金针菇FV908菌株液体培养工艺的研究

通过单因子试验统计分析 ,优化筛选了适于金针菇 (Flammulinavelutipes)FV90 8的适宜培养基和摇瓶培养条件 ,结果表明 ,其适宜的液体培养基组成为玉米粉 5 .0 % ,麸皮 2 .0 % ,KH2 PO4 0 .1% ,MgSO4 ·7H2 O 0 .0 5 % ,10 μgVB1/ 10 0mL ,5 0 μgVB2 / 10 0mL ;适宜的摇瓶培养条件为 :培养基的起始pH 6 .0～ 7.0 ,5 0 0mL摇瓶装量为15 0mL ,接种量为 10 % ,培养温度 2 5℃ ,摇床转速为 12 0r/min ,菌丝干收率 39g/L。     

金针菇FV908菌株液体培养工艺

通过单因子试验统计分析,优化筛选了适于金针菇(Flammulina velatipes)FV908的适宜培养基和摇瓶培养条件,结果表明,其适宜的液体培养基组成为5.0%玉米粉,2.0%麸皮,0.1%KHOP4,0.05%MgSO4*7H2O,10μgVB1/100ml,50μgVB2/100ml;适宜的摇瓶培养条件为培养基的起始pH6.0～7.0,500ml摇瓶装量为150ml,接种量为10%,培养温度25℃,摇床转速为120r/min,菌丝干收率4.1g/100ml.     

一株寡营养细菌胞外多糖的摇瓶发酵研究

从新疆的寡营养环境——古尔班通古特沙漠中分离到一株寡营养细菌Azotobacter sp．(1～15mg碳/L培养基),通过进行Azotobacter sp．菌的单因子优化培养基的试验、摇瓶培养工艺条件的优化试验(培养温度、培养时间、初始pH值、溶氧量),确定了菌种生长与营养需求等主要因子与胞外多糖产量、粘度的关系,结果表明,摇瓶发酵的最适宜条件为:以蔗糖为碳源,碳酸钙含量为2g/L,初始pH值为7左右,种龄72～84h,磷酸二氢钾、硫酸镁的含量分别为0．3g/L、0．1g/L,接种体积分数15%,于37℃摇瓶培养72h,250mL摇瓶装液量为50mL,在适宜条件下粘多糖的产量最大可达到1145．94μg/mL,粘性可达9200 mPa·s。     

提高蛋白激发子产量的培养基及发酵条件的优化

为了进一步提高极细链格孢菌产蛋白激发子的产量,通过单因子和多因子试验与分析,筛选优化了适于极细链格孢菌产生蛋白激发子的培养基和培养条件,并检测了发酵过程中pH、还原糖、氨基氮和菌丝量变化以及与蛋白激发子产量的关系。结果表明,土豆淀粉和黄豆粉对蛋白激发子产量影响最大,其次是蛋白胨和无机盐。优化的发酵培养基主要成分（g／L）：碳源I 15、葡萄糖5、玉米淀粉5、土豆淀粉20、谷氨酸10、氮源I5、黄豆粉10、硫酸铵5。确定了优化的培养条件,调整培养基起始pH为7．0～7．5,将18h菌龄的种子培养液按10％接种量接种到装液量为75mL的500mL摇瓶中,在温度（28±1）℃、摇床转速180r／min下培养可获得理想的蛋白产量。在优化的培养基和培养条件下,发酵12～48h该菌进入对数生长期,48h进入稳定生长期,60h菌丝扣蛋白激发子产量达最高。蛋白产量与菌体生物量呈正相关,当还原糖、总糖量消耗到最低水平时,菌丝产量和蛋白激发子产量达最高。优化的培养基菌丝干重收率迭3．9g／100mL,蛋白激发子产量达到5．17g／L,比普通的土豆液体培养基提高近4倍。     

