As a kind of eco-friendly material with wide application prospects, chitooligosaccharide (COS) has attracted increasing attention because of its unique bioactivities. In this study, novel polyphenol-functionalized COS pyridinium salts were designed and synthesized. The structural characteristics of the desired derivatives were confirmed by FT-IR and 1H NMR spectroscopy. Their antioxidant activities were evaluated in vitro by DPPH radical scavenging assay, superoxide anion radical scavenging assay, and reducing power assay. The solubility assay in common solvents and cytotoxicity assay against L929 cells using the MTT method in vitro were also performed. The antioxidant assay results showed that the compounds functionalized by polyphenol displayed improved antioxidant activities, which were enhanced with the increase of sample concentration and the number of phenolic hydroxyl groups. The solubility assay indicated that the prepared derivatives had good water solubility. Besides, the modified products were non-toxic to the cells tested. In short, the polyphenol-functionalized COS pyridinium salts with enhanced antioxidant activity and good biocompatibility could be employed as newly safe antioxidant in the fields of biomedicine and food.

Natural polysaccharides are abundant and renewable resource, but their applications are hampered by limited biological activity. Chemical modification can overcome these drawbacks by altering their structure. Three series of polysaccharide derivatives with coumarins were synthesized to obtain polysaccharide derivatives with enhanced biological activity. The biological activities were tested, including antioxidant property, antifungal property, and antibacterial property. Based on the results, the inhibitory properties of the coumarin-polysaccharide derivatives were significantly improved over the raw polysaccharide. The IC50 of the inhibition of DPPH, ABTS•+, and superoxide (O2•-) radical-scavenging was 0.06-0.15 mg/mL, 2.3-15.9 μg/mL, and 0.03-0.25 mg/mL, respectively. Compared with the raw polysaccharides, coumarin- polysaccharide derivatives exhibited higher efficacy in inhibiting the growth of tested phytopathogens, showing inhibitory indices of 60.0-93.6 % at 1.0 mg/mL. Chitosan derivatives with methyl and chlorine (Compound 10B and 10C) exhibited significant antibacterial activity against S. aureus (MIC = 31.2 μg/mL), E. coli (MIC = 7.8 μg/mL), and V. harveyi (MIC = 15.6 μg/mL), respectively. The results of the cytotoxicity assay showed no observed cytotoxicity when the RAW 264.7 cells were incubated with the synthesized polysaccharide derivatives at the tested concentrations.

Large amount of acidic wastewater containing plenty of organics were produced during the processing of sweet potato starch, the massive discharge and low pH of wastewater made it more difficult to treat. An efficient treatment technology for wastewater was developed in this study combined rapid separation, microorganism treatment and deep bed filtration. Firstly, the fast separation device was used to separate and recover more than 70% of the starch and protein in the wastewater. The separated wastewater was treated with Bacillus pumilus and Bacillus licheniformis under natural conditions, and 50% of the wastewater was updated daily from the third day. After filtered through the straw layer, the quality of treated water including COD, TP, TN and SS could reach the quality standard for indirect discharge. The result showed that this technology was simple and effective for wastewater during sweet potato starch production.

传统的"发酵动力学实验"教学以教师为主,在教学过程中,学生主要按照教师要求做实验,缺乏主动性和能动性.为贯彻OBE教学理念,采用以学生为主、教师为辅的教学方式,具体方法:让学生带着问题预习,弄通实验原理与方法,撰写实验方案并对实验中可能出现的问题进行预判,使学生能够在实验过程中及时发现异常现象并采取适当措施,以提高学生认识问题、分析问题和解决问题的能力,在整个实验过程中,教师根据出现的错误进行指导.此外,将课程思政融入实验教学,理论与实践紧密结合,探索以学生为主体的教学方式,注重过程性评价,着力培养学生的工程思维.实践结果表明:2017,2018级学生课程目标达成度均高于0.8,说明学生解决生物工程中复杂问题的能力得到了提高,能根据发酵过程参数的异常变化对操作变量作出相应的调整,正确构建发酵过程的动力学模型,教学方式的改革取得了较好成效,该研究成果可为生物工程专业的实践教学改革提供参考.

