[For further information on the FAO Biotechnology Forum see the Forum website.
Note, participants are assumed to be speaking on their own behalf, unless they state otherwise.]
Sent: 24 November 2008 12:59
Subject: 31: Bioethanol production from lignocellulosics - cellulases
This is from Chitra Raghavan, Australia, again, with a follow up on application of molecular tools for the production of lignocellulosic ethanol.
The message (number 29) from Alessandro Flammini was indeed very interesting. But in my message here I would like to convey my opinion on the use of biomass from agricultural residues, for example straw and other parts of the crop plant that is left after harvest. This agricultural residue is a significant resource of lignocellulosic complexes that should be exploited for ethanol (or bioethanol) production.
Cellulose present in plants cells is complexed with lignin and hemicellulose. The challenging steps in bioethanol production from lignocellulosics in crop residues is to release the cellulose from the lignocellulosic complex and then to hydrolyse it to oligosaccharides or to the monosaccharide glucose in a cost effective manner. Simple sugars such as glucose can subsequently be fermented for the production of ethanol.
Trichoderma reesei is an industrially important filamentous fungus that secretes large amounts of cellulases (exocellulases, endocellulases and beta-glucosidase) and therefore has potential for producing enzymes for the conversion of lignocellulosic biomass materials into industrially useful bioproducts or precursors. There is growing interest in genetically modifying crop plants to produce the enzymes in an inactive form within the plant itself, to be later activated post harvest and activate the self digestion of the crop residue material. This approach would overcome not only the cost impediment associated with adding exogenous cellulase enzymes but also eliminate the need for large bioreactors and processors to produce the exogenous enzymes required for large scale biofuel production.
To enhance the expression of heterologous (foreign) genes in plants, various molecular approaches have been employed to facilitate transcription and translation. So far in this field of research, powerful promoters and signal peptide sequences that control subcellular targetting of the heterologous protein (cellulases) have been employed to enable greater accumulation of cellulases. I refer readers to an excellent review on this approach, by L.E. Taylor et al., (2008) Trends in Biotechnology 26 (8) 413-24, and an article by E.E. Hood et al. (2007), Plant Biotechnology Journal 5:709-19.
Although developing countries are faced with other challenges such as hunger to overcome, I believe there should be involvement in research as discussed above. This approach would overcome the need of depending on developed countries for the enzymes too. Initial cost into such research may be high but would pave a path of independence with regards to biofuels. Crop plants that are grown locally need to be targeted. Plants like Agave and Jatropha could also could be targeted but in the hope that they don't encroach on arable lands. The consequence of generating genetically modified crops for purposes of food and fuel would be a debate by itself but over time I believe the concept would be readily accepted.
Dr. Chitra Raghavan
School of Applied Sciences
PO Box 71
Phone + (61) 3-9925-7141
Fax +(61) 3-9925-7110
email chitra.raghavan (at) rmit.edu.au
[Trichoderma reesei is the main industrial source of cellulases and hemicellulases used to break down biomass to simple sugars that are converted to chemical intermediates and biofuels, such as ethanol. In May 2008, D. Martinez et al. published in Nature Biotechnology an analysis of its genetic material with particular emphasis on its potential contributions to fuel biotechnology and other industrial applications. See Martinez et al. 2008. Genome sequencing and analysis of the biomass-degrading fungus Trichoderma reesei (syn. Hypocrea jecorina). Nature Biotechnology 26: 553-560 http://www.nature.com/nbt/journal/v26/n5/abs/nbt1403.html
Also, the two articles referenced by Chitra above were:
L.E. Taylor et al. 2008. Heterologous expression of glycosyl hydrolases in planta: a new departure for biofuels. Trends in Biotechnology 26: 413-424. http://linkinghub.elsevier.com/retrieve/pii/S0167779908001546
