To screen for lactic acid bacteria (LAB) with synergistic effects and explore the mechanisms of their synergistic interactions from a metabolic perspective, the growth of LAB, lactic acid production and free amino nitrogen metabolites, lactate dehydrogenase (LDH) activity, and transcription regulation were measured in both monocultures and co-cultures.These indicators were used to evaluate the interactions between LAB, and non-targeted metabolomics further elucidated metabolic mechanisms underlying their synergy.The results displayed that the number of bacteria in the mixed culture of Lactiplantibacillus plantarum HC 1775 (Lpl) and Lacticaseibacillus rhamnosus GG HC 1509 (LGG) was significantly enhanced, with total lactic acid production reaching 71.20 μg/mL, which was 23.52% and 38.68% higher than Lpl and LGG monocultures, respectively.The free amino nitrogen content was 64.68 μg/mL.When cell-free supernatant was added, the viable counts of Lpl increased by 23.70% and those of LGG by 32.83%.The ldh gene was significantly regulated in Lpl+LGG co-culture, with an expression level 2.15-fold higher than in single cultures.The results displayed that Lpl and LGG exhibited a synergistic relationship that promoted each other’s growth.Metabolomic profiling revealed distinct metabolic signatures in co-culture, characterized by elevated amino acid biosynthesis (notably aspartate and threonine) and heightened metabolic flux.Lpl and LGG exhibit synergistic interactions, with amino acids significantly increasing in the co-culture system, thereby influencing the metabolism of LAB.This mechanistic understanding of LAB interactions advances foundational knowledge for optimizing microbial consortia in industrial and probiotic applications.
[1] GEORGE F, DANIEL C, THOMAS M, et al.Occurrence and dynamism of lactic acid bacteria in distinct ecological niches:A multifaceted functional health perspective[J].Frontiers in Microbiology, 2018, 9:2899.
[2] ABDUL HAKIM B N, XUAN N J, OSLAN S N H.A comprehensive review of bioactive compounds from lactic acid bacteria:Potential functions as functional food in dietetics and the food industry[J].Foods, 2023, 12(15):2850.
[3] RUIZ RODRÍGUEZ L G, MOHAMED F, BLECKWEDEL J, et al.Diversity and functional properties of lactic acid bacteria isolated from wild fruits and flowers present in northern Argentina[J].Frontiers in Microbiology, 2019, 10:1091.
[4] LIU S N, HAN Y, ZHOU Z J.Lactic acid bacteria in traditional fermented Chinese foods[J].Food Research International, 2011, 44(3):643-651.
[5] ZHANG K, ZHANG T T, GUO R R, et al.The regulation of key flavor of traditional fermented food by microbial metabolism:A review[J].Food Chemistry:X, 2023, 19:100871.
[6] WANG Y Q, WU J T, LYU M X, et al.Metabolism characteristics of lactic acid bacteria and the expanding applications in food industry[J].Frontiers in Bioengineering and Biotechnology, 2021, 9:612285.
[7] WANG R, SUN J C, LASSABLIERE B, et al.UPLC-Q-TOF-MS based metabolomics and chemometric analyses for green tea fermented with Saccharomyces boulardii CNCM I-745 and Lactiplantibacillus plantarum 299V[J].Current Research in Food Science, 2022, 5:471-478.
[8] HAN D, ZULEWSKA J, XIONG K, et al.Synergy between oligosaccharides and probiotics:From metabolic properties to beneficial effects[J].Critical Reviews in Food Science and Nutrition, 2024, 64(13):4078-4100.
[9] GADAGA T H, MUTUKUMIRA A N, NARVHUS J A.The growth and interaction of yeasts and lactic acid bacteria isolated from Zimbabwean naturally fermented milk in UHT milk[J].International Journal of Food Microbiology, 2001, 68(1-2):21-32.
[10] DE SOUZA OLIVEIRA R P, TORRES B R, PEREGO P, et al.Co-metabolic models of Streptococcus thermophilus in co-culture with Lactobacillus bulgaricus or Lactobacillus acidophilus[J].Biochemical Engineering Journal, 2012, 62:62-69.
[11] LIU E N, ZHENG H J, SHI T, et al.Relationship between Lactobacillus bulgaricus and Streptococcus thermophilus under whey conditions:Focus on amino acid formation[J].International Dairy Journal, 2016, 56:141-150.
[12] ROGERS A T, BULLARD K R, DOD A C, et al.Bacterial growth curve measurements with a multimode microplate reader[J].Bio-protocol, 2022, 12(9):e4410.
[13] 杨江威, 王越, 安家彦.对羟基联苯比色法测定葡萄酒发酵过程中的乳酸[J].大连工业大学学报, 2012, 31(6):402-404.
