Yummy, Carbonated Light

On the topic of biofuels, solar technology developer Joule Unlimited, Inc. announced yesterday that they have been issued a U.S. patent (#7,794,969, titled "Methods and Compositions for the Recombinant Biosynthesis of n-Alkanes") covering its new energy conversion process. The process converts sunlight and waste carbon dioxide (CO2) into liquid hydrocarbons that the company claims are fungible with conventional diesel fuel. So unlike making traditional biofuels (where you turn sugar or algal or agricultural biomass into alcohol - see story below), this technique is a direct, single-step, continuous process requiring no raw material feedstocks. The company claims that this could be incredibly efficient and cost as little as $30 per barrel equivalent.

Alright. Cool. So what exactly is happening here? Well, Joule has these microorganisms (they don't say what kind) that function as biocatalysts that use only sunlight, waste CO2, and non-fresh water to produce hydrocarbons that are diesel range and chemically distinct from biodiesel. Oh, and they are compatible with the existing infrastructure. Wanna add some more good news? Apparently they are sulfur-free and ultra-clean.

Do I sound a little skeptical? Probably because I am a little skeptical. After all, this info is coming from a company press release. So I looked up the patent number to try to fill in a couple of holes in the story.

One of these holes is the microorganism they are using to convert the light and CO2 into fuel. Apparently they are using an engineered cyanobacterium that "comprises a recombinant acyl ACP reductase (AAR) enzyme and a recombinant alkanal decarboxylative monooxygenase (ADM) enzyme; and exposing said engineered cyanobacterium to light and carbon dioxide, wherein said exposure results in the conversion of said carbon dioxide by said engineered cynanobacterium into n-alkanes, wherein at least one of said n-alkanes is selected from the group consisting of n-tridecane, n-tetradecane, n-pentadecane, n-hexadecane, and n-heptadecane, and wherein the amount of said n-alkanes produced is between 0.1% and 5% dry cell weight and at least two times the amount produced by an otherwise identical cyanobacterium, cultured under identical conditions, but lacking said recombinant AAR and ADM enzymes."

Mmm-hmm, that's a lot of "said's." I would refer to the patent itself (link below) if you are interested in details like the actual amino acid sequences of said (*smile*) enzymes. Another hole is the productivity and/or efficiency of this process, and this is where I would again point you to the patent itself because it is a while lot of numbers. Although there are some figures that help to simplify the information. Based off of what I know of biofuels (which, admittedly, isn't all that much) it seems kinda impressive. That is, of course, if it works.

Another concern, or hole, they left, at least in their press release, was their plans for mass production. In my opinion, on of the problems with biofuel production is not just the efficiency (or lack of) of the process but actually scaling up the process to make an affordable product that anyone can buy anywhere. And that, I think, will be the thing to watch for with a story like this: Will we, average people, ever see this easily available to us?

Look up the patent using the U.S. Patent Number 7,794,969 at this website:
http://patft.uspto.gov/netahtml/PTO/srchnum.htm

This is the press release from Joule:
http://www.jouleunlimited.com/news/2010/joule-awarded-patent-renewable-diesel-production-sunlight-and-co2

This is where I originally found the story, but it says basically the same things as the press release:
http://www.newenergyworldnetwork.com/renewable-energy-news/by-technology/solar-by-technology-renewable-energy-news/joule-awarded-us-patent-for-liquid-fuel-from-the-sun-technology.html

(image from organiclightsculptures.com)

Algae Evolution Resolution

The kingdom-level taxon Chromista means "colored." Members of this group are photosynthetic but are not closely related to land plants or other algae. They contain chlorophyll c, fucoxanthin, lack the plasmodesmata, and do not store their energy in the form of starch. They also contain pigments not found in plants, pigments that give them their characteristic brown coloration. Phaeopheta, the brown algae, are the largest members of the Chromista group and are mostly marine organisms. They are typically coastal, found attached to rocks, coral, or other firm surfaces. Those large kelp forests that you see seals swimming through on nature programs are a good example of this group.

A new paper in Nature takes a look at the brown algal genome to understand the evolution of multicellularity and photosynthesis. Researchers sequenced the genome of Ectocarpus siliculosus, a large brown seaweed that occurs along temperate latitude coastlines. In their paper they report on the 214 million base pair genome sequence.

They found that the E. siliculosus genome includes several features that have evolved for surviving in hostile shoreline environments that vary in light intensity, temperature, salinity and wave action. The researchers found a light harvesting complex (LHC), 53 loci including a cluster of 11 genes with highest similarity to the LI818 family of light-stress related LHCs. Also, the genome is predicted to encode a light-independent protochlorophyllide reductase (DPOR). This allows for the synthesis of chlorophyll under dim light. Together LHC and DPOR allow for survival in environments with highly varying light conditions. The genome encodes 21 putative dehalogenases and two haloalkane dehalogenases that may serve to protect the alge against halogenated compounds produced by kelps as defence molecules. This allows the brown algae to grow epiphytically on these organisms. The cell walls contain alginates and fucans, polysaccharides with properties that help in the resistance to mechanical stress and protection from predators.

