我国每年甘薯产量约为5 200 万t.在甘薯淀粉的加工过程中会产生大量甘薯渣,这些甘薯渣常被作为廉价的动物饲料或直接丢弃,造成资源浪费和严重的环境污染.甘薯渣中含有较为丰富的淀粉、果胶、纤维素等成分.通过微生物发酵或改性等方法可实现甘薯渣的高值化利用,对提升甘薯经济价值、改善甘薯产业结构和减少环境污染具有重大意义.该文综述了目前国内外关于甘薯渣在生物发酵、食品加工、废水处理、能源制备等领域的研究进展.着重介绍了甘薯渣发酵生产各种产品的最新进展,并对存在的问题与未来的发展进行了分析与展望,有望为相关的研究人员提供一定的参考和借鉴.

ε-poly-L-lysine（ε-PL） is a natural antibacterial agent with a wide range of bacteriostatic spectrum. It is synthesized by the polymerization of 25 to 35 lysines linked by α-carboxyl group and ε-amino group. ε-PL is mainly produced by the fermentation of Streptomyces albulus, which is more efficient and environmentally friendly than chemical production. ε-PL has many excellent properties, such as good water solubility, heat resistance,edibility and nontoxicity to the environment, and has good application prospects. In this paper,the research progress of ε-PL on the bacteriostatic properties, bacteriostatic mechanisms, and bacteriostatic mechanism models of various microorganisms were reviewed. It was speculated that ε-PL may affect the expression of regulatory genes by destroying the cell membrane,changing the permeability of cells, or acting on the cells to cause the stress of reactive oxygen（ROS）, so as to play an antibacterial role. According to these two bacteriostatic methods,corresponding bacteriostatic models were established, respectively, namely the carpet model and the ROS-induced apoptosis model. This study provides references for the further study of ε-PL on microbial inhibition, and also puts forward a new model of ε-PL antibacterial mechanism, thus providing certain references for expanding the application field of ε-PL.

Garlic (Allium sativum L.), the underground bulb of the Allium plant in the family Liliaceae, is a common and popular spice that has historically been used to prevent and treat many different diseases such as pain, deafness, diarrhea, tumors, and other healthy problems. Garlic essential oil contains a variety of organosulfur compounds, such as the most representative diallyl disulfides (DADS) and diallyl trisulfides (DATS), which have attracted great interest in medicine, food, and agriculture because of their rich biological activities. This paper reviews the research progress on the composition and bioactivities of garlic essential oil mixtures and the bioactivity of some typical monomeric sulfides in garlic essential oil. The active mechanisms of representative sulfides in garlic essential oil were analyzed, and the applications of garlic essential oil in functional food, food additives, and clinical treatment were discussed. Combined with the current research status, the limitations and development direction of garlic essential oil in the study of molecular mechanism were discussed, which is of great significance to the development of garlic essential oil as a natural and safe alternative medicine for treatment.

采用单因素和Box-Behnken响应面法对超声波辅助提取紫薇果实挥发油(LIFVO)的提取工艺进行了优化.利用GC-MS测定挥发油的化学组分,并测试其抑菌活性.结果显示,挥发油的最优提取工艺为提取温度69℃、超声波功率562 W、液料比23.6:1(mL:g),超声提取时间47 min,在此条件下,LIFVO得率为2.72％±0.02％.从挥发油中共鉴定出27种化合物,主要成分是二十四烷、二十五烷和二十六烷,其相对含量分别为17.307％、12.731％、10.897％.抑菌实验显示,所有受试菌的生长均能被挥发油所抑制.挥发油中的主要抑菌成分是多种烃类、醇类、酚类及萜烯类化合物.

Ginseng (Panax ginseng) is a perennial herbaceous plant belonging to Panax genus of Araliaceae. Ginsenosides are a kind of important compounds in ginseng and minor ginsenosides are secondary metabolic derivatives of ginsenosides. Studies have shown that minor ginsenosides have many pharmacological effects, such as antioxidant, anti-tumor, anti-platelet aggregation, and neuroprotective effects. However, the therapeutic effects of minor ginsenosides are limited due to poor solubility in water, short half-life, and poor targeting accuracy. In recent years, to improve the application efficiency, the research on the nanocrystallization of minor ginsenosides have attracted extensive attention from researchers. This review focuses on the classification, preparation methods, pharmacological effects, and action mechanisms of minor ginsenoside nanoparticles, as well as existing problems and future direction of relevant research, which provides a reference for the in-depth research of minor ginsenoside nanoparticles.

