The microorganisms are in the air, on your hands, in the dirt... Basically everywhere. They will come with the worms. As far as I know, all you need to know about them is that they need oxygen, so you need holes that won't get plugged up on the bottom as well as towards the top of your bin. If the conditions are right for the worms (moisture, air, temp etc), they will be right for the microorganisms too.

They thrive on molasses, but they thrive on free food waste too.

Does anyone have more specific information?

advice given to me: inoculate the bin with some already existing verimpost or pure castings. compost tea (soilfoodweb.org) might also help when moistening bedding. these have the beneficial microbes in abundance.

I've seen that advice but you put anything organic in your bin and you are inoculating it with bacteria. Provide oxygen and moisture and you are providing them with the right conditions to reproduce. As susanfromhawaii says, they are everywhere.

By adding molasses; when making vermicompost tea for example, you are providing a simple sugar for the bacteria to feed on. In a worm bin this should not be necessary.

Thank you,
Did I not make myself clear? O.K. I will try again.
I was raised on a farm & redworms lived in raw manure from cows,horses,pigs,chickens, & ribbit. We never moved the worms, they had to move in the soil at night.
I started to raising nightcrawlers for my organic garden & compost pile. I heard about redworms/ EM's & AM's. I was told everything about redworms, then a hint about EM's but nothing to go on.
I now know that this is a real program, a Dr.Teruo Higal of Japan. Here in the U.S.A. Dr. Robert Linderman worked with E.M's & A.M.'s. Endomycorrhizae - 60lbs per acre or 1.4 lbs per 1000 sq. ft.
I made it though K-12, I know micro-organisms are everywhere, that why we wash hands before eating.
Nitrogen is in the soil,water, & air too. The best way to use it is with soil builder like clover, peas,comfrey & micro-organisms that connect to the plants roots.
Maybe I should have said friendly EM's?
Thank You for your advice.

Are you talking about the EM used in Bokashi Composting (lactobacillus bacteria)? This is a procedure I found for making your own EM for the purpose of using to make your own Bokashi Bran.

Add 1 part white rice to 2 parts water and thoroughly mix it. Strain the rice out of the water, it should be cloudy white, into a container that you can cover with a cheesecloth or teacloth or something similar. Air should be able to flow into the container. Place the container in a cool dark place for about a week. It should smell somewhat sour. Strain out any particles. Put the liquid in a larger container and add 10 parts milk or skim milk. Cover again and allow to ferment for about 2 weeks. Solids should start to float to the top, leaving a yellowish liquid, the liquid is the 'homemade' lactobacillus. Strain off the solids. Strain off the solids and harvest out the yellow liquid.

Haven't tried it though. I got interested in Bokashi Composting very briefly but found that it didn't make sense for me to continuously be buying Bokashi Bran just for waste disposal. And making your own was a lot of work as opposed to outdoor composting in conjunction with worm composting. My goal is to do it as simple as possible, the less steps involved the better.

I think the process is sound and it would be a neat experiment. What were you going to do with the EM?

Not Bokashi Bran, but thank you for the Whole program.
This is the kind of thing I wanted about EM's. I have found out that the sugar or molasses works like the milk in Bokashi compost. I have been told that the sugar feeds the Em's when mixed in the cast tea. I wonder if it is easier to just use more cast, then to feed the EM's.
This maybe why everyone on 5 sites, knows about & have worms, but no one seem to know about using sugar in cast tea. I KNOW, I never said this before about the cast tea with simple sugars. It is because until someone told me, I did not know the rest of the story.
Thank you all for putting up with me.