1. Vera C, Guerrero C, Illanes A. Trends in lactose-derived bioactives: synthesis and purification. Systems Microbiology and Biomanufacturing. 2022;2:393–412. http://doi.org/10.1007/s43393-021-00068-2
2. Nooshkam M, Babazadeh A, Jooyandeh H. Lactulose: Properties, technofunctional food applications, and food grade delivery system. Trends in Food Science and Technology. 2018;80:23–34. https://doi.org/10.1016/j.tifs.2018.07.028
3. Ryabtseva SA, Khramtsov AG, Budkevich RO, Anisimov GS, Chuklo AO, Shpak MA. Physiological effects, mechanisms of action and application of lactulose. Problems of Nutrition. 2020;89(2):5–20. (In Russ.). https://doi.org/10.24411/0042-8833-2020-10012; https://www.elibrary.ru/TNXHMW
4. Ryabtseva SA. Lactulose technology. Moscow: DeLi print; 2003. 232 p. (In Russ.).
5. Sitanggang AB, Drews A, Kraume M. Recent advances on prebiotic lactulose production. World Journal of Microbiology and Biotechnology. 2016;32(9):154. https://doi.org/10.1007/s11274-016-2103-7
6. Silvério SC, de Macedo EA, Teixeira JA, Rodrigues LR. Biocatalytic approaches using lactulose: end product compared with substrate. Comprehensive Reviews in Food Science and Food Safety. 2016;15(5):878–896. https://doi.org/10.1111/1541-4337.12215
7. Vera C, Illanes A. Lactose-derived nondigestible oligosaccharides and other high added-value products. In: Illanes A, Guerrero C, Vera C, Wilson L, Conejeros R, Scott F, editors. Lactose-derived prebiotics. A process perspective. Academic Press; 2016. pp. 87–110. https://doi.org/10.1016/B978-0-12-802724-0.00003-2
8. Wang M, Wang L, Lyu X, Hua X, Goddard JM, Yang R. Lactulose production from lactose isomerization by chemo-catalysts and enzymes: Current status and future perspectives. Biotechnology Advances. 2022;60:108021. https://doi.org/10.1016/j.biotechadv.2022.108021
9. Ryabtseva SA, Khramtsov AG, Shpak MA, Lodygin AD, Anisimov GS, Sazanova SN, et al. Biotechnology of Lactulose Production: Progress, Challenges, and Prospects. Food Processing: Techniques and Technology. 2023;53(1):97–122c. https://doi.org/10.21603/2074-9414-2023-1-2419; https://www.elibrary.ru/DVBEZS
10. de Albuquerque TL, de Sousa M, Gomes e Silva NC, Girão Neto CAC, Gonçalves LRB, Fernandez-Lafuente R, et.al. β-Galactosidase from Kluyveromyces lactis: Characterization, production, immobilization and applications - A review. International Journal of Biological Macromolecules. 2021;191:881–898. https://doi.org/10.1016/j.ijbiomac.2021.09.133
11. Lyutova LV, Naumov GI, Shnyreva AV, Naumova ES. Molecular polymorphism of β-galactosidase LAC4 genes in dairy and natural strains of Kluyveromyces yeasts. Molecular Biology. 2021;55(1):75–85. (In Russ.). https://doi.org/10.31857/ S0026898421010109; https://www.elibrary.ru/DXUCCI
12. Lyutova LV, Naumova ES. Inter-strain hybridization of Kluyveromyces lactis for creating efficient lactose-fermenting yeast. Biotekhnologiya. 2021;37(4):43–50. (In Russ.). https://doi.org/10.21519/0234-2758-2021-37-4-43-50; https://www.elibrary.ru/XZBKCB
13. Lyutova LV, Naumova ES. Comparative analysis of fermentation of lactose and its components, glucose and galactose, by interstrain hybrids of dairy yeast Kluyveromyces lactis. Biotechnology. 2023;39(1):3–11. (In Russ.). https://doi.org/10.56304/S0234275823010064; https://www.elibrary.ru/BMMPOR
14. Ruiz-Ramírez S, Jiménez-Flores R. Properties of β-Galactosidases derived from Lactobacillaceae species and its capacity for galacto-oligosaccharides production. Journal of Dairy Science. 2023;106(12):8193–8206. https://doi.org/10.3168/jds.2023-23392
15. Dorau R, Jensen PR, Solem C. Purified lactases versus whole-cell lactases-the winner takes it all. Applied Microbiology and Biotechnology. 2021;105:4943–4955. https://link.springer.com/article/10.1007/s00253-021-11388-7
16. Wang Q, Lillevang SK, Rydtoft SM, Xiao H, Fan M-T, Solem C, et.al. No more cleaning up - Efficient lactic acid bacteria cell catalysts as a cost-efficient alternative to purified lactase enzymes. Applied Microbiology and Biotechnology. 2020;104:6315–6323. https://link.springer.com/article/10.1007/s00253-020-10655-3
17. Hashem AM, El-Azeem Ismail SA, Helmy WA, El-Mohamady Y, Abou-Romia R. Factors affecting the production of lactulose by Lactobacillus acidophilus NRRL 4495 b-galactosidase and its biological activity. Malaysian Journal of Microbiology. 2013;9():1–6. http://doi.org/10.21161/mjm.43612
18. Ryabtseva SA, Kotova AA, Skripnyuk AA. Yeast in the processing of dairy raw materials. St. Petersburg: Lan; 2019. 120 p. (In Russ.).
