[Pops]

A paper on enzymatic conversion of cellulose to amylose.

Cellulose is the "woody" portion of plants - the stem of wheat for example, it's a carbohydrate but one we aren't able to digest.
Amylose is a polysaccharide, one half of typical starch. It is basically a long chain of individual glucose molecules. Because of the tight bonds between the glucose it is "resistant", meaning it takes longer to digest and so raises blood sugar loads slower than regular starch or HFCS which is 60% monosaccharide glucose.

This might be a big deal, not just as test tube food because we could make carbs from sawdust but because amylose is easier on the pancreas than "normal" starch contained in flour and for sure better than the straight glucose contained in HFCS, not to mention the fructose.

Oh, yeah, and it might be the key to cellulosic ethanol as a biofuel.

The global demand for food could double in another 40 y owing to growth in the population and food consumption per capita. To meet the world’s future food and sustainability needs for biofuels and renewable materials, the production of starch-rich cereals and cellulose-rich bioenergy plants must grow substantially while minimizing agriculture’s environmental footprint and conserving biodiversity. Here we demonstrate one-pot enzymatic conversion of pretreated biomass to starch through a nonnatural synthetic enzymatic pathway composed of endoglucanase, cellobiohydrolyase, cellobiose phosphorylase, and alpha-glucan phosphorylase originating from bacterial, fungal, and plant sources. A special polypeptide cap in potato alpha-glucan phosphorylase was essential to push a partially hydrolyzed intermediate of cellulose forward to the synthesis of amylose. Up to 30% of the anhydroglucose units in cellulose were converted to starch; the remaining cellulose was hydrolyzed to glucose suitable for ethanol production by yeast in the same bioreactor. Next-generation biorefineries based on simultaneous enzymatic biotransformation and microbial fermentation could address the food, biofuels, and environment trilemma.

http://www.pnas.org/content/early/2013/04/12/1302420110

A paper on amylose and insulin response compared to regular starch

[SeaGypsy]

Would be a big game changer if it works and is affordable. Knowing not much about this kind of chemistry, it looks like Phosphorus is involved, leading back to the peak issue on that element? Scant detail so far. Interesting this hasn't gotten much traction in the media yet, Chinese sour grapes perhaps, or lack of understanding how important this process could be? Patent was initially filed December last year, with this brief translation released in Feb this year, I wonder how long before more news on this?

[Pops]

Got a chance to google around a little:

Though the process works, it's expensive. Zhang estimates that, given the current price tag of the enzymes that his team used, it would cost about $1 million to turn 200 kilograms of crude cellulose into 20 kilograms of starch, about enough to feed one person's carbohydrate needs for 80 days. Still, after 5 to 10 years of further research, Zhang says companies could do the same thing for just $0.50 per person per day. "We do not see big obstacles to the commercialization of this process."

Optimistically assuming 100 billion tons of cellulose is available per year, "we will have a potential of approximately 4.5 billion tons of starch, which is nearly twofold the annual production of cereal—that is, 2.3 billion tons per year now," Zhang says. That would provide up to 30% of the food that prior studies estimate is needed to feed the world in 2050.

Still, it remains uncertain whether the approach will be economically viable, says energy economist Wallace Tyner of Purdue University in West Lafayette, Indiana, who did not participate in the study. "I am not saying it will not be—just that it is so early there are and so many uncertainties that it appears to be a very long way from a commercial process," he says. "That is usually the case when new processes are introduced."

http://news.sciencemag.org/sciencenow/2 ... tml?ref=hp

This bioprocess called "simultaneous enzymatic biotransformation and microbial fermentation" is easy to scale up for commercial production. It is environmentally friendly because it does not require expensive equipment, heat, or chemical reagents, and does not generate any waste. The key enzymes immobilized on the magnetic nanoparticles can easily be recycled using a magnetic force.

http://www.sciencenewsline.com/articles ... 00027.html


Then there is this from Robert Rapier, Gotta suck:
First Commercial Cellulosic Ethanol Plant in US Goes Bankrupt
http://www.energytrendsinsider.com/2013/03/19/first-commercial-cellulosic-ethanol-plant-goes-bankrupt/

[SeaGypsy]

If no waste, where does the other 180kg go (20 kilo starch/ 200 kilo cellulose)?

[Pops]

It says the portion of cellulose not converted to amylose converts to glucose.

