Can a micro-organism help replace fossil fuels with biofuels?

The world we are living in is so dynamic and vibrant. Let’s imagine for a while. What if the world suddenly runs out of coal, gas and oil. It is not hard to predict that the vehicle tanks would become dry, airplanes would be grounded, many industrial processes would be halted, tens of thousands of jobs would be lost and the economy would be in turmoil. Afterall, the dynamicity and vibrancy of the world would be stifled.

Figure 1: Air pollution caused by burning coal. Photo: Hugh Llewelyn, Creative Commons

Around 85 % of global energy demand is supplied from fossil fuels (coal, gas and oil). A mere 15 % is supplied from nuclear energy and renewable energy sources. Worryingly, the earth has a limited reserve of fossil fuels. Scientists predict that fossil fuels will be depleted from the Earth between 2069 and 2088 if we continue to exploit them at the rate we do now.

Fossil fuels are one of the major contributors to global warming. A huge amount of carbon dioxide gas is released into the atmosphere when we burn them to produce electricity, power motor vehicles and perform other activities. Carbon dioxide accounts for 81% of greenhouse gas which traps the reflected solar radiation from Earth and increases Earth’s surface temperature.

Figure 2: Jetstar Airways preparing to board biofuel flight. Photo: Jetstar Airways, Creative Commons

So, there is pressing need to find alternatives to fossil fuels. Biofuels are the best alternatives for now as they are compatible with most of the existing technologies and easily transportable. They are renewable energy sources as biofuel crops can be grown multiple times in the same location. Unlike fossil fuels, biofuels are carbon neutral as the released carbon dioxide gas while burning biofuels is what biofuel crops absorb from the atmosphere while growing.

Nevertheless, humanity cannot simply mask the problems of fossil fuels and carbon emission by production of biofuels. The agricultural expansion of land such as converting forested areas into agricultural land for production of biofuel crops brings about environmental problems. Since conventional biofuels are normally produced from crops like sugarcane, corn, soybean and palm oil, the crops compete with agricultural products and may raise food prices in the face of population growth.

Nowadays, the use of second-generation biofuels such as different varieties of grasses is gaining popularity. The main characteristic of second-generation biofuels is that the raw materials are not food crops.

Figure 3: Biofuel crops shall become products with high economic yield in major farmlands (Photo: Ngawang Thapke Sherpa)

Miscanthus or Mxg (Full scientific name Miscanthus x giganteus) is a perennial, second-generation biofuel feedstock which can grow up to 2 meters each year. It can be harvested every year and can be grown under low soil nutrition. It has the highest yield (more than 30-ton dry matter/ha/year) of all current second-generation biofuel feedstocks. As the stems of Miscanthus are strong, flexible and unbreakable while bending, they are also used as shelterbelts on dairy farms to protect the pasture grasses from adverse weather conditions, while allowing the use of pivot irrigators. Miscanthus also helps with decomposition of organic materials available in the soil, release of nutrients, increasing earthworm availability and enrichment of  biodiversity.

 

Figure 4: Miscanthus crop. Photo: Simon Mortimer, Creative Commons

The enhanced productivity of Miscanthus is important in terms of sustainable agricultural practices and economic benefit.  A group of research scientists including Ivan Chirino-Valle, Chris Littlejohn, Robert Hill, Nicholas Cummings and Stephen Wratten from Lincoln University carried out a research, which investigated on the effects of the use of a fungus called Trichoderma on the growth of Miscanthus. The Trichoderma species live in co-benefit with plants including maize, barley, and sugarcane.

The researchers carried out three different experiments. In their first experiment, they studied the effects of Trichoderma on the growth of Miscanthus in soil containing a harmful fungus called Rhizoctonia solaniMiscanthus growth was examined in two different groups of soil pots in the glasshouse. The first group of soil pots had Trichoderma mixed with the soil while the second group did not. Rhizoctonia solani was present in both soil types. After 17 months, they found that the percentage of roots colonized and the dry weights of shoot, root, and rhizome were significantly higher in soil pots containing Trichoderma compared to the other group.

The second experiment featured Miscanthus rhizomes that were soaked overnight in a solution containing a mixture of Trichoderma species which were then planted back in the soil pots. After 120 days, they found that the height and shoot dry weight of Miscanthus plants that were treated with Trichoderma species were significantly higher than the untreated plants. They also found that the green color pigment on the leaves and water-soluble carbohydrates in the shoots were significantly higher in the plant groups treated with Trichoderma species.

They carried out the third experiment in the field. At five months after plantation, they found that the heights of Miscanthus plants treated with Trichoderma species were taller than the untreated plants.

Figure 5: Field harvesting. Photo: Gordon Robertson, Creative Commons

Overall, the study proved that the Trichoderma species can enhance the productivity of biofuel feedstock plants. With the application of this beneficial fungus, the commercial production of biofuels can be substantially increased for little financial outlay, which is crucial to replace the conventional fossil fuels. With sufficient biofuels, we can envision a world with a clean air where the  development and dynamicity continue to flourish, unaffected by the loss of fossil fuels.

The author Ngawang Thapke Sherpa is a postgraduate student in the Master of Natural Resource Management & Ecological Engineering. He wrote this article as part of his assessment for ECOL 608 Research Methods in Ecology.

For additional details, please visit the link to the research paper.

Chirino-Valle, I., Kandula, D., Littlejohn, C., Hill, R., Walker, M., Shields, M., Cummings, N., Hettiarachchi, D., & Wratten, S. (2016).

Potential of the beneficial fungus Trichoderma to enhance ecosystem-service provision in the biofuel grass Miscanthus x giganteus in agriculture. 

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