Ginger bug made by combining fresh ginger root with sugar and water and then allowed to rest in an aerobic environment will encourage colonization of lactobacilli (found on skin of all fruits) and wild yeast.
The resulting liquid culture can be maintained indefinitely as long as it is fed intermittently with just sugar and water. Some feed with more ginger too. Same concept as a sourdough starter.
Ginger beer plant, the crystal like culture, looks like super small tapioca pearls but translucent, should not be confused with ginger bug or the stuff people make a 'plant' from using bread yeast-sugar-water-ground/fresh ginger is composed of two specific yeast and bacteria: Saccharomyces florentinus and Lactobacillus hilgardii (formerly Brevibacterium vermiforme). The origin of this GBP has never been confirmed, they have documentation going back to Crimean War, and some theorize it was found as a cluster of clear crystals on a ginger plant, but I have never stumbled across any lab recreation. Jim with
www.gingerbeerplant.net in the UK is probably the #1 source for ginger beer plant in the world. People are selling knock off ginger beer plant which is made from bread yeast, wine yeast, water kefir grains or hybrid water kefir grains. The two organisms in true GBP, which slowly produces new 'grains', are not the same as water kefir grains, which has many different names(tibicos, Indian sea rice, Japanese water bees, etc) and water kefir is commonly composed of lactobacilli, lactococci/streptococci, and yeast. It should be noted that water kefir grains and real GBP have one shared organism, Saccharomyces florentinus.
Read up about all things kefir including the common organisms found in milk kefir grains(30+ organisms) vs water kefir grains(10+ organisms),
http://users.sa.chariot.net.au/~dna/kefirpage.html. This kefir site is info provided by the kefir community's leading resource, Dom is his name. I own water kefir and Jim's GBP and use ginger bug, none are the same. You can make the same 'ginger beer' recipe but use each of these cultures and get three dofferent outcomes.
FWIW, I've even made a 'bug' using pineapple rind instead of ginger, the soda I make taste just like soda made from my ginger bug, even maintained the starter for about a year and eventually tossed it. Yemoos.com has a very good photo of ginger beer plant and water kefir grains, they are both crystal like gems but very, very different.
I would love to know what organisms are growing in your ginger bug, even the ginger for that matter.