Glycerol stock gave good results for me.

Skim milk preservation is recommended for lactobacilli

If they are important for your work I would choose cryobeads. Anyway if you are doing a screening and isolating strains skim milk preservation is good and cheaper:

Tryptone 2.25 gm

Milk powder (desnatada) 5 gm

Glycerol 20 ml

Distilled water 80 ml

This formula for 100 ml of medium

Many times recommended method may not work. You have to standardize the method for your culture. I have tried glycerol stock as well as skimmed milk methods with my lactobacillus and bacillus strains and glycerol stock gave better revival in both. You can also try lyophilization with skimmed milk and check the revival rate after 6 months.

all the best.

Hi, I also work with Lactobacillus strains. For my cultures, I have cryo-preserved using 2 methods: Glycerol and MAST beads. Revival of both give good results but the glycerol gives a slightly higher revival rate than the MAST beads. Goodluck.