Fish feed from wastes

With a global fish production/catch of about 100 million tons per year, fish feed is being more important in our daily life. Considering salmon as an example, we need 2,5 kg fish feed for producing each kg of the fish. We together with our parner companies, Cewatech AB and Nordic Paper in Säffle are developing zygomycetes fungi as fish feed in a large pilot plant. The pilot is now producing the fungus from the byproducts of the pulp industries, and the product is going to be tested by fishfeed indutries in large scales. These organisms are safe for humas as being used as daily food (tempeh) in Southeast Asia such as Indonesia for centuries. Let's hope this development lead to prevent catching small fishes for feeding large fishes.


(A zygomycete fungus used in this work. The picture was taken by our PhD student Patrik Lennartsson)

A PhD thesis on biological superabsorbents

Here is a PhD thesis by our former PhD student Akram Zamani about Superabsorbent Polymers from the Cell Wall of Zygomycetes Fungi. Akram started her PhD in Borås 2006 and defended her thesis in Oct. 2010. Here are the published articles from her thesis:

1- Determination of glucosamine and N-acetyl glucosamine in fungal cell walls. Journal of Agricultural and Food Chemistry 2008; 56 (18): 8314-8318.

2- Extraction and precipitation of chitosan from cell wall of zygomycetes fungi by dilute sulfuric acid. Biomacromolecules 2007; 8 (12): 3786-3790.

3- Production of low molecular weight chitosan by hot dilute sulfuric acid. BioResources 2010; 5 (3): 1554-1564.

4- Temperature shifts for extraction and purification of zygomycetes chitosan with dilute sulfuric acid. International Journal of Molecular Sciences 2010; 11(8): 2976-2987.

5- A new foaming technique for production of superabsorbents from carboxymethyl chitosan. Carbohydrate Polymers 2010; 80 (4): 1091-1101.

6- Effects of partial dehydration and freezing temperature on the morphology and water binding capacity of carboxymethyl chitosan-based superabsorbents. Industrial & Engineering Chemistry Research 2010; 49: 8094-8099.

7- Effect of carboxymethylation conditions on water binding capacity of chitosan-based superabsorbents. Carbohydrate Research, in press.

A PhD thesis on Citrus Waste Biorefinery

Here is a PhD thesis of our former PhD student Mohammad Pourbafrani, about Citrus Waste Biorefinery: Process Development, Simulation and Economic Analysis. He came to Borås as PhD student in 2006 and was graduated in May 2010. Here are the published papers from his thesis:

1- Protective Effect of Encapsulation in Fermentation of Limonene-contained Media and Orange Peel Hydrolyzate, International Journal of Molecular Science, 2007, 8(8), 777-787.
2- Optimization Study of Citrus Wastes Saccharification by Dilute-Acid hydrolysis, BioResources, 2008,3(1),108-122.
3- Production of biofuels, limonene and pectin from citrus wastes, Bioresource Technology, 2010,101(11), 4246-4250
4- Process design and economic analysis of a citrus waste biorefinery with biofuels and limonene as products, Bioresource Technology, 101(19): 7382-7388

Language and culture, a challenge in collaboration

In the last few years, I travelled all around the world and discussed with many people on converting wastes into value-added products. Having different language is an obvious problem, but we tried to find a common language, which is usually English. The other challenge is the culture. We should make sure that the audience understand what we mean, and not what we say. Therefore, talking about a sensitive issue through interpreter is not an easy task. Universities and their global networks with each other and local networks with their communities make a great help in this issue, and can be considered as link between societies.


(A funny video from Youtube about 24 different English accents)

Biological Superabsorbents from fungi cell wall

Zygomycetes are a class of saprophytic fungi, which can grow on different waste materials. We are working on this class since 1999, and have several publications. They can grow in harsch conditions and produce several metabolites such as ethanol and lactic acid, or different enzymes. However, their cell mass has about 20% cell wall, which compose mainly of chitosan. Our PhD student Akram Zamani worked for several years on these fungi, in order to characterize their cell wall and produce superabsorbents from them. She defend her thesis soon. Let's wish her a good success during the defense and afterward in her life!


(The cover of her thesis, which shows the steps from fungi to superabsorbents)

Viva scavengers

Latin America with 524 million population, produces about 130 million tons wastes per year. Brazil with 1.152 kg/day/person wastes stands for haft of this wastes. This wastes is practically dumped, and just about 2% is recycled. This recycling is carried out mainly by scavengers that are about 100,000 families in Latin America, of which 10-30% are children and are working with slavery conditions, as we heard from our friends both at Rio de Janeiro and Sao Paulo universities. Recognition of their work by the governments in the region and more attention in the media and help by people, may help to increase their recycling from 2% to the corresponding level in Sweden which is about 35%.

(Treatment and final deposition of wastes in Brazil, Ref: Alvaro Cantanhede, UFRJ, Brazil)

Good business with landfill gas in Brazil

Together with our friends from University of Sao Paulo in Brazil, we visited today the old landfill of Sao Paulo named "Bandeirantes". This landfill received 50 million tons wastes in 1979-2007, and converted a valley to a hill with 150 m height of the wastes. The landfill is now closed to new wastes and covered. A company named "Biogas" collect the landfill gas via 300 wells and convert them to electricity via engines. They had about 14000 m3/h gas with about 49% methane, which is now reduced to about 6000 m3/h. They sells 10 MW electricity now. In addition, the company is registered to CDM to sell also the carbon emission credits, which was 2000 tons/day in 2007 and 700 tons/day now. The price of each ton equivalent CO2 saving is about 8-10 Euro. The company says its 50 million USD investment was paid back in 2 years. Good investment for both the companies involved and also the environment!


(Bandeirantes landfill in Sao Paulo, Brazil with 1.2 km2 and 150 m height of the waste. The wells for gas collection are visible in the photo)

Electricity from nuclear or municipal waste in Iran?

The nuclear dispute of Iran is a well known subject. In 1970s, the king decided to build a German nuclear power plant with Persian Gulf in Bushehr, a decision which was not changed after the revolution and is now finished with the help of the Russians. This plant with 1,000 MW capacity was fueled today after 35 years. On the other hand, the country produces approximately 35 million tons municipal solid wastes per year. My calculation show the possibility to produce 4,000 MW electricity from this waste in Iran, a material which is practically dumping today. Let's hope that Iran put its attention to develop waste to electricity in the future!

Biogas in Germany

The development of biogas in Germany has many similarities and possible debate as ethanol in the USA. Germans use mainly grains and energy crops to produce biogas. The number of the plants was 850 in 1999 and is nowadays around 5000 units. The major application of biogas in this country is burning the gas into electricity. I should congradulate our neibouring country for this success. However, an important point here is the efficiency of heat to electricity, that is about 30-50% by e.g. engines, turbines or fuel cells. It means Germans are missing 50-70% of the energy produced. We use this energy in Sweden in form of district heat.

7,000,000,000 tons per year carbon emissions

In the last 110 years, the global carbon emission has increased by about 14 times to more than 7,000,000,000 tons/year. The earth has no capacity to re-absorb this amount of carbon and might collapse, if we continue in the same way!


(Ref: Ekonomifakta)