The thing that is different with this as far as food goes, is other cellulose conversions attempt to make 100% glucose: simple sugar, that can be fermented into ethanol. This process on the other hand makes amylose, which is the stable half of starch and that is important because starch is the basis of the carbs we eat the most; rice, wheat, potatoes. Because it's long chain structure is sticky and resistant to water and mild heat, amylose is the half of starch that makes flour thicken yer gravy and pudding and hold your crackers and other baked stuff together.

And that is important because it can substitute for other food ingredients such as flour and corn starch that glucose from other cellulose processes can't. If this were ever cheap enough it could also replace some of corn derived HFCS. ("corn syrup" is 100% di- and poly- saccharide glucose that's had some portion converted to fructose because fructose is sweeter)


I'm no chemist or biologist so some or all of that may be wrong and I'll be happy to be corrected.

[Tanada]

It says the portion of cellulose not converted to amylose converts to glucose.

The thing that is different with this as far as food goes, is other cellulose conversions attempt to make 100% glucose: simple sugar, that can be fermented into ethanol. This process on the other hand makes amylose, which is the stable half of starch and that is important because starch is the basis of the carbs we eat the most; rice, wheat, potatoes. Because it's long chain structure is sticky and resistant to water and mild heat, amylose is the half of starch that makes flour thicken yer gravy and pudding and hold your crackers and other baked stuff together.

And that is important because it can substitute for other food ingredients such as flour and corn starch that glucose from other cellulose processes can't. If this were ever cheap enough it could also replace some of corn derived HFCS. ("corn syrup" is 100% di- and poly- saccharide glucose that's had some portion converted to fructose because fructose is sweeter)


I'm no chemist or biologist so some or all of that may be wrong and I'll be happy to be corrected.

Sort of. Corn Syrup is made by heating corn starch and treating it just a small amount to form a liquid mess which is then filtered to get the remaining starch out for reprocessing. The first stage corn syrup is mostly Glucose, a Monosaccharide, with some Maltose, a Disaccharide made from two Glucose molecules stuck together and a few percent of Polysaccharides with 3 to 6 Glucose molecules stuck together shorter than Starch. If the food label just says Corn Syrup this is the stuff they are talking about. High Fructose Corn Syrup is made by taking some of this Glucose syrup and processing it chemically into Fructose by altering the chemical structure. The Fructose is them mixed back into regular Corn Syrup in either 55%/45% or 44%/56% ratio of Fructose to Glucose depending on how sweet the end user wants it to be. Table sugar, Sucrose, is a Disaccharide made from 50% Fructose bound to 50% Glucose. Fructose is very sweet, in its powdered form it is about 25% sweeter than Sucrose and 100% sweeter than pure Glucose powder, that is why they process corn syrup to make it into Fructose. If you want to sweeten something like soda or lemonade and you need 1 cup of table sugar for a pitcher (2 Liters) you only need 3/4ths of a cup of Fructose but you would need 1+1/2 cup of Glucose.

Unfortunately most of the cells in your body can not process Fructose very well. Even the cells in your digestive tract do not pass it into your blood very quickly, it takes three times as long to absorb Fructose as it does to absorb Glucose. Both are absorbed more quickly when they are mixed together as HFCS or Sucrose/table sugar. The problem with Fructose is only two kinds of cells deal well with it once it is in your blood stream, Liver and Kidney cells. Almost all other cells lack the receptors to allow them to absorb Fructose directly, while every cell in your body absorbs Glucose. This means that any Fructose in your diet beyond what you would get naturally from eating a few pieces of ripe fruit puts a lot of extra stress on your Liver and Kidneys. If you have been exercising or fasting before you take in Fructose your Liver cells will convert part of it to Glucose to rebuild your storage and part of it into fat for longer term storage. If you have not been exercising enough to deplete your glucose(glycogen) stores then nearly all of the Fructose will be converted into fat for long term storage. A lot of biochemists now agree that excess fructose in the western diet is a huge influence on obesity and fatty liver disease. Fatty liver disease is very similar to Cirrhosis which takes place when your liver has to convert Ethanol into Glucose.

So the high points, Corn Syrup is 90% monosaccharide Glucose, HFCS and table sugar Sucrose are about half Glucose and half Fructose. Too much Glucose makes you diabetic. Too much Fructose makes you fat. Too much HFCS or Sucrose causes about 30% of the population to become fat or diabetic or both. 20% of diabetics are skinny, 30% of fat people never have blood sugar problems or diabetes. Any food that has Carbohydrates in it greater than the Fiber content is broken down by your digestive system into simple sugars (monosaccharides) meaning Glucose, Fructose, Galactose. These are either used directly for cell metabolism, stored in Liver and skeletal muscle as Glycogen, or converted into Fat for long term storage. The lower a Diabetic keeps their dietary carbohydrate intake the easier it is for them to maintain a stable blood sugar level.

