Screening and Identification of Lactic Acid Bacteria with D-tagatose Production Capability

Abstract

Aims: D-tagatose is a natural ketohexose which can be used as a functional sweetener in foods, diary and beverages products. Isolation of new bacterial strains having the ability to produce D-tagatose is a continuously trending topic of research. Study Design: Screening of strains with D-tagatose production by identification and determination of its ability to produce D-tagatose content. Place and Duration of Study: School of Food and Biological Engineering, Jiangsu University between May 2018 and April 2019. Methodology: We initially screened and identified the strains capable of producing D-tagatose through kimchi liquid, and determined the species and genetic characteristics of the strain by physiological, biochemical and molecular biological identification, and then determined the content of D-tagatose by high performance liquid chromatography. Finally calculate the ability of the strain to produce D-tagatose. Results: In this study, 4 strains of lactic acid bacteria (LAB) were isolated from kimchi sample. The isolates were identified as Lactobacillus spp. (Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus salivarius) on the basis of morphological, physicochemical characteristics and analysis of 16S rDNA gene sequence. Because of the novelty, strain designated as L. salivarius UJS 003 was considered for D-tagatose yield. Fermentation of D-tagatose was carried out using galactose as substrate for 48 hr at 37 °C, and HPLC method was used to determine the yield. The experimental results exhibited a D-tagatose yield of 3.134 g/L by L. salivarius UJS 003. Conclusion: The strain UJS 003 represented as a potent D-tagatose producer and could be useful in a variety of biotechnological and industrial processes, particularly food and beverage industries.