News and Trends

Uruguay has achieved a 7% annual reduction in greenhouse gas emissions, the government announced recently. The figures came from a study conducted by Alcoholes de Uruguay (Alur).

The study was carried out by the Centre for Energy, Environmental and Technological Research of Spain, at the request of Alur and the National Energy Directorate, with the support of the National Research and Innovation Agency. The research suggests that when biodiesel is used as a substitute for oil-based diesel, greenhouse gas emissions are reduced by 70%, while bioethanol reduces emissions by 66%.

These results show that Uruguay is on course to meet its obligations under the Paris Climate Agreement, which set a target of a 15% reduction in the consumption of petroleum-derived fuels in transport.

Alur produces bioethanol from several feedstocks, including sugarcane and sorghum. The company also produces biodiesel from soybean and canola oil as well as oil used for frying.

The Slovenian government has recently adopted a strategy on alternative fuels where the registration of new diesel and petrol cars would be prohibited after 2030. The government expects that by 2030, 17% of the fleet in Slovenia, roughly 200,000 cars, will already be either electric vehicles or plug-in hybrids. The strategy extends to cargo transport as well, but the goals are more modest.

The government did not opt for an outright ban, instead putting a ceiling on a car's carbon footprint of 50 grams of CO2 per kilometer. Currently, only electric vehicles and plug-in hybrids conform to the ceiling. Latest data from car dealers show that 900 electric or hybrid vehicles were sold in the first eight months of this year, almost triple the number sold in the same period in 2016.

Slovenia has one of the highest car ownership rates in the world, 523 cars per 1,000 population as of last year.

Research and Development

David Kamanda Ngugi from King Abdullah University of Science and Technology in Saudi Arabia led a team of scientists from various research institutions to study the significance of symbionts in surgeonfishes and their roles in the digestive processes of their hosts. Herbivorous surgeonfishes are a group of reef fish that feed on marine algae.

Analysis revealed the wide diversity of microbiota involved in the degradation of algal biomass in these fishes. The microbiota was found to be simple relative to the complex microbiota of terrestrial herbivores. Analysis also found that over 90% of the enzymes for deconstructing algal polysaccharides come from members of "Candidatus epulopiscium" and other related giant bacteria.

These findings show that the metabolically distinct symbionts in hosts are key to digesting algae biomass and polysaccharides and could be pave the way for the advancement of algal biofuels.

Conversion of plant biomass into biofuels and bioproducts is vital to establish a robust biofuel industry. However, this requires a host that is capable of both assimilation of carbon sources and diversion of their metabolites toward specific bioproducts.

Junko Yaegashi of Joint BioEnergy Institute and Sandia National Laboratories evaluated the yeast Rhodosporidium toruloides for its ability to convert lignocellulose into bisabolene and amorphadiene, which have biofuel and pharmaceutical applications, respectively.

The team found that R. toruloides can efficiently convert a mixture of glucose and xylose from lignocellulose into these bioproducts. Moreover, its growth and productivity were enhanced in lignocellulosic hydrolysate. R. toruloides was also found to have superior growth in corn stover hydrolysates pretreated either with ionic liquid choline α-ketoglutarate or alkaline.

This study highlights the compatibility of R. toruloides with bioprocesses associated with lignocellulosic biorefineries and demonstrates its ability to produce valuable terpenes.

Microalgae are among the most promising species for producing renewable biofuels and chemicals. Ethanol and butanol are clean energy sources and are good alternatives to gasoline. However, synthesis of these two biofuels has not been achieved due to low tolerance of algal cells to ethanol or butanol.

Researchers led by Yongguang Jiang from Shenzhen University investigated the metabolic responses of the model green alga Chlamydomonas reinhardtii to ethanol and butanol. The team detected proteins which were differentially regulated by ethanol and butanol. The team found 41 and 59 proteins that were consistently regulated by ethanol and butanol, respectively.

Multiple metabolic processes were affected by ethanol or butanol, and various stress-related proteins, transporters, cytoskeletal proteins, and regulators were induced as the major protection mechanisms against toxicity of the organic solvents.

The study is the first view of the metabolic mechanisms used by C. reinhardtii to defend against ethanol or butanol toxicity. The proteomic analysis provides a resource for investigating potential gene targets for engineering microalgae with enhanced ethanol and butanol tolerance.

Energy Crops and Feedstocks for Biofuels Production

Genetic engineering of microalgae is necessary to produce economically important strains for biofuel production. Transcription factors (TFs) are emerging as good alternatives for engineering of microalgae, to increase production of biomaterials as well as to enhance stress tolerance.

The team of Nam Kyu Kang from Korea Advanced Institute of Science and Technology investigated the Wrinkled1 TF in Arabidopsis (AtWRI1), by expressing it in the industrial microalgae, Nannochloropsis salina designated as NsAtWRI1. The Wrinkled1 TF gene is a known regulator of lipid biosynthesis in plants. 

Results revealed that the total lipid contents and the fatty acid methyl ester yields (FAME) were greater in NsAtWRI1 transformants than in wild types under both normal and stress conditions. Further analysis indicated that the AtWRI1 transcription factor upregulated genes involved in lipid synthesis in N. salina, resulting in enhanced lipid production in the NsAtWRI1 transformants from early growth phase.

These suggest that expression of AtWRI1 TF can be used for efficient biofuel production in industrial microalgae.

Currently, the scientific community is keenly working on environment-friendly processes for the production of clean energy and sustainable development. Abeera A. Ansari of the National University of Sciences and Technology in Pakistan aimed to cultivate microalgae in raw institutional wastewater for water treatment, enriched production of biomass and CO2 sequestration.

The team used microalgaeScenedesmus sp. and Chlorella sp. strains isolated from Kallar Kahar Lake, Pakistan. Both strains were cultivated in synthetic growth medium to enhance biomass production. Microalgae cultures were then inoculated in wastewater sample under ambient conditions.

The two strains were able to successfully remove impurities in wastewater, as well as sulfates. Besides being useful in wastewater remediation, these microalgae strains can be harvested for lipid extraction for biofuel production.

The method evaluated in this study can be a cost-effective and alternative technology for wastewater treatment. Furthermore, the biomass obtained through this process can be used for the production of biofuels.

Greenbelt Resources Corporation has agreed to perform feedstock testing with Central Coast Wine Services (CCWS) to test various wastes generated in the winemaking process as potential biofuel feedstocks.

The wastes will be tested for Greenbelt's "Paso Robles ECOsystem" project, a local waste-to-energy system. Wastes with successful results will be locally converted by Greenbelt's technology into sellable bioproducts such as bioethanol, feed and fertilizer.

CCWS will be working with Greenbelt to test the viability of taking various streams of remaining ethanol-containing elements, such as by-products of the fermentation process, and converting it into high-grade bioethanol.

Waste derived feedstocks to be tested or are currently being tested include pomegranate husks, mandarin oranges, pistachio hulls, bagels, brewery wastes, sweet potatoes, sugar beets, and a variety of waste sugar and/or alcohol containing beverages.