Hội nghị sinh học quốc gia: Những vấn đề nghiên cứu cơ bản trong sinh học: Báo cáo khoa học. Hà nội, 2000

A new species isolated from a leaf of Litsea Euosma J. J. at Cuc Phuong National Forest

A ballistoconidiogenous yeast strain, isolated from a leaf of Litsea euosma J. J. Sm. at Cuc Phuong National Forest of Ninh Binh, Vietnam, was assigned to the genus Kockovaella based on morphological and chemotaxonomical characteristics by the reproduction of ballistoconidia, non-ballistosporous stalked conidia and budding cells, Q-10 as the major ubiquinone, and the presence of xylose in the cells. The phylogenetic tree was constructed based on the sequences of 18S rDNA in 1613 bases between VY-61 with 45 species of the genera Bullera, Cryptococcus, Fellomyces. Kockovaella and Udeniomyces by the neighbour-joyning method.

A preliminary study on seagrasses in the Truong Sa archipelago

In this paper, the authors have made a list of seagrass species, based on analyses of more than 20 seagrass specimens, obtained during the field surveys in 1995 (conducted at Nam Yet and Son Ca Islands), in 1996 (Thuyen Chai Islalld, Menzies and Scarborough Shoals) and in 1999 (Thuyen Chai and Phan Vinh Islands). The list included 7 species, belonging to 2 families: Halophila ovalis, Halophila sp., Thalassia hemprichii (Fam. Hydrocharitaceae), Cymodocea serrulata, C. rotundata, Halodule uninervis, Thalassodendron ciliatum (Fam. Cymodoceaceae). Among them are the 2 dominant species Thalassia hemprichii and Halophila ovalis with a higher frequency of occurrence.

A study of protective ability against radiation of lingshi mushroom Ganoderma Lucidum Kast. on some kinds of cells of white mice mus musculus l.

Microscopic and ultramicroscopic structures of some kinds of cells such as hepatocytes, splenocytes, epitelium cells of intectine, testicle cells were studied. The obtained results show that the microscopic and ultramicroscopic structures of the cells of radioactively controlled mice were seriously destroyed, even with low dose. The microscopic and ultramicroscopic structures of the cells of experimental mice (the medicine - drunk mice) were recoved, even after radiation with high dose (750R).

A study on the biology of the Abalone (Haliotis Ovina Gmelin, 1791)

Data obtained from investigation carried out from May 1995 to May 1998 show that: Suitable environmental parameters for H. Ovina are Salinity: more than 30% and steady. Bottom temperature: range from 24-30°C, normally more than 26oC. Clean and circulated water. In addition, the natural food of H. Ovina is mainly algae species belonging to Phaeophyceae and some species of Rhodophyceae, Chlorophycaea and Diatomaceae. During culture, Sargassum, Gracillaria, Ulva, Kappaphycus alvaregii and Laminaria were used to feed the abalone. Haliotis Ovina breed all the year round but most intensilely from April to August.

Analysis of genetic variability of Dunaliella (Cholorophyta) by RAPD-PCR technique

Genetic variability of four Dunaliella species were investigated by polymerase chain reaction (PCR) using random amplified pholymorphic DNA (RAPD) primers. 36 bands were reproduced with four random primers. Among of them, 31 bands (86.1 %) were polymorphic and 5 ones (13.9 %) were monomorphic. Based on the similarity coefficience, relationship among these 4 species was analysed and they could be classified into two groups. The significantly genetic variability between D. bardawil and D. sanila has not been clear, however.

Assessing rodent diversity in tropical forests ecosystem

The paper dealt with high diversity of rodent species in relation to structural complexity of habitats including vegetable and geography belonging to 6 studied areas. There were 27 known species in Hoang Lien Son, 22 species in Pumat, 11 species in Nui Ba-Bidoup natural reserves, 18 species in Houng Son, 10 species in Mau Son and 23 species in Kon Ha Nung forests. Data showed predominant species in each area. For example, Niviventer confucians is common in Hoang Lien Son, N. langbianis and Maxomys surifer in Pumat. Chirodopomys gliroides and Leopoldamys sabamus at 1250m elevation in Huong Son. The results also indicated that human activities have strongly effects on the distribution and relative abundance of rodents in each area. Some recommendations coud be discussed for government and local authorities to improve a better management of biodiversity in natural reserves.

