<p>Black tiger shrimps (<em>Penaeus monodon</em>) wereharvested andstored at 0⁰Cfor study. The quality index method (QIM) was developed to evaluate the freshness of black tiger shrimp, and was presented in this study. The terms used to describe all the changes related to the texture, color, and odor are carefully chosen. The development of a QIM scheme included three main steps:A preliminary scheme to evaluate all the changes of attributes related to quality – Final QIM scheme and training – Validation of QIM scheme and comparison estimate the remaining shelf life and actual shelf life. The results show that shelf life of black tiger shrimp in the ice storage is 8 days. Quality score involving attributes decreases during the storage timeand have a correlation close to the linear regression equation. The scheme validation quality of black tiger shrimp by QIM method allows the estimation of the remaining shelf life.</p>

In the present paper, a porous octahedral (ZnO/CuO) composite is synthesized from zinc/copper-based metal-organic framework-199, and its applications in visible-light-driven photocatalytic degradation of dyes are demonstrated. The precursors of Zn-BTC, Cu-BTC, and Zn/Cu-BTC (BTC: benzene-1,3,5-tricarboxylate) were synthesized using a microwave-assisted method. Benzene-1,3,5-tricarboxylate acts as a sacrificial template and was removed from the precursors via thermal decomposition to form CuO, ZnO, and ZnO/CuO. ZnO/CuO with a large specific surface area of 32.5 m 2 ·g -1 is composed of porous octahedral particles of 5-10 μm in diameter. Methylene blue (MB) was utilized as the dye model for photocatalytic degradation reactions. The porous octahedral ZnO/CuO exhibits superior visible-light-driven photocatalytic degradation of MB compared with single CuO or ZnO. The kinetic model of photocatalytic degradation was proposed as ð1/K L Þ × ln C + C = −k r t + ð1/K L Þ × ln C e + C e , where K L is the Langmuir equilibrium constant and C e is the MB concentration at equilibrium. The model significantly fits the kinetic data. In addition, the acquired catalyst manifests excellent photocatalytic degradation for several other dyes including phenol red, methyl orange, and Congo red.

Biopolymer template synthesis has attracted extensive interest for fabricating highly porous metal oxide nanostructures.

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<p><em>Curculigo orchioides</em> Gaertn. is used in traditional medicine in Vietnam. The antioxidant potential of <em>Curculigo orchioides</em> was<em> </em>evaluated through DPPH radical scavenging and total antioxidant capacity method. The data resulted from DPPH radical<em> </em>scavenging activities indicated that <em>Curculigo orchioides</em> displayed the good activities with low IC₅₀value (22.78μg/mL), approximately 1.5 times less than that of curcumin (34.34 μg/mL). The total antioxidant capacity of the extract of <em>Curculigo orchioides</em> contained 132.48 ± 1.48  mg GA/g or  264.45 ± 2.34 μmol AS/g. Content of compounds from Curculigo orchioides including the total phenolic, total flavonoid, polysaccharides, and saponin - triterpenoids were examined using the colorimetric method with reagents. The content of phenolic compounds, flavonoid compounds, polysaccharides, and saponin – triterpenoids found in <em>Curculigo orchioides</em> was  196.24 ± 1.45 mg GAE/g, 78.49 ± 1.78  mg QUE/g, 4.34 ± 0.08 %, 47.60 ± 0.24 mg Rb1/g (Rb1: (Gypenoside III)), respectively. Specifically, the total saponin - triterpenoid content of <em>Curculigo orchioides</em> has been reported for the first time.</p>

Strain Lactobacillus fermentum MC3 isolated from fermented bamboo shoots was used in this study. This isolate had a high exopolysaccharide (EPS) production capability. It was inoculated in the medium with a supplement of various concentrations of carbohydrate source (2, 3, 4, 5, and 6% (w/v)). The mixtures were then cultured under different conditions of initial cell density, temperatures, pH, and incubation time to identify the optimum parameters for the EPS biosynthesis of this strain. The EPS yield was measured using the phenolsulfuric acid method. The results showed that adding glucose, lactose, and sucrose to the culture medium significantly increased the EPS production with a maximum amount of 4% of sugars. The yield was the highest for glucose at 178.207 mg/L, and the obtained figures for lactose and sucrose were 148.614 mg/L and 152.272 mg/L, respectively. The results indicated that the EPS production by L. fermentum MC3 reached the maximum values at 200.728 mg/L in the medium supplemented with 4% glucose at 40 °C, pH 6.0, and initial cell density of 10 6 CFU/mL for 48 h cultivation. By methylation and gas-chromatography mass spectrometry (GC-MS), it was found that the exopolysaccharide is composed of D-mannose, D-glucose, and D-galactose at the molar ratio of 1:0.74:0.09. 10 min, 4 °C). The supernatant was precipitated with two volumes of chilled absolute ethanol.After standing overnight at 4 °C, the resultant precipitate was collected by centrifugation (12 g, 20 min, 4 °C), dissolved in distilled water, dialyzed against distilled water at 4 °C for 24 h, and lyophilized. The total of EPS (expressed as mg/L) was estimated in each sample with the phenol-

Biphenyl 2,3-dioxygenase (BphA) is an enzyme that participates in initiation step of the pathway of biphenyl degradation in bacteria. Biphenyl is an aromatic hydrocarbon including two benzene rings that causes a serious environmental pollution. This report presents the preliminary results on the cloning and expression of BphA gene of B. cepacia strains DF2 and DF4 which were isolated from dioxin contaminated soil in Vietnam. The coding DNA sequences of BphA genes are 897 bp long and 99% identical. Recombinant BphA enzyme (33 kDa) has strongly expressed in E. coli M15 after induction of 0.5 mM IPTG for 4 h at 37ºC.

The present study reports on the cloning, expression and characterization of catechol 1,2dioxygenase (CAT) of bacterial strains isolated from dioxin-contaminated soils in Vietnam. Two isolated bacterial strains DF2 and DF4 were identified as Burkholderia cepacia based on their 16S rRNA sequences. Their genes coding CAT was amplified with a specific pair of primers. Recombinant CAT (rCAT) was expressed in E. coli M15 cells and its activity was confirmed by the detection of cis,cis-muconic acid, a product from catechol, by highperformance liquid chromatography (HPLC) analysis. The rCAT of DF4 had an optimal pH and temperature of 7 and 30ºC, respectively. Metal ions, such as Zn 2+ and Mn 2+ , and surfactants, such as SDS, Tween 20 and Triton X100, strongly inhibited enzyme activity, while K + slightly increased the activity.