Utilization of amino acids and dipeptides by Lactobacillus plantarum from orange in nutritionally stressed conditions

Abstract

Aims: To investigate amino acid and dipeptide utilization by Lactobacillus plantarum N4 isolated from orange peel, in a nutritionally depleted medium based on MRS (Mann, Rogosa, Sharpe). Methods and Results: In MRS with 0·1 g l−1 of meat extract and without peptone and yeast extract, growth increased when essential and stimulatory amino acids and nonessential amino acid were added to the medium. Replacement of the essential amino acid, leucine, and the nonessential amino acid, glycine, by leucyl‐leucine (Leu‐Leu) and/or glycyl‐glycine (Gly‐Gly) significantly enhanced growth. Essential amino acids were mainly consumed and the dipeptides were almost completely used at the end of growth. Leucine and glycine accumulated internally from the peptides were higher than from the free amino acids. Glucose utilization increased in the media containing dipeptides compared with the medium containing free amino acids. Conclusions: In a N‐depleted medium, Leu‐Leu and/or Gly‐Gly were more effective than the respective amino acids in supporting growth of the micro‐organism. The more efficient internal accumulation of glycine and especially leucine from dipeptides confirmed the ability of the strain to assimilate mainly complex nitrogen molecules rather than simple ones. Significance and Impact of the Study: The ability of Lact. plantarum N4 to efficiently use dipeptides could contribute to spoilage development in the natural medium of the organism, orange juice.

Transcriptome response ofLactobacillus sakeito meat protein environment

“…Our results also showed that expression levels of intracellular oligoendopeptidases (pepF1 and pepF2) of L. sakei strain La22 were high in meat medium, similar to results in previous studies [16,24]. Some lactobacillus, for example L. lactis, can transport and metabolize certain amino acids when the carbohydrate source is exhausted, and these amino acids were from peptides hydrolyzed by internal endopeptidases rather than being free amino acids transported from outside the cell [26,27]. Even in L. sanfranciscensis and L. plantarum, transport of single amino acids was inefficient [28].…”

“…ClpE and ClpL are Clp proteins that function as chaperones and form the Clp proteolytic complex together with a structurally unrelated ClpP peptidase to specifically degrade misfolded proteins. ClpE belongs to the CtsR regulon and ClpL is the only one of degradation function of CtsR in all of the Clp‐related proteins . This may be explained why the two genes showed opposite expression in our study.…”

Optimization of probiotic and lactic acid production by Lactobacillus plantarum in submerged bioreactor systems

“…Whey and peptone are complex ingredients which contain several essential amino acids and important minerals and vitamins [22,26,30]. Bevilacqua et al [2] have shown that biomass production increased in a nonlinear way with increasing lactose up to a threshold value (20 g l -1 ) and for pH (6.0), but found that the effect of the interaction of pH and lactose in the model on biomass was small.…”

Transfer and subsequent growth and metabolism of Lactobacillus plantarum in orange juice medium during storage at 4 and 30°C

“…(1999) reported that L. plantarum N4 and N8 isolated from oranges peal were able to derive energy and ammonia from arginine or citrulline catabolism, which is interesting for micro‐organisms developing in a stressful environment. Saguir et al. (2008) demonstrated the ability of L. plantarum N4 to assimilate mainly dipeptides rather than amino acids in nutritionally deficient condition.…”