Assessment of diversity of flora in dry ecosystem on limestone mountain in Vietnam

In the paper, results of survey on biodiversity of vegetation of dry ecosystems on limstone hills in Vietnam (Phong Nha, Cuc Phuong, Hoa Binh, Na Hang, Ba Be and Cat Ba) are reported. Diversity of taxa, life-forms and phytogeographical elements are analyzed and evaluated. The paper also discussed about following surveys in the future to find measures for conservation and covering the open limeston hill areas.

Autioxidant effects of green bean (Vigna Radiata) in Vietnam

Chemical components of green bean were analyzed. The chemical component of tegument of green bean is falconoid (Vitamin and isovitexin). Protein have been found in the total green bean. MDA tests exert that green bean have antioxidant effect. Autimutagenic and antiteratogenic studies were carried out with bone marrow and testicular cells of mice (Mus museulus). The antioxidants of green bean exert in all biological tests. Autioxidants of tegument of green bean were analyzed.

Biodiversity in Hoan Kiem lake of Hanoi

In the history, Hoan Kiem lake is a residual part of one branch of the Red River. The lake is a famous historical place of Hanoi capital. Over past many years, the Environmental condition of Hoan Kiem lake has changed because of urban development. The research subject is carried out in the year of 1998 and 1999 in order to study the biodiversity of Hoan Kiem lake on three directions: water, sediment biodiversity and microalgae.

Biodiversity of scorpions in the Vietnam

8 species of scorpions were fount in the Vietnam, among them 3 species from family Buthidae, 5 species from Scorpionidae. Scorpion development have 5 times of larval molt, colour and size of body from larvae to adult have been differentiated. Almost discovered species of scorpions in the Vietnam have no sexual dimorphism as species Isometrus basilicus Karsch.

Bird colonies in the Mekong river delta of Vietnam

All bird colonies in the Mekong Delta are considerably important for waterbirds in Vietnam. This paper described the current status of these bird colonies, which have current been found in this region.

Characteristics of purple non-sulfur photosynthetic bacteria isolated from waste water in Hanoi area

Group of 90 bacreria were isolated from waste water in Hanoi area. The article found that they could grow photoheterotrophically. Under anaerobic - light conditions the color of cell suspension of them were purple-red, orange-brown, pinkish. The intracytoplasmic membrane of checked isolates were of the lamella type. In vivo absorption maxima at 375, 591, 804 and 863 NM indicated the presence of bacteriochlorophyll a. Most of them were not able to grow with Na2S as sole photosynthetic electron donor, 5 starch-utilizing isolates and 1 gelatin liquefying were found. All of the isolates were gram negative. The cell shape were rod, ovoid-rod, spiral with cell width ahout 0.8-1.0 um. These results indicated that all isolates were purple non-sulfur photosynthetic bacteria.

Characteristics of recombinant trichobakin

The paper presented the purification and characterization of active recomhinant trichohakin a type1 RIP from Trichosanthes sp. Bac Kan 8-98. The results of SDS-PAGE and electrospray ionization mass spectrometry showed that the protein has molecular mass of ahout 27 kDa. It was found that the protein can inhihit luciferase mRNA translation in the rabbit reticulocyte cell-free system with IC50 value of ahout 3.5 pM. The rRNA N-glycosidase activity of the protein was also proved at the above-mentioned concentration after rRNAs were treated with acid aniline. As it was shown hy the results of LD50 determinations on chicken embryo, the recombinant trichobakin can inhihit Gumboro virus by the Neutralization Index of ahout 10-1.58.

Characterization of lectins and nutritious proteins in relation to the diversity of Leguminous species (Fabaceae)

The relationship between lectins and reserve proteins from leguminous species was studied. The obstained results have pointed out that the content of total reserve proteins from 19 leguminous species is varied from 1 7.84% to 35.25%. The aminoacid composition of proteins is well - proportioned. The lectins from 4 species were purified and N-terminal aminoacid sequences of lectins from Canavalia ensiformis, Canavalia gladiata and Phaseolus vulgaris DB5 (Kidney bean) were determined. These results indicate that natural molecular lectins modification may be the evolutionary marker.

