BIOTROPIA - The Southeast Asian Journal of Tropical Biology
Not a member yet
547 research outputs found
Sort by
USING STREPTOMYCES XYLANASE TO PRODUCE XYLOOLIGOSACHARIDE FROM CORNCOB
Get PDFStreptomyces 234P-16 and SKK1-8 are xylanase-producing bacteria. Corncob xylan were extracted using acidified method. Crude enzymes (produced by centrifuging the culture) were used to hydrolyze xylan from 2 varieties of corncob. Crude extract activity was measured by using DNS (Dinitrosalisilic Acid) method. Xylanase from strain 234P-16 has the highest activity if cultivated in 1% Hawaii xylan, whereas strain SKK1-8 on 1.5% Bisma xylan. SKK1-8 xylanase can hydrolize corncob xylan (1% Hawaii or 1.5% Bisma xylan) within 4 hours and produce xylooligosacharide with polymerization degree of 4.76 and 6.37, respectively.
Key words: Xylanase, Xylooligosacharide, Streptomyces
HISTOPATHOLOGY OF THE TELENCEPHALON AND DIENCEPHALON OF T1LAPIA NILOTICA EXPOSED TO SUBLETHAL DOSE OF MALATHION S-[1,2-DI-(ETHOXYCARBONYL ETHYL) DIMETHYL PHOSPHOROTHIOLOTHIONATE]
Get PDFA 35-day exposure of Tilapia nilotica embryos to sublethal doses of 3.0 ppm and 0.3 ppm malathion, S-[l,2-di-(ethoxycarbonyl ethyl) dimethyl phosphorothiolothionate], commercial grade, EC 57, produces cellular and ultrastructure changes in the brain. A number of nuclear centers of the treated animals are markedly larger than those of the control. Aberrant features observed in day-45 embryos are the neoplastic masses and increased vascularization. Ultrastructure defects include the presence of nuclear blebs, cytoplasmic vacuolations and increased lysosomal bodies
NOTES ON THE ASTERACEAE OF SUMATERA
Get PDFAn account of the tribe composition, endemic taxa, comparison with adjacent areas and weedy Asteraceae of Sumatera is given. Based on the records of January 2000, there are 133 species of 74 genera in 11 tribes. The tribe Heliantheae is the largest, with 28% of the total number of the genera, followed by Astereae with 15%, Inuleae 12%, Senecioneae 10%, Anthemideae, Eupatorieae and Lactuceae 8%, the other tribes are represented by 4% or less. The most diverse genus is Blumea with 14 species. Other genera are only represented by 10 species or less, usually 4, or 3, or 2, and mostly by 1 species only. Thirty nine or about 53% are exotic genera and the native ones are less than half of the total number of the genera. In terms of indigenous and endemic species, Sumatera is richer than Java. There are 1 genus, 7 species and 2 varieties of Asteraceae endemic to Sumatera. A number of 43 important weed species were introduced from Tropical America, Africa, Asia and Europe. Among these Chromolaena odorata and Mikania micrantha are reported as the most noxious ones. List of the genera and species recorded in Sumatera is provided in this paper. Key words : Asteraceae/Sumatera/compositions/endemic species/distribution/weedy Asteracea
TRANSPOSITION AND EXPRESSION OF GEP GENE IN THE GENOME OF Vibrio harveyi TO MONITOR ITS ADHERENCE IN SHRIMP LARVAE
Get PDFExpression of green fluorescent protein encoded by GFP gene in Vibrio harveyi was investigated to understand the ability of the gene as a molecular marker for adherence of this pathogenic Vibrio in shrimp larvae. The GFP gene was inserted into pUC18Not and pUTmini-Tn5 to generate a recombinant plasmid pWGO2 and pWGO3, respectively, which was transferred into the three isolates of V. harveyi employing diparental mating. Recombinant E. coli carrying pWGO2 and pWGO3 resulted in green-fluorescent colonies and cells due to the production of GFP. However, al1 of mini-Tn5, including mini-Tn5-gfp were not successful1y transferred to V. harveyi. Therefore, we used mini-Tn10 (pLOFKm-gfp) for inserting of gfp gene into V. harveyi genome. Although we could obtain relatively high (l0 pangkat -8) transconjugans employing Tn10, only one of Tnl0 derived isolate of V. harveyi G3 (G3-Tn1Ogfp) showed gfp expression and was further employed for adherence assay. Fluorescent 03-TnlOgfp cells could be observed inside the digestive tract of shrimp larvae and could be distinguished from vibrio that naturally exist in shrimp larvae