为提升化工、生物工程等专业工程设计类课程的教学质量,构建了线上线下混合式教学模式.通过在线课程引导学生自主学习工程设计的理论知识;依托原创案例实施线下教学,重点讲解成果转化过程中的技术和工程问题,引导学生将理论知识应用于实践,切实掌握项目研发思路和技术转化过程.实践表明,这种教学方式可以有效提升学生的工程设计能力.

文章分析了生物工程专业毕业设计现状,据此以创新能力培养为导向,对生物工程毕业设计进行改革与实践,以期为培养综合性、创新型人才提供参考和借鉴.

In this work, a series of water-soluble fluorine-functionalized chitooligosaccharide derivatives were synthesized by conjugating nicotinic acid to chitooligosaccharide via nicotinylation reaction, followed by nucleophilic reaction with ethyl bromide, benzyl bromide and fluorobenzyl bromides. Synthesized derivatives were identified structurally by Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance. In addition, the antibacterial activities of chitooligosaccharide derivatives against several disease-causing bacteria were assessed by the broth dilution method and Kirby-Bauer method, the mycelium growth rate method was used to assessing the antifungal properties of samples against three plant-threatening fungi. Among the chitooligosaccharide derivatives, those containing benzyl or fluorobenzyl exhibited noteworthy antimicrobial activity. Specifically, the chitooligosaccharide derivative containing 2,3,4-trifluorobenzyl displayed remarkable antimicrobial activity, with an inhibition index of 84.35% against Botryis cinerea at a concentration of 1.0 mg/mL. Additionally, its MIC value against Staphylococcus aureus was found to be 0.03125 mg/mL, while the MBC value was determined to be 0.0625 mg/mL. The findings of the study revealed that the incorporation of pyridinium cations and fluorine into the chitooligosaccharide backbone may play a critical role in strengthening its ability to combat harmful microorganisms. Furthermore, the cytotoxicities of chitooligosaccharide derivatives against Huvec cells were evaluated through MTT assay, and all samples were not toxic. As a consequence, the water-soluble fluorinefunctionalized chitooligosaccharide derivatives possessed rapid microbicidal properties and good biocompatibility, which provided promising prospects for the development of a more effective and environmentally friendly antimicrobial agent.

"生物工程工厂设计"是生物工程专业重要的工程设计类实践课程,为切实提高教学效果,课程教学团队将在线学习、计算机仿真模拟和生产线观摩引入学生设计过程,采用边学习边应用的课程实施方式,学生自学、教师讲解与学生自主设计有机结合,引导学生将知识应用于实践,将工程教育认证理念贯穿整个实践环节.教学实践表明,这种教学方式可以有效提升学生的工程设计能力.

对《生物化学工程》的教学方法进行了改革,将传统的完全的理论教学方式转变为理论与实践相结合的教学方式,以训练学生的工程思维.为强化学生理论联系实践的能力,将这一思想延伸到《科研技能课》《生物工程与工艺综合实验》及《生物工程专业方向实验》的实践教学过程中,依托真正的科研任务,让学生把理论联系实践的思维方式落实好,切实提高学生理论联系实践的能力,提高学生的综合素质.

目的 对火焰原子吸收分光光度法(flame atomic absorption spectrophotometry,FAAS)与电感耦合等离子体原子发射光谱法(inductively coupled plasma atomic emission spectrometry,ICP-OES)进行方法学验证研究,以探究两种方法应用于检测生物材料钙含量的可行性,为制定生物瓣抗钙化性能检测方法标准提供参考.方法 将生物瓣植入3周刚断乳雄性Wistar大鼠背部皮下,8周后取出植入物,用FAAS法和ICP-OES法检测植入物中钙含量,并研究两种方法的线性、专属性、重复性、精密度、准确度及样品检测结果的差异.结果 当生物瓣的钙质量浓度为0～5.0μg/mL时两种方法的线性关系均良好,相关系数大于0.999.ICP-OES法测定时定量限更低、测准确性更好,与FAAS法相比更为优秀,且两种方法的回收率与相对标准偏差都能满足对生物材料中钙含量测定的要求.结论 FAAS法与ICP-OES法均可作为标准方法用于生物瓣中钙含量的测定,FAAS需要加入掩蔽剂,但测定过程灵活,可通过预估将检验液中钙浓度稀释至标曲浓度范围内后测定;ICP-OES受干扰少,但不能预估检验液的钙含量,因此适用于钙含量范围一定的大量样品的检测工作.