Cloning and expression of mosquito-larvicidal toxin gene of bacillus thuringiensis israelensis isolated in Vietnam

The cryIVA gene coding 130 kDa protein of Bacillus thuringiensis israelensis VN6 isolate has been cloned. Partial DNA sequences the 3.8 kb insert revealed that nucleotid sequence of cloned gene is simillar to that of cryIVA gene reported in acesion No D00248. The cryIVA gene expressed in Escherichia coli employing the pKK expression system. The expressed protein is readily visible in acrylamide gel stained with coomassieblue. The recombinant E. coli cells expressing high toxic protein towards Aedes aegypti (LC50: 0.0096mg/l, LC90: 0.0028mg/l).

Cloning and sequencing of a gene encoding ribosome inactivating protein from bittergourd (Momordica charantia)

Total genomic DNA was extracted from leaves of Vietnamese bitterground (Momordica charantia) and used for PCR amplification of a gene encoding rihosome inactivating protein (RIP). The PCR product was cloned into pBluescript (KS) vector and sequenced. The 801 bp sequence obtained codes for 264 amino acids of the mature RIP. It has 97.9% homology at nucleotide level and 94.8% similarity at amino acid level with those of the gene coding for MAP 30.

Cloning of 18S rRNA fragment from four entomopathogenic nematode strains (Steinernema and Heterorhabditis genus)

Total geneomic DNA was extracted from four entomopathogenic nematode strains: Steinemema TK10, S. THO, S. TL and Heterorhabditis MP11). Fragments of their l8S rRNA genes were amplified hy polymerase chain reaction. The 0.25 kb and 0.3 kb PCR products from three strains S. TKl0, S. TL and H. MP11, respectively, have been cloned into pBluescript KS (-) vector. The nucleotide sequence of the later strain has up to 86 % homology to those of known Heterorhabditis species indicating that it might be a new one.

Cloning of 18S-rRNA gene from Stephania plants for molecular systematics studies

The tubers of Stephania plants (Family Menispermaceae) are used in traditional medicine and content various alkaloids with antiinflammatory, antiallergic, immunomodulatory and other therapeutic activities. The alkaloid composition and their corresponding activities depend on the species. Seven to eleven species of the Genus Stephania have been descrihed in Vietnam. However, their identification by classical melhods is difficult and their phylogenetic relalionships are not understood. Using PCR technique, 18S-rRNA gene fragments from Stephania plant samples 83HT and 37MC were amplified.

Compare biodiversity of mammals in National Parks and Reserve of Vietnam's North

In the National Parks and Reserves on North-East of Tonkin and Ben En national park on the North of Truong Son North there are 65 mammal species belonging to 23 families and 8 orders in Ba Be National Park; 83 species (26 families, 9 orders) in Na Hang reserve; 62 species (21 families, 7 orders) in Tam Dao; 60 species (23 families, 8 orders) in Ba Vi; 71 species (24 families, 8 orders) in Cuc Phuong; 21 species (17 families, 9 orders) in Cat Ba and 62 species (25 families, 9 orders) in Ben En National Park. 40 species (51%) in these ecosystemes were listed in the Red Book of Vietnam (1992). In these there are the primates endemic species distributing in National Parks and Reserves of Vietnam North. In these National Parks and reserves the gaurs and elephants there are only in Ben En National Park. In Cat Ba National Park has been goldel-headed langur, ocean dolphin and dugong.

Conservation and utilization of Legume germplasm in Vietnam

Plant genetic resources in general, and legume genetic resources in particular, are very rich and diverse in Vietnam. The family Fabaceae consists of 669 species with 3 main components (a) indigenous species; (b) locally adapted species which were introduced before the green revolution, and (c) species introduced after the green revolution. The first surveys on plant species in South China and North Vietnam were conducted in late 1950s and early 1960 by the Council of Botanical Gardens of the former Soviet Union. From 1983 to 1991, Vietnam Agricultural Science Institute conducted 34 trips to 94 districts of 30 provinces and collected 5,516 accessions of crop species and wild relatives belonging to 70 different crop species of which 1,533 accessions belong to 10 species of the Fabaceae.

