response to the stress conditions. Results from the water loss rate and survival rate assays revealed that the transgenic line conferred improved tolerance to drought stress as evidenced by lower leaf water loss and significantly higher rate of survival than seen in the wild-type plants. Similarly, the survival rate assay for testing salinity effects on plants by growing the plants on MS medium supplemented with different NaCl concentrations also indicated that the transgenic plants had a better tolerance to salt stress as they displayed lower rate of root growth inhibition and higher survival rate. Taken these results altogether, it is suggested that GmNAC019 might play important role in aiding plant response to drought and salinity stresses. Specific functions of this gene should be elaborated in future studies to evaluate its potential application for crop improvement

Growth and development of transgenic peanut (Arachis hypogaea) lines containing chitinase 42 kDa gene from Trichoderma asperellum SH16

Peanut (Arachis hypogaea L.) is vulnerable to many diseases. Vietnam and other regions where peanut is widely cultivated have a high threat of fungal and other plant diseases. Various fungicides are available to control the fungal disease but these have various harmful effects on the natural flora, fauna, and environment. Transgenic peanut lines which possess antifungal activity provide a possible solution in managing fungal diseases apart from the traditional resistance and fungicide usage. Therefore, this study evaluated the probable growth and development of chitinase transgenic peanut lines against Sclerotium rolfsii, a pathogen that causes “southern blight” in plants, under greenhouse conditions. This study provided evidence that through Agrobacterium itumefaciens mediated transformation, 42 kDa chitinase genes from Trichoderma asperellum, which is under the regulation of 35S promoter, were successfully incorporated into the peanut’s (A. hypogaea L.) genome and expressed in their plants. This evidence also demonstrated that transgenic peanut lines were suitable for growing and developing in the greenhouse. Further, it was reported that transgenic peanut lines took approximately 133 to 145 days from planting to maturity. These results also revealed that various growth characteristics of transgenic peanut lines having two synthetic genes (syncod Chi42-2 i.e. S2-2, S2-4, S2-6, and syncod Chi42-1 i.e. S1-1, S1-2, S1-3) were greater than that from the wild-type Chi42 (WT-1, WT-2, and WT-3). In addition, yield-related parameters including the number of mature pods, 100 pods weight and 100 seeds weight for all the transgenic peanut lines were higher than that of the non-transformed plant. Among the transgenic lines, line S2-4 exhibited significantly higher growth and yield than the other transgenic lines. These results demonstrated that 42 kDa chitinase genes overexpressing peanut lines could be a candidate for improvement against plants to phytopathogenic fungus S. rolfsii and high yield.

Factors Affecting Cooperation in the International Supply Chain of Seafood Enterprises: the Case of Vietnamese

Purpose: The purpose of this research is to analyze and evaluate factors affecting cooperation in the international supply chain of Vietnamese seafood enterprises.   Theoretical framework: Operations in international business context are associated with high risks, so cooperation in supply chain helps to improve management flexibility. On the other hand, acccording to the theory of resource dependency, resource sharing and information sharing strategies can affect the quality and the level of cooperation among supply chain partners.   Design/methodology/approach: To achieve the aim of this study, a literature survey related to supply chain and supply chain cooperation is carried out, and empirical analysis is conducted among 327 partners in seafood industry with the results analyzed using Cronbach’s Alpha analysis, exploratory factor analysis (EFA), and linear regression analysis (RA).   Findings: Research results have confirmed that there are six main factors directly affecting the international supply chain cooperation of Vietnamese seafood enterprises including: (1) Trust; (2) Power; (3) Distance; (4) Government policy; (5) Cooperation strategies and (6) Information sharing.   Research/Practical & Social implication: The encouraging policies and simplified export regulations are to be implemented by the government, VASEP and enterprises so the knowledge about international supply chain cooperation will be promoted with the help of comprehensive future research directions.   Originality/value: This is literally one of the first research works in Vietnam to incorporate the information sharing component into the model of affecting factors for international supply chain cooperation. Regardless of business uncertainties, the study shed new light on supply chain cooperation and promote firms to gain an edge in the global marketplace

