[Digestion] Digestion Digest, Vol 7, Issue 12

Wed Mar 23 15:25:56 CDT 2011

I would add to Gasan's proper remarks that H2 is not only a substrate for
methanogens (most can use it) but also a regulator of the overall
methanogenic system. This is because H2 is inhibitive of
acidogenesis/acetogenesis, particularly those bacteria that use protons as
an electron sink (thereby producing H2).

Regarding "...around 800 species are involved in the biogas formation
community...", does this refer to methanogenic archaea per se, or to all
the diverse bacteria (and even eucaryota) involved in the overall
methanogenic system?

Could you provide the source for the "800 species" estimate?

Thanks,

Mel

Melvin S. Finstein, Ph.D.
Professor Emeritus
Rutgers University

105 Carmel Road
Wheeling, WV 26003
304.242.0341

> Send Digestion mailing list submissions to
> 	digestion at lists.bioenergylists.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
> 	http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org
>
> or, via email, send a message with subject or body 'help' to
> 	digestion-request at lists.bioenergylists.org
>
> You can reach the person managing the list at
> 	digestion-owner at lists.bioenergylists.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Digestion digest..."
>
>
> Today's Topics:
>
>    1. Re: The biology of biogas production (Gasan Osojnik)
>    2. Re: The biology of biogas production (David Fulford)
>    3. The biology of biogas production (Gasan Osojnik)
>    4. Biology of Biogas production. (Murali Krishna)
>    5. Re: Biology of Biogas production. (Murali Krishna)
>    6. Re: The biology of biogas production (Anand Karve)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Wed, 23 Mar 2011 08:49:55 +0100
> From: Gasan Osojnik <gasan.osojnik at gmail.com>
> To: digestion at lists.bioenergylists.org
> Cc: digestion-request at lists.bioenergylists.org
> Subject: Re: [Digestion] The biology of biogas production
> Message-ID:
> 	<AANLkTi=fk+1kCF-U1EVz6kYciy=dn+-3VxqhG7nb_Ts3 at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dear dr. Karve
>
> I do not wish to engage nor in a lengthy philosophical or physiological
> debate, but I do have one or two points to make:
>
> 1. Methanogenic archaea do not degrade sugar or even complex substances,
> they use either acetate or hydrogen + carbon dioxide to survive. They are
> old an primitive organisms, that originate back to the beginning of life,
> even before glucose was formed by other organisms, therefore they can
> feast
> on very basic energy sources.  There are not any other "methanogens" in
> other branches of the evolution tree.
> 2. The stechiometric ratio of methane/carbon dioxide fromation from
> carbohydrates is CH4/CO2 = 50/50, from fats = 62.5/37.5 and from proteins
> 71/29 (due to absorptive properties of the sediment), so the number
> mentioned is presumably based on anaerobic microbial protein degradation?
> 3. The chain of microorganisms is not only highly likely, but is confirmed
> by the means of certified analytical techniques, such as the techniques of
> molecular biology and can be even seen under the  electron microscope. The
> sole biochemistry and the termoenergetics of the methane formation process
> from polymers reveal, that it is impossible for the process to start and
> finish in only one type of unicellular procaryotic microorganisms (or any
> other). We have pictures of microorganisms of species that are literary
> "glued one another" for better substrate / intermediate exchange, and this
> is no exception but a necessity for their survival. Currently it is
> believed
> that around 800 species are involved in the biogas formation community
> (not
> all at the same time) but this number is increasing rapidly (e.g. 2008
> this
> number was around 400). Personally I believe this number to be much
> greater,
> as methanogenic microbiota is found on very diverse parts of the planet
> and
> is a common way of surviving in areas with no / low oxygen concentrations.
