Asitok Atim, Ekpenyong Maurice, Ogarekpe Nkpa, Antigha Richard, Takon Iquo, Rao Anitha, Iheanacho Juliet, Antai Sylvester
Environmental Microbiology and Biotechnology Unit, Department of Microbiology, University of Calabar, Calabar, Nigeria.
University of Calabar Collection of Microorganisms (UCCM), University of Calabar, Calabar, Nigeria.
Prep Biochem Biotechnol. 2023;53(5):542-556. doi: 10.1080/10826068.2022.2114010. Epub 2022 Aug 26.
Downstream processing is a significant part of a production process and accounts for 50-90% of the production cost of biotechnological products. Post-fermentation localization of a microbial metabolite contributes significantly to the recovery cost of the product. produced naturally, acidic lipase with a 0.023:1 extracellular localization ratio. This research aimed to re-direct the localization of lipase to the extracellular milieu to reduce recovery costs using multi-objective response surface optimization (MO-RSM). The approach resulted in a 1:0.32 extracellular: intracellular lipase ratio, with product formation kinetics of Luedeking-Piret function showing a significant switch from a completely growth-associated intracellular production to a predominantly non-growth-associated extracellular localization. The enzyme was purified by an aqueous two-phase system which extracted 95.22% lipase with 72.36 purity. Characterization of the enzyme showed a molecular weight of 55.7 kDa, kcat of 68.59 s, and a of 0.63 mmol. Lipase activity occurred optimally at pH 2.5-3.5 and 50 °C, and was stable in most organic solvents tested. The acidic lipase demonstrated pH-dependent enantioselective esterification in resolving (R, S)-ibuprofen ( = 14, pH 4.5) and (R, S)-Naproxen ( = 13, pH 2.5), with an enantioselective preference for (S)-enantiomer in both drugs thus underpinning its potential for pharmaceutical applications.
下游加工是生产过程的重要组成部分,占生物技术产品生产成本的50-90%。微生物代谢产物的发酵后定位对产品的回收成本有重大影响。天然产生的酸性脂肪酶细胞外定位率为0.023:1。本研究旨在利用多目标响应面优化(MO-RSM)将脂肪酶的定位重新导向细胞外环境,以降低回收成本。该方法使脂肪酶细胞外与细胞内的比例达到1:0.32,Luedeking-Piret函数的产物形成动力学显示出从完全与生长相关的细胞内生产到主要与非生长相关的细胞外定位的显著转变。通过双水相系统对该酶进行纯化,提取出纯度为72.36%的脂肪酶,提取率为95.22%。该酶的表征显示分子量为55.7 kDa,kcat为68.59 s,Km为0.63 mmol。脂肪酶活性在pH 2.5-3.5和50°C时最佳,并且在大多数测试的有机溶剂中稳定。该酸性脂肪酶在拆分(R,S)-布洛芬(E = 14,pH 4.5)和(R,S)-萘普生(E = 13,pH 2.5)时表现出pH依赖性对映选择性酯化,两种药物对(S)-对映体均具有对映选择性偏好,从而奠定了其在制药应用中的潜力。