No. No that wouldn't essentially do the same thing... not quite at all.
White table sugar is purified sucrose, as in a chemical substance. Blackstrap molasses is a complex mixture of substances; among them minerals, vitamins, and carbohydrates including some sucrose (a disaccharide). However, molasses also contains other carbohydrates, including the simple sugars (monosaccharides) glucose and fructose. Sucrose is a disaccharide, and it itself is comprised of the two monosaccharides glucose and fructose, containing one molecule of each.
Molasses also contains lesser amounts of other carbohydrates that are not simple sugars or complex carbohydrates. These are known as oligosaccharides and the primary in molasses is raffinose.
Why this is pertinent, besides the fact that pure table sugar contains absolutely no minerals (which microbes themselves require), is that different kinds of microbes tends to prefer or are able to utilize different carbohydrate sources. The most obvious and general example is bacteria versus fungi; bacteria are able to multiple rapidly and make quick use of simple sugars. But, many bacteria lack the enzymes required to harness the energy stored in the more complex carbohydrates. Fungi possess these enzymes, which allows them to break down cellulose, chitin and other complex organic polymers that are not carbohydrates.