红酵母NZ-01发酵条件的优化

以红酵母菌株NZ-01为试验菌株,研究其发酵工艺与中试生产。采用摇瓶发酵优化的方式,研究培养基组分与发酵工艺条件对该菌发酵的影响,并进行中试放大生产。结果显示,该菌最适生长培养基组分为葡萄糖10g/L,蔗糖10g/L,酵母膏10g/L,牛肉膏2.5g/L;色素合成最适培养基组分为葡萄糖15g/L,蔗糖10g/L,酵母膏2.5g/L,牛肉膏5g/L。最适生长起始pH值为6.0,最适接种量为8%,生长周期为44h;最适色素合成起始pH值为7.0,最适色素合成接种量为8%,色素合成周期为48h。发酵优化后的色素产量3.88μg/mL较优化前1.71μg/mL提高了127%。中试产量达3.05μg/mL。红酵母菌NZ-01优化后的发酵条件可以应用于中试生产虾青素,有规模化生产应用潜力。     

茴香酸产生菌发酵条件的优化

为提高微生物降解反式茴脑获得茴香酸的产量,对假单胞菌Pseudomonas sp.NT2的发酵参数进行优化,以提高降解过程的转化率。利用单因素试验考察碳氮源种类及浓度、反式茴脑添加量、发酵温度、接种量、初始pH以及装液量对茴香酸生成量、反式茴脑降解率的影响,通过Plackett-Burman试验和最陡爬坡试验确定影响茴香酸生成量的显著因素并获取中心点,最后采用Box-Behnken模型进行响应面优化得到最佳发酵条件并验证。结果表明氯化铵浓度、初始pH和装液量是显著影响因素,最佳发酵条件为:柠檬酸钠10 g/L,氯化铵1.26 g/L,反式茴脑添加量1%,发酵温度30℃,接种量4%,初始pH 7.9,装液量42 mL/250 mL。优化后茴香酸生成量为7.24 g/L,为优化前的3.5倍,茴香酸摩尔生成率为80.72%,反式茴脑降解率为89.81%,分别比优化前提高了270.28%和97.78%。综上,假单胞菌NT2是生物转化生产茴香酸的潜力菌株。响应面优化可以显著提高反式茴脑的降解率和茴香酸产量,这为大规模生产茴香酸奠定了基础。     

纳他霉素发酵培养基及发酵条件的优化

采用Plackett-Burman法、最陡爬坡实验和响应面实验(Box-Behnken设计法)相结合的方法对褐黄孢链霉菌合成纳他霉素的发酵培养基及发酵条件进行优化。结果表明,培养基中的蛋白胨、pH和摇瓶装液量是影响纳他霉素产量的主要因素。优化后的培养基组成为葡萄糖50 g/L、蛋白胨19.5 g/L、酵母粉7 g/L、pH 7.4~7.5;发酵条件为装液量60 mL/500 mL、接种量15%、发酵温度29℃、摇床转速200 r/min、发酵周期96 h。此条件下,纳他霉素的产量较优化前提高了94%,达到2.19 g/L。     

B群链球菌的培养及优化研究

为了研究B群链球菌的生长和荚膜多糖的合成规律,采用摇瓶试验,探讨不同的液体培养基、培养基的pH值、葡萄糖的含量、生长因子、种子菌的接种量和溶氧等因素对B群链球菌生长的影响,优化发酵参数。并放大到10 L发酵罐中培养,菌浓度最高可达到20亿/mL;荚膜多糖的含量在培养的5 h达到652μg/mL。经过多次试验,建立了稳定的GBS发酵工艺。     

D-核糖发酵条件研究

对枯草芽孢杆菌Bacillus subtilis ptn15-1的发酵条件进行优化。采用优化后的培养基对发酵液的pH、发酵温度、摇床转速、接种量、装液量等进行单因素实验。确定发酵最适发酵条件为：pH7.0,发酵温度37℃;摇床转速180r/min,接种量10%,300mL三角瓶装30mL发酵液,发酵时间为68h。在此条件下,该菌的D-核糖产量从31.7g/L提高到43.1g/L,提高了35.9%。     

