Suryo Gandasasmita

Oil productivity of the tropical marine diatom Thalassiosira sp.

To understand the potential of cultivating tropical marine diatom Thalassiosira sp. to produce biofuel, biodiesel product properties and growth characteristics of Thalassiosira sp. in three different media were investigated. After medium evaluation, significant Thalassiosira sp. cell growth was observed in both Walne and enriched seawater media, but not in plain seawater medium. The microalgae grew well in alkaline condition (pH range of 8.0-8.8). The average biomass density cultured in Walne and enriched seawater media on the 6th day was 4.36 and 2.50 g L(-1), respectively. Based on ESI-IT-MS spectra, the TAGs of algal oil were identified as POP, POO, and SOO, and the FAMEs as oleic acid methyl ester. The oil productivity of Thalassiosira sp. cultured in Walne and enriched seawater media were 150 and 290 μL L(-1) d(-1), respectively. The density and kinematic viscosity of Thalassiosira sp. biodiesel were 0.857 g mL(-1) and 1.151 mm(2) s(-1).

Yeast fuel cell: Application for desalination

Yeasts have been implicated in microbial fuel cells as biocatalysts because they are non-pathogenic organisms, easily handled and robust with a good tolerance in different environmental conditions. Here we investigated bakers yeast Saccharomyces cerevisiae through the oxidation of glucose. Yeast was used in the anolyte, to transfer electrons to the anode in the presence of methylene blue as mediator whereas K3Fe(CN)6 was used as an electron acceptor for the reduction reaction in the catholyte. Power production with biofuel cell was coupled with a desalination process. The maximum current density produced by the cell was 88 mA.m-2. In those conditions, it was found that concentration of salt was removed 64% from initial 0.6 M after 1-month operation. This result proves that yeast fuel cells can be used to remove salt through electrically driven membrane processes and demonstrated that could be applied for energy production and desalination. Further developments are in progress to improve power output to make yeast fuel cells applicable for water treatment.