Clifford Louime

Cellulosic Ethanol: Securing the Planet Future Energy Needs

Bioenergy is fairly recognized as not only a necessity, but an inevitable path to secure the planet future energy needs. There is however a global consensus that the overall feasibility of bioenergy will require an integrated approach based on diversified feedstocks and conversion processes. As illustrated in the Brazilian experience, the thrust of any bioenergy program should be centered on the principles and criteria of sustainable production. In general the trends are towards exploiting low value cellulosic materials to obtain high-end value energy products. To this end, it is expected that scientific or technical innovation will come to play a critical role on the future prospects and potential of any bioenergy initiative.

Resistance to Elsinoë Ampelina and Expression of Related Resistant Genes in Vitis Rotundifolia Michx. Grapes

Muscadine grapes (Vitis rotundifolia Michx) are considered as excellent genetic resources for grape breeding programs as they are known for their hardiness and resistance to pests and diseases. However, contrary to popular belief, our study indicated that not all muscadine cultivars are resistant to anthracnose disease. In order to identify a source of genetic tolerance towards anthracnose among muscadine cultivars, a series of in-situ and ex-situ experiments were conducted through strict and sensitive screening processes. Two consecutive years of field evaluation of 54 grape cultivars showed various levels of anthracnose incidence among the cultivars between a scale of 0 (tolerant) to 5 (highly-susceptible). Resistance bioassay by inoculation of different spore densities of Elsinoë ampelina on 40 cultivars presented similar results and was consistent with those obtained from the field test. A real-time PCR analysis was conducted to investigate differences of gene expression between susceptible and tolerant cultivars and to confirm results by phenotypic identification. Expression of genes encoding chalcone synthase, stilbene synthase, polygalacturonase-inhibiting protein, chitinase and lipid transfer-protein was only detected in tolerant cultivars. Resistant muscadine cultivars identified in this study could be excellent candidates for grape disease resistance breeding programs.

High Light Stress Regimen on Dunaliella Salina Strains For Carotenoids Induction

The microalgae Dunaliella salina is the richest source of commercial β-carotene known to man. This natural compound has been proven invaluable in medicine, industry and other fields of science, due to its provitamin A activity and potential disease suppression, as well as usage as a supplement for food and animal feed including as additive to food and cosmetics. However, β-carotene content in Dunaliella cells depends heavily on growth conditions and nutrient parameters. A set of experiments was conducted to determine the optimum high light stress regimen for Dunaliella salina to achieve the highest carotenoids induction. Three D. salina strains (D. salina CCAP 19/18, D. salina A9 and D. bardawil) were cultured in MD4 1.5M medium under stress condition at different regimens for a period of 26 days. Following the first phase of exponential growth, 3 different growth cycles were tested: a cycle of three-day at 800 μmol.photons/m2/s and one day at 50 μmol.photons/ m2/s, a cycle of one day at 800 μmol.photons/m2/s and three-day at 50 μmol.photons/m2/s and finally an all-time stress at 800 μmol.photons/m2/s. Total carotenoids were analyzed over the experimental period, including the antioxidant capacities and total phenolic contents of the algal carotenoid extract were simultaneously evaluated. Result revealed that all three D. salina strains produced the highest concentration of total carotene under the all-time stress regimen of 800 μmol.photons/ m2/s, and D. salina CCAP had higher total carotenoid content than D. salina A9 and D. bardawil in all stress conditions. This study could surely serve as the basis for scaling up this process to industrial-level applications, which will undoubtedly require further investigation and evaluation of the extraction and testing procedures. Introduction Currently there are 26 known or reported species of Dunaliella. These include among others Dunaliella salina, Dunaliella bardawil, Dunaliella tertiolecta [1-5]. Dunaliella salina is a type of unicellular and halophilic green biflagellate microalga without a rigid cell wall structure which can grow at very high salinities and levels of irradiance [6-9]. Dunaliella salina accumulates massive amounts of β-carotene in electrodense globules located within the inter-thylakoid spaces in the chloroplast. Various stress factors are known to interrupt the physiological balance of a normal Dunaliella salina cell. Therefore, in order to protect itself and continue to grow, Dunaliella cell generates additional β-carotene restoring its physiology balance under stress conditions [10]. Carotenoids are organic pigments that are known to be crucial for normal vision and have been associated with reducing the risk of several degenerative diseases, including cancer [11,12]. β-carotene is perhaps the most important carotenoid from over 600 types of carotenoids found in nature. It is highly valuable due to its nutritional benefit as a precursor of vitamin A and for its properties such as a color additive, antioxidant, anticancer, antiaging and immunomodulatory [13,14]. Recently, the rate and extent of carotenoid accumulation in Dunaliella salina has been researched under various stress conditions such as high salinity [15,16], high temperature [17,18] and these types of relationship are well established. However, according to scientific community, there are no reports on carotenoids induction in D. salina cultured under different high light stress regimens. Therefore, the Correspondence to: Duc Tran, Algae2Omega Holdings, 7625 17th Street, Vero Beach, FL 32968, USA, E-mail: tnducminh@yahoo.com

Genomics and Potential Bioenergy Applications in the Developing World

The finite nature of fossil fuels and the associated effects of global climate change are forcing governments worldwide to seek alternative sources of energy. These alternatives must be renewable, sustainable, and cost-efficient. Biomass seems to represent an attractive alternative as it is carbon neutral and constantly being replenished by photosynthesis. The Brazilian biofuels experience based on sugarcane is a great example of how energy independence can be achieved (Potter 2008). Today, to secure their future energy needs, United States (US) and European (EU) leaders are outlining bioenergy targets loosely based on the Brazilian biofuels initiative (FAO 2008). This resulting global biofuels expansion will provide a welcomed market opportunity for developing nations, where the most favorable conditions for biofuels feedstock development are encountered, such as warm climate, affordable labor, and abundant natural resources. However, for these nations to fully take advantage of these opportunities, an appropriate sustainability framework needs to be developed, which takes into account some of the social, economic, environmental, and technological indicators for each region. Only such an enabling environment can promote access to reliable energy, which for centuries has been the driving force behind economic and social empowerment (Polack 2010).

Perspective of Biotic and Abiotic Stress Research in Grapevines (Vitis sp.)

Most of the terrestrial plants including grapevines are targets for both biotic and abiotic stresses due to their adamant nature. These stresses have caused major concern worldwide with significant losses in crop yields and quality. Exposure to the wide array of stresses has enabled grapevines to develop an intricate defense mechanism. Data generated/accumulated from large-scale expressed sequence tag sequencing, cDNA/oligo microarray mRNA expression profiling, and more importantly the availability of complete genome sequence of Vitis vinifera cv. Pinot Noir will provide a platform to identify and implement useful genetic engineering strategies for improving biotic/abiotic stress tolerance in grapevines.

Fuels for Thought

When it comes to the marketing of the bioenergy brand, one of the catchiest slogans out these days is “25 by ‘25”. Adopted and supported by industries, academia and government agencies alike, this organization simply aims to supply 25 percent of our energy from renewable resources by the year 2025. By focusing its future efforts on wind, solar and biomass resources, the “25 by 25” initiative is expected to create new jobs, develop novel technologies, help mitigate the effects of global warming and reduce our dependence on fossil fuels. [...]