一株苝产醌类光敏剂丝状真菌AL18的液体发酵工艺研究

为研究一株丝状真菌AL18产苝醌类光敏剂的液体发酵工艺.以马铃薯综合培养基为发酵培养基,采用单次单因素实验法,研究了液体摇瓶培养条件对苝醌类光敏剂产量的影响.实验结果表明液体摇瓶最适培养条件为250ml三角瓶装液量40ml,接种量7.5%,接种种龄40h,初始pH5.75,摇床转数180r/min,30℃振荡培养48h.在此培养条件下,采用单因素法筛选了发酵培养基中的碳源、氮源和无机离子,选用L9(34)对筛选到的绵白糖(A)、蛋白胨(B)、蚕蛹粉(C)、CuSO4·5H2O(D)进行了正交试验.经优化后的发酵培养基配方为马铃薯200g/L,绵白糖30g/L,蛋白胨3g/L,蚕蛹粉12.5g/L,磷酸二氢钾1g/L,硫酸镁0.5g/L,硫酸铜0.05g/L,VB1 100mg/L.对此发酵培养基配方进行了5次验证实验,苝醌类光敏剂的平均产量为1.21g/L.     

Statistical optimization of culture media and conditions for production of mannan by Saccharomyces cerevisiae

In view of the increase in Saccharomyces cerevisiae mannan content, the culture medium and condition for S. cerevisiae were optimized in this study. The influence of culture medium ingredients such as carbon and nitrogen sources, inorganic ion, and enzyme activator on mannan production were evaluated using factional design. The mathematical model was established by the quadratic rotary combination design through response surface analysis. The optimized concentrations of culture medium were determined as follows: 4.98 g/100 mL, sucrose; 4.39 g/100 mL, soybean peptone; 3.10 g/100 mL, yeast extract; and 2.21 g/100 mL, glycerol. The optimized culture medium increased mannan production from 82.7 ± 3.4 mg/100 mL to 162.53 ± 3.47 mg/100 mL. The influence of original pH, inoculum size, temperature, and media volume on mannan production was evaluated and confirmed by orthogonale experimental design, with the order of effect as follows: media volume > temperature > initial pH > inoculation size. The optimized culture condition was pH, 5; inoculum size, 5 ml; temperature, 32°C; and media volume, 40 mL. The maximum mannan production increased to 258.5 ± 9.1 mg/100 mL at the optimum culture condition. It was evident that the mannan production was affected significantly by culture medium and condition optimization (p < 0.01).     

Peripheral mechanisms of sibutramine involving proximal gastric motility in dogs

Objective: Sibutramine, a serotonin‐norepinephrine uptake inhibitor, has been used for treating obesity. However, its possible mechanisms involving gastric motility have not been reported. The aim of this study was to evaluate the effects of sibutramine on gastric accommodation and antral motility. Research Methods and Procedures: The study was performed in seven dogs with a stomach cannula and composed of two separate experiments: antral contractions and gastric tone. Each experiment included two sessions on 2 separate days in a randomized order: a control session and a treatment session with sibutramine (5 mg/kg per os) administrated 2 hours before the study. Results: Sibutramine significantly increased fasting gastric tone; the gastric volume in the fasting state at baseline was 103.8 ± 12.3 mL and significantly decreased to 35.3 ± 16.0 mL with sibutramine (p = 0.0075). Sibutramine also impaired gastric accommodation. The average postprandial gastric volume was 472.1 ± 16.7 mL in the control session and reduced to 302.2 ± 53.6 mL with sibutramine (p = 0.013). The average postprandial increase in gastric volume during the 60‐minute postprandial period with sibutramine was significantly lower than the corresponding values in the control session: 266.8 ± 46.1 vs. 393.9 ± 15.3 mL (p = 0.03). Sibutramine had no effects on postprandial antral contractions. Discussion: Sibutramine increases gastric tone and impairs gastric accommodation to an orally ingested meal. The inhibitory effect of sibutramine on gastric accommodation may partially explain the reduced food intake with sibutramine in patients with obesity.     

Production of Trichoderma micropropagules as a biocontrol agent in static liquid culture conditions by using an integrated bioreactor system

ABSTRACT

In this study, we optimised the conditions for the production of micropropagules of Trichoderma harzianum EGE-K38 in static liquid culture in Modified Czapec Medium (MCM) containing 8?g/L glucose in an integrated tray bioreactor system designed by our research group. Incubation temperature, air flow rate, inoculum spore concentration, inoculation size, medium volume and the use of spores or agar plugs containing mycelia as inoculum were individually studied as one factor at a time. The maximum micropropagule count was 5.2?±?0.2?×?10^9?cfu/mL and dry cell weight was 17?±?2?g/L. For the subsequent drying processes, the maximum drying yield percentage ((viable micropropagule counts after drying/viable cells before drying)*100) after drying of micropropagules was 23.30% (cfu/cfu). Results obtained from our integrated tray bioreactor system showed that static liquid culture fermentation offers potential for industrial scale fungal BCAs production.     

