Aquaponics Digest - Fri 03/27/98
Message 1: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
from crystal
Message 2: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
from GCR
Message 3: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
from John Shannonhouse
Message 4: Safe plastics ?
from bard@rof.net
Message 5: Light Expanded Clay Aggregate
from bard@rof.net
Message 6: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
from "H.Doelle"
Message 7: Paula, NAVY BEING SUED!!
from S & S Aqua Farm
Message 8: Introduction
from S & S Aqua Farm
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| Message 1 |
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Subject: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
From: crystal
Date: Fri, 27 Mar 1998 13:53:41 -0800
"Donald Trotter Ph.D." quoted "clarkjd@server.multipro.com at cclink":
> What happens when increasing amounts of nitrogen over normal amounts
> are taken out of the atmosphere, or increased amounts of nitrogen are
> introduced in the soil?
Will there be more CO2 in the atmosphere? Increasing the greenhouse
effect - for example, if used on Mars?
> By introducing such bacteria into the soils of our earth, are we not
> opening the door to modifying radically the nutrient flow structure of
> the earth?
I don't think Gaia will break.
Best Regards,
Crystal.
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Subject: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
From: GCR
Date: Fri, 27 Mar 1998 08:25:24 +0000
Thank you Donald for that interesting and enlightening post.
Dear Crystal,
As in any engineered system, plants, animals, and machines are designed to
operate best within narrow, specific parameters. One of the wonders of
living systems is their ability to adapt somewhat to changes in the
parameters where machines cannot adapt.
Earth changes are observed in millenia, not days and years as we know it.
The mere fact that we can quantify changes in the earth's atmosphere and
biosphere in two decades should be cause for alarm. There is no basis for
saying that "gaia will not break".
Donna Fezler
At 01:53 PM 3/27/98 -0800, crystal wrote:
>"Donald Trotter Ph.D." quoted "clarkjd@server.multipro.com at cclink":
>> What happens when increasing amounts of nitrogen over normal amounts
>> are taken out of the atmosphere, or increased amounts of nitrogen are
>> introduced in the soil?
>
>Will there be more CO2 in the atmosphere? Increasing the greenhouse
>effect - for example, if used on Mars?
>
>> By introducing such bacteria into the soils of our earth, are we not
>> opening the door to modifying radically the nutrient flow structure of
>> the earth?
>
>I don't think Gaia will break.
>
>Best Regards,
>Crystal.
>
>
>
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Subject: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
From: John Shannonhouse
Date: Fri, 27 Mar 1998 12:37:48 -0600
Hello,
I think this article was poorly written. It tells me almost nothing:
<>
I don't believe that the legumes-Rhizobium system represents more
than a small fraction of nitrogen fixation. I saw a diagram of relative
amounts from different sources once, and the blue-green algae were the big
part, there were a bunch of other species and Rhizobium was a small
fraction (<<10%).
<>
Rhizobium have probably not been around any longer than flowering
plants. Rhizobium refers to a specific genus of bacteria that live in a
mutalistic relationship with legumes. Nitrogen-fixing cyanobacteria
(blue-green algaes) are probably far more ancient. Possible fossils of
cyanobacteria have been found that are over a billion years old. It is the
set of genes that fix nitrogen that are probably ancient (more on this in a
minute).
<>
Rhizobium are essential to legumes growing in poor soils. They do
make up an important part of the Earth's ecosystem and agricultural
systems, but life on Earth can do without them. There are many types of
bacteria that fix nitrogen. I believe most is done by cyanobacteria.
<>
<>
<>
So does this mean that it is unknown whether or not the bacteria
will increase crop yields or that it is unknown whether the bacteria will
fix more nitrogen?
<>
From later text, I believe that you mean "disease preventing
antibiotics."
<>
This is hardly a recent discovery. It was known at least as far
back as the 1940's, and probably before then.
<>
From Suzanne Wuerthele:
<>
If farmers are spending money on a product of dubious value, then I
think some scientific tests need to be done. The arguement that "we didn't
need this before" is fallacious. We didn't need antibiotics, indoor
plumbing, electiricity or even agriculture at some time or another. For
the possible benefits of this transgenic strain, the only questions that
need to be asked are (1) does coating the seeds with Rhizobium increase
yield and (2) does the increased rate of nitrogen fixation make a
difference to the plant (ie, once the plant has established its natural
Rhizobium colonies, is nitrogen no longer limiting?)?
