The National Research and Innovation Agency's Ejournal Portal
Not a member yet
7815 research outputs found
Sort by
SEASONAL MIGRATION AND COLONY BEHAVIOR OF THE TROPICAL HONEYBEE APIS DORSA TA F. (HYMENOPTERA: APIDAE)
No full textPartial Purification, Characterization, and Application of Extracellular Aspartic Protease from Lactobacillus casei WSP in Producing the Bioactive Peptides with Antibacterial and Antioxidant Activity
No full text Lactobacillus casei WSP-derived an aspartic protease was sequentially purified by using chromatography gel filtration sephadex G-50. It resulted in a 22.81-fold increase of specific activity (51.5 U/mg) with a final yield of 1.9%. The estimated molecular weight of the purified enzyme was 37 kDa and showed gelatinolytic activity in zymogram assay. The enzyme exhibited optimum activity at 40ºC and pH 6 with casein as the substrate. Enzyme activity was significantly inhibited by pepstatin A (0.5 mM and 1 mM), confirming that this enzyme is a group of aspartic proteases, while other inhibitors such as EDTA, PMSF and iodoacetic acid showed no inhibition effect on the activity of enzyme. The addition of metal ion to the enzyme decreased enzyme activity, indicating the proteolytic enzyme was metal ion- dependent. Denaturant such as DDT tended to increase caseinolytic activity. Furthermore, this enzyme was capable of generating the new peptides from skimmed milk with the size 8 kDa, 10 kDa and 15 kDa. These peptides have potential as antibacterial and antioxidant agents.
 
Amelioration of Salt Tolerance in Soybean (Glycine Max. L) by Plant-Growth Promoting Endophytic Bacteria Produce 1-Aminocyclopropane-1-Carboxylase Deaminase
No full text Salinity is a major abiotic stress that can induce ethylene synthesis beyond the normal limits as plants response to stress and hence reduces crop productivity. The 1-aminocyclopropane-1-carboxylase deaminase (ACCD)-producing bacteria can reduce excessive ethylene synthesis by taking ACC (ethylene precursor) as a nitrogen source. This study showed the possibility of using endophytic bacteria in order to reduce the undesirable effects of salinity. Strain Pseudomonas putida PIR3C and Roultella terrigena PCM8 exhibited promising performance for promoting the growth of plant under salinity stress conditions. The results showed that bacterial inoculation was effective even in the presence of higher salinity levels. Strain P. putida PIR3C was the most efficient strain compared to the other strains and significantly increased shoot length, root length, dry weight, germination percentage, and reduced stem diameter. The role of ACCD in reducing ethylene production under salinity stress conditions was also studied by measuring the evolution of ethylene in vitro by soybean seeds treated with some ACCD bacterial strain. The maximum ethylene lowering capacity was observed in R. terrigena PCM8, the strain reduced ethylene production from 622.81 nmol.g-1(control) to 352.78 nmol.g-1 (43% reduction). The production of α-ketobutyrate, chlorophyll content and germination percentage from P. putida PIR3C was higher than other strains. The results suggested that strain P. putida PIR3C and R. terrigena PCM8 can be employed for salinity tolerance in soybean seedlings and may have better prospects for an amelioration of stress condition. 
