通讯机构：
[Chen, Xiulai] J;Jiangnan Univ, State Key Lab Food Sci & Technol, Wuxi 214122, Jiangsu, Peoples R China.;Jiangnan Univ, Key Lab Ind Biotechnol, Minist Educ, Wuxi 214122, Jiangsu, Peoples R China.
摘要：
Cell division can perturb the metabolic performance of industrial microbes. The C period of cell division starts from the initiation to the termination of DNA replication, whereas the D period is the bacterial division process. Here, we first shorten the C and D periods of E. coli by controlling the expression of the ribonucleotide reductase NrdAB and division proteins FtsZA through blue light and near-infrared light activation, respectively. It increases the specific surface area to 3.7 mu m(-1) and acetoin titer to 67.2g.L-1. Next, we prolong the C and D periods of E. coli by regulating the expression of the ribonucleotide reductase NrdA and division protein inhibitor SulA through blue light activation-repression and near-infrared (NIR) light activation, respectively. It improves the cell volume to 52.6 mu m(3) and poly(lactate-co-3-hydroxybutyrate) titer to 14.31g.L-1. Thus, the optogenetic-based cell division regulation strategy can improve the efficiency of microbial cell factories. Manipulation of genes controlling microbial shapes can affect bio-production. Here, the authors employ an optogenetic method to realize dynamic morphological engineering of E. coli replication and division and show the increased production of acetoin and poly(lactate-co-3-hydroxybutyrate).
作者机构：
[张婧; 王思贤; 薛菲菲; 王晓玲; 张家顺; 刘高强] Hunan Provincial Key Laboratory of Forestry Biotechnology, International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry & Technology, Hunan, Changsha, 410004, China
作者机构：
[刘高强] Hunan Provincial Key Laboratory of Forestry Biotechnology, Central South University of Forestry & Technology, International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry & Technology, Hunan, Changsha, 410004, China
摘要：
Broken-rice starch nanoparticles with different mean particle diameters for 100, 200, 400 and 800 nm were prepared by nanopredpitation, alkali freezing, cross-linking and H2SO4 hydrolysis methods respectively, and their structural, morphological and physicochemical properties were systematically characterized. The results showed that broken-rice starch nanoparticles had higher water absorption rate, and the maximum water absorption rate was obtained from the 100 nm starch granules being 91.53%, which means an increase about 2.07-fold in water absorption rate as compared with native rice starch. The stability of native rice starch is the worst, but the viscosity characteristic value is always higher than that of starch nanoparticles in the whole gelatinization process. The FT-IR spectrum showed that only starch nanoparticles prepared by cross-linking method showed the characteristic peak of secondary amide structure at 1714 cm(-1), but the structure of was basically the same as native starch. The X-ray diffraction pattern revealed that there were obvious characteristic diffraction peaks near 20 for 15 degrees, 1 7 degrees 19 degrees and 23 degrees for the 800 nm starch nanoparticles and native rice starch, while the characteristic diffraction peaks of other starch nanoparticles disappeared in varying degrees due to the changed crystal structure. (C) 2020 Elsevier B.V. All rights reserved.
摘要：
Enzyme production as well as rice straw saccharification and fermentation were integrated to produce bioethanol in this study. Submerged fermentation of Na2CO3 pretreated rice straw to produce a complex enzyme for saccharification by Aspergillus fumigatus was performed. The major component of rice straw, that is cellulose, hemicellulose and lignin was almost completely degraded in 24 h. Using whole pretreated rice straw slurry as the substrate, the maximum concentrations of reducing sugar and ethanol were obtained with values of 63.6 g/L and 30.9 g/L, respectively, in a total hydrolysis and fermentation time at a substrate concentration of 8% (based on the original amount of rice straw). Fed-batch fermentation was employed for enzymolysis and fermentation of rice straw residue. Under a 32% total substrate concentration, 108.6 g/L ethanol was obtained in a total enzymolysis and fermentation time of 40 h. The results from different fermentation methods showed that the laccase produced by A. fumigatus in situ could effectively promote the enzymatic hydrolysis and fermentation through detoxifying the phenols produced during pretreatment and by the enzymatic hydrolysis processes. (C) 2020 Elsevier Ltd. All rights reserved.
