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Recent advancements in protein/enzyme engineering have enabled the production of a diverse array of high-value compounds in microbial systems with the potential for industrial applications. The goal of this review is to articulate some of the most recent protein engineering advances in bacteria, yeast, and other microbial systems to produce valuable substances. These high-value substances include α-farnesene, vitamin B12, fumaric acid, linalool, glucaric acid, carminic acid, mycosporine-like amino acids, patchoulol, orcinol glucoside, d-lactic acid, keratinase, α-glucanotransferases, β-glucosidase, seleno-methylselenocysteine, fatty acids, high-efficiency β-glucosidase enzymes, cellulase, β-carotene, physcion, and glucoamylase. Additionally, recent advances in enzyme engineering for enhancing thermostability will be discussed. These findings have the potential to revolutionize various industries, including biotechnology, food, pharmaceuticals, and biofuels.

Removal of trace heavy metal ions puts high demands on designing adsorbents with favorable surfaces. Crystal-plane engineering can provide controllable adsorption energy between surficial planes and adsorbents. Herein, we have creatively synthesized Mg-doped CaCO3 nanoarchitectures assembled by layered sheets (Mg-CaCO3 LSs) with high-index facets of ( 4 41 ¯ ) through a facile wet chemical process. Adsorption tests reveal that the layer-by-layer assembled sample exhibits a maximum Pb(II) adsorption capacity of 1961.9 mg·g−1, agreeing with the monolayer-adsorption Langmuir model. At an initial Pb(II) ion concentration of 20 mg·L−1, the adsorption can achieve a high removal rate near 99.0% within 1 min, and the adsorption kinetics follows a chemisorption pseudo-second-order model. Interestingly, the Mg-CaCO3 LSs show much-improved adsorption properties towards low-concentration Pb(II) ions, which could reduce the concentration from 1 mg·L−1 to ~ 2.9 μg·L−1 in 3 h (within 30 min decrease to less than 10 μg·L−1, meeting drinking water standard from WHO). For comparison, the commercial CaCO3 and collected CaCO3 scale show much lower adsorption values with Pb(II) ion residual concentration of ~ 935.0 and ~ 944.9 μg·L−1 in 3 h, respectively. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and inductively coupled plasma (ICP) characterizations on the Mg-CaCO3 LSs before and after adsorbing Pb(II) confirm that the high removal performance could be ascribed to fast metal ion exchange and excellent physical adsorption contributed by high-index planes. The density functional theory (DFT) calculations also confirm that the much-enhanced adsorption kinetics benefits from the optimal adsorption of the ( 4 41 ¯ ) planes. This work will provide a feasible route to design high-efficient low-cost adsorbents through crystal-plane engineering. 摘要: 有效去除水中痕量重金属离子对吸附剂的结构设计提出了很高的要求。利用晶面构建工程对催 化剂结构进行设计是一个有效地解决方法。在本工作中，我们通过湿化学合成法，制备了由( 4 41 ¯ ) 高指数面组装的 Mg 掺杂 CaCO3 纳米结构(Mg-CaCO3 LSs)。实验结果证明，层状组装结构 的Mg-CaCO3LSs对Pb(II)的最大吸附容量为1961.9 mg·g-1, 并符合单层Langmuir 吸附模型。当 Pb(II)的初始浓度为20 mg·L-1时, Mg-CaCO3 LSs表现出接近于99%的去除效率(吸附时间为1 min)。该吸附动力学过程遵循化学吸附准二级动力学模型方程。同时，在极低Pb(II)浓度下, Mg-CaCO3 LSs还表现出优异的吸附去除性能。当Pb(II) 的浓度为1 mg·L-1 时, Mg-CaCO3LSs能够在3 小时内将浓度降至~2.9 μg·L-1。其中，在30 分钟内就能将Pb(II)浓度降至10 μg·L-1以下, 这是符合WHO 所颁布的饮用水标准的。作为对比，商业CaCO3 和收集的CaCO3 水垢在相 同的测试条件下却分别只能将浓度降低至~935 μg·L-1 和~944.9 μg·L-1。通过对吸附前后Mg-CaCO3 LSs样品进行XRD, EDS 和ICP 表征，我们发现其优异的去除效果可归因于高指数晶面 的快速金属离子交换和物理吸附过程。理论计算 (DFT)进一步证明了( 4 41 ¯ ) 高指数面具有更优 的吸附动力学行为。本工作通过晶面构建工程，提供了一种设计高性能低成本的吸附剂材料的设计思路。 [ABSTRACT FROM AUTHOR]

