Category Archives: biofuels

Myco-bio-diesel

Previously I posted on an article on making biodiesel using the fungus Gliocladium roseum. Here is a new study reporting conversion of lipids to biodiesel using the basidiomycete Cryptococcus curvatus. There has been also other progress in this area where Mucor circinelloides can also be used to produce oils suitable for biodiesel production as reported in the paper and the press release – though it is a pathogenic fungus with interesting spore size dimorphism.

Thiru M, Sankh S, & Rangaswamy V (2011). Process for biodiesel production from Cryptococcus curvatus. Bioresource technology PMID: 21930373

Fill-er-up with Myco-diesel?

ResearchBlogging.orgSo this is actually old-ish news, but I saw this press release about paper published last year describing the ability of the fungus Gliocladium roseum to naturally synthesizes diesel compounds. The paper from Gary Strobel @Montana State and collaborators describes that G. roseum produces volatile hydrocarbon on cellulose media. Extracts from the host plant (Eucryphia cordifolia) were also able to support growth of the fungus alone. This production of products have been dubbed “myco-diesel”. G. roseum is an endophyte of E. cordifolia I wonder what kinds of advantages it might provide for the fungus or the plant to produce these hydrocarbons.

I wonder if it is better to focus on these organisms that have already evolved a way to make these hydrocarbons directly from cellulose rather than the multistep process of making easy to process sugars from different starting plant materials and then ethanol or other hydrocarbons from yeast or bacteria growing on that sugar. Growth rates, amenability to grow in bioreactors, etc certainly are considerations in building production systems, but I wonder whether these kind of finding represent inroads to solving our problems or if they are peripheral to the current bioengineering approaches that are underway.

Some of the earlier press releases I had missed it seems:

G. A. Strobel, B. Knighton, K. Kluck, Y. Ren, T. Livinghouse, M. Griffin, D. Spakowicz, J. Sears (2008). The production of myco-diesel hydrocarbons and their derivatives by the endophytic fungus Gliocladium roseum (NRRL 50072) Microbiology, 154 (11), 3319-3328 DOI: 10.1099/mic.0.2008/022186-0

Brown rotting fungal genome published

ResearchBlogging.orgPostia placenta genome is now published in early edition of PNAS.   Brown rotting fungi are import part of the cellulose degrading ecology of the forest as well (hopefully) providing some enzymes that will help in the ligin to biofuels process. Brown rotters break down cellulose but cannot break down lignin or lignocellulose while white rotters (like the previously sequenced Phanerochaete chrysosporium) are able to break down the lignin.  This fungus was chosen for sequencing as it is another potentially helpful fungus in the war on sugars (turning them into fuels) including recently published Trichoderma reesei and 1st basidiomycete genome Phanerochaete (all incidentally with the Diego Martinez as first author – go Diego!). It is also helpful to contrast the white and brown rotters to understand how their enzyme capabilities have changed and how these different lifestyles evolved.  There had been some issues with the initial assembly of this genome which is basically twice as big as one would expect because the dikaryon genome was sequenced – this is where two nuclei with different genomes are present as the result of fusion between two parents of opposite mating types.  When genome sequenced is performed it is hard to assemble these into a single assembly since there are really two haplotypes present.  So these haplotypes have to be sorted out to obtain the gene ‘count’ for the organism for those who like simple numbers. This is a similar situation to the Candida albicans genome, although those haplotypes are much more similar.  The main problem is that one has to generate twice as much sequence to get the same coverage of each haplotype without playing some tricks to collapse them into a consensus and them afterwards separate the haplotypes back out.  At any rate, this sequenced provided a good summary of the gene content and thus metabolic and enzymatic capabilities to match up functional data collected from LC/MS and transcriptional profiling. 

There are several other rotting fungi that are nearly done at JGI (but the task of writing and coordinating the analyses for the papers are ongoing!) include Schizophyllum commune and Pleurotus ostreatus. There are also several more mycorrhizal and plant pathogenic basidiomycete fungi as well as some classic model systems that have finished genomes and are in the process of finalizing papers.  It is an exciting time that is just beginning as these genome and transcriptional data are integrated and compared for their different ecological, morphological, and metabolic capabilities.

The article is unfortunately not Open Access so I haven’t even read it from home yet, but pass along this news to you, dear reader. Will get a chance to read through more than the abstract to see what glistening gems have been extracted from this genomic endeavor.
D. Martinez, J. Challacombe, I. Morgenstern, D. Hibbett, M. Schmoll, C. P. Kubicek, P. Ferreira, F. J. Ruiz-Duenas, A. T. Martinez, P. Kersten, K. E. Hammel, A. V. Wymelenberg, J. Gaskell, E. Lindquist, G. Sabat, S. S. BonDurant, L. F. Larrondo, P. Canessa, R. Vicuna, J. Yadav, H. Doddapaneni, V. Subramanian, A. G. Pisabarro, J. L. Lavin, J. A. Oguiza, E. Master, B. Henrissat, P. M. Coutinho, P. Harris, J. K. Magnuson, S. E. Baker, K. Bruno, W. Kenealy, P. J. Hoegger, U. Kues, P. Ramaiya, S. Lucas, A. Salamov, H. Shapiro, H. Tu, C. L. Chee, M. Misra, G. Xie, S. Teter, D. Yaver, T. James, M. Mokrejs, M. Pospisek, I. V. Grigoriev, T. Brettin, D. Rokhsar, R. Berka, D. Cullen (2009). Genome, transcriptome, and secretome analysis of wood decay fungus Postia placenta supports unique mechanisms of lignocellulose conversion Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0809575106