Annales Bogorienses

1-11

Authors: Wien Kusharyoto, Martha Sari, Asep Muhammad Ridwanuloh

Phytic acid is an antinutritional factor that forms 1–2% of most of the seeds and their co-products representing more than 60% of their total phosphorus. Monogastric and agastric animals are unable to utilize phytate phosphorus either due to lack of or insufficient amount of phytate degrading enzymes. Phytases (myo-inositol hexakisphosphate-phosphohydrolase) are a special class of phosphatases that catalyze the hydrolysis of phytic acid in a stepwise manner to lower inositol phosphates, myo-inositol and inorganic phosphate. Phytases are found naturally in plants and microorganisms and a sizeable number of phytases have been purified and characterized from various fungi, yeasts and bacteria. The present investigation involves studies on the effect of moisture content, pH value and different media ingredients such as carbon, nitrogen, and surfactants on the production of phytase by the fungus Aspergillus ficuum DSM 932 in solid-state fermentation (SSF) using rice bran as substrate. The production of phytase by SSF was favored, when the fungus was grown at a moisture content of 60% and pH 7.0, resulted in a phytase activity of 5.2 units/g dry substrate. There was a 20% increase in phytase yield in the presence of sucrose in SSF medium, while glucose and fructose were not effective in enhancing the phytase activity when used individually. Yeast extract was found to be a favorable nitrogen source for phytase production by SSF, which resulted in a 20% increase in phytase activity. There was no significant effect in increasing phytase production with the use of either soy peptone or tryptic soy as nitrogen source. Approximately 30% inhibition in phytase activity was shown in the presence of the surfactant Tween-80 or Triton X-100 in the SSF. By supplementing rice bran with sucrose and yeast extract, and performing the SSF in tray bioreactors, a phytase activity of 6.76 units/g dry substrate could be obtained.

21-28

Authors: Maria Imelda, Aida Wulansari, Laela Sari

Sukun (Artocarpus altilis (Parkinson) Fosberg) of the Moraceaae is a big tree which can grow to 15-20 m in height and native to the Asia-Pasific region. Beside its delicious fruit, sukun is also known as a traditional herbal medicinal plant in the region, including Indonesia. Nearly all parts of the plant, such as roots, stems and leaves are believed by local communities to be capable of curing liver disease, hypertension, cardiac arrest, toothache, renal problem and even skin itchiness. The collaborative research between LIPI and PR China, on developing herbal medicines indicated that sukun has a great potential for treating cardiovascular disease. However, the availability of raw materials still poses a big constraint for the industry of herbal medicines. Generally, sukun is propagated by root or stem cuttings, since in Indonesia sukun does not produce any seeds. However such method only produces limited planting materials. In general tissue culture propagated plants have many advantages, namely being clonal, free from pest and diseases, more uniform, and allowing a high rate of plant multiplication. Therefore, the technique for sukun propagation has been developed by the LIPI Research Centre for Biotechnology. In this research the effects of 1-5 mg/l benzyl amino purine (BAP) and 20-40 mg/l adenine sulphate (AS) on shoot bud proliferation were investigated using lateral shoot buds on a modified Murashige and Skoog (MS) medium with addition of 150 ml/l coconut water(CW). Shoots were rooted on MS medium without plant growth regulators (PGRs). The results showed that the best medium for in vitro shoot proliferation was a modified MS medium containing 2 mg/l BAP, 40 mg/l AS and 150 ml/l CW. The best medium for rooting is MS medium containing 1 mg indole butyric acid (IBA), producing roots within 3 weeks.

37-45

Authors: Amy Estiati, Satya Nugroho

Rice is one of the most important food crops in the world. Nearly half of the world population consume rice as their staple food (FAO, 2004). With the increasing of world population, the need to provide more food supplies including rice is obvious. Biotechnology is expected to play major roles in the improvement of crop productivity and quality. Unlike transgenic maize, eventhough many research have been done to improve rice performance by genetic engineering, transgenic rice has not been released or commercialized. Among those research to improve rice performance are the atempt to introduce biotic and abiotic stress tolerant traits, herbicide tolerant trait and beta-carotin biosynthetic pathway. Currently, several genetically modified rice cultivars have been and being tested on limited field trials.