A Novel Thermostable Cytochrome P450 from Sequence-Based Metagenomics of Binh Chau Hot Spring as a Promising Catalyst for Testosterone Conversion

Biotechnological applications of cytochromes P450 show difficulties, such as low activity, thermal and/or solvent instability, narrow substrate specificity and redox partner dependence. In an attempt to overcome these limitations, an exploitation of novel thermophilic P450 enzymes from nature via uncultured approaches is desirable due to their great advantages that can resolve nearly all mentioned impediments. From the metagenomics library of the Binh Chau hot spring, an open reading frame (ORF) encoding a thermostable cytochrome P450—designated as P450-T3—which shared 66.6% amino acid sequence identity with CYP109C2 of Sorangium cellulosum So ce56 was selected for further identification and characterization. The ORF was synthesized artificially and heterologously expressed in Escherichia coli C43(DE3) using the pET17b system. The purified enzyme had a molecular weight of approximately 43 kDa. The melting temperature of the purified enzyme was 76.2 ◦C and its apparent half-life at 60 ◦C was 38.7 min. Redox partner screening revealed that P450-T3 was reduced well by the mammalian AdR-Adx4-108 and the yeast Arh1-Etp1 redox partners. Lauric acid, palmitic acid, embelin, retinoic acid (all-trans) and retinoic acid (13-cis) demonstrated binding to P450-T3. Interestingly, P450-T3 also bound and converted testosterone. Overall, P450-T3 might become a good candidate for biocatalytic applications on a larger scale

H2_{2}O2_{2} production in Lactobacillus strains isolated from the intestinal microbiome of healthy people

Lactobacillus sp. in the digestive tract are capable of producing H2O2 to inhibit the growth of harmful bacteria and balance the gut microflora. In this study, we have isolated 115 strains of Lactobacillus spp. from stool samples of healthy people in Ha Noi. Of the 50 tested Lactobacillus strains, 9 strains were capable of producing H2O2, of which the Lac.VFE-14 strain produced highly H2O2 with a concentration of 2.183 mM, followed by Lac.VFE-08 strains (2.081 mM) and Lac.VFE-04 (2.067 mM). All three strains grew well in MRS medium supplemented with bile salts or adjusted to low pH value. With 0.3% of bile salt, the survival rates of these 3 strains were 99%, 95% and 97%, respectively. At pH 3.0, after 3 hours of cultivation, the survival rates of the three strains were 98.54%, 94.15% and 95.27%, respectively. In addition, each of the cell-free culture supernatants of these three strains that inhibit the growth of S. aureus ATCC-23235. The inhibition zone diameters of the three strains were 19.0±1.0 mm, 14.0±1.0 mm and 11.7±1.3 mm, respectively. The results of 16S rRNA gene analyses showed that Lac.VFE-14, Lac.VFE-08 and Lac.VFE-04 had high similarity scores with L. plantarum ZZU 23 (100%), L. rhamnosus JCM 1136 (99%) and L. plantarum S7 (98.65%), respectively. This study indicates that all three strains have the potential to be used as probiotics in the future. 

Prevalence of Antibodies against Avian Influenza A (H5N1) Virus among Cullers and Poultry Workers in Ho Chi Minh City, 2005

Background: Between 2003 and 2005, highly pathogenic avian influenza A (H5N1) viruses caused large scale outbreaks in poultry in the Ho Chi Minh City area in Vietnam. We studied the prevalence of antibodies against H5N1 in poultry workers and cullers who were active in the program in Ho Chi Minh City in 2004 and 2005. Methodology/Principal Findings: Single sera from 500 poultry workers and poultry cullers exposed to infected birds were tested for antibodies to avian influenza H5N1, using microneutralization assays and hemagglutination inhibition assay with horse blood. All sera tested negative using microneutralization tests. Three samples showed a 1:80 titer in the hemagglutination inhibition assay. Conclusions/Significance: This study provides additional support for the low transmissibility of clade 1 H5N1 to humans, but limited transmission to highly exposed persons cannot be excluded given the presence of low antibody titers in some individuals. © 2009 Schultsz et al.published_or_final_versio

Ventilator-associated respiratory infection in a resource-restricted setting: impact and etiology.

