Enhancing the capability of Klebsiella pneumoniae to produce 1, 3-propanediol by overexpression and regulation through CRISPR-dCas9 was written by Wang, Xin;Zhang, Lin;Liang, Shaoxiong;Yin, Ying;Wang, Pan;Li, Yicao;Chin, Wee Shong;Xu, Jianwei;Wen, Jianping. And the article was included in Microbial Biotechnology in 2022.Safety of (2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-(isopropylthio)tetrahydro-2H-pyran-3,4,5-triol The following contents are mentioned in the article:
Klebsiella pneumoniae is a common strain of bacterial fermentation to produce 1, 3-propanediol (1, 3-PDO). In general, the production of 1, 3-PDO by wild-type K. pneumoniae is relatively low. Therefore, a new gene manipulation of K. pneumoniae was developed to improve the production of 1, 3-PDO by overexpressing in the reduction pathway and attenuating the byproducts in the oxidation pathway. Firstly, dhaB and/or dhaT were overexpressed in the reduction pathway. Considering the cost of IPTG, the constitutive promoter P32 was selected to express the key gene. By comparing K.P. pET28a-P32-dhaT with the original strain, the production of 1, 3-PDO was increased by 19.7%, from 12.97 to 15.53 g l-1 (in a 250 mL shaker flask). Secondly, three lldD and budC regulatory sites were selected in the byproduct pathway, resp., using the CRISPR-dCas9 system, and the optimal regulatory sites were selected following the 1, 3-PDO production As a result, the 1, 3-PDO production by K.P. L1-pRH2521 and K.P. B3-pRH2521 reached up to 19.16 and 18.74 g l-1, which was increased by 47.7% and 44.5% resp. Overexpressing dhaT and inhibiting expression of lldD and budC were combined to further enhance the ability of K. pneumoniae to produce 1, 3-PDO. The 1, 3-PDO production by K.P. L1-B3-PRH2521-P32-dhaT reached 57.85 g l-1 in a 7.5 l fermentation tank (with Na+ neutralizer), which is higher than that of the original strain. This is the first time that the 1, 3-PDO production was improved in K. pneumoniae by overexpressing the key gene and attenuating byproduct synthesis in the CRISPR-dCas9 system. This study reports an efficient approach to regulate the expression of genes in K. pneumoniae to increase the 1, 3-PDO production, and such a strategy may be useful to modify other strains to produce valuable chems. This study involved multiple reactions and reactants, such as (2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-(isopropylthio)tetrahydro-2H-pyran-3,4,5-triol (cas: 367-93-1Safety of (2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-(isopropylthio)tetrahydro-2H-pyran-3,4,5-triol).
(2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-(isopropylthio)tetrahydro-2H-pyran-3,4,5-triol (cas: 367-93-1) belongs to alcohols. Alcohols are among the most common organic compounds. They are used as sweeteners and in making perfumes, are valuable intermediates in the synthesis of other compounds, and are among the most abundantly produced organic chemicals in industry. Alcohols may be oxidized to give ketones, aldehydes, and carboxylic acids. These functional groups are useful for further reactions. Oxidation of organic compounds generally increases the number of bonds from carbon to oxygen (or another electronegative element, such as a halogen), and it may decrease the number of bonds to hydrogen.Safety of (2R,3R,4S,5R,6S)-2-(Hydroxymethyl)-6-(isopropylthio)tetrahydro-2H-pyran-3,4,5-triol
Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts