[Digestion] Attachment to previous Article - More scientific based research and questions

Sat Oct 23 13:43:13 CDT 2010

Dear Dr. Martin,
I have just returned from a city called Wardha, where I attended a workshop
arranged jointly by the Research Councils of UK and the Department of
Science and Technology, Government of India. About 20 scientists each from
UK and India were invited to this meeting.
In the course of field visits organised during the workshop, Dr. Soham
Pandya, The Director of Centre of Science for Villages, an NGO in Wardha,
showed us an amazing biogas plant on his campus. This biogas plant accepts
about 1000 kg cattle dung as a one-time load and produces daily about 3
cubic meters of biogas, continuously over a period of about 180 days.  This
is not the only biogas plant constructed by him. Using funds from the
Department of Science and Technology, He has constructed a similar biogas
plant in another place called Hingoli, where a one-time load  of 1000 kg
dung yields biogas continuously for 6 months, to run an electricity
generator for daily 3 to 4 hours, to provide electric lighting to all the
houses in the village.  Officials of the Department of Science and
Technology vouched for the veracity of these claims. According to text book
knowledge, 1000 kg dung should have produced about 30,000 litres (or 30
cubic meters) biogas. But this particular biogas plant produces 540 cubic
meters of it.
Neither Dr. Pandya nor any other scientist could give a
scientific explanation to this phenomenally high yield of biogas. Dung of
Indian cattle consists mainly of lignin (from the veins and midribs of the
grass and leaves that they feed on) and micro-organisms. One has to assume
in this case, that there are microbes in the dung that feed on the lignin
and that the methanogens digested the lignin eating microbes.
Yours
A.D.Karve

On Mon, Oct 18, 2010 at 3:53 PM, Duncan Martin <duncanjmartin at gmail.com>wrote:

> Perhaps Dr Karve & I should agree to disagree?
>
> To argue that dung is not food for the methanogens because they need help
> to digest it is really a semantic quibble. It misses the point I was
> responding to - that the digestion process is not *completed *by the act
> of defaecation, it is merely *terminated* for the owner of the gut in
> question.
>
> I have never seen any serious literature suggesting that microbes are
> altruistic. However, the principles of commensalism are well established and
> I see no basis for dismissing them. Moreover, the complex web of metabolic
> interactions in AD has been extensively researched and is pretty well
> understood - though I am sure there is more to discover.
>
> Nor have I seen any literature whatsoever suggesting that the methanogens
> consume other microorganisms. I would be intrigued to see a proposed
> mechanism.
>
> To dismiss all the textbooks as wrong (see previous postings) is unhelpful,
> at best. Who could only say that unless he had read every one of them? Of
> course, there are mistakes - even in the best books - if only because
> science moves on, so any book becomes outdated. And there are indeed some
> layman's guides to AD that include some odd ideas - but who would take them
> as serious guides to the science?
>
> When we find such errors, let us use this forum to report them - giving
> exact references. But lets not confuse newcomers to the field by dismissing
> every other source of information as rubbish.
>
> Finally, let us accept that each of us is entitled to his opinion - but
> lets reserve this forum for the fruits of practical experience and
> evidence-based information.
>
> I suggest we draw a line under the present debate.
>
> Duncan Martin, PhD, MCIWM, MIChemE, MIEI
> Cloughjordan Ecovillage
> Ireland
>
> On 17 October 2010 16:39, Anand Karve <adkarve at gmail.com> wrote:
>
>> Dear Duncan,
>> I dont believe in the theory of a chain of micro-organisms, with one
>> species converting the cellulose into glucose, another converting the
>> glucose into an organic acid (e.g. citric acid), still another converting
>> the organic acid into acetic acid and ultimately the acetic acid being
>> converted by the methanogenic organisms into carbon dioxide and methane. If
>> this were true, one would have by now isolated the organism that converted
>> cellulose into glucose and used the glucose to produce alcohol. Cellulose is
>> the most ubiquitously found organic compount in the world and with this
>> simple process, one would have produced unlimited quantity of liquid fuel.
>> But even today, the conversion of cellulose into glucose is achieved in any
>> industrial process by using a cellulolytic enzyme extracted from a
>> cellulolytic organism. The reason for this is, that the glucose converted by
>> the organism from cellulose is consumed by the same organism. And once it is
>> consumed by an organism, it is converted into its cell all the way down to
>> carbon dioxide. The micro-organisms in the gut of an animal cannot be
>> expected to be so altruistic as to predigest the food and suply it to the
>> methanogens. I feel that the methanogenic organisms consume the fellow
>> micro-organisms in the gut of animals and digest them to produce methane and
>> carbon dioxide. Such dog-eat-dog reactions occur also in the soil supplied
>> with organic matter.
>>         In any case, once it is accepted that the methanogenic organisms
>> do not digest the dung directly and that they need the help of other
>> organisms to digest it, one cannot accept that dung is the food of the
>> methanogens. It is like saying that manure applied to a field is human food,
>> because through a number of biological processes it ultimately ends up into
>> products, which the humans eat.
>> Yours
>> A.D.Karve
>>   On Fri, Oct 15, 2010 at 4:27 PM, Duncan Martin <duncanjmartin at gmail.com
>> > wrote:
>>
>>>
>>> Yes, the gut methanogens do, in a sense, eat what the animal eats.
>>> However, it would be more accurate to say that their diet is derived from
>>> what the animal eats. The methanogens in the gut of a cow are surrounded by
>>> celluose and other biopolymers but they cannot digest them. They live on the
>>> waste products of other microbial processes. The web of metabolic
>>> interactions is well known.
>>>
>>> Where I would "hoot out" Dr Karve is his belief that dung cannot serve as
>>> food for the methanogens because they are "thrown out" of the body along
>>> with the dung. I don't understand the logic here.
>>>
>>>
>>>
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>> 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/
>>
>>
>>
>
> _______________________________________________
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>
> to Send a Message to the list, use the email address
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>
> 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 *
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