One possibility. I think it would work in some contexts but maybe not in others.

as in, "the ground zero of". "Ground zero" as a term seems to have many different meanings but after some research, it appears that it is used in this context. I don't think however the term is used in a necessarily positive or negative sense - it is more a case of "the very lowest point". See the examples attached. Hope this helps.

http://www.usatourist.com/francais/places/newyork/worldtrade...
plus connu sous le nom de "Ground Zero", "Niveau Zéro", est une phrase courante de nos jours


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http://www.crosscurrents.org/taylorfall2003.htm
The ground zero of melancholy has always been that one loses even the sense of what has been lost, even awareness of the source of the pain. To the extent that melancholy has a place in the cosmic order, as one of the “humours,” which is in turn connected by “correspondences” to other realities, one can escape the ground zero by portraying its characteristic symbols, as Dürer does.

http://www.aseansec.org/13965.htm
As I speak today, Thailand has emerged from the ground zero of economic crisis and bounced back.

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http://www.dissidentvoice.org/July05/Geels0702.htm
And so monotheism meets the ground zero of unreflective capitalism (i.e. the U.S.A.) to birth the continuing greed of a nation that is fundamentally unsustainable in the long run. At least the separation of church and state is now more defined by a speed bump than a solid wall!

perhaps not quite what you want. I presume you mean something that is rock bottom basic ? can't think....

not sure if this is negative enough