Objective: To observe the changes of growth hormone (GH)/insulin-like growth factor- 1(Igf-1) system in blood, kidney and bone tissue of rats, and to explore the preventive and therapeutic effect of Qing 'e pill on osteoporosis due to kidney deficiency and its mechanism, to provide the basis for studying the etiology and pathogenesis of osteoporosis due to kidney deficiency. Methods: The rat osteoporosis model was established by ovariectomy, they were randomly divided into normal group, model group, Western Medicine Group, Jianpi Group, high-dose group, middle-dose group and low-dose group, the levels of serum alkaline phosphatase (ALP), tartrate acid phosphatase (TRACP), growth hormone (GH) and GHR (Ghr) in kidney, bone and blood were determined by Elisa, the contents of insulin-like growth factor-1(Igf-1) and insulin-like growth factor-1 receptor (IGF-1R) were analyzed by SPSS 25.0 software. Results: 1. Compared with the normal group, the contents of TRACP and ALP in serum of the model group were significantly increased, suggesting that the rats developed high-conversion osteoporosis. 2. The levels of serum, bone and renal GHR, Igf-1 and insulin-like growth factor-1 receptor (IGF-1R) in the model group were significantly lower than those in the control group. 3. Compared with the model group, the contents of TRACP and ALP in the high, middle and low dose groups were significantly decreased. 4. Compared with the model group, the contents of GHR, Igf-1 and IGF-1R in blood, bone and kidney tissue of the high, middle and low dose groups were increased. Conclusion: 1. Qing 'e pill can improve the bone metabolism of osteoporosis. 2. Qinge pill may prevent and cure osteoporosis by increasing the contents of GHR, Igf-1 and IGF-1R in blood, bone and kidney. [ABSTRACT FROM AUTHOR]

BACKGROUND: Exoinulinase catalyzes the successive removal of individual fructose moiety from the non‐reducing end of the inulin molecule, which is useful for biotechnological applications like producing fructan‐based non‐grain biomass energy and high‐fructose syrup. In this study, an exoinulinase (KmINU) from Kluyveromyces marxianus DSM 5418 was tailored for increased catalytic activity and acidic adaptation for inulin hydrolysis processes by rational site‐directed mutagenesis. RESULTS: Three mutations, S124Y, N158S and Q215V distal to the catalytic residues of KmINU were designed and heterologously expressed in Pichia pastoris GS115. Compared to the wild‐type, S124Y shifted the pH‐activity profile towards acidic pH values and increased the catalytic activity and catalytic efficiency by 59% and 99% to 688.4 ± 17.03 s−1 and 568.93 L mmol−1 s−1, respectively. N158S improved the catalytic activity under acidic pH conditions, giving a maximum value of 464.06 ± 14.06 s−1 on inulin at pH 4.5. Q215V markedly improved the substrate preference for inulin over sucrose by 5.56‐fold, and showed catalytic efficiencies of 208.82 and 6.88 L mmol−1 s−1 towards inulin and sucrose, respectively. Molecular modeling and computational docking indicated that structural reorientation may underlie the increased catalytic activity, acidic adaptation and substrate preference. CONCLUSIONS: The KmINU mutants may serve as industrially promising candidates for inulin hydrolysis. Protein engineering of exoinulinase here provides a successful example of the extent to which mutating non‐conserved substrate recognition and binding residues distal to the active site can be used for industrial enzyme improvements. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]