Vietnam Journal of Biotechnology

Sâm Ngọc Linh (Panax vietnamensis Ha et Grushv.) là loài đặc hữu của Việt Nam được phát hiện tại vùng núi Ngọc Linh (Kon Tum/Quảng Nam). Kết quả khảo sát cho thấy những vùng đất có tầng mùn dày là nơi có điều kiện lý tưởng cho cây sâm Ngọc Linh sinh trưởng và phát triển. Chính vì vậy việc tìm hiểu về khu hệ vi sinh vật nói chung, vi khuẩn phân giải cellulose nói riêng trong đất trồng sâm là một trong những hướng đi tiềm năng cho nghiên cứu trồng di thực loài sâm này của Việt Nam. Từ mẫu đất trồng sâm Ngọc Linh tại Quảng Nam, chúng tôi đã phân lập được 05 vi khuẩn có hoạt tính phân giải cellulose (kí hiệu QN1, QN2, QN3, QN4, QN5 với kích thước vòng phân giải đo được trên môi trường chứa cơ chất CMC (0,1%) tương ứng đạt: 10, 11, 22, 7, 22 mm), hoạt tính cellulase đạt lần lượt là 1,31; 1,23; 2,99; 0,99; 2,51 U/ml. Kết hợp nghiên cứu một số đặc điểm nuôi cấy/sinh hóa và phân tích trình tự gen 16S rARN đã xác định vị trí phân loại của các vi khuẩn phân lập được như sau: QN1 và QN4 thuộc chi Pseudomonas; QN2, QN3 thuộc chi Bacillus; QN5 thuộc chi Roseomonas.

In recent years, the research and discovery of antioxidants of natural origin, such as those found plants, have increased dramatically. Ellagic acid is a bioactive compound found in many fruits and vegetables, which carries many biological activities, such as antioxidant, anti-inflammatory, anti-cancer and antibacterial activities. However, the low solubility of ellagic acid in water decreases its practical application. In this study, a complex of ellagic acid with hydroxypropyl-cyclodextrin was synthesized in the water-ethanol solvent. The results showed that the solvent with a volume content of EtOH of 20% was the most suitable for complex formation, with complexation yield of 46%. The complex was characterized by FTIR, DSC methods. The infrared spectrum of the complex is similar to that of HP-β-CD, however, the intensity and position of some oscillations in the complex have changed significantly, compared to spectra of EA and HP-β-CD. The sharp adsorbance band at 3475 cm-1 of the O-H bond of EA was not observed in the spectrum of the complex, indicating that the O-H group participated in the bonding and covered by the hollow cavity of the HP-β-CD molecules. The DSC curve of the complex shows that the melting points of EA and HPβCD in the complex are declined in terms of temperature and intensity. This is evidence that there is a complex interaction between EA and HPβCD. The complexation improved the solubility and antioxidant activity of EA. Especifically, the solubility of EA was increased by 3.2 times compared to raw EA; EC50 value of EA was reduced from 5.3x10-5 to 4.9x10-5mol. L-1 after complexation.

Dicarbonyl/L-xylulose (DCXR) was identified as a dehydrogenase. This type of enzyme was presented in various forms of lives including bacteria, fungi, plants and animals. Generally, it converts L-xylulose to xylitol in the presence of either cofactor NADH or NADPH in vitro. Previous studies reported the biochemistry properties and crystal structure but largely uncovered biological roles of DCXRs. It was impossible to dissect the functions in mice or human cells that had many DCXR homologs in their genomes. Interestingly, the wild-type Caenorhabditis elegans, a well-known model organism in biological research, has only nuclear genomic dhs-21 that encodes a unique homologous DCXR. Thus Ce.dhs-21 and the host C. elegans were relevant for investigation of the physiologically-vital functions of the DCXR. This research aimed to the expression of dhs-21 in vivo. We defined three promoters , manipulated three relative reporter-constructs that conjugated the dhs-21 gene and Green Flouresent Protein (known as GFP) one. The construct vectors were transferred into wild-type C. elegans N2 and as well as the hermaphroditic loss of function dhs-21(jh129) by microinjection. In the results, we found that the expression pattern of dhs-21 under the only p2-promoter construct was stable and similar to immunogold Electric Microscopy (EM) images. The dhs-21 gene was expressed in both sexes of at all larval stages till the deaths of worms. DHS-21 was expressed in the cytosol of the intestinal, gonad sheath and uterous seam cell (utse).