Contribution to study about the relieving pain and strengthening effect of Python glue on some experimental parameters

The results of study ahout the python glue effection (50mg/100g/day) on the rats and mice (at the diffrent groups of age and sex) are showed that: 1/ Time (s) -the rats are expressed pain in Hot-plate test and the rats s-pain threshold in Randu-Selitto test increase gradually according to observing time. In which, (s) and (g/s) of the python glue -treated, rats more increase than controlled ones (p<0.05) or (p<0.01); 2/ For the python glue-treated mice, the coefficient of strengthening (COS) and the couple of mice with COS(+) is 1.923 +- 0.333 and 14/15(93.33%) respectively; 3/ Time of temporary residing at the shined cage T(second) and percentage of the positive memory rats (PPMR) reduce gradually according to observing time. In which, T and PPMR of the python glue-treated rats less reduce than controlled ones (particulally for the treated femals) (p>0.05).

Determination of the best nutrition and condition medium for the Acetobacter xylinum strains T7 and A24 by planning practice method

Choosing the best nutrition and condition medium for Acetorbacter xylinum T7 and A24, the author used the douhle planing practice method with letter x1, x2, x3. Thus, he has passed the experiment: Saccaroze: 1 %; KH2PO4: 0.5 %; (NH4)2SO4: 0.8 %; pH: 4.5; temperature: 30oC; glucoze 0.12 %, (NH4)2HPO4: 0.06 %; K2HPO4: 0.06 %. The result of experiment shows that the cocconui the maximum value of 26.1 – 26.7 mm with two Acetorbacter xylinum T7 and A24.

Determining anticancer drugs by using human cell culture technique

After being complemented into the growth media of tow cancer cell lines MCF 7, Hep 2 and of the lymphocyte cell line HLT 90 , the anticancer drugs (ACn) extracted from 9 medicinal plans and animals, which are being used as ethnopharmacology, showed their activation as followings: - Four bioactivators AC 4, AC 5, AC 6, AC 8, added to the MCF 7 cell line's growth media. are capabel of inhibiting and killing MCF 7 cells in the dercending order as AC 5>TAM>AC 8>AC 6, AC 4 does not show this ability; - Four bioactivators AC 5, AC 7, AC 8, AC 9 added to the Hep 2 cell line’s growth media, are capabel of repressing and killing Hep 2 cells in the descending order as AC 8 > AC 7> VB > AC 9 = AC 5; - AC 1, AC 2, AC 3 and AC 4 neither inhibite nor kill tow cancer cell lines. AC 1 and AC 2 are able to promote the T lymphocyte's division and Lymphocyte transformation in the descending oder as AC 1 > con A > AC 2.

Developing the cryobanking and embryo technology as potential tool for conservation of animal biodiversity in Vietnam

The newest progress in biotechnology of animal reproduction in Vietnam, its capacity and potential for the protection of the biodiversity has been presented. The rapid and ultra-rapid freezing methods were inverted and completed for the cryopreservation of embryos, ocytes, sperms, tissues and cells of animal as the basic for the organization of a genetic-cryobank over time and space without limitation. The in-vitro fertilization (IVF) has been adapted for embryo production from ocytes and freezing sperm. The rate success in case of cattle IVF is 60.9% of eggs fertilized and 26.9% developed to morula and blastocyst stage. The technique of intra cytoplasmic sperm injection (ICSI) and the intracytoplasmic injection of round spermatid was established enhancing the potential of in-vitro embryo production in endangered species.