ANTAGONISTIC BACTERIA AGAINST SCHIZOPHYLLUM COMMUNE FR. IN PENINSULAR MALAYSIA
Get PDFSchizophyllum commune Fr., is one of the important fungi, causes brown germ and seed rot of oil palm. Biodiversity of antagonistic bacteria from oil palm plantations in Peninsular Malaysia is expected to support in development of biopesticide. Isolation with liquid assay and screening antagonistic bacteria using dual culture assay were carried out in the bioexploration. A total of 265 bacterial isolates from plant parts of oil palm screened 52 antagonistic bacterial isolates against 5. commune. Bacterial isolates were identified by using Biolog* Identification System i.e. Bacillus macroccanus, B. thermoglucosidasius, Burkholderia cepacia, B. gladioli, B. multivorans, B pyrrocinia, B. spinosa, Corynebacterium agropyri, C. misitidis, Enterobacter aerogenes, Microbacterium testaceum, Pseudomonas aeruginosa, P. citronellolis, Rhodococcus rhodochrous, Serratia ficaria, Serratia sp., S. marcescens, Staphylococcus sciuri, Sternotrophomonas maltophilia.Key words : Schizophyllum commune, biodiversity, antagonistic bacteri
CHARACTERIZATION OF XYLANASE FROM A XYLANOLYTIC- THERMOPHILIC BACTERIUM ISOLATED FROM GUNUNG PANCAR HOT SPRING, WEST JAVA
No full textA xylanolytic-thermophilic bacterium (IT-08) was isolated from Gunung Pancar Hot Spring after two days of enrichment in Modified Thermus Medium (MTM) supplemented with 0.5% oat spelt xylan. 16S-rRNA sequence analysis indicated that IT-08 resembles Bacillus thermoleovorans, a species of thermophilic bacteria. When grown on xylan containing media, IT-08 produces a thermoactive xylanase. Xylanase from IT-08 was active at temperatures between 40 and 100°C, at pH values between 4.0 and 9.0 with optimum values obtained at 80°C and pH 6.0, respectively. SDS-PAGE and zymogram analysis demonstrated that a crude xylanase complex of IT-08 comprised two active bands with molecular masses of 78 and 60 kDa. Keywords: xylanase / xylanolytic-thermophilic bacteri
ADHERENCE AND PATHOGENICITY ASSAY OF VIBRIO HARVEYI IN TIGER SHRIMP (PENAEUS MONODON) LARVAE FOR SCREENING BIOCONTROL AGENT
Get PDFRifampicin-resistant marker was employed as a reporter to detect the adherence and colonization of V. harveyi in shrimp larvae. Vibrio harveyi P1B and YA32.2 were isolated from dead shrimp larvae in Besuki, Northern Coast of East Java, while V. harveyi HB3, was isolated from pristine sea water in Pacitan, Southern Coast of East Java. Vibrio metschnikovii used as biocontrol agent was isolated from healthy shrimp larvae in Serang, West Java. Spontaneous mutation was conducted to generate V. harveyi P1B, YA32.2 and HB3 resistant to rifampicin. These mutants exhibited similar survival ability to their parental (wild type) strains. Significant larval mortality was observed in shrimp larvae inoculated with YA32.2 than that of larvae inoculated with P1B. Larvae inoculated with HB3 showed the lowest mortality. Bacterial cell count of Vibrio Rf* in dead larvae were 103-104 cells/larvae. Isolates of Vibrio metschnikovii Z and M as biocontrol candidates effectively reduced the growth and adherence ability of YA32.2 to shrimp larvae. Larval mortality in rearing water inoculated simultaneously with YA32.2 and V. metschnikovii was lower than the one inoculated with YA32.2 alone. Therefore, Vibrio metschnikovii Z or M could be developed as an effective probiotic or biocontrol agent for V. harveyi in shrimp hatcheries. Key words :  Biological control/Vibrio metschnikovii/shrimp \arvae/Penaeus mwu«fon/pathogenicity assay/Vibrio harvey
