News and Trends

Prof. Emeritus Aharon Gedanken from the Department of Chemistry at Bar-Ilan University in Israel, recently visited National Cheng Kung University in Taiwan, to continue his research in converting waste cooking oils into biodiesel with the research team in NCKU.

"We are converting basically waste cooking oil into biofuel and now we can convert 3 liters per hour," said Gedanken to NCKU president Hwung-Hweng Hwung.

Gedanken and his team in NCKU have developed a process that converts used cooking oil to biodiesel using microwaves and strontium oxide (SrO) as catalyst. The machine has been set up in the department and ready to yield more biofuel in the coming months, according to MSE Distinguished Professor Jiunn-Der Liao. He said that with Prof. Gedanken's help, NCKU is going to set up a converting station at An-nan campus.

Liao said they have received inquiries from Thailand, Malaysia, and at least three domestic enterprises regarding the process.

The Philippines' Sugar Regulatory Administration (SRA) and the Brazilian government are currently drafting a Memorandum of Understanding regarding exchange of information on sugar production techniques.

SRA Administrator Ma. Regina Martin recently visited Brazil and stated that the Brazilian government was looking to cooperate with the Philippines on the use of advanced sugar cultivation technologies and giving Philippines access to high-yielding and climate-resilient sugarcane varieties.

"Brazil, through EMBRAPA (Brazilian Enterprise for Agricultural Research) is willing to train our researchers and the University of Sao Carlos in Sao Paulo will allow us access to its sugarcane varieties through technical cooperation," said Martin.

Martin was part of the Philippine delegation to the 3rd Philippine-Brazil Bilateral Consultation Meeting held recently in Basilia, Brazil.

Six projects in West Africa and four projects in Ethiopia have been selected to receive project funding through the Feed the Future Innovation Lab for Collaborative Research on Sorghum and Millet.

The Feed the Future Innovation Lab for Collaborative Research in Sorghum and Millet, established in July 2013 at Kansas State University, is a consortium of research aimed at improving the adaptation and resilience of sorghum and pearl millet to the semi-arid climates of East and West Africa, particularly in Ethiopia, Senegal and Niger.

The Lab contributes technologies and knowledge toward improving profitability of sorghum- and millet-based production systems and value chains. In 2012, a study in Ethiopia found that investing in potential biofuel feedstocks, such as sorghum and pearl millet, in the region could potentially lead to higher food security for the region.

Research and Development

Many attempts have been made to increase lipid content of microalgae for biodiesel through genetic engineering. Lipid accumulation was previously achieved but had limited cell growth. In this study by Zanmin Hu of Chinese Academy of Sciences in China, soybean gene GmDof4, known to affect lipid content in Arabidopsis, was inserted into Chlorella ellipsoidea to determine the mechanism behind possible  enhancement of lipid content.

The overexpression of GmDof4 significantly enhanced the lipid content and did not affect the growth rate of the host cells. Transcriptome profiles indicated that several genes were differentially regulated, and in the transgenic strains, these include the 22 genes involved in lipid and fatty acid metabolism. Analysis revealed that GmDof4 significantly up-regulated the gene expression and activity of acetyl-coenzyme A carboxylase, a key enzyme for fatty acid synthesis, in the transgenics.

The expression of the GmDof4 gene from soybean significantly increased lipid content but did not affect the growth rate of C. ellipsoidea. The increase could be attributed to the large number of genes with regulated expression.

The expression of biomass-degrading enzymes, such as cellobiohydrolases, in transgenic plants can potentially reduce costs of biomass saccharification. Mark D. Harrison from Queensland University of Technology in Australia, and his team, expressed cellobiohydrolase in transgenic corn and evaluated it as an additive for two commercial cellulase mixtures for the saccharification of pretreated sugar cane bagasse.

Cellobiohydrolase, extracted from leaves of transgenic corn using tap water as a solvent, significantly enhanced the performance of two commercial cellulase mixture by up to four times on pretreated sugarcane bagasse  compared to the commercial cellulase mixture on its own. The accumulation of recombinant cellobiohydrolase in senescent, transgenic corn leaves is a viable strategy to reduce the saccharification cost associated with the production of fermentable sugars from pretreated biomass.

Rhizobium plays a pivotal role in symbiotic interactions with plants. However, the study by researchers from Korea Research Institute of Bioscience and Biotechnology extends this mutualism to several species of green algae.

Denaturing gradient gel electrophoresis (DGGE) and gene clone library experiments of Chlamydomonas reinhardtii, Chlorella vulgaris, Scenedesmus sp., and Botryococcus braunii revealed that the dominant bacteria hosted by these green algae were Rhizobium, Mesorhizobium, Shinella, Flavobacterium, and Pseudomonas

Rhizobium promoted algal cell count by about 72% when co-cultured with green algae. The growth rates of algae and Rhizobium increased by an average of 11% and 110%, respectively, confirming mutualistic interaction. Since Rhizobium sp. was found in several green algae, it must be a major mutualistic relationship among green algae. This interaction could be utilized in enhancing microalgal biomass to improve their bioenergy productivity.

Energy Crops and Feedstocks for Biofuels Production

Switchgrass (Panicum virgatum L.) has a conditional self-compatibility which can be used to produce inbreds for biomass production. However, efficient and reliable bagging methods are unavailable for development of inbreeding. Researchers from Oklahoma State University, led by Yanqi Wu, studied the efficacy of polyester bagging method to facilitate selfing in switchgrass.

The reliability of the bags was determined using simple sequence repeat (SSR) markers. Contaminants were grouped into outcrossing contaminants (OCs) and physical contaminants (PCs). From thirty-nine polyester bags tested, 35 bags showed 100 % selfed progeny while only four showed PC. Similarly, in 61 bags tested in another season, 50 bags produced 100 % selfed progeny, four bags produced OCs, five produced PCs and the other two had both OCs and PCs. No contaminants were identified from the test in the greenhouse, suggesting that high wind speed, physical damage or handling errors may have resulted in the contaminations in the field. 

The result of this experiment establishes the reliability of the polyester bagging method over previously tested methods for selfing switchgrass.

Giuseppe Olivieri, from UniversitÓ degli Studi di Napoli Federico II, and his team aim to identify an alternative disposal process for the high-sugar-content beverages (HSCB) industry as well as contribute to the study of butanol production from non-edible feedstocks. The team evaluated HSCBs as a feedstock for butanol production by Clostridium acetobutylicum DSM 792.

Four types of commercial beverages such as fruit juices, syrups, soft drinks, and a sport drink were investigated. These contained high levels of sugar, mainly glucose, fructose, and sucrose. These sugars were tested individually and in a mixture. The production rate of butanol increased in the following order: glucose, fructose, and sucrose. The tests on the sugars highlighted the feasibility of C. acetobutylicum metabolizing them to produce butanol. Among the beverages tested, the sport drinks gave the maximum butanol production rate of 12 g/L.