> 4. The issue of  CO2 which has ben adressed needs some basic insight in
> the
> process. The dissolved co2 that is produced intermediately in the proceses
> of acetogenesis (some also in the  hydrolysis ans acetogenesis) is, as
> said,
> a substrate for the production of methane, and is taken up very rapidly
> by
> the archaea. Therefore, you should not look at the intermediate CO2 as a
> product but as a reactant. As most of the biogas (at least up to 70%) is
> formed via acetate decarboxylation to methane and CO2. The partial
> pressures
> of surplus CO2 equilibrate in the headspace of the reactor and the liquid,
> so the CO2 that you get in biogas is actualy mostly the product of
> acetoclastic methanogenesis.
>
> BR, Gasan
>
>
> Dear Mr. Afilal,
> if you used any substance that is digested by humans,(sugar, starch,
> digestible protein or fat), it gets completely converted into biogas by
> the methanogens. 1 kg of any of these substances would yield about 1 kg
> biogas, containing the theoretically calculated proportion of roughly 25
> to
> 30% methane and 70 to 75% carbon dioxide. The presence of a chain of
> micro-organisms, with each one producing a product that serves as food for
> the next one in the chain is not believable. If it were really so, one
> would
> get a much higher concentration of carbon dioxide in the resultant biogas,
> because the intermediate organisms produce only carbon dioxide and not
> methane.
> Yours
> A.D.Karve
>
>
>
> On 22 March 2011 20:00, <digestion-request at lists.bioenergylists.org>
> wrote:
>
>> Re: The biology of biogas production
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.org/attachments/20110323/52ef9fd4/attachment-0001.html>
>
> ------------------------------
>
> Message: 2
> Date: Wed, 23 Mar 2011 08:18:48 +0000
> From: David Fulford <davidf at kingdombio.com>
> To: For Discussion of Anaerobic Digestion
> 	<digestion at lists.bioenergylists.org>
> Cc: Gasan Osojnik <gasan.osojnik at gmail.com>,
> 	digestion-request at lists.bioenergylists.org
> Subject: Re: [Digestion] The biology of biogas production
> Message-ID: <4D89ACE8.8090502 at kingdombio.com>
> Content-Type: text/plain; charset="iso-8859-1"; Format="flowed"
>
> Dear Gasan and listers,
>
> This is the sort of information we need on the biogas wiki. Can you
> provide us with some basic references (books, academic articles) that we
> can use for this data, especially on item 2. This is the clearest
> statement I have read on the relative proportions of CH4/CO2 from
> various substrates.
>
> Do you mean stochiometric, or is stechiometric another term that we need
> to learn?
>
> Thanks
>
> David F
>
> On 23/03/2011 07:49, Gasan Osojnik wrote:
>> Dear dr. Karve
>>
>> I do not wish to engage nor in a lengthy philosophical or
>> physiological debate, but I do have one or two points to make:
>>
>> 1. Methanogenic archaea do not degrade sugar or even complex
>> substances, they use either acetate or hydrogen + carbon dioxide to
>> survive. They are old an primitive organisms, that originate back to
>> the beginning of life, even before glucose was formed by other
>> organisms, therefore they can feast on very basic energy sources.
>> There are not any other "methanogens" in other branches of the
>> evolution tree.
>> 2. The stechiometric ratio of methane/carbon dioxide fromation from
>> carbohydrates is CH4/CO2 = 50/50, from fats = 62.5/37.5 and from
>> proteins 71/29 (due to absorptive properties of the sediment), so the
>> number mentioned is presumably based on anaerobic microbial protein
>> degradation?
>> 3. The chain of microorganisms is not only highly likely, but is
>> confirmed by the means of certified analytical techniques, such as the
>> techniques of molecular biology and can be even seen under the
>> electron microscope. The sole biochemistry and the termoenergetics of
>> the methane formation process from polymers reveal, that it is
>> impossible for the process to start and finish in only one type of
>> unicellular procaryotic microorganisms (or any other). We have
>> pictures of microorganisms of species that are literary "glued one
>> another" for better substrate / intermediate exchange, and this is no
>> exception but a necessity for their survival. Currently it is believed
>> that around 800 species are involved in the biogas formation community
>> (not all at the same time) but this number is increasing rapidly (e.g.
>> 2008 this number was around 400). Personally I believe this number to
>> be much greater, as methanogenic microbiota is found on very diverse
>> parts of the planet and is a common way of surviving in areas with no
>> / low oxygen concentrations.
