Wow. This article confirms basically everything I've ever said about the perceived competition.
So this is supposed to be a big breakthrough in protein fermentation, right? So now, they are celebrating an 8-fold improvement from the best methods of the past. This breakthrough is an improvement of up to 8 grams per liter. LOL, great!
But wait, there's more.
The best performing fibers they made from these yields have a tensile strength of 481 +/- 31 MPa.
What this means:
Point 1 Their 481 MPa tensile strength fibers are about 1/4 the strength of Kraig Lab's Dragon Silk. The extensibility is roughly the same as KBLB between 30%-40%. This gives their fiber a toughness of about 179 MJ/m3, which is about 1/2 of the toughness of Kraig Labs Dragon Silks. Please don't be misinformed by those on here who don't know the very basic difference between tensile strength and toughness. These people may try to convince you that fiber glass is twice as tough as spider silk. That is completely untrue and it exposes the lack of basic understandings of material properties. If I was simple enough to believe those things, I too, might not believe spider silk could have vast applications.
Point 2 This "breakthrough" has increases protein yields from roughly 1g/L to about 8g/L. So that means a typical large scale 2000L bioreactor can produce about 16 kilograms of this new spider silk/mussel fusion protein. So what exactly is in this bioreactor? I know these fermentation companies like to make people think it's just sugar feedstock and bacteria. Well, simply put, it's not. If you click on the full Nature article regarding this breakthrough, you can check out their methods. I will paste them below so people can see the real complexity of simply just growing and expanding the bacteria (we won't even get into extraction/filtration/fiber making, etc).
As you will see, even the most basic ingredient in this fermentation process is the culture medium that is used for the bacteria to live and expand. You'll see that they use a pretty typical and well known media called "Terrific Broth" (TB). TB is widely used in fermentation. You can buy this in bulk. The cheapest I've ever seen this culture media sell for is about $85/kilo dry. This new "breakthrough" process uses TB at about 45 grams per liter of water. This means that 2000L bioreactor would need 90 kilos of TB. So just this one ingredient would cost over $7,500 to make 16 kilos of this new protein (not even fiber yet!). I won't even get into all the other (and more expensive) ingredients needed in the process. But if you read the Methods I posted below, you can look them up for yourself. And again, this does not include all the other costs of ingredients, extraction process, skilled personnel, tank cleaning/maintenance, large energy requirements, etc.
Now how does this relate to our current "competition" in Spiber, Amsilk, etc? Well if this "breakthrough" just improved efficiency by 8-fold, then you can imagine that our competitors are using a process that is even 8 times less efficient then this new process. So that same $7,500 for that single ingredient would yield only about 2 kilos for Spiber and Amsilk. Notice how I left out Bolt Threads? that's because they already recognized how bad these economics are for fibers, which is why they already pivoted to mushroom leather. The above process is great if you are creating a protein drug that can sell for $100/mg or whatever. But not for making a fiber. This breakthrough shows just how bad of a position Spiber and Amsilk are in.
***This new breakthrough completely proves that Kraig Labs has no competition from the protein fermentation companies.***
New "breakthrough" methods below (from Nature article to help illustrate their complex process):
Protein expression in shake flasks Protein expressions were performed in shake flasks using Terrific Broth (TB) media (24?g/L yeast extract, 20?g/L tryptone, 0.4% v/v glycerol, 17?mM KH2PO4 and 72?mM K2HPO4, pH?=?7.2) containing 100?µg/mL ampicillin. Protein expression in shake flasks began with transformation of corresponding plasmids into E. coli NEB10ß strain. Once colonies grew on LB agar (5?g/L yeast extract, 10?g/L tryptone, 10?g/L NaCl and 15?g/L agar) plates, a single colony was selected to inoculate a seed culture of 50?mL LB media and cultivated at 37?°C with orbital shaking until OD600 reached 0.8. This seed culture was then used to inoculate TB media in 2?L shake flasks at 37?°C with orbital shaking until OD600 reached 3-5. All cultures were induced by addition of 0.4% arabinose and were allowed to grow at 30?°C with orbital shaking for additional 24?h. Cells pellets were collected by centrifugation and were stored at -80?°C before proceeding to purification.
Protein purification Protein purification protocol was modified from previous methods10,12,55. For insoluble proteins, including all FGA and KLV proteins, with or without btMfp5 fusion, cell pellets were lysed in buffer A (6?M guanidine hydrochloride, 50?mM K2HPO4 and 300?mM NaCl, pH?=?7.0) at a ratio of 40?mL buffer A per liter of cell culture, followed by centrifugation. The supernatant was subjected to Ni-NTA column chromatography and washed sequentially with buffer B (8?M urea, 50?mM K2HPO4 and 300?mM NaCl, pH?=?7.0) containing 0?mM, 20?mM, and 50?mM imidazole. The target proteins were eluted using buffer B containing 300?mM imidazole. For water-soluble proteins, such as titin, GFP, and SH3, cell pellets were lysed in PBS buffer (137?mM NaCl, 2.7?mM KCl, 1.8?mM KH2PO4 and 10?mM Na2HPO4, pH?=?7.4) at a ratio of 40?mL PBS buffer per liter of cell culture, using sonication followed by centrifugation. The supernatant was loaded onto a Ni-NTA column, washed with PBS buffer containing 0?mM, 20?mM, and 50?mM imidazole, and eluted with PBS buffer containing 300?mM imidazole. The purified proteins were dialyzed against 5% acetic acid, lyophilized, and stored at -80?°C before dissolved in HFIP to make spinning dopes.
