Results and discussion Effect of culture conditions and additives on fermentative production of folate The folate content in milk is low when compared to other folate rich foods (Konings et al. 2001) and pasteurization will result in further reduction of folate level. Fermentation of milk by folate producing probiotic bacteria could be an alternative to develop a functional fermented food with enriched levels of folate. The folate binding proteins present in milk can increase its stability and bioavailability and thus it is an ideal matrix for folate fortification (LeBlanc et al. 2007). The levels of folate in fermented milk are influenced by the cultivation conditions, presence of folate precursors, prebiotic supplementation etc. In the present study, the extracellular folate production by the LABisolate L.lactis CM28 was highest (18.66±0.36 μg/L) at 8 h of fermentation (Fig. 1) by using 4 % skim milk medium supplemented with 6 μM glycine and 6 μM methionine. The gradual decrease in folate level after 8 h of fermentation could be due to the increased utilization of folate for growth and cell division. There were previous reports where the folate production was highest between 6 and 8 h of fermentation (Lin andYoung2000;Padalinoetal.2012).For fermentation, the incubation temperature of 37 °C was found to be optimum resulting in 18.59±0.28 μg/L extracellular folate compared to 16.72±0.56 μg/L and 8.06±0.6 μg/L at 30 °C and 42 °C respectively. The optimum growth and higher biomass attained at 37 °C could be the reason for increased folate production (Gangadharan and Nampoothiri 2011;Iyeretal.2010). But, it was reported by Sybesma et al (2003b) that there was a ten fold increase in folate production when there was a 90 % decrease in specific growth rate.