Abstract:
We investigated environmental stresses tolerance of the extracellular vitamin B
12 producing lactobacilli cultures and confirmed the screening strategy of vitamin B
12 producing
Lactobacillus strains, isolated from the infants’ fecal sample. Three cultures (
L. plantarum NCDC958 and NCDC957, and
L. rhamnosus NCDC953) endowed with extracellular vitamin B
12 producing ability from our previous work were amplified for
cbiK gene with new primers designed in this study and their characteristics in tolerance to environmental stresses (such as temperature, salt, sugar, and ethanol) were studied for the first time with both optical density (OD) measurements and pour plate count method. We confirmed amplification of the 257 bp
cbiK gene in these cultures, which codes for important B
12-structural enzyme cobalt chelatase and successfully selected B
12-producing strains. These cultures showed tolerance upto 6% NaCl, 30% sucrose, 42 °C temperature and 8% ethanol. Importantly, extracellular vitamin B
12-producing culture
L. rhamnosus has first-time been reported for the environmental stress tolerance.
Manorama Kumari, Anusha Kokkiligadda, Pradip V Behare and SK Tomar. Evaluation of environmental stress tolerance of extracellular vitamin B12 producing lactobacilli cultures. J Pharmacogn Phytochem 2019;8(6):923-927.