作者机构：
[Liu, Yong-Nan; Liu, Bi-Yang; Liu, Gao-Qiang; Ma, You-Chu] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha, Peoples R China.;[Liu, Yong-Nan; Liu, Bi-Yang; Liu, Gao-Qiang; Ma, You-Chu] Cent South Univ Forestry & Technol, Int Cooperat Base Sci & Technol Innovat Forest Re, Changsha, Peoples R China.;[Yang, Hai-Long] Wenzhou Univ, Coll Environm & Life Sci, Wenzhou, Peoples R China.
通讯机构：
[Liu, Gao-Qiang] C;Cent South Univ Forestry & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha, Peoples R China.;Cent South Univ Forestry & Technol, Int Cooperat Base Sci & Technol Innovat Forest Re, Changsha, Peoples R China.
摘要：
The development of fungal fruiting bodies from a hyphal thallus is inducible under low temperature (cold stress). The molecular mechanism has been subject to surprisingly few studies. Analysis of gene expression level has become an important means to study gene function and its regulation mechanism. But identification of reference genes (RGs) stability under cold stress have not been reported in famous medicinal mushroom-forming fungi Cordyceps militaris. Herein, 12 candidate RGs had been systematically validated under cold stress in C. militaris. Three different algorithms, geNorm, NormFinder and BestKeeper were applied to evaluate the expression stability of the RGs. Our results showed that UBC and UBQ were the most stable RGs for cold treatments in short and long periods, respectively. 2 RGs (UBC and PP2A) and 3 RGs (UBQ, TUB and CYP) were the suitable RGs for cold treatments in short and long periods, respectively. Moreover, target genes, two-component-system histidine kinase genes, were selected to validate the most and least stable RGs under cold treatment, which indicated that use of unstable expressed genes as RGs leads to biased results. Our results provide a good starting point for accurate reverse transcriptase quantitative polymerase chain reaction normalization by using UBC and UBQ in C. militaris under cold stress and better support for understanding the mechanism of response to cold stress and fruiting body formation in C. militaris and other mushroom-forming fungi in future research.
摘要：
Chemical investigation on the peels of the cultivated edible mushroom Wolfiporia cocos led to the identification of 13 diterpenes and 4 steroids, including two new abietane diterpenes (1 and 2) and one new pregnane steroid (14). Structures of new compounds were determined by analysis of NMR, MS, and electronic circular dichroism (ECD) data. All compounds were evaluated for cytotoxicity (K562 and HepG2), antimicrobial and anti-inflammatory activity. Compounds 15, 17 showed strong cytotoxicity on K562 cells with the IC50 values of 5.4 and 7.5 mu M, respectively. Compounds 4, 9 and 17 displayed medium antibacterial activity against Staphylococcus aureus with MICs of 31.3, 48.5 and 12.5 mu M, respectively. Compounds 1-10, 14 and 16 showed inhibitory activity on the NO (nitric oxide) release in LPS-induced RAW 264.7 cells with IC50 values at the range of 16.8-75.8 mu M. This work confirms the potential of peels of W. cocos in the treatment of infection diseases.
作者机构：
[Liu, Gaoqiang; Chen, Zhifen; He, Tianpei; Wu, Yaohui; Jiang, Chenyang; Wu, YH; Wang, Yonghong; Chen, Xiaoyong] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha, Peoples R China.;[Zhao, Yunlin; Xu, Zhenggang; Wu, Yaohui; Wu, YH] Cent South Univ Forestry & Technol, Hunan Res Ctr Engn Technol Utilizat Environm & Re, Changsha, Peoples R China.;[Xu, Zhenggang] Hunan City Univ, Hunan Urban & Rural Ecol Planning & Restorat Engn, Yiyang, Hunan, Peoples R China.;[Ning, Ge] Hunan Univ Chinese Med, Int Educ Inst, Changsha, Peoples R China.
通讯机构：
[Wu, YH ] C;Cent South Univ Forestry & Technol, Hunan Prov Key Lab Forestry Biotechnol, Changsha, Peoples R China.;Cent South Univ Forestry & Technol, Hunan Res Ctr Engn Technol Utilizat Environm & Re, Changsha, Peoples R China.