Distribution and biodiversity of Bacillus Thuringiensis isolates from Vietnam

A total of 371 Bacillus thuringiensis were isolated from 117 soil samples and 168 leaf samples collected from some provinces of the North of Vietnam. Seventy five soil samples (64.1%) contain B. thuringiensis. The B. thuringiensis frequency and Bt index are variation ranging is from 30 to 100% and 0.11 to 0.75 respectively. Bacillus thuringiensis were found in 100% of collected examples of some areas. The results suggested that B. thuringiensis abundance in soil of Vietnam was remarkably higher than that in the other countries of the Southest Asia. The phase-contrast and electron microscopy showed that B. thuringiensis isolates produced different shapes of cystals: rhomboid (83%); spherical (9.1%); rectangular (1.9%); amorphous (5.7%). Serological tetsts of 54 Bt isolates showed that B. thuringiensis isolates represented 11 H serotypes indicating a varied flora of B. thuringiensis. SDS-PAGE analysis of some typical B. thuringiensis isolates were shown also. This is the first report on biodiversity of B. thuringiensis of Vietnam.

Distribution of essental oil plants in flora of Vietnam

In flora of Vietnam 646 essential oil-bearing species belong to 357 genera, 117 families revealed. Essential oil setting on plants haven’t a regulation, except for families Annonaceae, Asteraceae, Apiaceae, Lamiaceae, Rutaceae... The study on families Annonaceae, Asteraceae, Araliaceae, Lauraceae, Myrtaceae, Zingiheraceae is an urgent in the coming time.

Distribution of yeasts Lipomyces in soils of different ecosystems, their biological indicator and applied ability

The survey of soil yeasts Lipomyces in different ecosystems of Vietnam had carried out for 5 yeasts ( 1995-1999). The results showed that: In all soils samples of different ecosystems, Lipomyces were observed. The density of Lipomyces in soils of 10 cm depth is higher than it in soils of 30 cm depth. The number of Lipomyces in soil samples from forest ecosystem 3 time higher than that from agricultural ecosystem. Species composition of Lipomyces in soils of forest ecosystem is more diverse than in agricutural one. All 4 species of : L. tetrasporus, L. kononenkoae, L.starkeyi, L. lipofer were found in soils of forest ecosystem.

Diversity of ecology of some economical algues growing in lagoon and along the coast of Thua Thien Hue province

Gracilaria and Sargassum are two economical algues groups in Thua Thien Hue province. There are only 3 species of Gracilaria with the difference of distribution site and depth and growth season. That difference is showed by the abilities of growing, using light to photosynthetic, accumulating agar as well as agar qualities. There are 6 species of Sargassum. All of them grow in the sublitoral at different depths. The species growing at weak wave areas usually grow earlier and biomass also is larger, but their qualities are lower than that at the strong wave areas.

Diversity of lactic acid bacteria producing bacteriocins

Lactic acid bacteria (LAB) were isolated from the diversity of sources showed diversity of genus, the antibacterial spectrum and distrihution as well. However, non of the strains indicated bacteriocin activity against Gram negative bacteria. The interest was several strains showed activity against Salmonella, a Gram negative food-borne pathogen. It must be confirm whethers reals bacteriocin activity or caused by some no-protein compounds.

EBV gene activity and changes of HLA antigens in the development of NPC

EBV gene activity are detected indirectly by mRNA through RT- PCR and nested PCR with 2 EBNA1 primers 293 bpPCR product HLA antigens are detected by Terrasaki cytotoxicity (1964 for class 1) and by Van Root (1976 for class 2). Obtained results show that: + The GMT of IgAl VCA is high or very high (85-147), of IgGI EBNA is high (70- 389 IU/l) in the onset or relapse of disease; + The EBV gene activity are detected in 100% of investigated cases with UCNT (28/28 cases) and with non keratinizing carcinoma (2/2 cases). The unique NPC case with differentiated, keratinizing squamous cell carcinoma the gene and gene activity are not seen; + The changes of HLA antigens are concentrated is class 1 with significant differences on A11 (0.36 / 0.10), A2 (0.51/ 0.23) and B17 (0.58 / 0.26). The linkage desiquilibrium are detected with A2-B17 and A11- B17 (Ar: 1.44, p<0.01 and Ar = 1.59, p<0.01 respectively, or with the frequency of 14.6% and 14.55 comparing with the normal people 3.3% and 2.7%, respectively (p<0.05).