Pectinase Production and Clarification Treatments of Apple (Malus Domestica) Juice
No full textPectinases are a group of an enzyme that break down pectin, a polysaccharide that is found in plant cell walls. Today, the application of pectinolytic enzymes plays an important role in food technology for the maceration of fruits and vegetables, including for the extraction and clarification of juice. This research aimed to produce pectinase enzyme for clarifying of apple juice. A microbial culture was selected from cocoa bean fermentation samples and identified as Bacillus sp.. The highest enzyme activity was investigated after 48 hours of incubation. Citrus pectin as the carbon source and peptone as the nitrogen source was found as the best component for pectinase production. The optimum condition of pectinase activity was observed at pH 5, temperature 40 °C and the crude enzyme had the higher activity at one hour storage. Apple juice was treated with the enzyme at different concentrations (0%, 0.5%, 1%, 2%, 4%). Apple juice clarification was evaluated for its percent clarity and viscosity. The result showed that enzyme treatment at 4% in apple juice promoted juice clarification and decreased pH and viscosity. In conclusion, the quality of apple juice can be improved by enzymatic treatment using pectinase
An Application of Reverse Transcriptase Polymerase Chain Reaction in A Relative Quantification of Gene Expression
No full textThe ability to quantify steady state levels of individual messenger-RNA (mRNA) transcripts has been the key issue for study on the control of gene expression. Although two available techniques, Northern blot and nuclease protection assays (NPA) have been widely used tor detecting mRNA, these techniques have critical limitations. The most obvious limitation of these two techniques is the required number of target mRNAs to be detected. Reverse transcription-polymerase chain reaction (RT-PCR), which has been accepted as a highly sensitive and specific method, provides a means for detecting and quantifying gene expression using, theoretically only a single molecule of mRNA. The sensitivity and reliability of RT-PCR is dependent upon both the RT and PCR steps. The PCR step has been problematic because of the exponential nature of this reaction where small variation can lead to dramatic changes in final result. Therefore, the use of RT-PCR for quantification of gene expression requires pre-experimental planning and design. In this experiment, the procedure for pre-experimental planning, linear range determination and subsequent relative quantification of gene expression are described in detail. A study of ornithine decarboxyJase gene, a gene involved in the polyamine biosynthesis and temporally expressed, during embryogenesis of Musca domestica (housefly) was used as the model. The results show that during early embryogenesis (t-1 to t-4) the expression level was very low. The increase in expression profile was observed started at t-5, peaked at t-9, and followed by substantial decrease from t-10 to t-12
The Use of 16S rRNA and nodC Gene Sequence in Resolving The Phylogenetic Relationship of Rhizobia Associated With Paraserianthes falcataria (L.) Nielsen Plant
No full textStudies on genetic position of several isolates living symbiotically on Paraserianthes falcataria have been carried out using amplification and sequencing techniques of 16S rDNA and specific gene for nodulation. The phylogenetic tree constructed based on 16S rDNA showed that rhizobia growing symbiotically on Paraserianthes falcataria consisted of 3 groups. The first group, was fast growing rhIzobia which have close relationship to Rhizobium tropicii, the second and the third groups were slow-growing rhizobia which have close relationship to Bradyrhizobium elkanii and Bradyrhizobium japonicum. However, the phylogenetic tree constructed on the basis of partial nodC gene indicated the existence of an independent group, since they did not show any significant degree of relationship with the existing groups. This was also supported by differences in physiological characteristic i.e Indole Acetic Acid production and salt tolerance of the isolates. These differences shows us that direct sequencing method of certain specific genes could give a more specific result than would display more clearly the degree of relationship at species level
Agrobacterium-Mediated Transformation of Javanica Rice Plants With A Cry1b Gene Under The Control of Wound-Inducible Gene Promoter
No full textA cry1B synthetic gene of Bacillus thuringiensis has been used for the transformation of the javanica rice plants cv. Rojolele to confer resistance to an important pest yellow stem borer (Scirpophaga incertulas). Embryogenic callus were co-cultivated with the EHA105 strain of Agrobacterium tumefaciens harbouring binary vector pCAMBIA I301 containing cry1B gene under the control of wound inducible gene promoter (mpi), hygromycin resistance gene (hpt) as a selectable marker and intron-containing b-glucuronidase (gus intron) gene as a reporter gene driven by CaMV35S promoter. Previously. our histochemical assay and PCR analysis had proved the integration of cry1B gene into the genome of rice plants at first generation. However, the existence of the gene should remain stable throughout generation. In this study, the presence of the cry1B transgene in rice transgenic plants at second generation was confirmed by Polymerase Chain Reaction (PCR). Insertion of the cry1B gene in the genome of PCR positive plants was verified by Southern blot analysis and showed that integration of cry1B into the genomic DNA of javanica rice plants cv. Rojolele. An effective resistance of transgenic plants against stem borer was verified in bioassays