permaculture

["Lawrence F. London, Jr." <lflj@bellsouth.net>]

On 8/26/2012 10:59 PM, jcummins wrote:
> /*Synechocystis sp. PCC6803 is a freshwater cyanobacterium capable of
> both phototrophic growth by oxygenic photosynthesis in sunlight and
> heterotrophic growth by glycolysis and oxidative phosphorylation during
> dark periods. Transitions of light and dark phases are effectively
> anticipated by a circadian clock. If */carbon dioxide  can be used to
> produce ethylene  it seems that zero emission  could be possible.
> Ethylene can be burnt but also be used to produce a lot of products.

> Sustained photosynthetic conversion of CO2 to ethylene in recombinant
> cyanobacterium Synechocystis 6803
> Justin Ungerer ,  Ling Tao ,  Mark Davis ,  Maria Ghirardi , Pin-Ching
> Maness and Jianping Yu
> Energy Environ. Sci., 2012, Advance Article DOI: 10.1039/C2EE22555G

On 8/27/2012 12:39 AM, Alia Tsang wrote:>>
>> Nitrogen- and phosphorus-enriched seawater can support both growth 
>> and ethylene production.

> I wonder if this could also be a way to reclaim phosphorous from
> seawater. A solution for eutrophication?

Since phosphorous consumed by the gene-modified cyanobacteria should 
remain in its tissues after extraction of ethylene how easy would it be 
to recycle the byproduct as fertilizer?

I would imagine this material could be used as 1) livestock food 
supplement and 2) fertilizer, assuming there are no persistent toxic 
byproducts attached 3) if it is safe for human consumption maybe it 
could be used in the soft drink industry in place of phosphoric acid 
thus saving a non renewable resource, rock phosphate, also vitamins and
packaged prepared foods. Phosphate from seawater extracted on a massive 
scale concurrently with ethylene production could be a very fine thing.

Among other issues would be what percentage of the phosphate in a unit
volume of sea water or Mississippi River water (or Louisiana Delta 
water) would the cyanobacteria absorb? Whether it would be
a useful amount for the purpose of recycling the byproducts as a 
phosphate soil amendment is another matter though it could be worthwhile 
as an NPK fertilizer anyway. An industrial application might involve 
recycling the material as a nutrient to grow 1) NPK-rich seaweed or in 
freshwater, a variety of aquatic weeds including duckweed.
Which would be the better phosphate fertilizer, cyanobacteria or sea or 
fresh water aquatic weeds fed with cyanobacteria?