Acrylic acid and DMSP lyases in the green algae Ulva
Acrylic acid and DMSP lyases in the green algae Ulva
复制标题
DOI：
10.1016/j.algal.2023.103176
复制
发表时间：
2023-07
期刊：
影响因子：
--
通讯作者：
G. Pesante;Edith C F Forestier;Swen Langer;A. Danby;John Angus;Mark J. Gronnow;Joseph P. Bennett;T. Larson;T. Tonon
中科院分区：
文献类型：
--
作者：
G. Pesante;Edith C F Forestier;Swen Langer;A. Danby;John Angus;Mark J. Gronnow;Joseph P. Bennett;T. Larson;T. Tonon
石莼属的绿色大型藻类，通过转氨途径由甲硫氨酸产生二甲基磺基丙酸盐（DMSP）。DMSP通过DMSP裂解酶（DLs）转化为丙烯酸（AA），这是一种具有广阔市场的高价值化合物，因为其酯可用于生产塑料添加剂、纺织品、密封剂、粘合剂和表面涂料。目前对石莼产生的AA水平以及从这种生物质中提取AA的过程知之甚少。在这项研究中，实施了一种分析方法，同时测量AA，DMSP和途径中间体（4-甲硫基-2-氧代丁酸酯，4-甲硫基-2-羟基丁酸酯，和4-二甲基砜基-2-羟基丁酸酯）在石莼生物质。这些化合物的量-重点是AA -然后在用不同的化学，热和酶处理处理大型藻类后进行定量。AA的提取范围为藻干重的0.22- 0.45%。连续酶处理显示没有更高的产量相比，单独的酶处理或化学物理提取，一个令人鼓舞的结果，在工业中的应用的处理。通过密码子优化合成了两个突变石莼DL的候选基因，并在大肠杆菌中表达纯化。大肠杆菌的可溶性标签，并对这些重组裂解酶的生化特性进行了研究。两种酶UM021_MBP和UM030_Halo7的活性都低于它们的微藻对应物Alma 1，它们在氨基酸水平上分别与Alma 1共享33.9%和39.7%的相似性。UM030_Halo7表现出比UM021_MBP更高的活性，Km和Vm分别为7.10 mM和5.99 mM/min/mg蛋白。UM030_Halo7的最适pH值为6.0，最适温度为20 °C，NaCl浓度大于或等于0.5 M时对该菌有抑制作用，但H2 O2浓度大于50 μM时对该菌无抑制作用。这些结果在分子水平上推进了我们对石莼AA生物合成的理解，并可能有助于在生物炼制框架内实施从石莼物种中提取AA的过程。
Green macroalgae of the genusUlvacontain dimethylsulfoniopropionate (DMSP) produced from methionine through a transamination pathway. DMSP is converted by DMSP lyase enzymes (DLs) into acrylic acid (AA), a high-value compound with a vast market as its esters have applications in the production of plastic additives, textiles, sealants, adhesives and surface coatings. The levels of AA produced byUlvaspecies, and the processes to extract it from this biomass, are currently poorly understood. In this study an analytical method was implemented for the simultaneous measurement of AA, DMSP and the pathway intermediates (4-methylthio-2-oxobutyrate, 4-methylthio-2-hydroxybutyrate, and 4-dimethylsulfonio-2-hydroxybutyrate) inUlvabiomass. The amounts of these compounds – with a focus on AA – were then quantified after processing the macroalgae with different chemical, thermal, and enzymatic treatments. AA was extracted in the range of 0.22–0.45 % of the algal dry weight. Sequential enzyme treatments showed no higher yields compared to individual enzymatic treatments or chemico-physical extractions, an encouraging result for the application of the treatments in industry. Codon-optimised synthetic genes for two candidate DLs fromUlva mutabiliswere expressed and purified inE. coliwith solubility tags, and the biochemical characteristics of these recombinant lyases were investigated. Both enzymes UM021_MBP and UM030_Halo7 had lower activity than their microalgal counterpart Alma1, with whom they share 33.9 % and 39.7 % similarity at amino acid level respectively. UM030_Halo7 appeared more active than UM021_MBP, with Kmand Vmof 7.10 mM and 5.99 mM/min/mg protein respectively. UM030_Halo7 showed a preferred pH of 6.0, an optimal of temperature of 20 °C, was inhibited by NaCl concentration equal or higher than 0.5 M but not by H2O2up to 50 μM. These results advance our understanding of AA biosynthesis inUlvaat the molecular level, and could be useful to implement processes for extracting AA fromUlvaspecies within a biorefinery framework.