Sri Hartati

Overexpression of Poplar Cellulase Accelerates Growth and Disturbs the Closing Movements of Leaves in Sengon

In this study, poplar (Populus alba) cellulase (PaPopCel1) was overexpressed in a tropical Leguminosae tree, sengon (Paraserianthes falcataria), by the Agrobacterium tumefaciens method. PaPopCel1 overexpression increased the length and width of stems with larger leaves, which showed a moderately higher density of green color than leaves of the wild type. The pairs of leaves on the transgenic plants closed more slowly during sunset than those on the wild-type plants. When main veins from each genotype were excised and placed on a paper towel, however, the leaves of the transgenic plants closed more rapidly than those of the wild-type plant. Based on carbohydrate analyses of cell walls, the leaves of the transgenic plants contained less wall-bound xyloglucan than those of the wild-type plants. In situ xyloglucan endotransglucosylase activity showed that the incorporation of whole xyloglucan, potentially for wall tightening, occurred in the parenchyma cells (motor cells) of the petiolule pulvinus attached to the main vein, although the transgenic plant incorporated less whole xyloglucan than the wild-type plant. These observations support the hypothesis that the paracrystalline sites of cellulose microfibrils are attacked by poplar cellulase, which loosens xyloglucan intercalation, resulting in an irreversible wall modification. This process could be the reason why the overexpression of poplar cellulase both promotes plant growth and disturbs the biological clock of the plant by altering the closing movements of the leaves of the plant.

Enzymatic saccharification and ethanol production of Acacia mangium and Paraserianthes falcataria wood, and Elaeis guineensis trunk

We examined the saccharification and fermentation of meals from Acacia mangium wood, Paraserianthes falcataria wood, and Elaeis guineensis trunk. The levels of enzymatic hydrolysis of cellulose and ethanol production were highest for P. falcataria wood and lowest for A. mangium wood. Ultrasonication pretreatment of meal further increased the rates of hydrolysis and ethanol production in meal from P. falcataria wood. Through this pretreatment, hemicelluloses (xylan and xyloglucan) and cellulose were released in the meal from P. falcataria wood. Loosening of hemicellulose associations can be expected to make P. falcataria wood more useful for bioethanol production.

Improvement of fermentable sugar yields of mangium through transgenic overexpression of xyloglucanase

Recalcitrance to saccharifi cation is a major limiting factor of the conversion of lignocellulosic biomass to ethanol. Levels of wood saccharification and subsequent ethanol production were higher in transgenic mangium (Acacia mangium) trees overexpressing xyloglucanase than in wild-type plants, even after delignification of the wood. We propose that a decrease in the quantity of xyloglucan that is intercalated into cellulose microfibrils could facilitate the process of saccharification.

Enhancement of saccharification by overexpression of poplar cellulase in sengon

Lignocellulosic material from trees has great potential to form the basis of the second generation for bioethanol production because trees produce most of the biomass on the earth. We modified the wall structure of sengon (Paraserianthes falcataria) through overexpression of poplar cellulase in the cell walls. The overexpression did not decrease cellulose content but caused a decrease in xyloglucan bound to the walls. The level of saccharification and successive ethanol production was increased in the wood of the transgenic sengon overexpressing poplar cellulase compared with that of the wild type plant, and even after delignification of the wood. We propose that a xyloglucan intercalated into cellulose microfibrils could be one of the recalcitrant components in the saccharification of lignocelluloses.

Anti-hepatitis C virus activity of a crude extract from longan ( Dimocarpus longan Lour.) leaves

Infection with hepatitis C virus (HCV) results in hepatitis C, a disease characterized by chronic infection, cirrhosis, and hepatocellular carcinoma. Currently, the standard therapy is a combination of pegylated interferon-α plus ribavirin with NS3 protease inhibitors. Addition of NS3 protease inhibitors to the standard therapy improves response rates; however, use of NS3 protease inhibitors is also associated with significant adverse effects and an increase in the overall cost of treatment. Therefore, there is a need to develop safe and inexpensive drugs for the treatment of HCV infections. In this study, we examined the antiviral activity of a crude extract from Dimocarpus longan leaves against HCV (genotype 2a strain JFH1). The D. longan crude extract (DL-CE) exhibited anti-HCV activity with a 50% effective concentration (EC50) of 19.4 μg/ml without cytotoxicity. A time-of-addition study demonstrated that DL-CE has anti-HCV activity at both the entry and post-entry steps and markedly blocks the viral entry step through direct virucidal activity with marginal inhibition of virion assembly. Co-treatment of DL-CE with cyclosporine A, an immunosuppressant or telaprevir, an NS3 protease inhibitor, resulted in additive and synergistic antiviral effects, respectively. Our findings suggest that DL-CE may be useful as an add-on therapy candidate for treating HCV infections.

Overexpression of xyloglucanase (AaXEG2) accelerates heteroblastic development in mangium leaves

Transgenic mangium trees (Acacia mangium) overexpressing xyloglucanase (AaXEG2) were generated by spraying flower buds with Agrobacterium solution and allowing seeds to develop. The overexpression of xyloglucanase decreased xyloglucan content in the cell walls and increased stem length and diameter. The leaves of the transgenic seedlings exhibited accelerated heteroblastic development, proceeding from the stage of three bipinnate leaves to that of enlarging petiole 2 weeks earlier than wild type seedlings did.