YANG J W, WANG Y, AN J Y.Detection of lactic acid by p-hydroxybiphenyl colorimetry during wine fermentation[J].Journal of Dalian Polytechnic University, 2012, 31(6):402-404.
[14] ABERNATHY D G, SPEDDING G, STARCHER B.Analysis of protein and total usable nitrogen in beer and wine using a microwell ninhydrin assay[J].Journal of the Institute of Brewing, 2009, 115(2):122-127.
[15] E J J, ZHANG J Y, MA R Z, et al.Study of the internal mechanism of L-glutamate for improving the survival rate of Lactiplantibacillus plantarum LIP-1 after freeze-drying[J].Innovative Food Science & Emerging Technologies, 2023, 84:103253.
[16] ELSAYED Y, REFAAT J, ABDELMOHSEN U R, et al.Metabolomic profiling and biological investigation of the marine sponge-derived bacterium Rhodococcus sp.UA13[J].Phytochemical Analysis, 2018, 29(6):543-548.
[17] CHEN S, LIU H H, ZHAO X M, et al.Non-targeted metabolomics analysis reveals dynamic changes of volatile and non-volatile metabolites during oolong tea manufacture[J].Food Research International, 2020, 128:108778.
[18] WU S M, YU Q Y, SHEN S, et al.Non-targeted metabolomics and electronic tongue analysis reveal the effect of rolling time on the sensory quality and nonvolatile metabolites of congou black tea[J].LWT, 2022, 169:113971.
[19] LI X, CHEN Y G, ZHAO S, et al.Efficient production of optically pure L-lactic acid from food waste at ambient temperature by regulating key enzyme activity[J].Water Research, 2015, 70:148-157.
[20] 顾悦. 环境胁迫及酵母菌对乳酸菌LuxS/AI-2群体感应系统的影响[D].呼和浩特:内蒙古农业大学, 2017.
GU Y.The effects of environmental stresses and yeast on LuxS/AI-2Quorum sensing system of lactic acid bacteria[D].Hohhot:Inner Mongolia Agricultural University, 2017.
[21] KANG C D, ZHANG Y Y, ZHANG M Y, et al.Screening of specific quantitative peptides of beef by LC-MS/MS coupled with OPLS-DA[J].Food Chemistry, 2022, 387:132932.
[22] SACCENTI E, HOEFSLOOT H C J, SMILDE A K, et al.Reflections on univariate and multivariate analysis of metabolomics data[J].Metabolomics, 2014, 10(3):361-374.
[23] YUAN Y X, WANG G, ZOU J H, et al.Study on comparative analysis of differential metabolites in Guanzhong dairy goat Semen before and after freezing[J].Theriogenology, 2023, 197:232-239.
[24] BECKONERT O, BOLLARD M E, EBBELS T M D, et al.NMR-based metabonomic toxicity classification:Hierarchical cluster analysis and k-nearest-neighbour approaches[J].Analytica Chimica Acta, 2003, 490(1-2):3-15.
[25] CHEN L, ZHANG Y H, ZOU Q, et al.Analysis of the chemical toxicity effects using the enrichment of Gene Ontology terms and KEGG pathways[J].Biochimica et Biophysica Acta (BBA) - General Subjects, 2016, 1860(11):2619-2626.
[26] RAVI P V, MAHARAJAN A, PATTABIRAMAN A, et al.Straightforward paper sensors for the detection of SSRI drugs using tyrosine functionalized GQDs:Fluorescence ‘turn-off’ turns on the crucial dosage monitoring[J].Diamond and Related Materials, 2023, 139:110407.
[27] ZHANG H, CHEN Y P, LI Y, et al.L-Threonine improves intestinal mucin synthesis and immune function of intrauterine growth-retarded weanling piglets[J].Nutrition, 2019, 59:182-187.
[28] ADEVA M M, SOUTO G, BLANCO N, et al.Ammonium metabolism in humans[J].Metabolism, 2012, 61(11):1495-1511.
[29] ZHAO L, ZHANG X T, LIU L J, et al.Effects of amino acids on growth and bacteriocin synthesis of Lactobacillus plantarum KLDS1.0391[J].Food Science, 2021, 42(18).
[30] 盖昱梓, 孙静娴, 黄刚, 等.苹果酸-乳酸发酵细菌乙醇胁迫应答机制研究进展[J].食品与发酵工业, 2021, 47(3):288-293.
GAI Y Z, SUN J X, HUANG G, et al.The response mechanism of bacteria to ethanol stress in malolactic fermentation[J].Food and Fermentation Industries, 2021, 47(3):288-293.