海洋来源链霉菌MY0504产纤溶酶的发酵条件优化

【目的】以发酵液纤溶酶活力为指标,优化海洋来源的链霉菌菌株MY0504的发酵条件。【方法】在菌株生长曲线及单因素试验基础上,采用Plackett-Burman设计筛选影响纤溶酶活性的主要因素,进一步用最陡爬坡试验及Box-Behnken中心组合设计法优化发酵条件。【结果】纤溶酶活性最高的发酵条件为:葡萄糖21.68 g/L,酵母粉25.31 g/L,NaCl5.0 g/L,K_2HPO_4·3H_2O3.0 g/L,MgSO_4·7H_2O 0.5 g/L,FeSO_4·7H_2O 0.02 g/L,装液量50 mL(250 mL摇瓶),接种量10%(体积比),初始pH 7.5,温度24°C,转速200 r/min,培养时间4.5 d。发酵液纤溶酶活性可达2 190.6 U/mL。【结论】确定了MY0504菌株产纤溶酶的最优发酵条件,为该酶的进一步分离纯化及性质研究奠定基础。     

金针菇几丁质合成酶基因家族鉴定及其表达分析

【背景】几丁质是真菌细胞壁的重要成分,由几丁质合成酶（chitin synthase,CS）催化合成。几丁质合成酶编码基因在大型食用真菌金针菇中的数量及表达规律尚不明确。【目的】探究几丁质合成酶基因在金针菇中存在的数量及其在子实体不同发育时期的表达规律,为其在大型真菌子实体生长发育过程中的功能研究提供基础。【方法】基于已有的金针菇菌株L11基因组数据,结合NCBI其他真菌CS序列鉴定金针菇中几丁质合成酶编码基因的数量,并对其进行生物信息学分析。进一步根据金针菇F19转录组数据以及实时荧光定量PCR （RT-qPCR）技术分析金针菇CS基因家族的表达规律。【结果】在金针菇单核体菌株L11的基因组中鉴定到9个几丁质合成酶基因,系统发育分析表明它们在子实体发育过程中的表达模式可分为4类（皮尔森相关系数=0.85）。【结论】金针菇CS基因家族表达模式在金针菇不同生长发育时期均存在差异,可能参与了子实体发育不同时期和组织的形态建成。     

千层塔内生真菌SHB发酵产石杉碱甲条件的研究

为提高千层塔产黄青霉属内生真菌SHB液体发酵产石杉碱甲的产量,通过单因子和正交试验研究了真菌SHB液体发酵的条件。结果表明,千层塔内生真菌SHB液体发酵产石杉碱甲的适宜条件：温度为28℃,起始pH为6．4,接种量为12％,种龄为48h,转速为160r／min,发酵时间为8d。在此条件下,石杉碱甲的产量可达4．761μg／mL。     

Optimization of Mixed Cultivation of the Moderate Thermophilic Bioleaching Microorganisms for High Cell Density Using Statistical Methodology

The low functional microbial population density in the industrial bioleaching process has been a limiting factor for the high leaching efficiency, making the microbial cultivation and continuous inoculation an alternative for sustaining the microbial activity. In the present experiment, the defined mixed cultivation of Leptospirillum ferriphilum YSK, Sulfobacillus acidophilus TPY, Acidithiobacillus caldus S2, and Ferroplasma thermophilum L1 was evaluated and optimized by Statistical Methodology. Going through the Plackett–Burman experimental design, pH value, temperature, and c(MgSO₄·7H₂O) were considered as the most significant factors in the defined range. Then, the relationships were analyzed using the steepest ascent design, the central composite design, and finally the response surface methodology. It was suggested that the optimum parameters were pH 1.38, MgSO₄·7H₂O 0.552?g/L, temperature 44?°C, FeSO₄·7H₂O 40?g/L, sulfur 8?g/L, yeast 0.02% w/v, (NH₄)₂SO₄ 3g/L, K₂HPO₄ 0.5g/L, KCl 0.1g/L, Ca(NO₃)₂ 0.01?g/L, in which allowed total cell density of the microbial community to reach 7.63?×?10⁸ cells/mL in the cultivation period. The lab experiments were routinely undertaken with the expectation that the L. ferriphilum YSK, S. acidophilus TPY, A. caldus S2, F. thermophilum L1 could rapid grown from initial cell density of 0.25?×?10⁷ cells/mL to 2.82?×?10⁸ cells/mL, 1.68?×?10⁸ cells/mL, 2.76?×?10⁸ cells/mL, 2.51?×?10⁷ cells/mL, respectively in 58?h. It demonstrates a possibility to co-culture these microbes in a single reactor, providing an efficient way to regenerate of inoculation for biomining process.     

