Background AflatoxinB1(AFB_(1))is a prevalent contaminant in agricultural products,presenting significant risks to animal health.CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading myc...Background AflatoxinB1(AFB_(1))is a prevalent contaminant in agricultural products,presenting significant risks to animal health.CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading mycotoxins in vitro test.The efficacy of Bacillus CotA laccase in animals,however,remains to be confirmed.A 2×2 factorial design was used to investigate the effects of Bacillus CotA laccase level(0 or 1 U/kg),AFB_(1) challenge(challenged or unchal-lenged)and their interactions on ducks.The purpose of this study was to evaluate the efficacy of Bacillus CotA laccase in alleviatingAFB_(1) toxicosis of ducks.Results Bacillus CotA laccase alleviatedAFB_(1)-induced declines in growth performance of ducks accompanied by improved average daily gain(ADG)and lower feed/gain ratio(F/G).Bacillus CotA laccase amelioratedAFB_(1)-induced gut barrier dysfunctions and inflammation testified by increasing the jejunal villi height/crypt depth ratio(VH/CD)and the mRNA expression of tight junction protein 1(TJP1)and zonula occluden-1(ZO-1)as well as decreasing the expression of inflammation-related genes in the jejunum of ducks.Amino acid metabolome showed that Bacillus CotA laccase amelioratedAFB_(1)-induced amino acid metabolism disorders evidenced by increasing the level of glu-tamic acid in serum and upregulating the expression of amino acid transport related genes in jejunum of ducks.Bacil-lus CotA laccase amelioratedAFB_(1)-induced liver injury testified by suppressing oxidative stress,inhibiting apoptosis,and downregulating the expression of hepatic metabolic enzyme related genes of ducks.Moreover,Bacillus CotA laccase degradedAFB_(1) in digestive tract of ducks,resulting in the reduced absorption level ofAFB_(1) across intestinal epithelium testified by the decreased level ofAFB_(1)-DNA adduct in the liver,and the reduced content ofAFB_(1) residues in liver and feces of ducks.Conclusions Bacillus CotA laccase effectively improved the growth performance,intestinal health,amino acid metabolism and hepatic aflatoxin metabolism of ducks fedAFB_(1) diets,highlighting its potential as an efficient and safe feed enzyme forAFB_(1) degradation in animal production.展开更多
CotA漆酶在环境保护、食品工业和纸浆漂白等工业中具有重要的应用价值.将重组表达载体pET-22b/CotA转入大肠杆菌BL21(DE3),得到工程菌株,采用单因素实验和正交实验相结合的方法,研究诱导表达条件和发酵培养基对重组大肠杆菌产CotA漆酶...CotA漆酶在环境保护、食品工业和纸浆漂白等工业中具有重要的应用价值.将重组表达载体pET-22b/CotA转入大肠杆菌BL21(DE3),得到工程菌株,采用单因素实验和正交实验相结合的方法,研究诱导表达条件和发酵培养基对重组大肠杆菌产CotA漆酶量的影响.结果表明,初始pH 7.5的培养基中,添加0.6 mmol L-1 Cu2+,1 g L-1葡萄糖作碳源、15 g L-1蛋白胨和2 g L-1硫酸铵作氮源,以10%的接种量,37℃、200 r/min,直到菌液的D600 nm值为1.0,加入终浓度为1.0 mmol L-1的IPTG,25℃诱导12 h,漆酶的产量最高.优化前发酵液的粗提液的漆酶活性仅为1 190 U mL-1,优化后达到3 526 U mL-1,正交实验优化后漆酶活性提高了2.96倍.纯化的CotA漆酶最适反应温度为45℃,最适pH值为7.2.CotA漆酶对RBBR的脱色率在90%以上,此CotA漆酶在短时间内对染料能够有效地脱色,能够成为有潜力的工业用酶.展开更多
2,5-Furandicarboxylic acid (FDCA) is a potential biorenewable chemical for applications including plastics, polyamides, drugs, etc. The selective biosynthesis of FDCA from 5-hydroxymethylfurfural (HMF) by a speci c en...2,5-Furandicarboxylic acid (FDCA) is a potential biorenewable chemical for applications including plastics, polyamides, drugs, etc. The selective biosynthesis of FDCA from 5-hydroxymethylfurfural (HMF) by a speci c enzyme poses a great challenge. In this study, we reported an e cient strategy to produce FDCA from HMF by the tandem biocatalysis of laccase (CotA-TJ102@UIO-66-NH 2 ) and Novozym 435. For the rst step, a nanoparticle metal organic framework was synthesized as a carrier to immobilize CotA-TJ102@UIO-66-NH 2 , which was assigned for the production of 5-formyl-2-furancarboxylic acid (FFCA) and featured an enzyme loading of 255.54 mg/g, speci c activity of 135.90 U/mg, and solid loading ratio of 99.65%. Under optimal conditions, an ideal FFCA yield of 98.5% was achieved, and the CotA-TJ102@UIO-66-NH2 pre- sented a high recycling capacity after 10 cycles. For the second step, Novozym 435 was applied for the further conversion of FFCA into FDCA, presenting a high FDCA yield of 95.5% under the optimized conditions. Novozym 435 also exhibited a high recyclability after eight cycles. As a result, the tandem biocatalysis strategy provided a 94.2% FDCA yield from HMF, indicating its excellence as a method for FDCA production.展开更多
基金National Key Research and Development Program of China(2021YFC2103003)National Natural Science Foundation of China(31972604)+1 种基金Jinan Introductory Innovation Team Project(No.202228037)China Postdoctoral Science Foundation(2023M730998).
