News and Trends
In Jakarta, the first US-Indonesia municipal waste-to-bioproducts project, known as JababECO, was recently launched at an event attended by US vice president Mike Pence and the Indonesian vice president Jusuf Kalla.
The municipal waste-to-bioproducts plant will process food waste into bioproducts, including bioethanol. When complete, JababECO will produce approximately 500,000 gallons of bioethanol, as well as a protein concentrate to be used as liquid fertilizer and animal feed.
Setyono Djuandi Darmono, chairman and founder of Jababeka & Co believes his company is breaking new ground in dealing with Indonesia's waste management. He believes that cities of the future need new and innovative approaches to outgrow challenges, and believes that JababECO will prove to be an ideal waste solution for Jakarta's needs.
Air Canada recently announced its participation in the Civil Aviation Alternate Fuel Contrail and Emissions Research project (CAAFCER). It is a research project led by the National Research Council of Canada (NRC) to test the environmental benefits of biofuel use on contrails.
The project will measure the impact of biofuel blends on contrail formation by aircraft on five biofuel flights operated by Air Canada between Montreal and Toronto. A reduction in the thickness and coverage of contrails produced by jet engines of aircraft could reduce aviation's impact on the environment, a beneficial effect of biofuel use in aviation.
During the biofuel flights, the National Research Council of Canada will trail the Air Canada aircraft with a modified T-33 research jet to sample and test the contrail biofuel emissions. The sustainable biofuel is produced by AltAir Fuels from used cooking oil and supplied by SkyNRG.
Air Canada has been taking steps to reduce its carbon footprint. One of its most notable recent accomplishments is a 40% improvement in average fuel efficiency between 1990 and 2016.
The United Nations University has recently published a paper reviewing the potential of a biofuels industry for Zambia, both domestic and the potential South African market. This comes after South Africa announced its plans to start blending mandates.
The report also identifies potential biofuel feedstocks as crucial factors for establishing a viable industry in the country. These feedstocks include sugarcane, cassava, sweet sorghum, and maize. Soybeans, sunflower, and groundnuts are also specified as likely feedstocks of choice for biodiesel production.
Currently, the production levels for these identified feedstocks are not enough to meet growing biofuels demand, and there is a need for increasing production.
Al Mana Restaurants & Food Company, the owner and operator of McDonald's franchise in Qatar, has announced that the fast food chain will reduce its environmental footprint and adopt innovative ways to manage its wastes.
McDonald's has developed an oil recycling program in collaboration with Green Brokerage for Oil (GBO). GBO will collect used oil from the fast food to process it in biodiesel plants. In 2016, the 40 outlets of McDonald's used about 108,780 liters of cooking oil, while in the first three months of 2017, a total of 47,960 liters of cooking oil has already been used.
The program will ensure that used oil from McDonald's restaurants in Qatar doesn't end up in water bodies and that it is recycled for other uses. The biodiesel produced from waste vegetable oils produces less toxic pollutants and greenhouse gasses than petroleum diesel. Experts believe that using biodiesel can reduce greenhouse gasses up to 78%.
Research and Development
Lignocellulose from hardwood species is a good source of sugars for biofuels. However, extensive acetylation of hardwood xylan impedes lignocellulose saccharification by blocking xylan hydrolysis and causing inhibitory acetic acid during fermentation. The team of Xiaoyu Zhu and Yan Zhou from Chinese Academy of Sciences aimed to improve aspen saccharification through the introduction of the acetyl xylan esterase AnAXE1 from Aspergillus niger into aspen, to facilitate deacetylation of xylan.
AnAXE1-expressing plants exhibited reduced xylan acetylation and grew normally. Without pretreatment, their lignocellulose yielded 25% more glucose per unit mass of wood than wildtype plants. After acid pretreatment, glucose yields still slightly improved. Further analysis revealed that AnAXE1 expression in aspen also reduced the molecular weight of xylan and xylan–lignin complexes, increased cellulose crystallinity, altered the lignin composition, and increased lignin solubility in dioxane and hot water.
This study revealed several changes in plant cell walls caused by deacetylation of xylan. Deacetylating xylan not only increased its susceptibility to hydrolytic enzymes but also changes the cell wall architecture, increasing the extractability of lignin and xylan and aiding saccharification.
The production of lignocellulolytic enzymes is transcriptionally regulated by multiple transcription factors. Liwei Gao, together with Shandong University researchers have previously engineered a Penicillium oxalicum for improved cellulase production via manipulation of three genes in the cellulase regulatory network. However, the potential of modifying multiple regulators while overexpressing their targets has not been fully explored.
The team recently verified that a point mutation XlnRA871V in the transcription factor XlnR enhanced the expression of lignocellulolytic enzymes, particularly hemicellulases, in P. oxalicum. The overexpression of XlnRA871V was then combined with the overexpression of the cellulase transcriptional activator ClrB and deletion of carbon catabolite repressor CreA.
The resulting strain RE-7 showed significant increases in cellulase and xylanase production compared to the starting strain. Further overexpression of two major cellulase genes cbh1-2 and eg1 enabled an additional 13% improvement in cellulase production. However, XlnRA871V also led to decreased production of β-glucosidase and amylase due to reduced transcription of enzyme-encoding genes.
These results illustrate that combinational manipulation of transcription factors and their target genes can be a viable strategy for efficient production of lignocellulolytic enzymes in filamentous fungi.
Nutrient limitation, such as nitrogen depletion, is the most used method for improving microalgae fatty acid production. However, these harsh conditions also significantly inhibit algal growth. To avoid these problems, a team of researchers from Shenzhen University used artificial microRNA (amiRNA) technology to manipulate metabolic pathways and increase fatty acid contents effectively in Chlamydomonas reinhardtii.
Aiming to downregulate the expression of phosphoenolpyruvate carboxylase (PEPC), the team designed amiRNAs against two CrPEPC genes, which catalyzes the formation of oxaloacetate and regulates carbon flux, and transformed them into Chlamydomonas cells. These amiRNAs were then induced by heat shock treatment.
The transcription levels of amiRNAs increased 16–28 times, resulting in the remarkable decreases of the expression of CrPEPCs. This resulted in the inhibition of the expressions of the CrPEPC genes which significantly increased the total fatty acid content in the transgenic algae, thus, also increasing the content of C16–C22 fatty acids.
These results suggest that amiRNAs can effectively downregulate the expression of CrPEPCs in C. reinhardtii, resulting in an increased fatty acid synthesis.
Policy and Regulation
Abu Dhabi will soon start to turn waste into biodiesel under a new recycling scheme.
The Centre of Waste Management in Abu Dhabi, Tadweer will now provide permits to companies allowing them to produce biodiesel for use in buses and lorries. Leftover cooking oil, fat, and grease from kitchens in homes and restaurants across the country could be collected and used as part of the scheme.
A similar system is already in operation in Dubai, where a waste management company recycles 227,000 liters of waste oil per day. Aside from being used for biofuel production, the oil is also sold to companies in India and Pakistan to be used to produce soap.
UAE still spends millions each year clearing blocked drains and sewers despite heavy fines issued to companies caught disposing of leftover oil inappropriately.