Microalgae biofuel potentials (review).

With the decrease of fossil based fuels and the environmental impact of them over the planet, it seems necessary to seek the sustainable sources of clean energy. Biofuels, is becoming a worldwide leader in the development of renewable energy resources. It is worthwhile to say that algal biofuel production is thought to help stabilize the concentration of carbon dioxide in the atmosphere and decrease global warming impacts. Also, among algal fuels' attractive characteristics, algal biodiesel is non toxic, with no sulfur, highly biodegradable and relatively harmless to the environment if spilled. Algae are capable of producing in excess of 30 times more oil per acre than corn and soybean crops. Currently, algal biofuel production has not been commercialized due to high costs associated with production, harvesting and oil extraction but the technology is progressing. Extensive research was conducted to determine the utilization of microalgae as an energy source and make algae oil production commercially viable.

Characterization of hydrocortisone bioconversion and 16S RNA gene in Synechococcus nidulans cultures.

A unicellular cyanobacterium, Synechococcus nidulans (Pringsheim) Komárek, was isolated from paddy-fields and applied in the biotransformation experiment of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25 degrees C for 14 days of incubation. The obtained products were chromatographically purified followed by their characterization using spectroscopic methods. 11beta,17beta-dihydroxyandrost-4-en-3-one (2), 11beta-hydroxyandrost-4-en-3,17-dione (3), and androst-4-ene-3,17-dione (4) were the main bioproducts in the hydrocortisone bioconversion. The observed bioreaction characteristics were the side chain degradation of the substrate to prepare compounds (2) and (3) following the 11beta-dehydroxylation for accumulation of the compound (4). Time course study showed the accumulation of the product (2) from the second day of the fermentation and compounds (3) and (4) from the third day. All the metabolites reached their maximum concentration in seven days. Cyanobacterial 16S rRNA gene was also amplified by PCR. Sequences were amplified using the universal prokaryotic primers which amplify a approximately 400-bp region of the 16S rRNA gene. PCR products were sequenced to confirm their authenticity as 16S rRNA gene of cyanobacteria. The result of PCR blasted with other sequenced cyanobacteria in NCBI showed 99% identity to the 16S small subunit rRNA of seven Synechococcus species.