[PCR] Different amplification-efficiency of varying DNA - (Aug/23/2006 )

HI!
I heard about the fact, that there is a possible difference in the amplification-efficiency of different templateDNA. Means: If I have a mixture of two different Template strands (e.g in a environmental sample), one of these may be better amplified than the other one.

Is that possible? Why?
Conformational aspects? different melting/annealing-behavior?
Is there a Paper about this aspect?

Thanks in advance

One of the most basic reasons is due to origin of template. Different organism maintain their genomic dna differently (for example, methylation). Other organisms have differing genomic properties. For example, some fungi have GC rich genomes and some bacteria have AT rich genomes. All of these contribute to differing kinetics during amplification.