多杀菌素是一种由刺糖多孢菌产生且具有优秀抗虫活性的生物农药.目前多杀菌素产量普遍较低,而提高其产量的关键之一是选育高产菌株.尽管刺糖多孢菌全基因组序列已完成解析,但由于多杀菌素生物合成途径的复杂性及对其调控机制认识的匮乏性,构建高产基因工程菌株依然存在很大困难.利用诱变技术选育多杀菌素高产菌株,是一种有效便捷的方法.除了传统的物理化学诱变外,新型诱变育种技术如核糖体工程、等离子体技术、基因组重排、航天诱变育种等在高产菌株选育中都发挥了重要作用.本文综述了近年来相关研究,阐述了高通量筛选技术,并对其未来的研究方向进行展望.

为评价不同采集时间及制作方式对同一地点洞庭碧螺春茶活性成分的影响,采用国标法及常用实验方法对常规活性成分、矿质元素及氨基酸进行测定和分析评价.结果表明:在水分含量上,明前茶与明后茶相差不大;可溶性蛋白含量明前茶显著高于明后茶,而在鲜叶与炒制茶之间差异不显著;灰分含量最高的是明后鲜叶,最低的是明前炒制茶.维生素C、有机酸和灰分含量,鲜叶显著高于炒制茶,其中明后鲜叶含量最高.四种碧螺春茶中粗脂肪含量差异显著,炒制茶显著高于鲜叶,其中明后炒制茶含量最高.六种矿质元素在明后茶中的含量显著高于明前茶,同时在鲜叶中的含量也要高于相应的炒制茶中.氨基酸测定结果表明,明前茶的总氨基酸含量及风味氨基酸含量显著高于明后茶,鲜叶与相应炒制茶之间的总氨基酸及风味氨基酸含量差异不大.

生物化学实验是生物学专业重要的基础实验课程.近年来,为了适应学科的发展、 专业培养方案的改进、 学生素质的变化以及技术手段的革新,相关指导教师不断对生物化学实验教学进行思索和实践,通过实验教学目的的理清、 实验教学项目的调整、 教学模式的创新、 教学手段的更新、 实验过程的优化等方面的努力,提高了学生的学习主动性,训练了学生的基本实验技能,锻炼了学生分析和解决问题的能力,促进了实验教学的改革,获得了较好的教学效果.

通过耐盐及1-氨基环丙烷-1-羧酸脱氨酶活性测定,从江苏南通沿海滩涂的互花米草根际土壤中分离筛选出耐盐促生菌株6,其中Y3菌株的耐盐及产酶活性最强.采用形态学特征和分子生物学方法对Y3菌株进行鉴定,并测定Y3菌株对黄瓜发芽的耐盐促生作用,同时对Y3菌株的适宜生长条件进行研究.结果表明,Y3菌株为甲基营养型芽孢杆菌,其适宜培养条件为盐浓度6％、 温度30℃、pH 4.0,并以振荡方式进行暗培养.Y3菌株能显著促进盐胁迫下黄瓜种子的发芽率及幼苗的生长,并具有较强的产IAA、 嗜铁素、NH3的能力和固氮的能力.因此,Y3菌株在盐碱土地开发中具有较好的应用价值.

目的 以诱变菌株SaccharopolysporaspinosaAEG3-1为试验株,研究山茶油对该菌株发酵生产多杀菌素的影响.方法 首先单因素实验筛选到最佳植物油脂,再利用响应面实验设计对发酵培养基中最佳植物油脂、葡萄糖、糊精、棉籽蛋白4种成分进行优化,最后在5L罐进行验证.结果 最佳植物油脂是山茶油,在0h添加15.0g/L效果最好.在此基础上,获得优化发酵培养基(g/L):山茶油15.1、葡萄糖51.6、糊精19.73、棉籽蛋白21.8,其产量达318.25mg/L,提高了55.61％.在5L罐中,利用优化培养基,分批和补料发酵产量分别达到361.97和512.36mg/L.结论 通过添加山茶油,诱变株的多杀菌素产量显著提高,说明该生产工艺确实可行,可为多杀菌素大规模生产提供可靠的依据.

目的 研究人参炔三醇(PXT)对肺癌NCI-H1299细胞增殖和凋亡的影响,并探讨其潜在作用机制.方法 MTT检测PXT对NCI-H1299细胞增殖的影响;流式细胞术检测PXT对NCI-H1299细胞凋亡的影响;Western blotting检测PXT作用前后ERK1/2和mTORC1通路相关因子及凋亡相关因子Bcl-2的表达.结果 PXT可有效抑制肺癌NCI-H1299细胞的增殖,且抑制效果与作用浓度和时间呈正相关(P<0.05).PXT作用于NCI-H1299细胞后,凋亡细胞数明显增加(P<0.05).PXT可降低p-ERK1/2、p-mTORC1及下游调控因子p65的磷酸化水平,并降低抗凋亡因子Bcl-2的蛋白表达水平(P<0.05).结论 PXT可通过下调ERK1/2和mTORC1通路来抑制肺癌NCI-H1299细胞的增殖,并诱导其凋亡.

