I was reading a post earlier regarding maple syrup being left out overnight.  They were asking if their beloved Maple syrup was still safe to consume.  In the comments I believe someone brought up this question I am asking, I'm sure I could do the research and find out but hey whats the fun in that.  So here's my question does the sugar in Maple syrup or any product for that matter inhibit the growth of mold.   Also if its true, how much sugar is needed percentage wise?  Does it matter what type of sugar?  
TLDR;  Yes. Sugar does inhibit growth of mold.  How does this work?  Several reasons:    Sugar prohibits growth through osmosis / dehydration.      "The most notable is simple osmosis, or dehydration. Salt or sugar,   whether in solid or aqueous form, attempts to reach equilibrium with   the salt or sugar content of the food product with which it is in   contact."   Source: http://www.scientificamerican.com/article/how-do-salt-and-sugar-pre/   Sugar weakens the molecular structure of pathogens' DNA      Salt and sugar's other antimicrobial mechanisms include interference   with a microbe's enzyme activity and weakening the molecular structure   of its DNA. Sugar may also provide an indirect form of preservation by   serving to accelerate accumulation of antimicrobial compounds from the   growth of certain other organisms.   Source: http://www.scientificamerican.com/article/how-do-salt-and-sugar-pre/ 