Medicinal plants have been widely explored for hairy root culture and their secondary metabolites. Hairy root is the potential source of natural compounds for generating pharmaceutical, cosmetic and food products. The current study focuses on root biomass production using transgenic technology whichl contribute to yield major sources of root biomass of Ngoc Linh ginseng. There are several advantages of culturing Ngoc Linh ginseng hairy roots in reducing drawbacks of micropropagation system such as low yield and plant growth regulator residues. In this study, Agrobacterium rhizogenes strain (ATCC 15834) mediated transgenic hairy roots of Ngoc Linh ginseng were rapidly multiplied in 3 liter bioreactor (Korea) containing 1.5 liters of SH medium and 50 g/l sucrose. Results indicated that transgenic hairy roots (with initiate fresh weight of 7.5 g) reached the maximum biomass yield of approximately 5 g dried weight with the total saponin content of 0.72% after 8 weeks of culture. Qualitative and quantitative analyses also showed that the hairy roots consisted of the three main saponin (Rg1, Rb1 and MR2). Among the two dose treatments (1.38 g/kg and 2.76 g/kg) and the control treatment (distill water), mice administered the extract from transgenic hairy root for 7 days continuously at the dose of 1.38 g/kg could prolong the swimming time up to 160.36 min and swimming time rate 455.71%, significantly higher when compared with the other treatment and the control. This result indicated that the transgenic hairy root of Ngoc Linh gingseng cultured in vitro has the enhancing effect on physical endurance of the animals tested.

Scutellaria barbata D.don is a medicinal herb that is widely distributed in Vietnam. In the traditional medicine, this plant is efficient in treating cancer patients. Thus, the plant gained much attention of researchers. Recently, the two novel neo-cleodane compounds which are scutebata S and scutebata T has been isolated from Scutellaria barabata D.don of Vietnam (Thao et al., 2014). These compounds showed fair cytotoxic activity on different tested cancer cell lines. In this study, the antioxidant activities and immunomodulating properties of scutebata S and T were evaluated. The results indicated that both scutebata S and scutebata T reduced the lipid peroxidation and protected liver cells against H2O2. However scutebata T possessed stronger activities than those of scutebata S. At the concentration of 100 µg/ml, scutebata T resulted 16.07% inhibitory effect of lipid peroxidation and maintained the hepatocyte viability up to 76.21% in compared with H2O2 alone (54,74%). The immunomodulating properties of these compounds were assessed throught the proliferation of lymphocytes and macrophage cellular lysosomal enzyme activity. Scutebata S inhibited the proliferation of lymphocytes at all study concentrations. Whereas, scutebata T stimulated lymphocyte proliferation and enhanced cellular lysosomal enzyme activity of macrophages at concentrations in the range of 0.08 µg/ml/ml to 20 µg/ml. Therefore, scutebata S and T demonstrated their positively immunomodulated activities at in vitro level.

Breast cancer is the most frequently diagnosed cancer in women globally. The tumor microenvironment plays a vital role in epithelial-to-mesenchymal transition (EMT), leading to the invasion and metastasis of cancer cells. The tumor microenvironment includes all components of the tumor cells, including the extracellular matrix, tumor vasculature, mesenchymal stem cells, immune cells, and fibroblasts. Understanding the interactions between mesenchymal stem cells and cancer cells is essential in determining the role of mesenchymal stem cells in diagnosing and treating breast cancer. In this study, we present the result of co-culture between adipose tissue mesenchymal stem cells (ADMSCs) and breast cancer cells (MCF-7 cell line) and determine the expression levels of transcription factors involved in EMT, including Twist and Snail. The results showed that the proliferation of MCF-7 co-cultured with ADMSCs was not increased compared to MCF-7 mono-cultured. Determination of gene expression levels by qRT-PCR revealed a significant increase in the EMT-related transcription factors (Twist and Snail) in breast cancer cells upon co-culture with ADMSCs. There were also significant differences between the expression levels of IL-6 and AhR in MCF-7 cells co-cultured with ADMSCs and MCF-7 cells mono-cultured. The results suggested that ADMSCs promoted the EMT of MCF-7 cells, potentially via AhR/NF-κB pathways.

In this study, genes encoding chitinaseswere obtained by mining the rhizosphere metagenome database of 2-year-old replanted coffee trees in Dak Lak province and annotating using CAZy data. These sequences predictably are covered 90% of chitinase domains by BLASTp and range from 33% to 99% identity in comparison with published sequence data of chitinase genes. In order to find new funtional chitinase gene(s), among 8/56 chitinase genes with sequence identity less than 75%, ChiA_2 sequenceshowed the highest max score andsignificant homology (72%) was initially selected. Analysis of in silico sequence identified a protein motif for a signal peptide of 30 amino acid residues at the N- terminal using SignalP 4.1 server. By InterProscan software, the ChiA_2 gene sequence is predicted to have conserved active site FDGIDIDWE located at 134-142. The ChiA_2 sequence consisting of 1167 nucleotides, encoding for 389 amino acids with a predicted molecular mass of 43 kDa was synthesized, cloned into the pET21 a(+) vector and transformed into E. coli BL21 (DE3) by heat shock. ChiA_2 protein was specifically expressed in the recombinant E. coli BL21 (DE3) cell with an activity of 4.9 U/ml. In this study, analyzing metagenomic data from the soil sample of rhizosphere provided relatively sufficient genetic information of chitinase gene and initially successful expression and functional evaluation of ChiA_2 sequence, encoding Chitinase 2.