A novel polyisoprenyl benzophenone derivative from Garcinia eugeniaefolia

A novel polyisoprenyl benzophenone derivative named eugeniaphenone (1) was isolated from the stem bark of Garcinia eugeniaefolia Wall. Its structure was elucidated by spectroscopic methods, including 1D and 2D NMR techniques, and confirmed by single-crystal X-ray diffraction analysis. It is the first example in which an isoprenyl unit formed a cyclobutane-containing side chain in the polyisoprenyl benzophenone derivatives.

Production Of Malto-Oligosaccharides From Cassava Cultivar Kuning

Characteristic the physic-chemical of Indonesia cassava starch from four cultivated varieties has been conducted for maltooligosaccharide production. Result of proximate analysis of the extracted starch indicated that the extracted starch was quite pure. The purity of the extracted starch was visually confirmed by microscopic analysis by using SEM micrographs at 2500X magnifications show that the integrity of the granules starch as intact. Based on the amylopectin and amylase content showed that one of cultivated variety of cassava, cultivated variety Kuning contain the amylopectin higher than amylase was compared with the other cultivated variety. The next focus research was analysis potential of starch from cultivated variety Kuning for maltooligosaccharide production by enzymatic hydrolysis by ?-amylase from marine bacterium Brevibacterium sp. The optimum hydrolysis condition for cultivated variety Kuning was obtained substrate concentration 4.5% (b/v), comparison of substrate: enzyme 1:2, temperature reaction 30oC with reducing sugars concentration of 13.359 ppm. The hydrolysis products of cassava starch cultivated variety Kuning were maltooligosaccharides mixture, yielding maltose, maltotriose, maltotetraose, maltopentaose. This result showed that cassava starch of cultivated varieties Kuning potential for maltooligosaccharides production. PRODUKSI MALTOOLIGOSAKARIDA DARI UBI KAYU VARIETAS KUNINGKarakteristik fisiko kimia karbohidrat dari empat varietas kultivar asal Indonesia dilakukan untuk melihat potensinya sebagai bahan baku untuk produksi maltooligosakarida. Analisa proksimat karbohidrat hasil ekstraksi dari keempat varietas kultivar ubi kayu mengindikasikan bahwa karbohidrat yang dihasilkan cukup murni. Kemurnian dari karbohidrat tersebut terlihat setelah dikonfirmasi dengan analisa mikrokospis dengan menggunakan mikroskop electron SEM dengan pembesaran 2500X yang menunjukkan bahwa granulanya utuh. Berdasarkan kadar amilopektin dan amilosa menunjukkan bahwa salah satu varietas kultivar ubi kayu yaitu varietas Kuning mengandung amilopektin lebih tinggi dibandingkan kadar amilosanya jika dibandingkan dengan tiga varietas kultivar lainnya. Fokus penelitian selanjutnya adalah analisa potensi karbohidrat varietas kultivar Kuning tersebut untuk produksi maltooligosakarida dengan hidrolisis enzimatis oleh ?-amylase dari Brevibacterium sp. Kondisi optimum hidrolisis dari varietas kultivar Kuning diperoleh pada konsentrasi substrat 4.5% (b/v), perbandingan substrat dan enzim 1:2, suhu reaksi 30oC dengan kadar gula reduksi yang diperoleh 13.359 ppm. Produk hidrolisis dari ubi kayu varietas kultivar Kuning adalah berupa campuran maltooligosakarida yang terdiri atas maltose, maltotriose, maltotetraose, maltopentaose. Hasil ini menunjukkan bahwa karbohidrat ubi kayu dari varietas kultivar Kuning mempunyai potensi untuk digunakan sebagai bahan baku untuk produksi maltooligosakarida.

Antioxidant activities of phenolic compounds isolated from the leaves of Macaranga allorobinsonii Whitmore

Two secondary metabolites compounds, gallic acid (1) and methyl gallate (2) have been isolated from the ethyl acetate fraction of the methanol extract of the leaves of Macaranga allorobinsonii Whitmore. Isolation and purification of the secondary metabolite compounds conducted using chromatography methods, and structure elucidation determined based on NMR, mass spectroscopic data and compared with appropriate references.Two secondary metabolites compounds, gallic acid (1) and methyl gallate (2) have been isolated from the ethyl acetate fraction of the methanol extract of the leaves of Macaranga allorobinsonii Whitmore. Isolation and purification of the secondary metabolite compounds conducted using chromatography methods, and structure elucidation determined based on NMR, mass spectroscopic data and compared with appropriate references.

CLONING OF THE GENE ENCODING SAGI OF LOCAL ISOLATE TOXOPLASMA GONDII IN ESCHERICHIA COLI DH5a

CLONING OF THE GENE ENCODING SAGI OF LOCAL ISOLATE TOXOPLASMA GONDII IN ESCHERICHIA COLI DH5a