Maintworld Magazine 4/2023

BIOCATALYSIS
including the microbiological and biotechnological
solutions, than by just discharging
the organic loads into the water and maritime
ecosystems, or to the atmosphere."
This principle could be equally applicable
in the "cradle of Finnish industries" in Tampere,
as well as globally in any place where
forest or other biomass industries will be
developed into true circulation economics
(see above).
BIOHYDROGEN SOURCE
In 1874, French writer Jules Verne predicted
in his book "Mysterious Island" the
future we aim for and head toward. This
old reasoning and imagination of one of the
most eminent early science fiction authors
illustrates the roots of an essential and potential
avenue for future development: biohydrogen.
Its implementation could now
lead to sustainable planning of cities, their
food production and traffic, and societies in
general too. See Fig. 2.
Quotations of the "Mysterious Island"
(1874) by Jules Verne:
• "...I believe that water will one day be
employed as fuel, that hydrogen and
oxygen which constitute it, used singly
or together, will furnish an inexhaustible
source of heat and light of an
intensity of which coal is not capable."
• "Some day the coalrooms of steamers
and the tenders of locomotives will,
instead of coal, be stored with these
condensed gases, which will burn in
the furnaces with enormous calorific
power..."
• "...there will be no want of either light
or heat as long as the productions of
the vegetable, mineral or animal kingdoms
do not fail us. I believe, then,
that when the deposits of coal are
exhausted, we shall heat and warm
ourselves with water. Water will be
the coal of the future."
In the previous Maintworld article (in volume
3/2023), Elias Hakalehto took up the
potential of biologically produced hydrogen,
or biohydrogen, in solving global and local
energy needs. It could be made using anaerobic
bacteria or other microbes to split the
water in renewable energy sources into Hydrogen
and Oxygen (Fig. 3). These microbes
could be photosynthetic ones, such as algae
or cyanobacteria, or the fermentative anaerobic
bacteria using their enzymes to split
the water molecule. Then, the various steps
for utilising the bio-catalytically liberated
energies could also include their capture,
purification, storage and use in the fuel cells
or elsewhere. Such motors could power future
flying vehicles, for instance.
Biohydrogen could be converted and
reacted into other gaseous fuels, such as
methanol or ammonia. Besides in the aviation
industries, they could be applied for
maritime, industrial fuels, etc. Hydrogen
gas can be coupled with biogas methane,
thus forming hythane. If Carbon dioxide is
simultaneously emitted in this reaction, it
could be separated from biohydrogen and
used for greenhouses, where it is a precious
raw material for plant growth.
RETURN TO THE ROOTS OF
INDUSTRIAL BIOTECHNOLOGY
In 1904, one of the founders of the industrial
fermentation, Chaim Weizmann,
became a lecturer at the University of
Manchester. His method for the microbiological
production of acetone was piloted
in London in 1915. He used Clostridium
acetobutylicum (the Weizmann organism)
to produce acetone, butanol, ethanol
and hydrogen gas (Fig. 4). Later on, in
1939, in Helsinki, a Dutch microbiologist,
A.J. Kluyver took for the first time up the
potential of microorganisms to assimilate
Carbon dioxide. - What an opportunity
for climate-friendly bio-based production
and sequestration of carbon-containing
molecules, substances, polymers, etc.! -
We have also proven that the generation
of Carbon dioxide significantly boosts the
onset of microbiological or bioprocess
reactions (Hakalehto and Hänninen 2012,
Gaseous CO2 signal initiate growth of
butyric acid producing Clostridium butyricum
both in pure culture and in mixed
cultures with Lactobacillus brevis, in the
Canadian Journal of Microbiology). The
same phenomenon was also documented
for the Weizmann bacterium (Hakalehto
2015, Enhanced microbial process in the
sustainable fuel production. In: Jinyue,
Y (ed.), Handbook of clean energy systems,
by JR Wiley & Sons).
Fig 4. A simplified scheme of the central metabolism of Clostridium acetobutylicum
bacterium. Acetone, butanol and ethanol are the liquid end-products of the solvetogenic
reactions. Hydrogen gas is generated as a function of ferredoxin enzymes. The starting
molecule of the cascade is glucose, which usually results from the hydrolysis of organic,
plant-derived macromolecules such as cellulose or starch. The by-product Carbon dioxide
is readily usable in greenhouses or algal ponds.
UPSTREAM AND DOWNSTREAM
IN BIOTECHNOLOGY
The former term designates in microbial
biotechnology the production of valuable
chemicals or gases by biological organisms,
whereas downstreaming means the collection,
purification and concentration of
these biorefinery products into applicable
forms. This is a well-studied field nowadays,
but more research and development is always
needed to boost the applications. And,
as Professor Malcolm D. Lilly often stated
during his most excellent bioengineering
lectures in 1984-5 at the University College
London: "Downstream processing is a losing
game", meaning that it is impossible to
reach perfection or complete recovery of
the produced bio-based (or other) products
in the industries. On the contrary, there are
some losses at every step of that effort. But
as developers, both scientific and societal,
we should ensure that we could end up as
victorious as possible.
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