BACKGROUND: Ventilator-associated respiratory infection (VARI) is a significant problem in resource-restricted intensive care units (ICUs), but differences in casemix and etiology means VARI in resource-restricted ICUs may be different from that found in resource-rich units. Data from these settings are vital to plan preventative interventions and assess their cost-effectiveness, but few are available. METHODS: We conducted a prospective observational study in four Vietnamese ICUs to assess the incidence and impact of VARI. Patients ≥ 16 years old and expected to be mechanically ventilated > 48 h were enrolled in the study and followed daily for 28 days following ICU admission. RESULTS: Four hundred fifty eligible patients were enrolled over 24 months, and after exclusions, 374 patients' data were analyzed. A total of 92/374 cases of VARI (21.7/1000 ventilator days) were diagnosed; 37 (9.9%) of these met ventilator-associated pneumonia (VAP) criteria (8.7/1000 ventilator days). Patients with any VARI, VAP, or VARI without VAP experienced increased hospital and ICU stay, ICU cost, and antibiotic use (p < 0.01 for all). This was also true for all VARI (p < 0.01 for all) with/without tetanus. There was no increased risk of in-hospital death in patients with VARI compared to those without (VAP HR 1.58, 95% CI 0.75-3.33, p = 0.23; VARI without VAP HR 0.40, 95% CI 0.14-1.17, p = 0.09). In patients with positive endotracheal aspirate cultures, most VARI was caused by Gram-negative organisms; the most frequent were Acinetobacter baumannii (32/73, 43.8%) Klebsiella pneumoniae (26/73, 35.6%), and Pseudomonas aeruginosa (24/73, 32.9%). 40/68 (58.8%) patients with positive cultures for these had carbapenem-resistant isolates. Patients with carbapenem-resistant VARI had significantly greater ICU costs than patients with carbapenem-susceptible isolates (6053 USD (IQR 3806-7824) vs 3131 USD (IQR 2108-7551), p = 0.04) and after correction for adequacy of initial antibiotics and APACHE II score, showed a trend towards increased risk of in-hospital death (HR 2.82, 95% CI 0.75-6.75, p = 0.15). CONCLUSIONS: VARI in a resource-restricted setting has limited impact on mortality, but shows significant association with increased patient costs, length of stay, and antibiotic use, particularly when caused by carbapenem-resistant bacteria. Evidence-based interventions to reduce VARI in these settings are urgently needed

Molecular Characterization of HIV-1 CRF01_AE in Mekong Delta, Vietnam, and Impact of T-Cell Epitope Mutations on HLA Recognition (ANRS 12159)

To date, 11 HIV-1 subtypes and 48 circulating recombinant forms have been described worldwide. The underlying reason why their distribution is so heterogeneous is not clear. Host genetic factors could partly explain this distribution. The aim of this study was to describe HIV-1 strains circulating in an unexplored area of Mekong Delta, Vietnam, and to assess the impact of optimal epitope mutations on HLA binding.We recruited 125 chronically antiretroviral-naive HIV-1-infected subjects from five cities in the Mekong Delta. We performed high-resolution DNA typing of HLA class I alleles, sequencing of Gag and RT-Prot genes and phylogenetic analysis of the strains. Epitope mutations were analyzed in patients bearing the HLA allele restricting the studied epitope. Optimal wild-type epitopes from the Los Alamos database were used as reference. T-cell epitope recognition was predicted using the immune epitope database tool according to three different scores involved in antigen processing (TAP and proteasome scores) and HLA binding (MHC score). with a Vietnamese specificity held by two different haplotypes. The percentage of homology between Mekong and B consensus HIV-1 sequences was above 85%. Divergent epitopes had TAP and proteasome scores comparable with wild-type epitopes. MHC scores were significantly lower in divergent epitopes with a mean of 2.4 (±0.9) versus 2 (±0.7) in non-divergent ones (p<0.0001).Our study confirms the wide predominance of CRF01_AE in the Mekong Delta where patients harbor a specific HLA pattern. Moreover, it demonstrates the lower MHC binding affinity among divergent epitopes. This weak immune pressure combined with a narrow genetic diversity favors immune escape and could explain why CRF01_AE is still predominant in Vietnam, particularly in the Mekong area