{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T14:01:06Z","timestamp":1791986466530,"version":"4.4.0"},"reference-count":41,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2023,7,24]],"date-time":"2023-07-24T00:00:00Z","timestamp":1690156800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Green Bio-fabrication Program of China","award":["2021YFC2100900"],"award-info":[{"award-number":["2021YFC2100900"]}]},{"name":"Green Bio-fabrication Program of China","award":["111\u20132-06"],"award-info":[{"award-number":["111\u20132-06"]}]},{"name":"Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions, the 111 Project","award":["2021YFC2100900"],"award-info":[{"award-number":["2021YFC2100900"]}]},{"name":"Top-Notch Academic Programs Project of Jiangsu Higher Education Institutions, the 111 Project","award":["111\u20132-06"],"award-info":[{"award-number":["111\u20132-06"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>L-tryptophan (L-trp), produced through bio-manufacturing, is widely used in the pharmaceutical and food industries. Based on the previously developed L-trp-producing strain, this study significantly improved the titer and yield of L-trp, through metabolic engineering of the shikimate pathway and the L-tryptophan branch. First, the rate-limiting steps in the shikimate pathway were investigated and deciphered, revealing that the combined overexpression of the genes aroE and aroD increased L-trp production. Then, L-trp synthesis was further enhanced at the shaking flask level by improving the intracellular availability of L-glutamine (L-gln) and L-serine (L-ser). In addition, the transport system and the competing pathway of L-trp were also modified, indicating that elimination of the gene TnaB contributed to the extracellular accumulation of L-trp. Through optimizing formulas, the robustness and production efficiency of engineered strains were enhanced at the level of the 30 L fermenter. After 42 h of fed-batch fermentation, the resultant strain produced 53.65 g\/L of L-trp, with a yield of 0.238 g\/g glucose. In this study, the high-efficiency L-trp-producing strains were created in order to establish a basis for further development of more strains for the production of other highly valuable aromatic compounds or their derivatives.<\/jats:p>","DOI":"10.3390\/ijms241411866","type":"journal-article","created":{"date-parts":[[2023,7,25]],"date-time":"2023-07-25T01:21:27Z","timestamp":1690248087000},"page":"11866","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Engineering of Shikimate Pathway and Terminal Branch for Efficient Production of L-Tryptophan in Escherichia coli"],"prefix":"10.3390","volume":"24","author":[{"given":"Shuai","family":"Liu","sequence":"first","affiliation":[{"name":"The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bing-Bing","family":"Wang","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0750-6875","authenticated-orcid":false,"given":"Jian-Zhong","family":"Xu","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei-Guo","family":"Zhang","sequence":"additional","affiliation":[{"name":"The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800# Lihu Road, Wuxi 214122, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1007\/s00253-016-7772-5","article-title":"Rational design and metabolic analysis of Escherichia coli for effective production of L-tryptophan at high concentration","volume":"101","author":"Chen","year":"2017","journal-title":"Appl. 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