为评价苏州特有的'苏州圆叶芹'的营养品质、挥发油成分及其抑菌活性,采用国标法及其他测定方法,对'苏州圆叶芹'可食用部分的维生素C、灰分、粗脂肪、氨基酸、矿质元素等营养成分进行测定,并结合气质联用测定技术及滤纸片法,对其挥发油的化学成分和抑菌活性进行研究.结果表明,'苏州圆叶芹'中营养成分丰富,其中维生素C含量比普通水芹要高.'苏州圆叶芹'中18种氨基酸齐全,总量为265.22 mg·g-1,其中精氨酸含量最高,谷氨酸含量最少,8种人体必需氨基酸含量为77.94 mg·g-1."脯氨酸+酪氨酸"是'苏州圆叶芹'蛋白中的第一限制性氨基酸,必需氨基酸比值范围为0.44～3.90,氨基酸比值系数范围是0.39～3.46.'苏州圆叶芹'挥发油中鉴定出13种化合物,占挥发油总量的97.02％,其主要成分为棕榈酸(38.56％)、蒎烷(25.02％)、棕榈酸甲酯(5.95％)及棕榈酸乙酯(6.56％)等.'苏州圆叶芹'挥发油具有良好的抑菌活性,挥发油对大肠杆菌、金黄色葡萄球菌、李斯特菌和枯草芽孢杆菌的最低抑菌浓度分别为2.5、1.25、5.0和2.5 mg·mL-1.

[目的]从人参中找寻具有抗肿瘤活性的内生菌,并研究其抗肿瘤效果和机制.[方法]使用假单胞菌基础培养基进行分离,通过16s rDNA分子鉴定,采用MTT比色法、western blot等在乳腺癌细胞MDA-MB-231胞系中检测抗肿瘤活性.[结果]所分离菌株G13476经BLAST比对,确定其为假单胞菌;MTT数据和western blot结果显示,菌株G13476通过下调Bcl-2、上调Bax实现对三阴性乳腺癌的抑制.[结论]该研究结果为人参内生假单胞菌G13476在抗肿瘤药物的开发和应用提供技术支撑和理论基础.

To analysis and evaluate nutrient quality of abandoned branches and leaves of Biluochun (ABLB), using the na-tional standard methods and some other methods, total anthocyanin contents, total polyphenols, total flavonoids, mineral ele-ments and some other nutritional components were determined. And total antioxidant capacity (T－AOC) of ABLB was investigat-ed. The results indicated that there are many kinds of nutrients in ABLB. And contents of anthocyanin , polyphenol and flavnoid were 0.77 mg cyanidin 3－galactoside／g(DW), 165.22 mg gillic acid／g(DW) and 52.62 mg rutin／g(DW), respectively. The contents of moisture,ash,crude fat,crude fiber,total soluble protein and total soluble sugar in ABLB were 76.77%,4.80%, 3.66%,0.16%,2.99% and 3.86%. The ABLB had 18 kinds of amino acids, total amino acid and essential amino acid were 55.8 mg／g and 20.53 mg／g, respectively. The amino acids of Thr, Val, Leu, Phe+Tyr and Lys were higher than that in the pattern of FAO／WHO and Leu, Lys were higher than the pattern of egg. The extract of ABLB had good antioxidant activity and the content of ABLB was positively correlated with antioxidant capacity. So, the ABLB appear to have a good prospect of exploitation and application. And it is worth our in－depth development and utilization.

为了优化硝普钠法(sodium nitroprusside method,SNP)测定发酵液中的蛋氨酸(Met)含量的实验条件,利用紫外可见分光光度计分析不同氨基酸中加入各SNP反应试剂、反应不同时间对反应液吸收峰的影响.在甘氨酸(Gly)添加量、NaOH加入量、SNP加入量、H3PO4加入量、各试剂加入后的反应时间等单因素实验的结果上,利用响应面法优化SNP法.结果 表明:与SNP试剂反应后,除了组氨酸(His)外,其它氨基酸不会对Met的测定产生影响.反应试剂H3PO4的加入对513 nm处吸收峰的形成起决定性作用;发酵液中各成分SNP反应后,最大吸收峰无明显变化.利用单因素和响应面法优化SNP法,得出较佳测定方案:发酵液1500×g离心15 min;5 mL上清液中加入0.74 mL 5 mol/LNaOH和0.15 mL 10％ SNP溶液,摇匀试管,放置30 main;将2mLH3PO4逐滴加到混合物中,振荡试管,反应5 min,在513 nm处测吸收值.当Met浓度为1.0 g/L时,最佳测定条件下吸收值为1.952.通过光谱分析确认Gly的加入会降低Met和His反应的吸收峰值,可通过分析最大吸收峰波长是否在513 nm处,判断样品中是否有组氨酸影响测定.实验获得的SNP法可用于迅速筛选蛋氨酸高产菌.

