固定化假单胞菌产L-多巴

PRODUCTION OF L DOPA BY IMMOBILIZED PSEUDOMONAS SP.

选择海藻酸钙和聚乙烯醇凝胶为固定化载体包埋假单胞菌（Ｐｓｅｕｄｏｍｏｎａｓｓｐ．），以提高该菌以Ｌ－酪氨酸为底物生产Ｌ－多巴的效率．海藻酸钙和聚乙烯醇固定的假单胞菌分别将发酵周期缩短了８和１４ｈ．半连续发酵的结果表明，海藻酸钙和聚乙烯醇固定化细胞分别能重复使用５次和１４次，Ｌ－多巴生产效率比游离细胞分别提高了１６％和１６０％．聚乙烯醇固定化细胞经过热处理和在生理盐水中振荡处理可明显提高Ｌ－多巴的生产效率和产量。

PVA(polyvinyl alcohol) and Ca alginate gel were selected as the immobilization carrier to stabilize the tyrosinase in Pseudomonas sp. for repeat production of L Dopa from L tyrosine. Comparing with the free cells, the Ca alginate and PVA immobilized cells shortened the fermentation cycle by 8 hours and 14 hours respectively. In semi continuous fermentation, the two kinds of immobilized cells were able to use 5 and 14 times repeatedly, and the fermentation efficiency were 16% and 160% higher than that of free cells. It was found that the productivity of L Dopa was apparently increased when the PVA immobilized cells were treated with heat or shaken in the physiological saline solution. Excessive amount of substrate was unfavorable for the repeat use of immobilized cells.