>> 4. The issue of  CO2 which has ben adressed needs some basic insight
>> in the process. The dissolved co2 that is produced intermediately in
>> the proceses of acetogenesis (some also in the  hydrolysis ans
>> acetogenesis) is, as said, a substrate for the production of methane,
>> and is taken up very rapidly  by the archaea. Therefore, you should
>> not look at the intermediate CO2 as a product but as a reactant. As
>> most of the biogas (at least up to 70%) is formed via acetate
>> decarboxylation to methane and CO2. The partial pressures of surplus
>> CO2 equilibrate in the headspace of the reactor and the liquid, so the
>> CO2 that you get in biogas is actualy mostly the product of
>> acetoclastic methanogenesis.
>>
>> BR, Gasan
>>
>>
>> Dear Mr. Afilal,
>> if you used any substance that is digested by humans,(sugar, starch,
>> digestible protein or fat), it gets completely converted into biogas by
>> the methanogens. 1 kg of any of these substances would yield about 1 kg
>> biogas, containing the theoretically calculated proportion of roughly
>> 25 to
>> 30% methane and 70 to 75% carbon dioxide. The presence of a chain of
>> micro-organisms, with each one producing a product that serves as food
>> for
>> the next one in the chain is not believable. If it were really so, one
>> would
>> get a much higher concentration of carbon dioxide in the resultant
>> biogas,
>> because the intermediate organisms produce only carbon dioxide and not
>> methane.
>> Yours
>> A.D.Karve
>>
>>
>>
>> On 22 March 2011 20:00, <digestion-request at lists.bioenergylists.org
>> <mailto:digestion-request at lists.bioenergylists.org>> wrote:
>>
>>     Re: The biology of biogas production
>>
>>
>>
>> _______________________________________________
>> Digestion mailing list
>>
>> to Send a Message to the list, use the email address
>> Digestion at bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>> http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org
>>
>> for more information about digestion, see
>> Beginner's Guide to Biogas
>> http://www.adelaide.edu.au/biogas/
>> and the Biogas Wiki http://biogas.wikispaces.com/
>>
>
> --
>
> ********************************************************************
> Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5 4PU
> d.j.fulford at btinternet.com <mailto:d.j.fulford at btinternet.com>, Tel:
> +44(0)118 326 9779 Mob: +44(0)7746 806401
> Kingdom Bioenergy Ltd, www.kingdombio.com <http://www.kingdombio.com>,
> davidf at kindombio.com <mailto:davidf at kindombio.com>
>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.org/attachments/20110323/0d68aab5/attachment-0001.html>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 23 Mar 2011 09:38:13 +0100
> From: Gasan Osojnik <gasan.osojnik at gmail.com>
> To: David Fulford <davidf at kingdombio.com>,
> 	digestion at lists.bioenergylists.org
> Subject: [Digestion] The biology of biogas production
> Message-ID:
> 	<AANLkTikycHe17mnMCxmKiA2f6M90y=UQK0_0MZOcxgO0 at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dear David,
>
> My engineering book covers most of the written topics (Deublein &
> Steinhauser's Biogas form waste and renewable resources (Willey, 2009)),
> encluding the biochemisty of the biogas formation from various sources
> (points 2. and 4.), but i guess pollution engineering handbook should do.
> I
> will get back to you with the references for the microbiological part.
>
> Excuse me on my quick-fingers terminology, nor "stochiometric" or
> "stechiometric" but "stoichiometric" should do fine :)
>
> BR, Gasan
>
>
> On 23 March 2011 09:18, David Fulford <davidf at kingdombio.com> wrote:
>
>>  Dear Gasan and listers,
>>
>> This is the sort of information we need on the biogas wiki. Can you
>> provide
>> us with some basic references (books, academic articles) that we can use
>> for
>> this data, especially on item 2. This is the clearest statement I have
>> read
>> on the relative proportions of CH4/CO2 from various substrates.
>>
>> Do you mean stochiometric, or is stechiometric another term that we need
>> to
>> learn?
