Right now, technology focuses on controlling cellulose hydrolysis and processing in factories, but perhaps in the future humans could serve as the machine for extracting energy from cellulose, especially since the enzymes used to hydrolyze cellulose are hard to isolate in large quantities for industrial use.
Termites themselves are tiny creatures, but as a colony, they can break down houses and entire structures. A healthy human digestive system already carries an estimated 1 kg of bacteria, so adding a couple of extra harmless types should not pose a problem Termites and ruminants serve as a great example of how organisms can use microbes effectively.
However, the human body would need some adjustments to introduce the microbes into the body. Our stomach is much too acidic for most microbes to survive. The acid, among other secretions and enzymes, follows the food into the small intestine, where the microbes might end up competing with us for food.
By the time the food has reached the large intestines, only the cellulosic material is left for dehydration and possibly hydrolysis. However, our large intestines lack the ability to absorb the sugars that the microbes would produce from hydrolysis. Perhaps another organ could be added to the end of the human gastrointestinal tract to especially accommodate cellulose-digesting microbes.
Modern medicine allows safe inter-species transplantation, but the ideal solution would be to genetically engineer humans to develop the organs themselves to avoid he complications of surgery and organ transplantation.
Genetic engineering for the purpose of treating disease and illness is still undergoing intense debate, so nonessential pursuits such as cellulose digestion will not be possible until the scientific and medical communities accept genetic engineering as a safe and practical procedure. A simpler solution would be to take supplements similar to the ones used to treat lactose intolerance. Cellulose broken down in the stomach can be absorbed as glucose.
Extracting the right enzymes to work in the human stomach can bypass the problems of supporting microbes inside the human body. Additionally, since the process would occur inside the human body, the limitations that posed a problem for commercial hydrolysis of cellulose would become necessary biological controls. In the case of lactose intolerance, lactase is easily extracted from yeast fungi such as Kluyveromyces fragilis , so perhaps the easiest solution for cellulose indigestion is to extract the appropriate enzyme from the right microbes As mentioned previously, the commercial extraction of enzymes is not yet practical.
As previously stated, this field of human enhancement does not receive much research because companies and funding institutions are much more interested in the lucrative biofuel industry. Consequently, many questions remain unasked and unanswered. For example, what would the removal of cellulose weight from stool do to the process of defecation? What other effects might the microbes have on the human body?
How do we deal with the other byproducts of cellulose hydrolysis such as methane production? These questions could be analyzed through observation. Other mammals have survived many millennia by digesting cellulose with microbes, and since humans are mammals, there are no underlying reasons why human bodies cannot be compatible with these organisms.
The microbes that currently reside in the human body already produce gases inside the digestive system, ten percent of which is methane 3. Methane production used to be viewed as a problem at cattle ranches and dairy farms, but methane itself is a highly energetic biogas that can be used as fuel. Harnessing it might prove difficult considering that current social graves do not favor open flatulence even for the sake of renewable energy.
However, certain diets richer in alfalfa and flaxseed have been proven to reduce methane production in cows, which could potentially solve that problem Vegetation, which is severely lacking in the modern diet, is the major source of insoluble fiber.
Vegetables contain many vitamins, nutrients, and soluble fiber, which has numerous health benefits as mentioned in the introduction. Adding these foods to our diet after adding cellulose-digesting capabilities could help assuage the obesity epidemic and significantly improve human health. Ultimately, improving human digestion could vastly reduce waste generated by humans and increase the efficiency of human consumption. We only need to better observe and understand those particular microbes to integrate them into our bodies, which are already structurally favorable for such a change.
With the successful integration of microbes, we could cut down on food intake by making use of the energy in previously indigestible cellulose, reduce cellulosic waste by turning it into food, solve problems of food shortages by making algae, grass, straw, and even wood edible, and eventually turn human bodies into a source of renewable energy.
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Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume Article Contents Introduction. Materials and methods. The cellulose-degrading microbial community of the human gut varies according to the presence or absence of methanogens.
Christophe Chassard , Christophe Chassard. Oxford Academic. Eve Delmas. Annick Bernalier-Donadille. Editor: Julian Marchesi. Revision received:. Select Format Select format. Permissions Icon Permissions. Open in new tab. Open in new tab Download slide. Molecular diversity, cultivation and improved detection by fluorescent in situ hybridization of a dominant group of human gut bacteria related to Roseburia spp. Google Scholar Crossref. Search ADS.
Interaction between H 2 -producing and non-H 2 -producing cellulolytic bacteria from the human colon. Characterization of the xylan-degrading microbial community from human faeces. Assessment of metabolic diversity within the intestinal microbiota from healthy humans using combined molecular and cultural approaches.
A simple and versatile microcomputer for the determination of most probable number. Most probable number enumeration of H 2 -utilizing acetogenic bacteria from the digestive tract of animals and man. Proposal of Roseburia faecis sp.
Interactions and competition within the microbial community of the human colon: links between diet and health. Polysaccharide utilization by gut bacteria: potential for new insights from genomic analysis. Molecular cloning, expression and characterization of a new endoglucanase gene from Fibrobacter succinogenes S Physiology and genetics of xylan degradation by gastrointestinal tract bacteria.
Dietary fiber intake and risk factors for cardiovascular disease in french adults. Google Scholar PubMed. Differential carbohydrate media and anaerobic replica plating techniques in delineating carbohydrate utilizing subgroups in rumen bacterial populations. Composition and metabolic activities of bacterial biofilms colonizing food residues in the human gut. Quantification by real-time PCR of cellulolytic bacteria in the rumen of sheep after supplementation of a forage diet with readily fermentable carbohydrates: effect of a yeast additive.
Postinoculation protozoan establishment and association patterns of methanogenic archaea in the ovine rumen. The cellulolytic microflora of the human colon: evidence of microcrystalline cellulose-degrading bacteria in methane-excreting subjects. Interspecies H 2 -transfer in cellulose degradation between fibrolytic bacteria and H 2 -utilising microorganisms from the human colon.
Bacteroides cellulosilyticus sp. Books Brett, C. Physiology and Biochemistry of Plant Cell Walls. London: Unwin Hyman, Periodicals Benedict, C. Young, Stephen. Anaerobic —Describes biological processes that take place in the absence of oxygen. Cell wall —The tough, outer covering of plant cells composed of cellulose microfibrils held together in a matrix. Cellulose synthetase —The enzyme embedded in the plasma membrane that synthesizes cellulose. Colon —The terminal portion of the human digestive tract.
Golgi body —The organelle that manufactures, sorts, and transports macromolecules within a cell. Lignin —A polysaccharide that forms the secondary cell wall in some plants. Matrix —The material, composed of polysaccharides and protein, in which microfibrils of cellulose are embedded in plant cell walls. Methane —A gas produced during the anaerobic digestion of cellulose by bacteria in certain animals. Microfibril —Small fibrils of cellulose; consists of parallel arrays of cellulose chains.
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