为获得耐盐促生菌株并明确其促生特性,通过耐盐试验和ACC脱氨酶活性对沿海滩涂盐碱地土壤中的微生物进行分离筛选,得到5株耐盐菌株,其中B7的耐盐活性最强.接着采用平皿法和盆栽法研究了盐胁迫下黄瓜种子发芽及盆栽试验中B7对黄瓜的耐盐促生作用.同时对B7的多种促生能力进行测定,最后通过菌株形态、生理生化特征测定及其16S rDNA序列鉴定出B7菌株为巨大芽孢杆菌(Bacillus megaterium).研究结果表明,该菌株能明显提高黄瓜耐盐促生能力,同时具有产吲哚乙酸(IAA)、产氨、固氮及解磷等多种促生能力,因而具有广泛的应用前景.

[目的]研究生物复菌剂"苗壮素"在盐胁迫条件下对黄瓜生长的影响.[方法]以"新超越"黄瓜品种为试验材料,研究盐胁迫下生物复菌剂"苗壮素"对黄瓜促生抗逆作用的影响.[结果]盐胁迫下"苗壮素"生物复菌剂能够促进黄瓜生长,种子发芽率、种苗鲜重及总根长、总投影面积、总根表面积、平均根系直径、根尖数等生长指标差异显著.使用"苗壮素"后根际土壤中速效氮、速效磷、速效钾含量增加,VC、可溶性糖、可溶性固形物含量提高,亚硝酸盐含量下降,黄瓜品质和产量得到提升. [结论] "苗壮素"对黄瓜具有较明显的促生抗逆作用.

本文综述了一种提高作物耐盐能力促生菌的筛选及其应用.通过对沿海滩涂盐碱地土壤中的微生物进行分离纯化,并采用耐盐和解盐试验对分离纯化出的根际微生物进行耐盐促生筛选,得到高耐盐活性促生菌B7.对B7的16S rDNA、生理生化性质及促生能力进行测定,最后采用培养皿法和盆栽法对B7提高黄瓜耐盐能力进行测试.结果表明,该菌株耐盐度为6％,利用B7制备的微生物菌剂能在盐胁迫下显著提高黄瓜的耐盐能力,减缓盐害现象,增加生物量,达到促进黄瓜生长的效果.

[目的]考察东太湖地区湿地水质与浮游细菌群落结构之间的关联,探索对湿地水质具有指示作用的微生物.[方法]应用高通量测序研究浮游细菌群落结构;通过相关性分析考察了浮游细菌群落多样性与水质的关联,并运用LEtSe分析定位不同水质水样的标志微生物.[结果]东太湖湿地浮游细菌主要分布于放线菌门(相对丰度34.78％)、变形菌门(26.30％)及蓝细菌门(19.28％)等7个门;水质指标综合得分与浮游细菌群落香农-威纳指数和辛普森指数分别显著相关(r=-0.597,p ＜0.05;r =0.694,p＜0.01);蓝细菌门与伯克氏菌科的相对丰度在不同水质水样中差异最为显著(LDA得分＞4.0).[结论]东太湖地区,较高的浮游细菌多样性表征较好的湿地水质;蓝细菌相对丰度较高(27.80％)指示湿地水质较差,而伯克氏菌相对丰度较高(5.48％)指示湿地水质相对较好.

The antioxidant activity of four solvent (petroleum ether,ethyl acetate,normal butyl alcohol and aqueous) extracts from Brassica chinensis L. were determined using five antioxidant assay, including DPPH radical,superoxide scavenging effect, hydroxyl radical, ABTS radical and reducing power. At the same time, total antioxidant activity of these four extracts was evaluated by subordination function method. The results showed that all of the extractions from Brassica chinensis(EBC) L. had antioxidant activity and the content of E-BC had a highly significant correlation with the activity. And the ethyl acetate extraction of Brassica chinensis showed the highest antioxidant activity , while the water extraction of Brassica chinensis L. showed the lowest antioxidant activity. So, the Brassica chinensis L. has great applied foreground and research value.