ISOLATION AND CHARACTERIZATION OF MANNANOLYTIC THERMOPHILIC BACTERIA FROM PALM OIL SHELL AND THEIR MANNANASE ENZYME PRODUCTION PROPERTIES
Get PDFA mannanolytic thermophilic bacterium (L-07) was isolated from palm oil shell after 2 days ofenrichment in liquid medium supplemented with 1% palm kernel meal as mannan source. Sequenceanalysis of 16S-rRNA indicated that L-07 was similar (98%) to Geobacillus stearothermophilus, aspecies of thermophilic aerobic bacteria. We found that G. stearothermophilus L-07 producedextracellular β-1,4-mannanases, but no β-manosidase and α-galactosidase activities. The growth of L-07reached its maximum (3.0 x 106 cell/ml) at 12-20 hours, while the highest β-mannanase activity (0.52U/ml) was observed in culture medium after 36 hours of cultivation at 60oC. The medium containinglocust bean gum was the best for producing extracellular β-1,4-mannanases compared with kolang kaling,konjak, and palm kernel meal. SDS-PAGE and zymogram analysis demonstrated that crude mannanasecomplex of L-07 from locust bean gum containing medium comprised three active bands with molecularweight of 85, 73 and 50 kDa.  Keywords : Extracellular enzyme/mannanase/Geobacillus stearothermophilu
EFFECT OF ANTANAN (CENTELLA ASIATICA) AND VITAMIN C ON THE BURSA OF FABRICIUS, LIVER MALONALDEHIDE AND PERFORMANCE OF HEAT-STRESSED BROILERS
Get PDFHigh environmental temperatures may cause heat stress in poultry. This may increase water consumption, decrease feed consumption and in rum, decrease productivity level. In addition, high temperature contributes to oxidative stress, a condition where oxidant activity (free radicals) exceeds antioxidant activity. In our research, antanan (Centelta asiatica) and vitamin C were utilized as anti heat-stress agents for heat-stressed broilers. We used 120 male broilers 2 - 6 weeks old, kept at 31.98 ± 1.94 °C during the day and 27.36 ± 1.31 °C at night. The data collected were analyzed with a completely randomized factorial design of 2 x 3 (2 levels of vitamin C, 3 levels of antanan at 4 replications) and continued with the contrast-orthogonal test when significantly different. The results indicate that the treatments of 5 and 10% of antanan with or without 500 ppm of vitamin C and vitamin C alone significantly (
ALIMENTARY CANAL ANATOMY AND HISTOLOGY OF THE WORKER TERMITE NEOTERMES BOSEI
Get PDFAs social insects, termites live in a colony that consist of reproductive (drone and queen), and non-reproductive (soldiers and workers) castes. Workers obtain their food directly from wood, humus, and other substances that contain cellulose. The objective of this study was to examine the alimentary canal of the Neotermes bosei workers. Observations of gut transverse section were carried out through the length, perimeter, and area of each alimentary canal region. The results showed that total length of N. bosei alimentary canal was 13.71+1.28 mm. The canal was divided into fore-, mid-, and hindgut which were 24, 28, and 48%, respectively of the gut total length. Two types of alimentary canal epithelial cells were found, i.e. the squamous and transitional cells. Areas covered with thick muscular tissues were crop, proventriculus, and rectum. Proventriculus was characterized with six large dentitions. There was no gastric caeca in N. bosei midgut, which commonly occurred in chewing insect. Secretory cells .were observed at proventriculus and ventriculus regions. Cardiac valve was found at the anterior end of ventriculus. Area with the largest outer perimeter was the rectum pouch. Enteric valve had three internal folds.Key words: drywood termites, alimentary canal, histology, Kalotermitida