The researchers also predicted the pattern of loss and gain of gene families during the evolution of a broad range of eukaryotes. A comparison of genomes showed that the major eukaryotic groups "have retained distinct but overlapping sets of genes since their evolution from a common ancestor, with new gene families evolving independently in each lineage. On average, lineages that have given rise to multicellular organisms have lost fewer gene families and evolved more new gene families than unicellular lineages. However, we were not able to detect any significant, common trends, such as a tendency for the multicellular lineages to gain families belonging to particular functional (gene ontology) groups." They found many genes for kinases, transporter and transcription factors, that are also commonly found in land plants. They suspect that these kinases play a key role in the origin of multicellular organisms. These data also relate to the idea that brown algae arose from the fusion of green alga and red alga as a high proportion of the genes that are characteristic of green algae, including the kinases and transporters typical of land plants, were found in the brown alga.

Here's the paper (its a little dense, especially if you are not a geneticist):

Cock, J. Mark, et al. (2010) The Ectocarpus genome and the independent evolution of multicellularity in brown algae. Nature: 465 (7298), 617-621. (DOI: 10.1038/nature09016)

(image from oceanexplorer.noaa.gov)

Soiled

In a new paper published online in Nature Geoscience, researchers from UC Irvine and Yale have found that as global temperatures increase, soil microbes become less efficient over time at converting soil carbon into carbon dioxide.

Soil microbes are extremely abundant in most ecosystems around the world. The most numerous of these microbes are bacteria followed by actinomycetes then fungi, soil algae, cyanobacteria, and protozoa. For the purposes of this post I am not including the diverse set of animals that live in soils such as nematodes, microarthropods, earthworms, larger insects, etc. Soil microbes are extremely important in the cycling of the soil nutrients carbon (C), nitrogen (N), phosphorus (P), and sulfur (S). They can regulate the quantities of nitrogen available to plants (think natural fertilizer), and are hugely important in recycling nutrients tied up in organic materials. Many of the soil microbes require organic carbon compounds to oxidize for energy (microbial or soil respiration, usually expired as CO2) and the building materials for their cells. Some microbes get this carbon from CO2, but much of this carbon is collected through the decomposition of organic materials. Soil respiration is known to be affected by such factors as temperature, soil moisture, and nutrient availability.

Naturally, the high abundance of soil microbes and their release of CO2 through respiration has caused many scientists to take a special interest in this system and how it relates to global climate change. It stands to reason that even a few degrees of warming will shift these microfauna into overdrive, increasing the atmospheric CO2. However, this new research shows that, in a warmer environment, soil respiration increases for a short period of time, but if the higher temperatures remain constant, the less efficient use of carbon causes the microbes to decrease in number. This decrease in number decreases soil respiration (decrease in CO2 "exhaled" from soils). The microbes get overheated and "burned out," if you will.

These results contradict some of the results in older models which assume microbes will stay at constant numbers or increase; older models usually do not include enzyme production/activity which is sensitive to temperature and important in the reactions that break down organic carbon. When you get down to the mechanism, its all about how efficiently the microbes can use soil organic carbon. If they are less efficient then populations decrease. If they stay efficient, or adapt to remain as efficient or more so (and remember that microbes can adapt very quickly), then respiration/CO2 emission will stay the same or increase.

Read more here:
Allison Steven D., Matthew D. Wallenstein and Mark A. Bradford (2010) Soil-carbon response to warming dependent on microbial physiology Nature Geoscience: published online (DOI: 10.1038/ngeo846)

and
http://www.physorg.com/news191482974.html
http://www.sciencedaily.com/releases/2010/04/100426131612.htm

(image from www.sustainabilityninja.com)

Sexy Algae

Boy meets girl. Boy and girl fall for each other. Boy and girl generate other boys and girls. Its a tale as old as time. Well, kinda. Evolutionarily speaking, there weren't always boys and girls, just its. Those Its reproduced asexually, an efficient if not always a genetically or evolutionarily advantageous reproductive strategy. The evolution of two sexes that swap genes with each other allows for a more diverse and robust gene pool. Usually a great thing. But how did it get that way, at what point did we go from It to Us?

A new study in the journal Science takes a look at Volvox carteri, a multicellular green algae, for the answer to that very question. The authors of the paper compared the sex determining region of V. carteri to that of Chlamydomonas reinhardtii, a unicellular algal relative. They found that this region differed dramatically between these species. The expansion of this region allows for a greater diversity of genes which code for the production male and female gametes. The gametes of C. reinhardtii look identical, but those of V. carteri are distinctly different (egg and sperm).

The mating locus genes of the two species share many genes, but V. carteri's region is almost five times larger, mainly due to additional genes under the control of either male or female programs. Some of these new, additional genes have counterparts in C. reinhardtii that have nothing to do with sex. V. carteri has taken these genes, incorporated them into the mating locus, and started using it in its sexual reproductive cycle. Specifically, the mating locus gene MAT3 has evolved a new role in sexual differentiation, likely a role in controlling cell division and male/female reproductive development.

Future research will involve Gonium, an evolutionarily intermediate species between Volvox and Chlamydomonas. This intermediate will allow researchers to take a look at those in-between steps in the evolutionary process to better understand how this evolutionary change occurred.

Here's the Science article:
Ferris, Patrick et al. (2010) Evolution of an Expanded Sex-Determining Locus in Volvox. Science: 328 (5976), 351. (DOI: 10.1126/science.1186222)

and http://www.sciencedaily.com/releases/2010/04/100415141125.htm

(image from eebweb.arizona.edu)