In this paper, a series of target derivatives were synthesized by introducing coumarin into inulin structure using three-step chemical modification, and their structures were characterized by FTIR, H-1 NMR, and C-13 NMR. At the same time, the antioxidant activities of inulin derivatives were determined, including DPPH-radical scavenging activity, superoxide-radical scavenging activity, PTIO-radical scavenging activity and reducing ability. The test results showed that the antioxidant activities of inulin derivatives containing coumarin were significantly increased. Especially, inulin derivatives showed excellent DPPH radical-scavenging ability (IC50 0.09-0.11 mg/mL). Meanwhile, the scavenging ability of PTIO-radical was increased by more than 80%, and the IC50 values were all between 0.23 and 0.26 mg/mL. At the concentration below 1 mg/mL, the scavenging rate of all inulin derivatives could even reach 100%. This study provides a feasible way to synthesize inulin derivatives with significant activity, which may be developed into new antioxidants in medicine and cosmetics.

In order to biodegrade natural chitin, in this study, chitin was used as the sole carbon source, obtain chitin deacetylase strains which could produce chitosan from natural chitin by biological method. Results showed that, the strains were identified by color plate screening and enzyme activity rescreening, morphological characteristics and 16S rRNA sequence analysis. A bacterium X4 with higher activity of chitin deacetylase was obtained, and was identified as Lysinibacillus sp.. The fermentation culture of the strain showed that the activity of chitin deacetylase produced by X4 could reached 8.210 U/mL, and the deacetylation degree of chitin was 8.642%. The results was valuable for the green biological utilization of chitin.

渤海近岸、河口海域镉(cadmium,Cd)污染严重,且盐度低于正常海水盐度,因此,有必要研究低盐对Cd毒性效应的影响.本研究以太平洋牡蛎(Crassostrea gigas)为研究对象,在正常盐度(31.4 psu)和低盐度(15.7 psu)条件下驯化后,在不同浓度的Cd(5、20、80和240 μg·L-1)海水环境中暴露7 d,通过检测牡蛎鳃中Cd和必需金属元素含量以及生物标志物,探究低盐对Cd毒性效应的影响.结果显示,Cd破坏了牡蛎鳃中钠(Na)和镁(Mg)离子平衡,而Cd和低盐复合胁迫对钾(K)含量变化存在显著交互作用.Cd和低盐均诱导牡蛎鳃氧化应激和能量代谢紊乱,低盐还影响了 Cd的毒性效应,表现为Cd和低盐复合胁迫对丙二醛(malondialdehyde,MDA)含量和异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)活性的影响存在显著交互作用.综合生物标志物响应(integrated biomarker response,IBR)分析结果显示,Cd对牡蛎产生的压力随Cd暴露浓度升高不断加大;Cd和低盐复合胁迫对牡蛎产生的压力高于Cd单一胁迫,表明低盐加剧了 Cd对牡蛎的毒性效应.因此,为了更全面地评估近岸海域痕量金属的环境风险,应充分考虑低盐这一环境因素对污染物毒性的影响.

