US application 20150045537 to MIT on release of lipid-containing vesicles from cyanobacteria

US application 20150045537 was published last week on 12 Feb. 2015. The listed inventors are

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Chisholm; Sallie Watson; (Watertown, MA) ; Biller; Steven James; (Watertown, MA) ; Thompson; Anne Williford; (Santa Cruz, CA)

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and the title is --EXTRACELLULAR RELEASE OF LIPIDS BY PHOTOSYNTHETIC CELLS --. Priority goes to a provisional patent application filed Mar 16, 2012 .

The first three claims are

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1. A method for harvesting lipids, comprising: culturing in growth medium a photosynthetic cyanobacteria that secretes lipid-containing vesicles into the growth medium; and separating the secreted lipid-containing vesicles from the cyanobacteria and/or from the growth medium.

2. The method of claim 1 further comprising collecting the lipid-containing vesicles.

3. The method of claim 1 wherein the photosynthetic cyanobacteria is of the genus Prochlorococcus, Synechococcus, Synechocystis or Nostoc.

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The first example is

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Example 1

Production of Outer Membrane Vesicles by Cells Such as Prochlorococcus Cells

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One notes that Example 2 is written in the present tense (suggesting work not done; "prophetic")

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Example 2

Optimization of Vesicle Production in Prochlorococcus and Synechococcus

[0079] Investigation is conducted into which strains of Prochlorococcus and Synechococcus produce lipid vesicles and whether production varies significantly among different strains. Prochlorococcus cells isolated from the upper regions of the ocean have significant differences in both genomic content and physiology from those isolated from deeper depths, so vesicle production could co-vary with some of these traits. Vesicle production is also investigated in Synechocystis sp. PCC6803, a cyanobacterium widely used in biofuel research. Initial measurements of vesicle size and concentration are made using the NanoSight, and corroborated with standard scanning and transmission electron microscopy techniques. A systematic survey of vesicle production is conducted in one or a few selected strains under a variety of conditions. Using the NanoSight, vesicle production is followed across a complete growth curve, from lag phase to mid-exponential and stationary phase, to see if rates of lipid release vary. How vesicle production might vary in cultures grown under constant irradiance as opposed to a typical day-night cycle, at different salinities, temperatures, and under various stress conditions is also investigated. Together these studies elucidate the physiological variables that influence vesicle production, useful information for maximizing lipid production in a biofuel production context.

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**The corresponding PCT application is PCT/US13/30516. The written opinion was mailed 5 June 2013 and found the 36 examined claims to be obvious, in part over a published application by Wim Vermaas.

Those following the field will recall a paper published a bit more than one year ago:

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Bacterial Vesicles in Marine Ecosystems, Science 10 January 2014:
Vol. 343 no. 6167 pp. 183-186

authors: Steven J. Biller1,*, Florence Schubotz2, Sara E. Roggensack1, Anne W. Thompson1, Roger E. Summons2, Sallie W. Chisholm1,3,*

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The paper in Science was received at Science 18 July 2013 (after the unfavorable written opinion for the PCT).

A post at Wired had observed:

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Because they are so abundant, and because they contain various biomolecules, these vesicles constitute a significant source of organic carbon, nitrogen, and phosphorus on which other organisms might feed. Indeed, Chisholm and her colleagues showed that other, nonphotosynthetic bacteria can grow using the cyanobacterial vesicles as their only source of carbon. “That’s kind of neat,” says Marvin Whiteley, a microbiologist at the University of Texas, Austin, who wasn’t involved in the study. “It really changes how we think about marine ecosystems and how they’re set up and how nutrients are provided.”

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