das
Regeneration In Process
There were some Jews around before the Enlightenment,
When I first read that, I thought you meant Jews at all. Would be weird for them to appear due to the Enlightenment...
but the Enlightenment era lead to the emancpation of the Jews throughout Europe.
We're talking about Jewish bankers, not Jews generally. Your average Jew's contribution to Europe wasn't much bigger then your average German's.

But, Jewish scientists did make many contributions to Europe's technological advancement that would have been delayed to a later date if it were left up for the rest of the population to discover it.
Most Jewish scientists were a) 19th-20th century and b) more humanitarian-inclined, in general (or physicists - but we delayed physics as well!). This only reinforces my point, you know.
I said that because there simply would have been less scientists around.
Why that? The percentage of scientists would probably not change much, its rather likely to be larger then in OTL (more practical science is likely to result in according political developments and support for science). This world would be less advanced philosophically and culturally, but the Industrial Revolution, for instance, will come much earlier.
The Enlightenment also liberated other European minorities that developed many important technological advancements that the World would have had to wate for if they had not been liberated.
Somehow I didn't get that refference. Whom else did it "free" (well, more like started the proccess leading to emancipation of)? I guess you might be talking about the Irish, but although their cultural contributions were quite notable, as far as science goes they don't seem to be very important, as compared to the Jews or the majorities of the great powers.