>>
>> Thanks
>>
>> David F
>>
>>
>> On 23/03/2011 07:49, Gasan Osojnik wrote:
>>
>> Dear dr. Karve
>>
>> I do not wish to engage nor in a lengthy philosophical or physiological
>> debate, but I do have one or two points to make:
>>
>> 1. Methanogenic archaea do not degrade sugar or even complex substances,
>> they use either acetate or hydrogen + carbon dioxide to survive. They
>> are
>> old an primitive organisms, that originate back to the beginning of
>> life,
>> even before glucose was formed by other organisms, therefore they can
>> feast
>> on very basic energy sources.  There are not any other "methanogens" in
>> other branches of the evolution tree.
>> 2. The stechiometric ratio of methane/carbon dioxide fromation from
>> carbohydrates is CH4/CO2 = 50/50, from fats = 62.5/37.5 and from
>> proteins
>> 71/29 (due to absorptive properties of the sediment), so the number
>> mentioned is presumably based on anaerobic microbial protein
>> degradation?
>> 3. The chain of microorganisms is not only highly likely, but is
>> confirmed
>> by the means of certified analytical techniques, such as the techniques
>> of
>> molecular biology and can be even seen under the  electron microscope.
>> The
>> sole biochemistry and the termoenergetics of the methane formation
>> process
>> from polymers reveal, that it is impossible for the process to start and
>> finish in only one type of unicellular procaryotic microorganisms (or
>> any
>> other). We have pictures of microorganisms of species that are literary
>> "glued one another" for better substrate / intermediate exchange, and
>> this
>> is no exception but a necessity for their survival. Currently it is
>> believed
>> that around 800 species are involved in the biogas formation community
>> (not
>> all at the same time) but this number is increasing rapidly (e.g. 2008
>> this
>> number was around 400). Personally I believe this number to be much
>> greater,
>> as methanogenic microbiota is found on very diverse parts of the planet
>> and
>> is a common way of surviving in areas with no / low oxygen
>> concentrations.
>> 4. The issue of  CO2 which has ben adressed needs some basic insight in
>> the
>> process. The dissolved co2 that is produced intermediately in the
>> proceses
>> of acetogenesis (some also in the  hydrolysis ans acetogenesis) is, as
>> said,
>> a substrate for the production of methane, and is taken up very rapidly
>> by
>> the archaea. Therefore, you should not look at the intermediate CO2 as a
>> product but as a reactant. As most of the biogas (at least up to 70%) is
>> formed via acetate decarboxylation to methane and CO2. The partial
>> pressures
>> of surplus CO2 equilibrate in the headspace of the reactor and the
>> liquid,
>> so the CO2 that you get in biogas is actualy mostly the product of
>> acetoclastic methanogenesis.
>>
>> BR, Gasan
>>
>>
>> Dear Mr. Afilal,
>> if you used any substance that is digested by humans,(sugar, starch,
>> digestible protein or fat), it gets completely converted into biogas by
>> the methanogens. 1 kg of any of these substances would yield about 1 kg
>> biogas, containing the theoretically calculated proportion of roughly 25
>> to
>> 30% methane and 70 to 75% carbon dioxide. The presence of a chain of
>> micro-organisms, with each one producing a product that serves as food
>> for
>> the next one in the chain is not believable. If it were really so, one
>> would
>> get a much higher concentration of carbon dioxide in the resultant
>> biogas,
>> because the intermediate organisms produce only carbon dioxide and not
>> methane.