文摘Background AflatoxinB1(AFB_(1))is a prevalent contaminant in agricultural products,presenting significant risks to animal health.CotA laccase from Bacillus licheniformis has shown significant efficacy in degrading mycotoxins in vitro test.The efficacy of Bacillus CotA laccase in animals,however,remains to be confirmed.A 2×2 factorial design was used to investigate the effects of Bacillus CotA laccase level(0 or 1 U/kg),AFB_(1) challenge(challenged or unchal-lenged)and their interactions on ducks.The purpose of this study was to evaluate the efficacy of Bacillus CotA laccase in alleviatingAFB_(1) toxicosis of ducks.Results Bacillus CotA laccase alleviatedAFB_(1)-induced declines in growth performance of ducks accompanied by improved average daily gain(ADG)and lower feed/gain ratio(F/G).Bacillus CotA laccase amelioratedAFB_(1)-induced gut barrier dysfunctions and inflammation testified by increasing the jejunal villi height/crypt depth ratio(VH/CD)and the mRNA expression of tight junction protein 1(TJP1)and zonula occluden-1(ZO-1)as well as decreasing the expression of inflammation-related genes in the jejunum of ducks.Amino acid metabolome showed that Bacillus CotA laccase amelioratedAFB_(1)-induced amino acid metabolism disorders evidenced by increasing the level of glu-tamic acid in serum and upregulating the expression of amino acid transport related genes in jejunum of ducks.Bacil-lus CotA laccase amelioratedAFB_(1)-induced liver injury testified by suppressing oxidative stress,inhibiting apoptosis,and downregulating the expression of hepatic metabolic enzyme related genes of ducks.Moreover,Bacillus CotA laccase degradedAFB_(1) in digestive tract of ducks,resulting in the reduced absorption level ofAFB_(1) across intestinal epithelium testified by the decreased level ofAFB_(1)-DNA adduct in the liver,and the reduced content ofAFB_(1) residues in liver and feces of ducks.Conclusions Bacillus CotA laccase effectively improved the growth performance,intestinal health,amino acid metabolism and hepatic aflatoxin metabolism of ducks fedAFB_(1) diets,highlighting its potential as an efficient and safe feed enzyme forAFB_(1) degradation in animal production.
文摘CotA漆酶在环境保护、食品工业和纸浆漂白等工业中具有重要的应用价值.将重组表达载体pET-22b/CotA转入大肠杆菌BL21(DE3),得到工程菌株,采用单因素实验和正交实验相结合的方法,研究诱导表达条件和发酵培养基对重组大肠杆菌产CotA漆酶量的影响.结果表明,初始pH 7.5的培养基中,添加0.6 mmol L-1 Cu2+,1 g L-1葡萄糖作碳源、15 g L-1蛋白胨和2 g L-1硫酸铵作氮源,以10%的接种量,37℃、200 r/min,直到菌液的D600 nm值为1.0,加入终浓度为1.0 mmol L-1的IPTG,25℃诱导12 h,漆酶的产量最高.优化前发酵液的粗提液的漆酶活性仅为1 190 U mL-1,优化后达到3 526 U mL-1,正交实验优化后漆酶活性提高了2.96倍.纯化的CotA漆酶最适反应温度为45℃,最适pH值为7.2.CotA漆酶对RBBR的脱色率在90%以上,此CotA漆酶在短时间内对染料能够有效地脱色,能够成为有潜力的工业用酶.
基金Supported by "948" Project of National Forestry Bureau(No.2012-4-03)National Science and Technology Foundation Project(No.2014FY210400)National Natural Science Foundation of China(No.31470489)~~
基金supported by the National Key R&D Program of China (No. 2017YFB0306502)the Science Fund for Creative Research Groups (No. 21621004)+2 种基金the Project funded by China Postdoctoral Science Foundation (2019)the Key Project of Tianjin Science and Technology Committee (No. 17YFZCSY01080)the Program of Beiyang Young Scholar of Tianjin University (2012)
文摘2,5-Furandicarboxylic acid (FDCA) is a potential biorenewable chemical for applications including plastics, polyamides, drugs, etc. The selective biosynthesis of FDCA from 5-hydroxymethylfurfural (HMF) by a speci c enzyme poses a great challenge. In this study, we reported an e cient strategy to produce FDCA from HMF by the tandem biocatalysis of laccase (CotA-TJ102@UIO-66-NH 2 ) and Novozym 435. For the rst step, a nanoparticle metal organic framework was synthesized as a carrier to immobilize CotA-TJ102@UIO-66-NH 2 , which was assigned for the production of 5-formyl-2-furancarboxylic acid (FFCA) and featured an enzyme loading of 255.54 mg/g, speci c activity of 135.90 U/mg, and solid loading ratio of 99.65%. Under optimal conditions, an ideal FFCA yield of 98.5% was achieved, and the CotA-TJ102@UIO-66-NH2 pre- sented a high recycling capacity after 10 cycles. For the second step, Novozym 435 was applied for the further conversion of FFCA into FDCA, presenting a high FDCA yield of 95.5% under the optimized conditions. Novozym 435 also exhibited a high recyclability after eight cycles. As a result, the tandem biocatalysis strategy provided a 94.2% FDCA yield from HMF, indicating its excellence as a method for FDCA production.
