It is interesting and significant that KAIST has been able to produce High MW protein based fibers in the lab.
However the 96 mer protein they tested is produced only as a low percentage of the various MW proteins that their bacterial system creates.
From the figures in the PNAS article I would estimate it at less than 10% of the total protein production.
Since their total production was about 1 or 2 grams per liter they would need to grow, process, extract, filter, centrifuge, etc. about ten liters per gram, 10,000 liters per kilogram, and to produce the proverbial metric ton (1000Kg),
10 Million liters of bacterial growth solution.
It is Going to be quite some time before that becomes a commercial source of high strength silk fiber!
In contrast, one gram of Monster Silk(TM), or Big Red(TM), or Dragon Silk(TM), approximately is produced by one silk worm.
1 million cocoons is a lot of cocoons, but it pales to insignificance compared to 10 Million liters of scummy water.
And the worms work for the joy of eating mulberry mush and making more worms!
Mike L.
PS. there is also some question about the details of Kim's exclusive license from UW of the spider silk genes.
Depending on the details of that license,and the courts' decision on the patentability of such information, KRAIST/Amsilk/Spiber/whomever may find themselves the target of Kim Thompson's Biggest ever IP lawsuit if/when they ever become profitable and commercial.