Optimization of culturing conditions of <Emphasis Type="Italic">Porphyridium cruentum</Emphasis> using uniform design

The red microalga Porphyridium contains many valuable compounds such as polysaccharides, polyunsaturated fatty acids, and phycoerythrin (PE). In this study, a uniform design method and regression analysis were used to investigate the effects of initial pH, light intensity, inoculation ratio, and liquid volume in flask on the optimal biomass, exopolysaccharides (EPS), and PE production of Porphyridium cruentum in a batch culture at laboratory scale. Using regression analysis, we obtained the models to clarify the effects of individual factors and their interactions on the biomass, EPS, and PE production of P. cruentum. The optimal condition for the biomass was the following: pH 5.0, light intensity 7098.0 lx, inoculation ratio 1:17.2, and liquid volume 100.0 ml; for EPS was pH 5.0, light intensity 4501.0 lx, inoculation ratio 1:20, and liquid volume 100.3 ml; while pH 8.0, light intensity 7100.0 lx, inoculation ratio 1:20, and liquid volume 100.3 ml was the best for PE production. The maximum biomass 3.27 g/l, EPS production 543.1 mg/l, and PE production 132.0 mg/l were demonstrated by confirmatory experiment to the optimum culture conditions in a reciprocal shaker. The statistical methods used in the present study are useful strategies for optimizing of culture conditions for other microalgae.     

AM真菌对煤矿沉陷区不同复合基质上 紫花苜蓿生长和生理特性的影响

该研究采用盆栽试验法,以紫花苜蓿(Medicago sativa)为材料,将煤矸石(CG)、粉煤灰(FA)和沙土(SS)按不同质量配比设置T1(CG∶FA∶SS=75%∶25%∶0%)、T2(CG∶FA∶SS=60%∶25%∶15%)、T3(CG∶FA∶SS=45%∶25%∶30%)、T4(CG∶FA∶SS=30%∶25%∶45%)四组混合基质以模拟,并以T5(CG∶FA∶SS=0%∶0%∶100%)为对照,AM真菌选用摩西斗管囊霉(F.m)和幼套近明球囊霉(C.e),通过单接菌和混合接菌,探索其对紫花苜蓿根系的侵染率、幼苗生长、抗氧化物酶活性和渗透调节物质变化的影响。结果表明:(1)在五组基质上,接种AM真菌显著提高了紫花苜蓿根系的菌根侵染率和菌根依赖性,且基质T4接种F.m+C.e[F.m∶C.e=1∶1(W/W)]的值最大(64.31%和86.24%)。(2)接种AM真菌不同程度提高了紫花苜蓿株高、基径、叶面积和生物量,且混合接菌的效果优于单接菌。(3)基质中填加过量煤矿废弃物抑制了植株根系的生长,接种AM真菌后显著提高了紫花苜蓿总根长、根表面积、根体积,降低了根平均直径。(4)不同接菌处理的紫花苜蓿叶片POD、SOD、CAT活性以及可溶性糖、可溶性蛋白含量总体表现为F.m+C.eC.eF.mnon-AMF,且接种F.m+C.e的增长幅度最大。研究表明煤矿废弃物复合逆境抑制紫花苜蓿的生长,接种AM真菌显著提高了幼苗生长、抗氧化物酶活性和渗透调节物质,提高了植物抗逆性能,且以基质T4接种F.m+C.e的效果最佳。