EFFECT OF NITROGEN SUPPLY IN CULTURE MEDIA AND LIGHT INTENSITY ON PHOTOSYNTHESIS OF Chlamydomonas reinhardtii

oai:ejurnal.bppt.go.id:article/15Pengaruh Suplai Nitrogen pada Media Kultur dan Intensitas Cahaya Terhadap Proses Fotosintesis Chlamydomonas reinhardtiiOrganisms use nitrogen to produce, among others, amino acids, proteins, and nucleic acids. In this study, the effects of various concentrations of ammonium in culture media on the photosynthetic performance of Chlamydomonas reinhardtii were done under two light conditions: low and high intensity. The microbes were grown at low (75% NH4Cl dosage), normal (100% NH4Cl dosage, which was 2 M NH4Cl), and high (125% NH4Cl dosage) nitrogen content. Cells density and chlorophyll content were quantitatively determined. Immunoblotting technique was used to separate proteins based on molecular mass. In both low and high light intensity, cells grown in 75% NH4Cl dosage culture medium showed lower cell density and chlorophyll concentration than those grown in 100% and 125% NH4Cl dosage media. The later two media produced almost the same amount of cell density and chlorophyll concentration. In conclusion, 75% NH4Cl dosage was insufficient for C. reinhardtii cells to grow well. The results also showed that accumulation of photosystem I (PsaA and PsaD/F) and light harvesting complex II (LHCII) were higher in low light than in high light intensity.AbstrakOrganisme menggunakan nitrogen diantaranya untuk memproduksi asam amino, protein, dan asam nukleat. Dalam percobaan ini pengaruh berbagai konsentrasi amonium dalam media pada fotosintesis Chlamydomonas reinhardtii dilakukan di bawah dua kondisi cahaya: intensitas rendah dan tinggi. C. reinhardtii ditumbuhkan dalam medium dengan dosis nitrogen (N) rendah (75% dosis NH4Cl), normal (100% dosis NH4Cl, yakni NH4Cl 2 M), dan tinggi (125% dosis NH4Cl). Parameter yang diukur adalah  kepadatan sel dan konsentrasi klorofil. Analisis protein dilakukan dengan imunobloting untuk memisahkan protein berdasarkan massa molekul. Pada intensitas cahaya rendah dan tinggi, sel-sel pada medium dengan 75% NH4Cl menunjukkan kepadatan sel dan konsentrasi klorofil lebih rendah dibandingkan dengan 100% NH4Cl dan 125% NH4Cl, di mana kedua media ini menghasilkan kepadatan sel maupun konsentrasi klorofil yang hampir sama. Dengan demikian dapat disimpulkan bahwa 75% NH4Cl tidak cukup bagi C. reinhardtii untuk tumbuh dengan baik. Selain itu, akumulasi fotosistem I (PsaA dan PsaD/F) dan kompleks pemanenan cahaya II (LHCII) lebih tinggi pada sistem fotosintesis dengan intensitas cahaya rendah dibandingkan cahaya tinggi.Kata kunci: Chlamydomonas reinhardtii, fotosintesis, intensitas cahaya, klorofil, nitroge

VOC in printers and its elimination by means of thermally activated oxide semiconductors (TASC)

VOCs (volatile organic compounds) arising from fusers in printers, solvent inks in inkjet printers, or wet POD systems cause environmental problems at present. Therefore, efficient elimination technologies are in high demand. In this paper, we will present our novel VOC elimination system based upon thermally activated semiconductors (TASC) characterized by compact, lightweight, and low costs. Because of these appealing features, this system can easily be integrated into office printers or wet POD systems. The TASC technology dates back to our accidental finding that the semiconductor exhibits significant oxidative effects when heated at 350-500°C ; whereas quite inactive at room temperature. The present phenomenon has been applied to the complete decomposition of VOCs. The destruction mechanism is composed of the following three steps : 1. oxidation, i.e. creation of radicals, 2. radical splitting, i. e. fragmentation of the giant molecule, and 3. reaction with oxygen, i. e. complete combustion into H2O and CO2.ArticleJournal of the Imaging Society of Japan. 53(1):28-34 (2014)journal articl

Iron Emission Lines on the Galactic Ridge Observed with Suzaku

In order to elucidate origin of the Galactic Ridge X-ray Emission, we analyzed Suzaku data taken at various regions along the Galactic plane and studied their Fe-K emission line features. Suzaku resolved the Fe line complex into three narrow lines at ~6.4 keV,~6.7 keV and ~6.97 keV, which are K-lines from neutral (or low-ionized), He-like, and H-like iron ions, respectively. The 6.7 keV line is clearly seen in all the observed regions and its longitudinal distribution is consistent with that determined from previous observations. The 6.4 keV emission line was also found in various Galactic plane regions (b~0). Differences in flux ratios of the 6.4 keV/6.7 keV and 6.97 keV/6.7 keV lines between the Galactic plane and the Galactic center regions are studied and its implication is discussed.Comment: Accepted for publication in PASJ Suzaku 3rd special issu