E.E. Hood et al, 2007. Subcellular targeting is a key condition for high-level accumulation of cellulase protein in transgenic maize seed. Plant Biotechnology Journal 5:709-719. http://dx.doi.org/10.1111/j.1467-7652.2007.00275.x ...Moderator]
Sent: 24 November 2008 13:02
Subject: 32: Biotechnology applications for bioenergy: small-scale farmers
This is from Christina Seeberg-Elverfeldt and I have just started to work at FAO as a Bioenergy and Environment Officer in FAO's Bioenergy Unit. Since I am going to be dealing with a variety of issues connected with bioenergy, especially looking also at the usefulness of applications for small-scale farmers in developing countries and which options might be provided through biotechnology, I am very interested in this conference and to listen about the different views and information available on these issues.In particular, I would like some reactions to my question below:
Climate Change and Bioenergy Unit (NRCB)
Natural Resource Management and Environment Department;
UN Food and Agriculture Organisation (FAO)
Via delle Terme di Caracalla
Phone: 0039 06 570 54481; Fax: 0039 06 570 53250
E-mail: christina.seebergelverfeldt (at) fao.org
Sent: 24 November 2008 15:37
Subject: 33: Biogas units / applications of biotechnologies
This is from Ruzena Svedelius, again, commenting on Section 3.3b of the background document, about biogas.
Biogas units, when both biogas and biofertilisers are produced in a proper way, can positively affect waste and water management, sanitation, cultivated soils, food production, bioenergy utilisation, job creation ('green jobs' i.e. jobs supporting sustainability) etc.
Anaerobic digestion (AD) takes place almost everywhere in nature, such as in human and animal intestines, in garbage bins, in wet soils, at landfill sites, in digesters (bioreactors = reactors where biological processes take place), etc. Anaerobic means without oxygen - oxygen is always present in organic matter and in water and is essential for all living organisms.
Pre-treatment for AD can be seen as cooking for microorganisms. Living in Africa, people have to take the 'raw material' that is available for food. Living in Sweden, I can choose the most suitable 'raw material' and use more advanced recipes. Still, I do not need accurate knowledge about all the kinds of proteins, carbohydrates, enzymes and microorganisms that appear during cooking. The situation is similar when carrying out biogas production. For successful AD we need to know basic 'recipes' suitable for 'raw material' available in Africa or Sweden. In the meantime, we can extend our knowledge.
Plant biomass on average includes 16 essential elements as presented by Sune Petersson, 1984. Dry matter weight in plant biomass contain 45% carbon, 45% oxygen, 6% hydrogen (energy elements?) and the remaining 4% are nitrogen, potash, calcium, magnesium, phosphorus, sulphur, chloride, boron, manganese, zinc, cuprum and molybdenum (macro and micro nutrients that should go back to cultivated soils). On average, about 70% of plant biomass is water and that is the appropriate environment for most of the microorganisms.
My thoughts on applications of 'old' and 'novel' biotechnologies in developing countries:
1) Since a long time ago, 'old biotechnologies' (first-generation?) are applied, using microorganisms when baking, producing cheese, wine and beer, preserving food and feed by anaerobic fermentation (sauerkraut, ensilage) and AD for production of biogas. Efficiency in biogas units can be increased by collecting microorganisms from various cities and using them at other places in the world. When building simple/uncomplicated biogas units, experience/'recipes' on the 'old biotechnology' from Nepal, China, Vietnam, India, Morocco, etc. can be applied. FAO can collect the information and use it as a base for further development of biogas and biofertiliser production. The biofertilisers will improve soils, especially water and nutrients holding capacity. This will decrease the pressure on scarce water resources (comment to Section 2.6c of the background document) and increase crop yields for food. For increasing efficiency, novel equipment is needed - 'product development = new jobs'!
