Prospective and impacts of whole cell mediated alcoholysis of renewable oils for biodiesel production

Abstract

Biodiesel has received considerable attention during the past decade as a renewable, biodegradable and environmentally friendly fuel. There are extensive reports about immobilized lipase-mediated alcoholysis for biodiesel production and much progress has been achieved. In recent years, much attention has been paid to whole cell as the catalyst for biodiesel production. Whole cell process can be expected to reduce the biocatalyst cost considerably since separation and immobilization can be realized spontaneously during the process of cell cultivation. Currently, research related to whole cell mediated alcoholysis for biodiesel production is mainly focused on the following three aspects: (1) the optimization in cultivation of whole cell catalyst to obtain the maximal lipase activity; (2) the modifi cation of whole cell catalyst to improve its catalytic performance; and (3) the application of whole cell catalyst for biodiesel production. This mini-review covers the aforementioned research fi elds and the prospects of whole cell catalyst applied to biodiesel production are also discussed.

Heterogeneous biocatalytic processes of vegetable oil interesterification to biodiesel

“…The reaction mixture of soybean oil and methanol was circulated through a layer of a biocata lyst prepared by culturing R. oryzae in the presence of nonwoven fibrous material; after 23 hours of the reac tion under optimum conditions, the biodiesel yield was ≥70% [18]. A popular method for preparing whole cell biocatalysts is the cross linking of cell bio mass (e.g., R. oryzae) by the bifunctional agent glut araldehyde, followed by drying and the formation of granules [19][20][21][22][23]. Under optimum conditions, a high yield of Me ethers equal to 80-90% was obtained for 20 periodic reaction cycles (12 hours each).…”

“…The authors [18][19][20][29][30][31][32][33][34][35][36] investigated and analyzed the role of water contained both inside the biocatalysts and in the organic solvents and the gas phase. They showed that in order to achieve high activity and stability of whole cell biocat alysts, the internal water content must be optimal (5-15%); the biocatalysts in this case function as effec tively as those prepared on the basis of the extracellular (soluble) lipases.…”

“…3). The estimated Michaelis constant for the oil was 0.017 M; for acetate, it was 0.75 M. The maximum rate of interesterification was observed when the molar ratio of oil to ethyl acetate was 1 : (15)(16)(17)(18)(19)(20).…”

“…When the ratio of biocatalyst mass (g) to the vol ume (mL) of the reaction mixture varied from 1 : (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), study of the interesterification kinetics showed that at the minimum ratio of 1 : 6, the reaction rate was the highest during the first 6-10 hours; at the ratio of 1 : 20, the amount of esters grew almost linearly for 28 hours. Reducing the ratio of the biocatalyst mass to the volume of the reaction medium thus leads to more rapid accumulation of fatty acid esters.…”

Whole Cell Biocatalyst for Soyasapogenol B Production from Soybean Saponin

“…On the other hand, utilizing whole cell producing saponin hydrolase in which the purification and stabilization of the enzyme are not necessary instead of conventional immobilized enzyme for SB production is a potential way to reduce the biocatalyst cost, because immobilization can be carried out spontaneously during the process of cell cultivation [15]. For the best of our knowledge, there have been no reports of SB production using whole cells producing saponin hydrolase in the enzyme reaction mixture.…”