Reductive activity of free and immobilized cells of cyanobacteria toward oxophosphonates-comparative study.
This report, based on the previous studies, compares the reductive activity of different modes of following photobiocatalysts (on laboratory and preparative scale):Arthrospira maxima,Nostoccf.muscorumandNodularia sphaerocarpa, toward diethyl esters of 2-oxopropylphosphonate (1), 2-oxo-2-phenylethylphosphonate (2), and 2-oxobutylphosphonate (3). It was confirmed that immobilization in alginate matrix do not affect the activity and viability of the biocatalysts. Corresponding (S)-hydroxyphosphonates (1a-3a) were obtained with similar efficiency compared to the free-cell mode with the yield and of the optical puritye.erespectively (e.g.,N. sphaerocarpaexperiments): (1) yield: 21 %,e.e. 84 %; (2) yield 97 %,e.e. 97; (3) yield 21 %,e.e.89 %. Scaling up the processes for the best biocatalyst,N. sphaerocarpa, indicated that the use of free-living cells of cyanobacteria is more effective (640 mg of substrate 2, 44 % of yield, 91 % ofe.e.), compared to the column bioreactor packed with immobilized cells of this photobiocatalyst (384 mg of substrate 2, 38 % of yield, 86 % ofe.e). In the case of free and immobilized cells ofN.cf.muscorum, agitation of the medium was the crucial activity mediator. Shaking culture of free cells ofN.cf.muscorumconverted the diethyl 2-oxo-2-phenylethylphosphonate (2) with the yield of 43 % (99 % ofe.e.) compared to 18 % (99 % ofe.e., stationary culture). Immobilized cells of this cyanobacterium were also more active toward (2) under shaking conditions (28 % of yield, 99 % ofe.e.) than free ones without agitation.
Department of Bioorganic Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Monika
M
Górak
Department of Bioorganic Chemistry, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Ewa
E
Żymańczyk-Duda
Biotransformation; Cyanobacteria; Immobilization; Phosphonates