In this study, chitooligosaccharide-niacin acid conjugate was designed and synthesized through the reaction of chitooligosaccharide and nicotinic acid with the aid of N,N′-carbonyldiimidazole. Its cationic derivatives were prepared by the further nucleophilic substitution reaction between the chitooligosaccharide-niacin acid conjugate and bromopropyl trialkyl ammonium bromide with different alkyl chain lengths. The specific structural characterization of all derivatives was identified using Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR), and the degree of substitution was obtained using the integral area ratio of the hydrogen signals. Specifically, the antibacterial activities against Escherichia coli, Staphylococcus aureus, Pseudoalteromonas citrea and Vibrio harveyi were evaluated using broth dilution methods. In addition, their antifungal activities, including Botrytis cinerea, Glomerella cingulate and Fusarium oxysporum f. sp. cubense were assayed in vitro using the mycelium growth rate method. Experimental data proved that the samples showed antibacterial activity against four pathogenic bacteria (MIC = 1–0.125 mg/mL, MBC = 8–0.5 mg/mL) and enhanced antifungal activity (50.30–68.48% at 1.0 mg/mL) against Botrytis cinerea. In particular, of all chitooligosaccharide derivatives, the chitooligosaccharide derivative containing pyridinium and tri-n-butylamine showed the strongest antibacterial capacity against all of the test pathogenic bacteria; the MIC against Vibrio harveyi was 0.125 mg/mL and the MBC was 1 mg/mL. The experimental results above showed that the introduction of pyridinium salt and quaternary ammonium salt bearing trialkyl enhanced the antimicrobial activity. In addition, the cytotoxicity against L929 cells of the chitooligosaccharide derivatives was evaluated, and the compounds exhibited slight cytotoxicity. Specifically, the cell viability was greater than 91.80% at all test concentrations. The results suggested that the cationic chitooligosaccharide derivatives bearing pyridinium and trialkyl ammonium possessed better antimicrobial activity than pure chitooligosaccharide, indicating their potential as antimicrobial agents in food, medicine, cosmetics and other fields.

Abstract The characteristics and dynamic succession of biofilm on the surface of attached materials at different phosphate levels were studied. Phosphate showed significant effect on the formation of biofilm. The dry weight, dry weight without ash, chlorophyll-a, and extracellular polymeric substances (EPS) of biofilm all increased with the increase of phosphate level, and reached the peak value at 40 µg/L, then stabilized and slightly decreased with the increase of phosphate concentration. The proportion of polysaccharides in EPS of each layer in biofilm increased from outside to inside (from Soluble EPS to Loosely Bound EPS to Tightly Bound EPS), in contrast, the proportion of protein showed the opposite. EPS of various types in biofilms enhanced with the increase of phosphate level, the amounts of protein and polysaccharide in EPS showed similar trend. When the phosphate concentrations were lower than 40 µg/L, the ratio of protein to polysaccharide (PN/PS) increased with the increase of phosphate level, and decreased somewhat when the phosphate was higher than 50 µg/L. The proportion of bacteria in microbial population of biofilm decreased with the increasing of phosphate level and immersion time of the attached material, while the proportion of diatoms increased gradually. The study was helpful to understand the dialectical relationship between environmental factors and biological factors in the aquaculture environment, and provides a theoretical basis for exploring the mechanism of marine biofilm formation.

文章首先分析了新工科背景下大学生创新创业教育现状,然后论述了新工科背景下大学生创新创业教育体系建设,包括结合专业教育,构建科学规范的创新创业教育体系;打造高素质教学队伍,做好教师培训和激励;整合校内外资源,搭建实践平台体系.