Converting Cellulose to Starch would be good for two things, feeding people who are not diabetic and feeding biofuel producers. You could also use it to feed livestock, the reason grass fed beef grow slower and fatten less is they don't digest much of their food compared to grain fed beef. Give them treated cellulose starch and they will fatten up just like they would eating grain, because just like humans starch digests easily into glucose and excess food converts to fat storage.

[Pops]

Glucose doesn't cause diabetes but let's not get sidetracked here.

The big thing is not just that this might be able to economically produce sugar from cellulose but that amylose is the "resistant" carb in starch that does all the stuff that starch is used for. That means it's resistant to digestion and is the insoluble dietary fiber part that makes starch important for the chemistry of cooking; it makes soups thicken and breads hold together even with low gluten flour. In most starch it is only about 20% by weight, with the much more easily digested amylopectin constituting 70-80%. Amylopectin is the part of starch that is soluble and easier for enzimes to break apart so is quickly absorbed to rapidly increase the glycemic load on the body. So really amylose is much better even for diabetics as a replacement for "regular" starch in the chemistry of cooking.

I think that's the main thing here, conversion of cellulose to sugar of course but one important in food processing and that actually has a low glycemic index so not only provide calories but calories that aren't nearly as "hot" as HFCS


One of the problems feeding concentrates to ruminants, is that without roughage they don't ruminate: chew their cud. When they graze normally they swallow grass nearly whole then regurgitate it to chew and mix it with saliva - and saliva contains much of the amylase they produce. Amylase is the enzyme that breaks down amylose... so ... since they don't chew cud much when fed only concentrates they might not be able to utilize the amylose well. But I don't know.


And this is po.com! So even if the amylose portion of the reaction wouldn't be good for fermenting to ethanol because it's insoluble, the glucose that is the "by-product" of the reaction certainly would.

Of course there is the argument that there really isn't any agricultural waste, that whatever isn't used should go back to feed the soil. But this could expand the types of plants that can be used for food/fuel and that could be important.

[Tanada]

I wasn't trying to step on any toes Pops, just explain the biochemistry as it is currently understood. The amount of glucose in the blood of a person with a meter reading around 100 is only 4.9 grams for their entire blood supply. That amounts to one teaspoon of corn syrup dissolved in 5 liters of blood. That works out to about 20 calories of energy, the amount you need to sit in front of your computer typing for about an hour because your body consumes about 60 calories of Fat per hour when you are sitting and the rest of your resting metabolic rate is made up from proteins and other cell products.

If you live an active life and don't sit down for most of the day you burn more, if you are a couch potato watching TV or reading all day you burn less. Nothing mysterious about it.

[Pops]

No biggie T, just not sure what your point was relative to the topic. Amylose is insoluble dietary fiber that takes a long time to break down into simple sugars. In fact it is the very fiber that docs are urging us to get more of in our diet, the kind that lowers the glucose load and may actually increases insulin sensitivity. That was the part of the story that really caught my eye. Unlike the last green revolution that made starch cheap and corn sweeteners and animal production ubiquitous, this could also increase the food supply but actually be healthier than what we eat now.


..
Since the site is down, I'll prattle on. Glucose isn't bad, cells prefer it and store it locally and it is such an important energy source it can be produced from non-carb substrates by the liver and to a lesser extent by the kidneys and intestine through gluconeogenesis. This is a feature, not a fault, all animals have redundant energy pathways or we'd have never been able to outrun the bear.

Since I'm a type I (insulin dependent) diabetic, I can illustrate that process (always look on the bright side, right? LOL).

The presence of insulin in the bloodstream indicates to the liver that there is also plenty of glucose in the blood and there is no need to convert it from fats and proteins in the diet or from stored fat or even muscle mass. So since I don't make my own insulin, my liver thinks I'm starving all the time and so wants to synthesize glucose all the time. Even though I eat a very low carb diet, less than 15g most days (about 1 slice of bread), I still need to inject 30u of insulin a day just to tell my liver to cool it and not continually synthesize more and more glucose.

ETA: To give a little context to how much 30u of insulin is, I usually I take 1u for each 12g of carb at a meal so that would be 30*12 or 360g worth of insulin. But that insulin helps all cells to absorb glucose and since the normal pancreas dumps insulin straight into the liver via the bile duct the concentration in the liver is higher than in the blood. Sooo I'd guess that 30u of insulin is preventing or offsetting perhaps 150-200g of glucose produced by my liver.