Algal biomass and diesel emulsions: An alternative approach for utilizing the energy content of microalgal biomass in diesel engines

The use of algal biomass for the production of sustainable biofuels has attracted significant interest due to the fast reproduction rates and high lipid content of many microalgal species. However, existing methods of extracting algal cellular lipids are complex and expensive, with regards to both energy input and economic costs. This work explores an alternative method of utilizing the energy content of microalgae through the preparation of wet algal biomass slurry/fossil diesel emulsions containing up to 6.6% wt/wt algae biomass, using a specific surfactant combination, for direct injection diesel engine combustion of microalgae without prior biomass drying or lipid extraction. A high lipid containing green microalgae, Chlorella sorokiniana, was used to produce algal biomass for the study. The preparation of wet algal slurry/diesel emulsions from algae grown under standard conditions, and also those under conditions intended to increase cellular lipid content or growth rates was investigated, and in all cases a surfactant pack of Span80, CTAB and butanol was found to produce a stable emulsion. A correlation between the engine work produced during combustion of the emulsions in a modern direct injection compression ignition and the lower heating value of the wet slurry emulsions was found, with no evidence of individual algae cells persisting to the engine exhaust. Engine exhaust emissions of nitrogen oxides (NOx) and particulate matter were lower for all of the wet algal slurry/diesel emulsions relative to a reference fossil diesel tested under similar conditions, while in the case of the emulsion prepared from algal biomass to which a flocculating agent had been added, emissions of carbon monoxide (CO) were found to increase significantly

Effect of algal inhibitors on higher plant tissues, The

Includes bibliographical references.OWRT Project no. A-031-COLO

EFFECTS OF PRESCRIBED FIRE ON BIOLOGICAL SOIL CRUSTS AND THEIR SUBSEQUENT RECOVERY IN A GREAT BASIN JUNIPER WOODLAND

A prescribed burn was conducted in a juniper woodland approximately 40 km south of Tooele, Utah on 05 October 2006. Conditions were sub-optimal, and the fire did not encroach into mid- or late-successional areas; only the early-successional area burned successfully. This study evaluated the effects of the prescribed burn on biological soil crusts that occupy the soil surface and are important for soil stability, soil nutrient cycling, and the germination and survival of vascular plants. Biological soil crusts are composed primarily of cyanobacteria, green algae, lichens and mosses. Mosses were rare under juniper trees, so the effects of the fire were negligible; the burn significantly reduced the cover of mosses under sagebrush and in shrub interspaces. Lichens were uncommon under juniper and sagebrush. They were more common in shrub interspaces, but because the fire was spotty and of low intensity in the interspaces, they were minimally affected there. The burn significantly reduced the biomass of green algae and cyanobacteria under juniper and sagebrush; it was unaffected in the shrub interspaces. Similar trends were seen in algal density. This conclusion was confirmed by measurement of the density of green algae and cyanobacteria which also showed a significant decline in juniper and sagebrush understory, but not in the interspaces. Nitrogen fixation was significantly reduced under juniper trees but not under sagebrush or in the interspaces. Nitrogen fixation was approximately an order of magnitude greater in the shrub interspaces than beneath juniper and sagebrush. Because the interspaces were not greatly affected by the burn itself, there was no significant impact on nitrogen fixation there. In general, it appears that, while the burn negatively affected some components of biological soil crusts in some parts of the early successional stage of the juniper woodland, the overall impact on the crusts was minimal. If the intent of prescribed burning is a reduction in juniper, burning of early successional juniper woodland is appropriate because most affected trees were killed. Control of sagebrush can likewise be accomplished by low intensity, cool season fires without eliminating the crust component. Due to the spotty nature of the fire in the shrub interspaces, where most biological soil crusts occur, they were only minimally affected by the fire and may provide a good source of algal inoculants to re-colonize the soil in the juniper and sagebrush vegetation patch types which were more affected by the fire. The data suggest that intense fires should be avoided due to the potential for greater encroachment into the shrub interspaces which contain the majority of biological soil crust organisms. This information, plus the fact that late successional juniper woodlands are difficult to burn, suggests that burning of early successional juniper may be a preferred method for controlling juniper encroachment on western rangelands

Origin and Evolution of Kinesin-Like Calmodulin-Binding Protein

Kinesin-like calmodulin-binding protein (KCBP), a member of the Kinesin-14 family, is a C-terminal microtubule motor with three unique domains including a myosin tail homology region 4 (MyTH4), a talin-like domain, and a calmodulin-binding domain (CBD). The MyTH4 and talin-like domains (found in some myosins) are not found in other reported kinesins. A calmodulin-binding kinesin called kinesin-C (SpKinC) isolated from sea urchin (Strongylocentrotus purpuratus) is the only reported kinesin with a CBD. Analysis of the completed genomes of Homo sapiens, Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, and a red alga (Cyanidioschyzon merolae 10D) did not reveal the presence of a KCBP. This prompted us to look at the origin of KCBP and its relationship to SpKinC. To address this, we isolated KCBP from a gymnosperm, Picea abies, and a green alga, Stichococcus bacillaris. In addition, database searches resulted in identification of KCBP in another green alga, Chlamydomonas reinhardtii, and several flowering plants. Gene tree analysis revealed that the motor domain of KCBPs belongs to a clade within the Kinesin-14 (C-terminal motors) family. Only land plants and green algae have a kinesin with the MyTH4 and talin-like domains of KCBP. Further, our analysis indicates that KCBP is highly conserved in green algae and land plants. SpKinC from sea urchin, which has the motor domain similar to KCBP and contains a CBD, lacks the MyTH4 and talin-like regions. Our analysis indicates that the KCBPs, SpKinC, and a subset of the kinesin-like proteins are all more closely related to one another than they are to any other kinesins, but that either KCBP gained the MyTH4 and talin-like domains or SpKinC lost them