Comparative Study of Sugar Fermentation and Protein Expression Patterns of Two Lactobacillus plantarum Strains Grown in Three Different Media

Abstract

A comparative study of two strains of Lactobacillus plantarum (REB1 and MLBPL1) grown in commercial medium (MRS broth), cucumber juice, and liquid pig feed was performed to explore changes to the metabolic pathways of these bacteria, using a proteomics approach (two-dimensional electrophoresis and liquid chromatography-tandem mass spectrometry) combined with analyses of fermentable sugars and fermentation end products. The protein expression showed that even with an excess of glucose in all media, both strains could metabolize different carbohydrates simultaneously and that hexoses could also be used via a phosphoketolase pathway with preferential expression in liquid feed. Sugar analyses showed that the fermentation of sugars was homolactic for all media, with some heterolactic activity in liquid feed, as shown by the production of acetate. Cucumber juice (the medium with the highest glucose content) showed the lowest hexose consumption (10%), followed by liquid feed (33%) and MRS broth (50%). However, bacterial growth was significantly higher in cucumber juice and liquid feed than in MRS broth. This discrepancy was due to the growth benefit obtained from the utilization of the malate present in cucumber juice and liquid feed. Despite different growth conditions, the synthesis of essential cellular components and the stress response of the bacteria were unaffected. This study has improved our understanding of the mechanisms involved in the growth performance of an appropriate lactic acid bacterium strain to be used for food and feed fermentation, information that is of crucial importance to obtain a high-quality fermented product.Lactic acid bacteria (LAB) represent a group of microorganisms that are functionally related by their ability to produce lactic acid during fermentation. Acidification due to lactic acid production and other enzymatic processes contribute to the flavor, texture, and keeping qualities of fermented food and feed products (2,14). Understanding the mechanisms involved in the growth performance of an appropriate LAB strain to be used for food and feed fermentations is of crucial importance to obtaining high-quality fermented product.Lactobacillus plantarum is a facultative heterofermentative LAB encountered in a large number of environmental niches, from dairy and meat products to a variety of vegetable and plant fermentations (8). It is also one of the Lactobacillus species present in the human intestinal tract (1). Due to its high acid tolerance, L. plantarum has been used as the starter culture of food and feedstuffs (16,24), but it has also been used as a probiotic (6, 12) and as a delivery vehicle for therapeutic compounds (14, 18) due to its ability to survive and persist in the gastrointestinal tract. Therefore, studies of the adaptation of L. plantarum to different environmental niches are of great interest due to the extensive use of this bacterium in food and feed fermentations.The two strains of L. plantarum used in this study (REB1 and MLBPL1 strains) are used in starter culture...

Apple juice as a medium for fermentation by the probiotic Lactobacillus plantarum PCS 26 strain

“…Passos et al (2003), in their research on growth kinetics of L. plantarum MOP-3, found out that the biomass yield coefficient (mg cells/mmol hexoses) was significantly increased while the maintenance coefficient (mmol hexoses/mg cells h) was significantly reduced in the presence of malic acid, indicating that the culture had lower demand for hexoses. Similar results were published by Plumed-Ferrer et al (2008), who compared the growth of two strains of L. plantarum, both in MRS broth and in cucumber juice. They reported that the strains grown in cucumber juice showed relatively low hexose consumption of around 10 %, even though the media contained an excess of glucose.…”

Effect of inactivation of ccpA and aerobic growth in Lactobacillus plantarum: A proteomic perspective

“…Indeed, the study by Cohen et al reporting the proteomic map of L. plantarum WCFS1, did not give any indication of the expression of PDH complex subunits [40]. Differential proteomic studies on L. plantarum strains, did not show evidence of PDH biosynthesis [41,42]. Coherently, our proteomic data clearly indicated that the A, B and C subunits of PDH were never detectable in the wild type strain, while the biosynthesis of these proteins was triggered by ccpA inactivation, regardless of growth condition.…”

Lactobacillus: the Next Generation of Malolactic Fermentation Starter Cultures—an Overview

“…can be applied in the future (Borneman et al 2010). Proteomic approaches have been used to study the sugar fermentation patterns in L. plantarum (Plumed-Ferrer et al 2008) and the effect of tannic acid on Lactobacillus hilgardii (Bossi et al 2007). Metabolomics have been used to compare the effect of L. plantarum and O. oeni on primary and secondary metabolite production in wine.…”