The thermophilic cyanobacterium Thermosynechococcus elongatus was examined for the ability to sequester CO₂ while producing hydrogen (H₂), polyhydroxybutyrate (PHB), lipids, and glycogen. H₂ was produced at a maximum rate of 188 nmol H₂ mg Chl a⁻¹ hr⁻¹. Hydrogen production occurred in the presence of methyl viologen but the cells were...
Nitrosomonas europaea (ATCC19718) participates in the biological removal of nitrogen from wastewater by oxidizing ammonia to nitrite, the first step in nitrification. This bacterium is sensitive to heavy metals (Zn²⁺, Cd²⁺, Cu²⁺, and Hg²⁺) and cyanide, compounds commonly encountered in wastewater treatment plants. Therefore, we characterized physiological and transcriptional responses...
Photobiological hydrogen production from live cells of the cyanobacterium Synechocystis sp. PCC 6803 encapsulated in silica gel was investigated. Hydrogen is a dense energy carrier with potential to reduce dependence on fossil fuels, provided a renewable and sustainable means of production can be achieved. Under certain conditions, Synechocystis sp. PCC...
Photobiological hydrogen production -- the use of photosynthesis to split water into hydrogen and oxygen -- presents an opportunity for efficient and large-scale solar biofuel development. One of the major challenges in this area is competition for reductant between the hydrogen-evolving hydrogenase enzyme and other metabolic pathways. In this work...
The methane monooxygenase (MMO) enzyme, used by methylotrophs
to oxidize methane, has been shown to possess quite broad substrate
specificity, being able to oxidize many organic compounds including
n-alkanes, n-alkenes, ethers, and aromatic, alicyclic, and
heterocyclic compounds. In this research, it was sought to
determine whether a gas-permeable-membrane-supported (GPMS) biofilm...
Cometabolic biodegradation processes, important for bioremediation of hazardous waste sites, are not well understood and have not been modeled thoroughly. Toxic effects and bacterial responses to toxicity may change intracellular enzyme levels, rendering traditional enzyme kinetics models inappropriate. This document presents a novel cometabolic enzyme kinetics model that incorporates enzyme...
Many conditions affecting hydrogen (H₂) production by the cyanobacterium, Synechocystis sp. PCC 6803, were optimized to yield maximum H₂ accumulation. Biological H₂ production from photosynthetic species is a promising form of renewable energy since an abundant supply of sunlight hits the Earth every day, and photosynthetic bacteria can harness this...
The growth characteristics of Thermosynechococcus elongatus on elevated CO₂ were studied in a photobioreactor. Cultures were able to grow on up to 20% CO₂. The maximum productivity and CO₂ fixation rates were 0.09 ± A 0.01 and 0.17 ± A 0.01 mg ml⁻¹ day⁻¹, respectively, for cultures grown on 20%...
Cyanobacteria inhabit nearly every ecosystem on earth, play a vital role in nutrient cycling, and are
useful as model organisms for fundamental research in photosynthesis and carbon and nitrogen fixation.
In addition, they are important for several established biotechnologies for producing food additives,
nutritional and pharmaceutical compounds, and pigments, as...