{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T01:30:44Z","timestamp":1786325444581,"version":"build-2736575974"},"reference-count":39,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,8]],"date-time":"2026-08-08T00:00:00Z","timestamp":1786147200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Science and Technology Program Project of Nanping","award":["N2023Y015"],"award-info":[{"award-number":["N2023Y015"]}]},{"name":"Key Science and Technology Program Project in the Future Industry of Xiamen","award":["3502Z20254020"],"award-info":[{"award-number":["3502Z20254020"]}]},{"name":"Science and Technology Program Project of Xiamen","award":["3502Z20251003"],"award-info":[{"award-number":["3502Z20251003"]}]},{"name":"Science and Technology Program Project of Xiamen","award":["3502Z20251008"],"award-info":[{"award-number":["3502Z20251008"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>D-tagatose, a low-calorie sugar substitute, widely used in the food and pharmaceutical industries, can be produced from the substrate D-galactose using L-arabinose isomerase (L-AI). L-AI genes derived from Lactobacillus fermentum (LFAI), Lactobacillus brevis (LBAI), Lactobacillus plantarum (LPAI), and Lactobacillus sakei (LSAI) for the bioconversion of D-galactose into D-tagatose using whole Escherichia coli (E. coli) cells were investigated. The temperature, time, pH, whole-cell concentration, and metal ion concentration were optimized to enhance catalytic production. The results revealed that at the low substrate concentration of 10 g\/L, LFAI, LBAI, LPAI, and LSAI exhibited considerable catalytic activity, with conversion rates of 55.31%, 68.17%, 61.45%, and 58.22%, respectively. In contrast, at the high substrate concentration of 250 g\/L, their conversion rates were 19.78%, 18.47%, 20.26%, and 36.24%, respectively, with LSAI demonstrating superior catalytic performance. In order to facilitate the industrial production of D-tagatose, site-directed mutagenesis was performed on LSAI. Among the engineered LSAI variants, the P99H, K142R, and L465R mutants all showed increased catalytic rates for D-tagatose. Specifically, at the high substrate concentration of 250 g\/L, the P99H mutant achieved a conversion rate of 45.73%, representing a 32.7% improvement compared to the optimized LSAI. These results indicate that the designed site-directed mutagenesis strategy effectively enhanced whole-cell bioconversion performance of LSAI toward D-galactose.<\/jats:p>","DOI":"10.3390\/molecules31162756","type":"journal-article","created":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T01:20:03Z","timestamp":1786324803000},"page":"2756","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Engineering the L-Arabinose Isomerase from Lactobacillus sakei for Whole-Cell Conversion Production of D-Tagatose Under High Substrate Concentration Conditions"],"prefix":"10.3390","volume":"31","author":[{"given":"Ren","family":"He","sequence":"first","affiliation":[{"name":"Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen 361021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Liu","sequence":"additional","affiliation":[{"name":"Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen 361021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bingyi","family":"Tao","sequence":"additional","affiliation":[{"name":"Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen 361021, China"},{"name":"College of Chemical Engineering, Huaqiao University, Xiamen 361021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shaoxiong","family":"Liang","sequence":"additional","affiliation":[{"name":"College of Chemical Engineering, Huaqiao University, Xiamen 361021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xuchong","family":"Tang","sequence":"additional","affiliation":[{"name":"Academy of Advanced Carbon Conversion Technology, Huaqiao University, Xiamen 361021, China"},{"name":"BaYeCao Health Industry Research Institute Co., Ltd., Xiamen 361021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"177","DOI":"10.1038\/163177b0","article-title":"Composition of the gum of Sterculia setigera: Occurrence of D-tagatose in nature","volume":"163","author":"Hirst","year":"1949","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"2020","DOI":"10.1002\/jsfa.8687","article-title":"Rare sugars, D-allulose, D-tagatose and D-sorbose, differently modulate lipid metabolism in rats","volume":"98","author":"Nagata","year":"2018","journal-title":"J. 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