摘要：
In the present work, a series of magnetically separable Fe3O4/g-C3N4/MoO(3)nanocomposite catalysts were prepared. The as-prepared catalysts were characterized by XRD, EDX, TEM, FT-IR, UV-Vis DRS, TGA, PL, BET and VSM. The photocatalytic activity of photocatalytic materials was evaluated by catalytic degradation of tetracycline solution under visible light irradiation. Furthermore, the influences of weight percent of MoO(3)and scavengers of the reactive species on the degradation activity were investigated. The results showed that the Fe3O4/g-C3N4/MoO3(30%) nanocomposites exhibited highest removal ability for TC, 94% TC was removed during the treatment. Photocatalytic activity of Fe3O4/g-C3N4/MoO3(30%) was about 6.9, 5, and 19.9-fold higher than those of the MoO3, g-C3N4, and Fe3O4/g-C(3)N(4)samples, respectively. The excellent photocatalytic performance was mainly attributed to the Z-scheme structure formed between MoO(3)and g-C3N4, which enhanced the efficient separation of the electron-hole and sufficient utilization charge carriers for generating active radials. The highly improved activity was also partially beneficial from the increase in adsorption of the photocatalysts in visible range due to the combinaion of Fe3O4. Superoxide ions (center dot O-2(-)) was the primary reactive species for the photocatalytic degradation of TC, as degradation rate were decreased to 6% in solution containing benzoquinone (BQ). Data indicate that the novel Fe3O4/g-C3N4/MoO(3)was favorable for the degradation of high concentrations of tetracycline in water.
作者机构：
[薛菲菲; 雷含珺; 张漾泓; 王晓玲; 何含杰; 刘高强] Hunan Provincial Key Laboratory of Forestry Biotechnology, International Cooperation Base of Science and Technology Innovation on Forest Resource Biotechnology of Hunan Province, Central South University of Forestry & Technology, Hunan, Changsha, 410004, China
摘要：
Tung meal is the main byproduct generated during tung oil extraction from tung tree (Vernicia fordii) seeds and contains approximately 36-45 wt% crude protein. The disposal of large amounts of this resource has attracted increasing attention in relation to its value-added utilization. In this study, a new strain Pseudomonas aeruginosa LYT-4, was isolated for the bioconversion of tung meal into free amino acid fertilizer. Solid-state fermentation analysis showed that the protease activity of P. aeruginosa LYT-4 treatment was significantly higher than that under natural treatment throughout the fermentation period. The total percentage of free amino acids increased from 46.5% under natural fermentation to 55.5% under P. aeruginosa LYT-4 treatment. Pot experiments revealed that P. aeruginosa LYT-4 fermented-tung meal efficiently promoted spinach growth by increasing biomass and was more effective than both naturally fermented tung meal and chemical fertilizer. Furthermore, P. aeruginosa LYT-4 exhibited efficient in vitro antagonistic activity against three plant pathogens, Colletotrichum lini, Rhizoctonia solani and Fusarium oxysporum, possibly due to the abundant secondary metabolite clusters in its genome based on genomic analysis. In conclusion, P. aeruginosa LYT-4 exhibited a promising prospect for the industrial production of free amino acid fertilizer from tung meal with simultaneous potential biocontrol capacity. (C) 2020 Elsevier Ltd. All rights reserved.
摘要：
Native and acetylated broken-rice starches (nanocrystals) with different degrees of substitution (DS) and their corresponding films were individually prepared, and the drug release profiles, weight loss, solubility and dispersion and surface morphology were comparatively studied. Bovine serum albumin (BSA) was used as a model drug. Acetylated native starch (ANS) DS 2.58, acetylated starch nanocrystals (ASN) DS 0.98, ASN DS 1.86, and ASN DS 2.72 were observed to be very soluble in chloroform. BSA was released rapidly from the native rice starch (NS) and ANS DS 2.58 films. ASN with high DS significantly slowed down the release of BSA from films, the percentages of BSA released from film ASN DS 2.72 only reached to 13% after 3.5?weeks release, and the release data followed Korsmeyer-Peppas equation. Further studies reveal that the particle size of ASN DS 2.72 was smallest, and the weight loss of ASN DS 2.72 film was lowest. The results demonstrate that acetylation and nanometer particle form of rice starch film can effectively retard protein drug release, and the prepared films based on ASN with high DS from broken rice may be suitable for the controlled protein delivery. (C) 2019 Elsevier B.V. All rights reserved.