>> Yours
>> A.D.Karve
>>
>>
>>
>> On 22 March 2011 20:00,
>> <digestion-request at lists.bioenergylists.org>wrote:
>>
>>> Re: The biology of biogas production
>>
>>
>>
>> _______________________________________________
>> Digestion mailing list
>>
>> to Send a Message to the list, use the email address
>> Digestion at bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web
>> pagehttp://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org
>>
>> for more information about digestion, see
>> Beginner's Guide to Biogashttp://www.adelaide.edu.au/biogas/
>> and the Biogas Wiki http://biogas.wikispaces.com/
>>
>>
>> --
>>
>> ********************************************************************
>> Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5 4PU
>> d.j.fulford at btinternet.com, Tel: +44(0)118 326 9779 Mob: +44(0)7746
>> 806401
>>
>> Kingdom Bioenergy Ltd, www.kingdombio.com, davidf at kindombio.com
>>
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> <http://lists.bioenergylists.org/pipermail/digestion_lists.bioenergylists.org/attachments/20110323/7ba7e398/attachment-0001.html>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 23 Mar 2011 18:25:26 +0530
> From: Murali Krishna <bmkrishna6 at gmail.com>
> To: Digestion at bioenergylists.org
> Subject: [Digestion] Biology of Biogas production.
> Message-ID:
> 	<AANLkTik7SM=tiX3a3Ty8tp0yknKk7w9cnbt0YwY6E3ji at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Dear BR, Gasan,
>
> I  absolutely agree with you on  "intermediate CO2 as a product but as
> a reactant. As most of the biogas (at least up to 70%) is formed via
> acetate decarboxylation to methane and CO2. "   I believe that there
> will be more number of species than 800 involved in the process.  If
> we mailntain ideal conditions in the digester the rest of things we
> can leave it to the species unless we want to speeden the process `
>
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 23 Mar 2011 18:28:25 +0530
> From: Murali Krishna <bmkrishna6 at gmail.com>
> To: Digestion at bioenergylists.org
> Subject: Re: [Digestion] Biology of Biogas production.
> Message-ID:
> 	<AANLkTi=+qtB96c=nj-zH2Zsah_onSaYaGmWk=x-Zyvjx at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Dear BR, Gasan,
>
>  I  absolutely agree with you on  "intermediate CO2 as a product but as
>  a reactant. As most of the biogas (at least up to 70%) is formed via
>  acetate decarboxylation to methane and CO2. "   I believe that there
>  will be more number of species than 800 involved in the process.  If
>  we maintain ideal conditions in the digester the rest of things we
>  can leave it to the species unless we want to speeden the process.
>
> Regards,
>
> Krishna
>
>
>
>
> On Wed, Mar 23, 2011 at 6:25 PM, Murali Krishna <bmkrishna6 at gmail.com>
> wrote:
>> Dear BR, Gasan,
>>
>> I ?absolutely agree with you on ?"intermediate CO2 as a product but as
>> a reactant. As most of the biogas (at least up to 70%) is formed via
>> acetate decarboxylation to methane and CO2. " ? I believe that there
>> will be more number of species than 800 involved in the process. ?If
>> we mailntain ideal conditions in the digester the rest of things we
>> can leave it to the species unless we want to speeden the process `
>>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Wed, 23 Mar 2011 21:53:37 +0800
> From: Anand Karve <adkarve at gmail.com>
> To: For Discussion of Anaerobic Digestion
> 	<digestion at lists.bioenergylists.org>
> Subject: Re: [Digestion] The biology of biogas production
> Message-ID:
> 	<AANLkTi=oCqi-Ko-HmYfVjJJNfw3DJRszHW6Zkz-rfF3s at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Thanks, Mr. Osojnik for the information.
> Yours
> A.D.Karve
>
> On Wed, Mar 23, 2011 at 3:49 PM, Gasan Osojnik <gasan.osojnik at gmail.com>
> wrote:
>> Dear dr. Karve
>>
>> I do not wish to engage nor in a lengthy philosophical or physiological
>> debate, but I do have one or two points to make:
>>
>> 1. Methanogenic archaea do not degrade sugar or even complex substances,
>> they use either acetate or hydrogen + carbon dioxide to survive. They
>> are
>> old an primitive organisms, that originate back to the beginning of
>> life,
>> even before glucose was formed by other organisms, therefore they can
>> feast
>> on very basic energy sources.? There are not any other "methanogens" in
>> other branches of the evolution tree.
