Screening and identification of Lactobacillus with potential cadmium removal and its application in fruit and vegetable juices

Cadmium (Cd) is a non-degradable heavy metal pollutant, which is harmful to human health. The aim of this study is to screen out excellent Lactic acid bacteria strains for cadmium removal. Among the tested 35 strains of lactic acid bacteria, 12 strains with strong Cd-resistant and cadmium removal ability were screened. The inhibition rate was below 30%, and the Cd removal rate was in the range of 10.91–35.08%. It is noted that the strain of L19 exhibits the outstanding Cd removal rate (51.00 ± 0.56%), which was identified by 16S rDNA as Lactobacillus fermentum. Under the conditions of 3% inoculation, pH = 6, and 3 h adsorption time, the Cd removal rates of Lactobacillus fermentum L19 in grape juice, tomato juice, apple juice, cucumber juice, and carrot juice were 43.67, 97.67, 55.33, 31.00, and 33.50%, respectively. Under the same conditions, the strain was inoculated into normal saline (final cadmium concentration of 5 mg/L), and the removal rate of cadmium was 52.75%. This study suggests that Lactobacillus fermentum L19 has a great cadmium removal effect in tomato juice and apple juice, which can be used for biosorption of cadmium in food industry. The results demonstrate that the fermentation by Lactobacillus fermentum could be considered as a strategy for the development of Cd-free foods.