I'm a little rusty on my genetics of nitrogen fixation, but I'm not
even sure what the genetic engineers did. The article seemed to be written
more to frighten than to educate, but, in all fairness, it was not aimed at
people who knew anything about the nif operon. Did they just introduce a
part of the nif operon that Rhizobium does not have ("nif" is the nitrogen
fixation geneticists' jargon for nitrogen fixation, and an operon is a set
of genes that are expressed together in bacteria)? If so, then Rhizobiums
have probably recieved this set of genes before. Many permutations of the
nif operon exist in nature, and operons are fairly easy to transmit between
bacterial species. It is probably not to the Rhizobium's advantage to have
them.
John Shannonhouse
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Subject: Safe plastics ?
From: bard@rof.net
Date: Fri, 27 Mar 1998 12:20:23 -0800
Does anyone have information about the inertness of plastics, in
relation
to using them for holding and transfering systems for aquaponics ? I
understand that fish and plants do not seem to show any immediate signs
of illness due to the use of plastics, but has anyone ever compared the
effects of using 'natural' holding facilities, and transfering medium
to that of the standardized plastics-based systems ? Are there any
materials available that are completely natural ? What are they made
from ? Thank You
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Subject: Light Expanded Clay Aggregate
From: bard@rof.net
Date: Fri, 27 Mar 1998 12:29:47 -0800
Has anyone used LECA as a growing medium ? I would like to know about
any negitive effects that this medium may have. Does it keep the root
temperature consistant ? Is it very heavy ?
Thank you in advance
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| Message 6 |
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Subject: Re: Genetically Modified Rhizobium a BIG CONCERN !!!
From: "H.Doelle"
Date: Sat, 28 Mar 1998 06:27:06 +1000
Dear John,
Unfortunately I have not read the article mentioned above. Although I am
also very cautious with any genetically engineered microorganism, unless it
is used in PC2 labs, I believe the MIRCEN in Porte Allegre in Brazil were
able to increase total yields with genetically improved Rhizobium up to
4-fold in many cases. I think the genetical help is on the nif gene to
improve nitrogen fixation.
I fully agree that cyanobacteria are better nitrogen fixers. I go even
further saying that all free living nitrogen fixers may be better than just
Rhizobium, but one has to be careful and it depends where you are in the
world and what temperatures you are living in.
I have seen in southern China the enormous use of cyanobacteria as
fertiliser for rice crops and have seen Rhizobium now experimentally
planted with Rhizobium.
Personally I prefer also the use of legumes as intercropping for colder
climates and cyanobacteria in tropical climates as nitrogen fertilisers.
The formaer had been done in my youth days and the latter is done in China
for centuries.
Since geneticists are not normally very get in thermodynamics and
physiology, one should be cautious with all that engineering in food and
agriculture.
Anyhow, why engineering rhizobium when we have so many natural methods
available for fertilising ?
There may, however, be a reason for trying to extend the nitrogen fixation
from legumes to other crops such as rice, but here again, why when we have
so good free living nitrogen fixers.
I would not be game to say which one is better, except, that cyanobacteria
are difficult to grow in cold climates, but there you you have also
Azotobacter and many other bacteria.
I enjoyed your explanations.
Horst Doelle
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Subject: Paula, NAVY BEING SUED!!
From: S & S Aqua Farm
Date: Fri, 27 Mar 1998 21:00:43 -0600
Received the following from Donald Trotter - it concerns the recent post on
Navy testing as posted:
>FEBRUARY 24 (11:45 A.M.) - LFA Sonar (Low Frequency Active Sonar)
>>testing is to begin by the Navy on February 25 off the Northwest coast
>>of the Big Island of Hawaii, right in the heart of the Humpback Whale
>>birthing and breeding season, and is expected to last for four weeks.
Anyone who would like the rest of this post is invited to contact Donald
Trotter at the address below:
>Date: Fri, 27 Mar 1998 11:01:29 -0800
>To: snsaquasys@townsqr.com
>From: donald trotter
>Subject: Paula, NAVY BEING SUED!!
>
>Hi Paula!
>Thought you would use this. Did not publish on list. If you think
>subscribers can use I'll forward this message to each privately.
>
>Thanks,
>Don>
>
S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
Web page http://www.townsqr.com/snsaqua/
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| Message 8 |
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Subject: Introduction
From: S & S Aqua Farm
Date: Fri, 27 Mar 1998 21:03:16 -0600
Date: Fri, 27 Mar 1998 10:04:55 -0600
From: Alejandro Gallardo Valencia
Subject: Aquaponics discussion group
I=B4m an oceanographer in M=E9xico and i=B4ve been fascinated by the concept
of aquaponics ever since i found out about it a couple months a go. I
would like to participate in the discussion group and i=B4m eager to hear
from anyone with this particular interest as well as people interested
in investing in proyects of this kind in M=E9xico.
Alejandro Gallardo.
I've included Alejandro in our mail group. Any comments on aquaponics in
Mexico?
Paula
S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
Web page http://www.townsqr.com/snsaqua/
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