Exploitation of Soybean Oil Acid Degumming Waste: Biocatalytic Synthesis of High Value Phospholipids

Abstract

The acid degumming waste of the seeds oil refining industry is currently disposed of, but, instead, it could be exploited as an important source for the preparation of many products. In this work, the waste coming from the soybean oil refining step was first recovered and treated, allowing the isolation of a fraction enriched of phospholipids (PLs). Then, the latter was transformed, via an enzymatic reaction catalysed by phospholipase D (from Streptomyces netropsis), into more valuable products: polar head modified PLs-enriched mixtures containing phosphatidylserine (PS), phosphatidylglycerol (PG), phosphatidyle-thanolamine (PE) and phosphatidylhydroxybutyrate (PB). In the following we show how biocatalysis can be exploited for the production of value-added PLs, to be used as functional food and nutraceutical ingredients, from a renewable feedstock. This alternative to the industrial usual disposal procedures should impart to the whole process a greater value in terms of carbon recycling, in agreement with the paradigms of bioeconomy for a wiser reuse of renewable resources in a circular economy perspective.

Phospholipase D Immobilization on Lignin Nanoparticles for Enzymatic Transformation of Phospholipids

“…The supported enzyme preparations were, within each PX preparation, successfully completely recycled with high activity retention over four synthetic cycles (complete ESI/MS spectra are reported in Figures S4, S5, S6 for PG, PS and PE respectively). It is important to underline that this method of enzyme immobilization allowed, compared to the previously cited literature, to recover the desired products in high yields (consistently with our previous works), [39] constantly over the cycles, and that the enzyme activity remained quite unchanged without losing efficiency. Moreover, the immobilized enzyme showed a higher activity with respect to the free one, allowing to reduce the reaction times.…”

“…In these aforementioned studies of Li et al [40] and Han et al [28] , a notable shift in the optimal temperature and pH occurred, which no longer correspond to the conditions under which the transphosphatidylation reactions are performed. Instead, in the present study the immobilized PLD preserved its optimal reaction conditions, without shifting of temperature, allowing to perform the transphosphatidylation reactions at 40 °C, as previously reported in literature [42] …”

“…Microrganism fermentation . PLD was obtained from the fermentation broth of Streptomyces netropsis (DSM 40093) as reported in our previous works (see Figure S7) [39] . The medium for strain growth and maintenance was composed of glucose 4 g/L; yeast extract 5 g/L; malt extract 10 g/L whereas the medium for PLD preparation contained glucose 5 g/L, yeast extract 5 g/L, malt extract 10 g/L, peptone from soybean 3 g/L, peptone from casein 1 g/L, MgSO 4 0.2 g/L, NaCl 0.2 g/L.…”

“…Instead, in the present study the immobilized PLD preserved its optimal reaction conditions, without shifting of temperature, allowing to perform the transphosphatidylation reactions at 40 °C, as previously reported in literature. [42]…”

“…PLD was obtained from the fermentation broth of Streptomyces netropsis (DSM 40093) as reported in our previous works (see Figure S7). [39] The medium for strain growth and maintenance was composed of glucose 4 g/L; yeast extract 5 g/L; malt extract 10 g/L whereas the medium for PLD preparation contained glucose 5 g/L, yeast extract 5 g/L, malt extract 10 g/L, peptone from soybean 3 g/L, peptone from casein 1 g/L, MgSO 4 0.2 g/L, NaCl 0.2 g/L. The fermentation was performed aerobically, setting a minimum air flow of 2 L/min (0.5 v/v/min), in a sterilized fermenter vessel of a 5 L bioreactor (Biostat A BB-8822000, Sartorius Stedim, Göttingen, Germany) containing 4 L of medium.…”