Calcium malate

Abstract: Absorption of calcium from a highly soluble form of calcium, a mixed calcium citrate-malate salt (CCM), was tested against calcium carbonate and milk in both rats and humans. The rat method estimated absorption from the 6-day retention of an oral tracer, and the human method employed the standard double-isotope procedure. CCM was given both as a dry powder and in an orange juice beverage. In two experiments in rats calcium from CCM was absorbed at least as well as, if not better than from calcium carbonate or milk. In two separate experiments in humans, calcium from CCM was absorbed significantly better than from calcium carbonate or milk. We conclude that CCM exhibits excellent bioavailability and that this formulation is a useful addition to the forms of calcium now available either for direct supplementation or for food fortification.

Abstract: In order to establish a cost-efficient biodiesel biorefinery, valorization of its main by-product, crude glycerol, is imperative. Recently, Ustilago trichophora TZ1 was found to efficiently produce malic acid from glycerol. By adaptive laboratory evolution and medium optimization, titer and rate could be improved significantly. Here we report on the investigation of this strain in fed-batch bioreactors. With pH controlled at 6.5 (automatic NaOH addition), a titer of 142 ± 1 g L−1 produced at an overall rate of 0.54 ± 0.00 g L−1 h−1 was reached by optimizing the initial concentrations of ammonium and glycerol. Combining the potential of bioreactors and CaCO3 as buffer system, we were able to increase the overall production rate to 0.74 ± 0.06 g L−1 h−1 with a maximum production rate of 1.94 ± 0.32 g L−1 reaching a titer of 195 ± 15 g L−1. The initial purification strategy resulted in 90 % pure calcium malate as solid component. Notably, the fermentation is not influenced by an increased temperature of up to 37 °C, which reduces the energy required for cooling. However, direct acid production is not favored as at a lowered pH value of pH 4.5 the malic acid titer decreased to only 9 ± 1 g L−1. When using crude glycerol as substrate, only the product to substrate yield is decreased. The results are discussed in the context of valorizing glycerol with Ustilaginaceae. Combining these results reveals the potential of U. trichophora TZ1 to become an industrially applicable production host for malic acid from biodiesel-derived glycerol, thus making the overall biodiesel production process economically and ecologically more feasible.

Abstract: The objective of this study was to evaluate the effects of malate supplementation on growth rate, feed efficiency, and diet digestibility in growing lambs. Twenty-four Merino lambs with a mean BW of 15.3 +/- 0.22 kg were divided into 3 homogenous groups. Each group was randomly allocated to 1 of 3 malate (16% disodium malate:84% calcium malate) levels: 0 (control), 4 (MAL-4), or 8 (MAL-8) g/kg of concentrate. Lambs were fed concentrate and barley straw ad libitum for 35 d. After a 20-d period, diet digestibility was determined, and microbial N flow at the duodenum was estimated from the urinary excretion of purine derivatives. Blood samples were taken on d 0, 20, and 35. On d 35, lambs were slaughtered and ruminal fluid samples were collected. There were no effects (P = 0.18 to P = 0.95) of malate on concentrate or straw intake, ADG, carcass yield, and apparent digestibility of OM, CP, NDF, or ADF. Malate supplementation did not influence (P = 0.80) the daily urinary excretion of total purine derivatives, and therefore there were no treatment effects (P = 0.77) on estimated microbial N flow at the duodenum. No differences (P > 0.05) among treatments were observed for plasma concentrations of glucose, cholesterol, triglycerides, urea-N, lactate, or VFA, but malate addition increased (P = 0.003) the molar proportion of butyrate in ruminal fluid (4.29, 6.14, and 5.45% of total VFA for control, MAL-4 and MAL-8, respectively). The use of malate as a feed additive under the conditions of the current study did not influence diet intake or digestion, and consequently did not improve lamb performance.

Abstract: After over 100 strains of Aureobasidium spp isolated from mangrove system were screened for their ability to produce poly(β-malic acid) (PMA), it was found that Aureobasidium sp. P6 strain among them could produce high level of Ca2+-PMA. Fourteen percent glucose and 6.5 % CaCO3 in the medium were the most suitable for Ca2+-PMA production. Then, 100.7 g/l of Ca2+-PMA was produced using Aureobasidium sp. P6 strain within 168 h at flask level. During 10-l batch fermentation, when the medium contained 12.0 % glucose, 98.7 g/l of Ca2+-PMA in the culture and 14.7 g/l of cell dry weight were obtained within 156 h, leaving 0.34 % reducing sugar in the fermented medium. When glucose concentration in the fermentation medium was 14.0 %, 118.3 g/l of Ca2+-PMA in the culture and 16.4 g/l of cell dry weight were obtained within 168 h, leaving 0.4 % reducing sugar in the fermented medium. After purification of Ca2+-PMA from the culture and acid hydrolysis of the pure Ca2+-PMA, analysis of HPLC showed that Aureobasidium sp. P6 strain only produced two main components of Ca2+-PMA and minor amount of calcium malate and that the hydrolysate of PMA was mainly composed of calcium malate. This is the first time to report that the novel yeast strain Aureobasidium sp. P6 strain isolated from the mangrove systems can produce such high amount of Ca2+-PMA.