News and Trends

Used cooking oil (UCO) may be harmful to health, but ascience can turn it into an environment savior. Davao-based Emiliano Quitiol found this out back in 2003 when he started working on his own biofuel. Fourteen years later, he has perfected his product, EFQ Bioforce, in which he used UCO as a raw material. He believes this will pave the way for solving the disposal problem of UCO.

Adding 1 ml of his product  to a liter of fuel will rearrange the molecular structure of the conventional fuel into chain branching of hydrocarbons. This allows more efficient fuel combustion and may reduce air pollution.

His idea stemmed from his will to stop pollution. He hopes that his invention will eventually help restore bodies of water affected by spillage and contaminants that pollute and destroy marine life.

Nigeria's state oil corporation has recently signed a memorandum of understanding (MoU) with the Kebbi State Government (KBSG) to build a bioethanol plant. The plant is expected to use cassava and sugarcane as a feedstock and produce 84 million liters of ethanol annually.

A range of benefits is expected to come from the project including creation of rural wealth, generation of at least 1 million direct and indirect jobs, co-generation of electricity to power the plant, and  production of animal feeds and refined sugar. The project will also involve the development of 20,000 hectares of an integrated plantation and processing plant complex.

The Nigerian government is investing in biofuels as it aims to reduce its dependence on oil and diversify its economy.

Research and Development

The properties of branched long-chain fatty alcohols (BLFLs) make them more suitable as diesel fuel replacements and for other industrial applications than their straight-chain counterparts. While microbial production of straight long-chain fatty alcohols has been achieved, synthesis of BLFLs has never been done.

The team of Wen Jiang from Washington State University engineered four different biosynthetic pathways in Escherichia coli to produce BLFLs. The team then used a modular engineering to optimize the supply of precursors to their resulting strains. This optimization improved BLFL yield concentrations by up to 6 times. The best performing strain overexpressed 14 genes from 6 engineered operons and produced 350 mg/L of BLFLs in fed-batch fermenter.

This work provides knowledge for the production of BLFLs and related chemicals in high concentrations and yields.

High temperature inhibits cell growth and ethanol fermentation of Saccharomyces cerevisiae. Previous studies, however, have found that overexpression of stress-related transcription factor genes in yeasts can improve the stress tolerance of the hosts. To increase ethanol yield of high-temperature fermentation, the team of Pengsong Li and Xiaofen Fu from Tsinghua University in China developed a series of S. cerevisiae strains by expressing eight transcription factor genes from S. cerevisiae and seven transcription factor genes from the thermotolerant Kluyveromyces marxianus in S. cerevisiae.

Their results showed that the KmHsf1 and KmMsn2 TF genes can enhance cell growth of S. cerevisiae at 4042C. Batch fermentation results at 43C that the KmHSF1 and KmMSN2-expressing strains could reach a significantly higher ethanol concentrations compared to the control strain.

Analysis found that the expression of KmHSF1 and KmMSN2 resulted in 55 and 50 differently expressed genes, respectively. Further analysis revealed that KmHsf1 could increase ethanol production by regulating genes related to transporter activity while KmMsn2 could promote ethanol fermentation by regulating genes associated with glucose metabolic process. In addition, KmMsn2 may also help to cope with high temperature by regulating genes associated with lipid metabolism.

Genetically engineered biofuel crops, such as switchgrass (Panicum virgatum L.), that produce their own cell wall-digesting cellulase enzymes could reduce costs of biofuel production. One potential source for enzyme genes is herbivorous insects that digest plant cell walls. Oak Ridge National Laboratory's Jonathan D. Willis expressed the TcEG1 cellulase from the red flour beetle (Tribolium castaneum) in swithcgrass and tested its potential in biofuel production.

The TcEG1 produced from transgenic switchgrass exhibited good endoglucanase activity. TcEG1 activity of air-dried leaves from green tissues was unchanged, but was greatly decreased when dried in a desiccant oven. Saccharification was increased in transgenic events by up to 28% and also had a 9% decrease in lignin content. Transgenic plants also produced more and narrower tillers, but  with equivalent biomass as the control.

Switchgrass overexpressing the TcEG1 gene appeared to be morphologically similar to its non-transgenic control and produced equivalent dry biomass. Therefore, we propose TcEG1 transgenics could be bred with other transgenic germplasm to yield new switchgrass with reduced recalcitrance to biofuel production.

Energy Crops and Feedstocks for Biofuels Production

Recalcitrance, one of the major barriers to the development of lignocellulosic feedstock, can be reduced by targeting genes involved in cell wall biosynthesis. However, this can have unintended consequences that compromise the agronomic performance under field conditions. West Virginia University now reports the results of a field trial of transgenic Populus deltoides lines that had previously demonstrated reduced recalcitrance without yield penalties under greenhouse conditions.

Survival and productivity of the trial were excellent in the first year, and there were no evidence of any reduced performance of the transgenic lines. Traits related to yield, crown architecture, herbivory, pathogen response, and frost damage showed few significant differences between target gene transgenics and wild types.

However, lines overexpressing the DUF231 gene, a putative O-acetyltransferase, showed early bud flush and marginally increased height growth. Meanwhile, lines overexpressing the DUF266 gene, a putative glycosyltransferase, had significantly decreased stem internode length and slightly higher volume index. Finally, lines overexpressing the PFD2 gene, a putative member of the prefoldin complex, had a slightly reduced volume index.

This field trial demonstrates that these cell wall modifications, which decreased cell wall recalcitrance under laboratory conditions, did not seriously compromise first-year performance in the field. This bodes well for the potential utility of these lines as advanced biofuels feedstock.

In Israel, Scientists from the American Associates-Ben-Gurion University of the Negev have found a new use for turkey droppings. They believe turkey and other poultry waste hold promise as a renewable fuel for heat and electricity.

The potential of poultry poop is large since huge amounts of it are produced worldwide, and the production will continue to increase as the world population grows and consumes more animal protein. The scientists also believe that treated poultry waste could replace as much as 10% of coal used in generating electricity.

The scientists compared two processes that turned poultry droppings into fuel. In the first process, they heated the excrement to create biochar, a fuel that looks and burns like charcoal. In the second, they made hydrochar using a process known as hydrothermal carbonization that mimics natural coal formation. They found that hydrochar generated 24% more energy than the biochar.

This technology could turn waste into a significant source of energy and nutrients, helping to reduce dependence on fossil fuels.

Biofuels Processing

The efficiency of enzymes is important in industrial refinery processes, including biofuel production. Chemical methods have been effective for breaking the recalcitrance of lignocellulose biomass. However, these methods have a detrimental effect on the environment. The team of Kiyota Sakai from Meijo University in Japan tested whether oxygen-radical pretreatment can enhance cellulolytic activity. The team first developed a radical generator based on non-thermal atmospheric pressure plasma technology.

Results showed that oxygen-radical pretreatment of carboxymethyl cellulose (CMC) and wheat straw enhanced the degradation of cellulose by cellulases from Phanerochaete chrysosporium. Further analysis showed that compared with non-pretreated CMC, oxygen-radical pretreatment significantly increased the production of reducing sugars. Meanwhile, the amount of reducing sugars from oxygen-radical-pretreated wheat straw was found to be 1.8 times greater than those from non-pretreated wheat straw.

These findings indicated that oxygen-radical pretreatment of plant biomass offers great promise in pre-treatment processes.