19. Botvynko A, Bednářová A, Henke S, Shakhno N, Čurda L. Production of galactooligosaccharides using various combinations of the commercial β-galactosidases. Biochemical and Biophysical Research Communications. 2019;517(4):762–766. https://doi.org/10.1016/j.bbrc.2019.08.001
20. Inchaurrondo VA, Yantorno OM, Voget CE. Yeast growth and beta-galactosidase production during aerobic batch cultures in lactose-limited synthetic medium. Process biochemistry. 1994;29(1):47–54. https://doi.org/10.1016/0032-9592(94)80058-8
21. Guerrero C, Vera C, Plou F, Illanes A. Influence of reaction conditions on the selectivity of the synthesis of lactulose with microbial b-galactosidases. Journal of Molecular Catalysis B: Enzymatic. 2011;72(3–4):206–212. https://doi.org/10.1016/j.molcatb.2011.06.007
22. Hua X, Yang R, Shen Q, Ye F, Zhang W, Zhao W. Production of 1-lactulose and lactulose using commercial b-galactosidase from Kluyveromyces lactis in the presence of fructose. Food Chemistry. 2013;137(1–4):1–7. https://doi.org/10.1016/j.foodchem.2012.10.003
23. Sitanggang AB, Drews A, Kraume M. Influences of operating conditions on continuous lactulose synthesis in an enzymatic membrane reactor system: A basis prior to long-term operation. Journal of Biotechnology. 2015;203:89–96. https://doi.org/10.1016/j.jbiotec.2015.03.016
24. De Albuquerque TL, Gomes SDL, D’Almeida AP, Fernandez-Lafuente R, Gonçalves LRB, Rocha MVP. Immobilization of β-galactosidase in glutaraldehyde-chitosan and its application to the synthesis of lactulose using cheese whey as feedstock. Process Biochemistry. 2018;73:65–73. https://doi.org/10.1016/j.procbio.2018.08.010
25. Neto CACG, Silva NCGE, de Oliveira Costa T, de Albuquerque TL, Gonçalves LRB, Fernandez-Lafuente R, et.al. The beta-galactosidase immobilization protocol determines its performance as catalysts in the kinetically controlled synthesis of lactulose. International Journal of Biological Macromolecules. 2021;176:468–478. https://doi.org/10.1016/j.ijbiomac.2021.02.078
26. Lee Y-J, Kim CS, Oh D-K. Lactulose production by beta-galactosidase in permeabilized cells of Kluyveromyces lactis. Applied Microbiology and Biotechnology. 2004;64:787–793. http://doi.org/10.1007/s00253-003-1506-1
27. Guerrero C, Vera C, Conejeros R, Illanes A. Transgalactosylation and hydrolytic activities of commercial preparations of β-galactosidase for the synthesis of prebiotic carbohydrates. Enzyme and Microbial Technology. 2015;70:9–17. https://doi.org/10.1016/j.enzmictec.2014.12.006
28. Ryabtseva SA, Skripnyuk AA, Kotova AA, Khramtsov AG, Rodnaya AB, Lodygin AD, et al. Method for combined enzyme beta-galactosidase production. Russia Patent Ru 2622078. 2017.
29. Zhao R, Chen Z, Liang J, Dou J, Guo F, Xu Z, et.al. Advances in Genetic Tools and Their Application in Streptococcus thermophilus. Foods. 2023;12(16):3119. https://doi.org/10.3390/foods12163119