2) The 'novel biotechnologies' (second-generation?) can be used when studying microorganisms and by genetic modification (GM) improving their enzymatic activity. "For example, Tuskan (2007) describes some genome sequencing projects that are aiming ultimately to find genes to produce new enzymes for plant cell wall breakdown." (from 3.2c of the background document). Transport of enzymes is cheap as only small amounts are needed for pre-treatment of some feedstocks. AD "could be accelerated in several ways, such as using more efficient micro-organisms in these processes, although knowledge of these microbial communities is generally still quite basic" (from Section 3.3b of the background document). Instead of 'basic' it should be written 'very poor' !!
I know that many people are against GM. I am also very unhappy when plants are modified for increased use of man-made agrochemicals that negatively affect the environment and our health. It is unsustainable managing of natural resources. What will happen in the long term? Who is responsible? Politicians that set up weak rules? Can FAO influence improvement leading to more sustainable development?
Dr. Ruzena Svedelius,
Nobbelovs Torg 29,
SE 226 52 Lund,
Biological Transformation of Renewable Organic Material
Phone: +46 707 33 11 20
E-mail: rsvedelius (at) hotmail.com
Sent: 24 November 2008 15:50
Subject: 34: Relative importance on biotechnology for biofuel production - Uganda
This is from Hanns-Andre Pitot, again
Here in Northern Uganda, the issue is not too much about the kind of biotechnology issues discussed in the background document. It is about how to produce quantities large enough to render biofuels economically feasible. Then it's about attracting investors, predominantly foreign, that would be willing to invest in fuel production facilities. For the second to happen, the first issue has to be resolved. So, it's all about producing large quantities. In that regard, the issues I am seeing are about water and irrigation, in order to get over the dry period of several months we have here, about soil fertility, and about crops that are able to produce high yields under the local agronomic circumstances.
Technical Advisor Water and Sanitation
Adjumani Town Council
E-mail: hapitot (at) yahoo.com
DED - German Development Service
Sent: 24 November 2008 17:56
Subject: 35: Microalgae and biotechnology
This is from Dele Raheem from Nottingham, UK, again.
The current interest in the application of microalgae as a second generation biofuel is commendable and would hopefully generate collaborations among scientists both in the 'developing and developed' countries. I would like to para-phrase from two recent contributions below:
Message 30 by Ruzena Svedelius: "Why is there so much talk about ligno-cellulosic feedstocks and ethanol production in the future? Only for supporting the present liquid fuelled cars? Why is it so quiet about gas fuelled cars? Lobbying? Ligno-cellulosic feedstocks are also suitable for methanogenic fermentation for production of biogas. We have to use bioconversion technology based on biological rules."
Message 29 by Alessandro Flammini: "Currently, two of the main challenges that technology is going to face are in the oil extraction in respect of biofuel production from algae and in the production of resistant and inexpensive enzymes in respect of ligno-cellulosic conversion technologies."Now a few personal random thoughts:
I reckon countries with abundant energy resources need to assess and analyze the pros and cons of the economic viability at this stage. The cost of production - harvesting and extracting the oils from microalgae such as by ultrasonification from biomass will play a major factor. A country like Australia with lots of non-arable land is frantically leaving no stone unturned in taking advantage of this application (biodiesel from microalgae).
Dr. Dele Raheem
draheem (at) gmail.com
[The unicellular green alga Chlamydomonas reinhardtii can produce molecular hydrogen (H2) under special conditions. Hydrogenase (an enzyme that catalyses the oxidation of hydrogen) expression in Chlamydomonas reinhardtii can be artificially induced by anaerobic adaptation or is naturally established under sulphur deprivation. (see e.g.
- Kamp, C. et al. 2008. Isolation and first EPR characterization of the [FeFe]-hydrogenases from green algae. Biochim Biophys Acta. 1777:410-416 http://www.ncbi.nlm.nih.gov/pubmed/18355437 or
- Melis, A. 2007. Photosynthetic H2 metabolism in Chlamydomonas reinhardtii (unicellular green algae). Planta. 226: 1075-1086. http://www.springerlink.com/content/u232516325123037/fulltext.pdf ...Moderator]