Creatianon
8/24/2025, 11:03:34 PM
No.16761844
>>16758634
>>16761841
One of the first papers written about this can be found at https://www.pnas.org/doi/epdf/10.1073/pnas.81.8.2421. It discusses how “Waste water from nylon factories contains...6-aminohexanoic acid cyclic dimer...it was found, as early as 1975, that Flavobacterium Sp. KI72 could grow in a culture medium containing 6-aminohexanoic acid cyclic dimer as the sole source of carbon and nitrogen...two enzymes responsible for this metabolism of 6-aminohexanoic cyclic dimer were identified...”.
So the first important thing to note is that this enzyme does not “digest nylon”, it digests two molecules (“dimer”) of 6-aminohexanoic acid joined head-to-tail in a ring formation (“cyclic”). This is not nylon, it is a waste byproduct of nylon production. As https://www.jbc.org/article/S0021-9258(20)59178-3/fulltext explicitly describes it: “responsible for the degradation of nylon-6 industry by-products”.
And what’s more, this type of bacteria already have always had a protein that could digest this. As it continues to say: “ its analogous enzyme (EII′) that has only ∼0.5% of the specific activity toward the 6-aminohexanoate-linear dimer”.
I.E. it already has a protein that can digest this type of material. The paper agrees, saying: “It was also established that the EII-analogous protein (EII′) is located on a different part of the [plasmid]. EII′ has 88% homology to EII (7) but has very low catalytic activity (1/200 of EII activity) toward the 6-aminohexanoate-linear dimer (Ald), suggesting that EII has evolved by gene duplication followed by base substitutions from its ancestral gene (8).”
In other words it could already do this, it just got better at it. How?
>>16761841
One of the first papers written about this can be found at https://www.pnas.org/doi/epdf/10.1073/pnas.81.8.2421. It discusses how “Waste water from nylon factories contains...6-aminohexanoic acid cyclic dimer...it was found, as early as 1975, that Flavobacterium Sp. KI72 could grow in a culture medium containing 6-aminohexanoic acid cyclic dimer as the sole source of carbon and nitrogen...two enzymes responsible for this metabolism of 6-aminohexanoic cyclic dimer were identified...”.
So the first important thing to note is that this enzyme does not “digest nylon”, it digests two molecules (“dimer”) of 6-aminohexanoic acid joined head-to-tail in a ring formation (“cyclic”). This is not nylon, it is a waste byproduct of nylon production. As https://www.jbc.org/article/S0021-9258(20)59178-3/fulltext explicitly describes it: “responsible for the degradation of nylon-6 industry by-products”.
And what’s more, this type of bacteria already have always had a protein that could digest this. As it continues to say: “ its analogous enzyme (EII′) that has only ∼0.5% of the specific activity toward the 6-aminohexanoate-linear dimer”.
I.E. it already has a protein that can digest this type of material. The paper agrees, saying: “It was also established that the EII-analogous protein (EII′) is located on a different part of the [plasmid]. EII′ has 88% homology to EII (7) but has very low catalytic activity (1/200 of EII activity) toward the 6-aminohexanoate-linear dimer (Ald), suggesting that EII has evolved by gene duplication followed by base substitutions from its ancestral gene (8).”
In other words it could already do this, it just got better at it. How?