Utilization of citrate by lactobacilli isolated from dairy products

Abstract

SummaryTwenty-five strains of lactobacilli isolated from dairy products, includingLactobacillus casei, Lactobacillus plantarumandLactobacillus brevisspecies, were grown in semi-defined media and examined for their ability to ferment citrate and produce formate. Of 7 strains ofL. casei, all utilized citrate to varying extents, as did 9 of 10 strains ofL. plantarumand 3 of 8 strains ofL. brevis.L. caseiproduced 19–35% of the theoretical yield of formate from the citrate utilized,L. plantarum0–11% andL. brevis0–28%. Of 2 strains ofL. caseitested for their abilities to ferment citrate in the presence of 2% lactose, strain C 5 was unaffected by lactose whereas strain C 2 showed a 45% decrease in the citrate utilized. However, lactose used at 2% concentration greatly reduced formate production byL. caseiC 5, which produced 62% of the theoretical yield of formate from citrate after 35 days in the absence of lactose and only 8% in its presence. The yield of diacetyl produced byL. caseiC 5 from citrate plus lactose (both at 2% concentration) was 145 times that produced from citrate alone, and 800 times that from lactose alone.

Ca 2+ -Citrate Uptake and Metabolism in Lactobacillus casei ATCC 334

“…A number of studies have suggested that Lb. casei is able to derive metabolic energy from citrate metabolism, and energy-producing pathways have been proposed based on the genome sequence and metabolic flux analyses (26,27,36). ATP production by acetate kinase plays a pivotal role in these models.…”

Conditions required for citrate utilization during growth of Lactobacillus casei ATCC334 in chemically defined medium and Cheddar Cheese extract

“…Consequently, the NSLAB are excluded from utilizing lactose as an energy source. Potential energy sources for NSLAB in ripening cheese include nucleic acids derived from the autolysis of SLAB (Thomas 1986), amino acids (Kieronczyk et al 2001;Kristoffersen 1956), sugars liberated from glycoproteins or glycolipids present in milk (Fox et al 1998;Williams and Banks 1997), and citrate (Branen and Keenan 1977;Campbell and Gunsalus 1944;Fryer 1970;Fryer et al 1970;Starrenburg and Hugenholtz 1991).…”

“…Citrate utilization by NSLAB has been the subject of numerous publications. These research efforts have focused on determining the influence of factors such as pH, the presence of monovalent and divalent cations, the presence and absence of a carbohydrate source, the carbohydrate type and the presence of mixed cultures on citrate utilization by NSLAB (Branen and Keenan 1977;Campbell and Gunsalus 1944;Fryer 1970;Fryer et al 1970;Perry and Sharpe 1960;Starrenburg and Hugenholtz 1991;Williams et al 2000). Most of these studies were conducted in complex media such as milk or MRS.…”

13C nuclear magnetic resonance analysis of glucose and citrate end products in an ldhL-ldhD double-knockout strain of Lactobacillus plantarum

“…Glucose and citrate degradation pathways proposed for the L. plantarum wild-type strain (NCIMB8826) and LDH-defective strain (TF103). [1], LDH; [2], pyruvate formate-lyase; [3], acetaldehyde dehydrogenase; [4], alcohol dehydrogenase; [5], phosphotransacetylase; [6], acetate kinase; [7], pyruvate oxidase; [8], pyruvate decarboxylase; [9], ␣-acetolactate synthase; [10], ␣-acetolactate decarboxylase; [11], 2,3-butanediol dehydrogenase; [12], nonenzymatic decarboxylation; [13], pyruvate carboxylase; [14], malate dehydrogenase; [15], fumarase; [16], fumarate reductase; [17], malolactic enzyme; [18], citrate lyase; [19], oxalacetate decarboxylase; [20], mannitol-1-phosphate dehydrogenase; [21] (28), and the authors hypothesized the involvement of hydroxyisocaproate dehydrogenase activities. However, we did not detect any hydroxyisocaproate dehydrogenase activity in TF103 cell extracts using several ␣-keto acids as substrates.…”