In this study, eukaryotic microbial communities associated with coral Acropora formosa and its natural surroundings, sediment and seawater, in a coral reef ecosystem of Whale Island, Nha Trang Bay, Vietnam were investigated. First, genetic material was taken from Acropora formosa’s surface mucus layer (SML) as well as the sediment underneath and seawater above the colonies from four different sampling locations in a coral reef ecosystem. Subsequently, the data were sequenced using 18S rRNA gene amplicon sequencing method. Sequences (reads) were then analyzed in Rstudio version 4.2.0. Bioinfomatic tools such as DADA2 pipeline clustered the sequences into amplicon sequence variants (ASVs), to which the taxonomy was assigned using SILVA 132 database. The majority of the sequences was categorized at the kingdom and phylum levels, but fewer sequences were identified at genus and species level. The visualization of the results revealed changes in abundance and composition of the eukaryotic communities in all samples. The results demonstrated that phylum Dinoflagellata had the highest relative abundance in coral samples. Meanwhile, Ochrophyta was the most prevalent phylum in seawater samples. Notably, after filtering out the sequences with abundance less than 2%, only genus Symbiodinium appeared significantly in coral samples. The composition of samples from coral sampling sites was more consistent. The same was true for samples of seawater, whereas the composition of sediment samples varied more. Alpha and beta diversity indices confirmed that there were significant differences (p < 0.05) in abundance and composition of eukaryotic communities among three different habitats. These findings come as the first effort to explore the diversity of eukaryotic communities in different habitats and could be valuable for further study in functional profiling or metabolic functions of microbial communities in the coral ecosystem.

In the current paper, random amplified polymorphic DNA (RAPD) markers were used to evaluate genetic of native Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) derived from Ngoc Linh mountain (area of Kontum and Quang Nam provinces) and acclimatized plants cultured in Bidoup national park (area of Lam Dong province). PCR products were electrophoresed on a 1.5% agarose gel and showed 93 monophorphic bands and 5 polymorphic bands (5.1 %). Out of 15 primers screened, OPA-05 and OPB-14 produced a single monomorphic band whereas OPA-13 resulted in no band pattern. The electrophoresis of PCR products of RAPD markers were scrored in a binary matrix and then used to generate genetic matrix using NTSYSpc 2.1 software. This similarity matrix was then used for clustering of the genotypes by SAHN of the software by UPGMA (unweighted pair group with arithmetic mean). The results indicated that 10 plants were grouped into 2 clusters: group 1 included 6 plants (LD1, LD2, LD3, LD4 derived from Lam Dong and QN7, QN9 derived from Quang Nam), group 2 included 4 plants (KT5, KT6 derived from Kontum and QN8, QN10 derived from Quang Nam) with similarity coefficient of 0.9820 and 0.9762, respectively. 12 remain primers were used to evaluate genetic stability of regenerants obtained through somatic embryogenesis. The data showed that there were no visually detectable differences in phenotype were observed between 32 somatic embryo derived plantlets. The plantlets were successully transferred to the nursery garden with the survival rate above 60 %. The results indicated the usefulness of somatic embryogenesis in mass propagation of this precious and economic medical herbal with high genetic stability.

Scanning electron microscope (SEM) is a popular tool used for observing bacteria surface and morphology. Using Pseudomonas aeruginosa as a model, this work aimed to show a SEM preparative procedure that is simple and economical but does not result in considerable data loss. This was accomplished via testing fixing ability of 10% formalin versus 2.5% glutaraldehyde, efficiency of air drying versus t-butyl alcohol drying method. Following that, polypropylene, dialysis tubing and agar were also assessed for their ability to serve as a supporting material for cell adhesion in preparing sample for SEM. Consequently, obtained data showed that the procedure using 24-hour 10% formalin fixation and t-butyl alcohol drying preserved well bacterial morphology. With this procedure, little cell or membrane damage was seen while extracellular structures were clearly observed. Furthermore, when this procedure was applied with different types of substrates including polypropylene, dialysis tubing, and agar, it showed that sample fixed on polypropylene maintained well extracellular structures meanwhile sample fixed on agar presented well bacterial morphology. In conclusion, our data suggested that coating samples on polypropylene, followed by 24-hour 10% formalin fixation and t-butyl alcohol drying was appropriate for observing bacteria under SEM.