Heavy metal\ncadmium exists widely in the deep-sea environment, and deep-sea microorganisms\nhave evolved mature and diverse mechanisms of cadmium tolerance to maintain\ntheir growth and reproduction in the cadmium environment. In addition,\ncompounds coexisting with cadmium in the environment such as cysteine can\nsignificantly affect the cadmium resistance of deep-sea microorganisms. In the\nprocess of studying the mechanism of cadmium tolerance of Pseudomonas\nstutzeri<\/em> 273, it was found that the presence of cysteine could effectively\npromote the formation of cadmium sulfide nanoparticles and significantly\nimprove the cadmium resistance and removal rate of bacteria (Figure 1). Through\nproteomics and gene knockout methods, it was found that the threonine dehydrase\n(TD) produced by the bacteria had cysteine desulfurization activity, which\nparticipated in the process of cadmium tolerance by catalyzing the\ndesulfurization of cysteine to produce hydrogen sulfide. Through the\nheterologous expression and purification of TD, it was further confirmed that\nthe recombinant threonine dehydratase (rTD) still had cysteine desulfurase\nactivity in vitro, and the process of its catalytic reaction was analyzed.<\/p>\n\n\n\n

\"\" — Figure 2. Formation of cadmium sulfide nanoparticles mediated by cysteine catalyzed by threonine dehydratase. <\/figcaption><\/figure><\/div>\n\n\n\n
The cysteine desulfurization process catalyzed by rTD is divided into two steps: first, cysteine reacts with water to form L-serine and hydrogen sulfide, and then L-serine is deaminated to pyruvate and ammonia (Figure 2). Finally, the researchers established a single enzyme system for the biosynthesis of cadmium sulfide nanoparticles, which can efficiently catalyze the synthesis of cadmium sulfide nanoparticles with rTD as the catalysis enzyme, cysteine as the sulfur donor, and cadmium chloride as the cadmium donor. rTD not only acts as a catalytic enzyme to control the reaction process, but also has the role of coating, which can control the formation rate and particle size of cadmium sulfide nanoparticles. This strain of P. stutzeri<\/em> has good mercury removal ability and can produce polysaccharides that inhibit the formation of biofilm of multi-drug-resistant *P. stutzeri<\/em>. It has good application potential in the field of environmental protection and biomedicine.<\/p>\n\n\n\n*
Ma, N., Cai, R., & Sun, C. (2021). Threonine dehydratase enhances bacterial cadmium resistance via driving cysteine desulfuration and biomineralization of cadmium sulfide nanocrystals. Journal of Hazardous Materials, 126102.<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"
Cadmium sulfide nanoparticles (CdS nanoparticles) have the characteristics of light absorption and autofluorescence, which are widely used in the fields<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[31],"tags":[],"class_list":["post-301","post","type-post","status-publish","format-standard","hentry","category-quantum-dots"],"_links":{"self":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/301","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/comments?post=301"}],"version-history":[{"count":1,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/301\/revisions"}],"predecessor-version":[{"id":304,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/301\/revisions\/304"}],"wp:attachment":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/media?parent=301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/categories?post=301"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/tags?post=301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}