As one of the most promising and eco-friendly oligosaccharides with a variety of potential biological activities, chitooligosaccharide has attracted much attention because of its unique properties. The modification of chitooligosaccharide has been used for synthesizing novel chitooligosaccharide derivatives with excellent antimicrobial activities. In this work, chitooligosaccharide-niacin acid conjugate was firstly synthesized by using N,N′-carbonyldiimidazole as catalyst and its cationic derivatives were obtained by further nucleophilic reaction between chitooligosaccharide-niacin acid conjugate and halogenated benzyl bromide. The structural characteristics of chitooligosaccharide derivatives were investigated by FTIR and NMR. In addition, the antimicrobial property of three end products against three plant-threatening fungal pathogens and four harmful bacteria was evaluated by the disc diffusion method. The in vitro antimicrobial activities results presented a significantly improved inhibition capability against pathogenic microorganisms of cationic chitooligosaccharide derivatives bearing N-halogenated benzyl pyridinium as compared to chitooligosaccharide and chitooligosaccharide-niacin acid conjugate. Specifically, all end products possessed significant enhancement in antimicrobial activities, the inhibition zones of the derivatives were from 6.3 to 19.4 mm against fungi and compounds also had excellent bacteriostatic activity (7.7–20.8 mm). Specially, chitooligosaccharide derivative bearing 4-chlorobenzyl showed the strongest antifungal activity, its inhibition zone reached up to 19.4 mm against F. oxysporum, which was close to the carbendazim (22.3 mm), it also showed excellent antibacterial activity against harmful bacterial, its bacteriostatic diameter was astonishingly 20.8 mm. These data indicated that the introduction of pyridinium salt with halogenated benzyl by the reaction of halogenated benzyl bromide groups and chitooligosaccharide-niacin acid conjugate could conspicuously enhance the antimicrobial effect. Chitooligosaccharide derivatives with enhanced antimicrobial activities could serve as potential biomaterial for antimicrobial applications.

目的 探究羟基磷灰石(HA)涂层对3D打印钛合金材料生物安全性的影响.方法 将3D打印钛合金材料分为有HA涂层材料和无HA涂层材料两个样品组.分别进行细胞毒性、刺激、急性毒性、溶血、回复突变、小鼠淋巴瘤试验和细胞致癌试验,将两种材料的生物安全性评价进行对比,观察羟基磷灰石(HA)涂层对3D打印钛合金髋臼杯材料的生物安全性的影响.结果 在细胞毒性试验中,有HA涂层组的细胞存活率为(117±6)％,无HA涂层组的细胞存活率为(106±14)％,均大于75％;在刺激试验中,两种材料生理盐水浸提液组的积分均为0,玉米油浸提液组的积分均为0.06;在急性毒性试验中,各组小鼠体重均稳步增长;在溶血试验中,有HA涂层材料的溶血率为0.125％,无HA涂层材料的溶血率为-0.257％;在Ames试验中,两种材料的回复突变菌落数均在正常值范围内;在小鼠淋巴瘤试验中,各剂量组的突变频率MF均大于或小于阴性对照组,且稍微高于阴性对照组的剂量组均不超过126×10-6.结论 两种材料均不具有细胞毒性、急性毒性、刺激和遗传毒性,同时也证明了两种材料都不具有溶血作用.有HA涂层材料和无HA涂层材料均表现出良好的生物安全性,证明HA涂层材料是安全可靠的,这也为未来开钛合金材料通过添加涂层改性提供了安全依据.

为了研究油桃采后保鲜新技术,提高其采后贮藏品质,本研究以'126油桃'为试验材料,采用200 μmol/L褪黑素对油桃进行浸泡处理,研究室温(25±1)℃贮藏时,褪黑素对油桃采后的腐烂指数、失重率、呼吸强度、硬度、VC、可溶性固形物、可滴定酸和可溶性蛋白等的影响.结果 表明,200μmol/L外源褪黑素处理可以显著降低果实的腐烂指数及贮藏后期的失重率,抑制果实呼吸强度的增加,提高糖酸比,并有效延缓油桃果实硬度、可溶性固形物、可溶性蛋白及维生素C含量的下降,使油桃在贮藏期内仍能保持较高的营养价值.

实践类课程是培养理工类学生创新、创业和综合实践能力的重要环节,在实践类课程教学中实施课程思政,是提高课程教学质量的重要保障.文章从分析实践类课程特点和当前的现状入手,以理工类大学生实习实训课程为例,提出实践教学活动中思政教育教学范式,并以案例形式围绕"劳动精神、工匠精神、民族自信与爱国主义情怀、工程伦理、职业素养"等方面进行课程思政教学实践,最后通过访谈与文问卷调查方式对实施效果进行反馈,为实践类课程中实施"课程思政"提供范式参考.