>> 2. The stechiometric ratio of methane/carbon dioxide fromation from
>> carbohydrates is CH4/CO2 = 50/50, from fats = 62.5/37.5 and from
>> proteins
>> 71/29 (due to absorptive properties of the sediment), so the number
>> mentioned is presumably based on anaerobic microbial protein
>> degradation?
>> 3. The chain of microorganisms is not only highly likely, but is
>> confirmed
>> by the means of certified analytical techniques, such as the techniques
>> of
>> molecular biology and can be even seen under the? electron microscope.
>> The
>> sole biochemistry and the termoenergetics of the methane formation
>> process
>> from polymers reveal, that it is impossible for the process to start and
>> finish in only one type of unicellular procaryotic microorganisms (or
>> any
>> other). We have pictures of microorganisms of species that are literary
>> "glued one another" for better substrate / intermediate exchange, and
>> this
>> is no exception but a necessity for their survival. Currently it is
>> believed
>> that around 800 species are involved in the biogas formation community
>> (not
>> all at the same time) but this number is increasing rapidly (e.g. 2008
>> this
>> number was around 400). Personally I believe this number to be much
>> greater,
>> as methanogenic microbiota is found on very diverse parts of the planet
>> and
>> is a common way of surviving in areas with no / low oxygen
>> concentrations.
>> 4. The issue of? CO2 which has ben adressed needs some basic insight in
>> the
>> process. The dissolved co2 that is produced intermediately in the
>> proceses
>> of acetogenesis (some also in the? hydrolysis ans acetogenesis) is, as
>> said,
>> a substrate for the production of methane, and is taken up very rapidly?
>> by
>> the archaea. Therefore, you should not look at the intermediate CO2 as a
>> product but as a reactant. As most of the biogas (at least up to 70%) is
>> formed via acetate decarboxylation to methane and CO2. The partial
>> pressures
>> of surplus CO2 equilibrate in the headspace of the reactor and the
>> liquid,
>> so the CO2 that you get in biogas is actualy mostly the product of
>> acetoclastic methanogenesis.
>>
>> BR, Gasan
>>
>>
>> Dear Mr. Afilal,
>> if you used any substance that is digested by humans,(sugar, starch,
>> digestible protein or fat), it gets completely converted into biogas by
>> the methanogens. 1 kg of any of these substances would yield about 1 kg
>> biogas, containing the theoretically calculated proportion of roughly 25
>> to
>> 30% methane and 70 to 75% carbon dioxide. The presence of a chain of
>> micro-organisms, with each one producing a product that serves as food
>> for
>> the next one in the chain is not believable. If it were really so, one
>> would
>> get a much higher concentration of carbon dioxide in the resultant
>> biogas,
>> because the intermediate organisms produce only carbon dioxide and not
>> methane.
>> Yours
>> A.D.Karve
>>
>>
>>
>> On 22 March 2011 20:00, <digestion-request at lists.bioenergylists.org>
>> wrote:
>>>
>>> Re: The biology of biogas production
>>
>> _______________________________________________
>> Digestion mailing list
>>
>> to Send a Message to the list, use the email address
>> Digestion at bioenergylists.org
>>
>> to UNSUBSCRIBE or Change your List Settings use the web page
>> http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org
>>
>> for more information about digestion, see
>> Beginner's Guide to Biogas
>> http://www.adelaide.edu.au/biogas/
>> and the Biogas Wiki http://biogas.wikispaces.com/
>>
>>
>>
>
>
>
> --
> ***
> Dr. A.D. Karve
> President, Appropriate Rural Technology Institute (ARTI)
>
> *Please change my email address in your records to: adkarve at gmail.com *
>
>
>
> ------------------------------
>
> _______________________________________________
> Digestion mailing list
>
> to Send a Message to the list, use the email address
> Digestion at bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
> http://lists.bioenergylists.org/mailman/listinfo/digestion_lists.bioenergylists.org
>
> for more information about digestion, see
> Beginner's Guide to Biogas
> http://www.adelaide.edu.au/biogas/
> and the Biogas Wiki http://biogas.wikispaces.com/
>
>
>
> End of Digestion Digest, Vol 7, Issue 12
> ****************************************
>