蛹虫草液体培养条件的优化及生长动力学考察

为了优化蛹虫草菌的液体培养条件 ,对液体培养菌丝的生长情况进行了研究。采用摇瓶培养的方法 ,以发酵得率为指标确定培养条件。结果表明 :优化培养基成分确定为蛋白胨 1.5 % ,葡萄糖 2 % ,KH2 PO4 0 .15 % ,Mg SO40 .0 5 %、VB1 5 m g/ L .2 ,4 - D 2 mg/ L .该培养基下发酵得率达 1.4～ 2 .2 g/ 10 0 m L ;考察了蛹虫草菌液体培养的外部条件 ,确定为 :装料系数为 30 % ,培养基 p H为 5 .5 ,接种量为 0 .0 3g,摇床振荡频率为 12 0 r· m in- 1 ;利用优化培养基得到了生长代谢曲线。在相同条件下 ,优化培养基比原来培养基的发酵得率提高了 4 .5 % ,研究初步得到蛹虫草菌液体培养条件和生长动力学 ,为工业化生产提供了一定的依据     

虫草液体培养的研究进展

论述了液体培养主要涉及的碳源、氮源、碳氮比和其他元素等营养因素和温度、通气、pH等环境条件对虫草菌丝产量和活性成分(以多糖和虫草素为主)产量的影响,展望了虫草液体培养的发展趋势.     

蛹虫草液体培养条件优化及有效成分含量分析

为优化蛹虫草菌的液体培养条件,对蛹虫草菌丝体进行液体摇瓶培养。以干菌丝体得率为指标,对影响发酵产量的重要因子设计正交试验,得出最佳培养条件。在最优条件下扩大培养,检测此时菌丝体中虫草素及虫草多糖含量。结果表明:蛹虫草菌丝体液体发酵的最适条件为:接种量10 % (v/v) ,发酵初始pH7 0 ,发酵温度2 7℃,发酵时间96h。扩大培养后,测得菌丝体中虫草素的含量为5 1 785mg/10 0g ,虫草精多糖含量为1 92g/10 0g。     

液体培养蛹虫草虫草素和腺苷的代谢量

为提高虫草素和腺苷的代谢量,用高效液相色谱法作检测手段,以二者含量为检测指标,对液体培养的氮源种类、氮源水平、碳源水平、动态变化、培养体系的虫草素及腺苷含量和总量进行研究,结果表明:不仅蚕蛹粉,豆粕和豆粉也是很好的氮源;培养液以3%氮源、4%碳源为佳;振荡培养8d,培养液中虫草素总量是菌丝体中虫草素总量的6倍多;振荡培养7~9d,可使每瓶培养物的虫草素和腺苷总量达到10mg以上。     

蛹虫草菌丝产虫草素液体培养条件的研究

通过对蛹虫草菌丝产虫草素液体培养条件的研究,明确蛹虫草菌丝产虫草素的适宜碳源及浓度,适宜氮源及浓度,最适pH值,最适培养温度,最适转速以及最适培养时间,以便应用于虫草素的工厂化生产。结果表明,蛹虫草菌丝产虫草素的条件：适宜碳源为D-果糖,最适浓度为10g/L;适宜氮源为蛋白胨,最适浓度为15g/L;最适初始pH为7,最适培养温度为24℃,最适转速为180r/min,最适培养时间为9d,其培养液虫草素含量可达到0.537g/L。     

不同培养条件和前体对蛹虫草液体发酵产虫草素的影响

蛹虫草能产生虫草素等多种活性物质。为考察不同液体发酵方式及添加前体物质对虫草素积累的影响,选用蛹虫草08Y1菌株,通过光照振荡、光照静置、黑暗振荡、黑暗静置四种培养条件和添加前体物质（腺嘌呤1g/L+甘氨酸16g/L）,发酵16d后检测虫草素和腺嘌呤含量。结果表明：08Y1菌株在黑暗振荡培养条件下,虫草素积累达1,015.0mg/L,腺嘌呤利用率达98.5%,说明黑暗振荡培养并添加前体物质是提高虫草素产量的有效方法。     

泰山虫草子实体形态特征与rDNA变异位点分析

用光学显微镜和扫描电镜对采自泰山的虫草子实体可孕部分进行形态观察,结果表明泰山虫草在子实体形态、子囊的排列方式、子囊的包埋方式、子囊壳的形态等与九州虫草完全一致。对虫草核糖体DNA的18S、28S、ITS区克隆测序,并进行序列比对后发现两种虫草的碱基差异较小,其同源性高达99%,符合种内遗传特性。结合形态学和分子生物学两方面的特征,初步推断两者可能都是九州虫草。     

蛹虫草液体发酵产多糖的条件优化

多糖是蛹虫草Cordyceps militaris产生的重要活性成分。为提高其液体发酵胞外多糖的产量,通过单因素轮换法、方差分析、正交试验对蛹虫草菌株YCC-H产胞外多糖的发酵条件进行了优化。单因素结果表明液体发酵最适初始pH为5,最适葡萄糖浓度(质量分数)为6%,最适氮源为酵母膏,最适装液量为80 mL/250 mL,最适接种量(体积分数)为12%;在不同培养条件下菌体生物量变化较大;通过方差分析及正交试验进一步优化,结果显示：装液量(A)、氮源(B)、接种量(C)对蛹虫草产胞外多糖影响程度为B>A>C,最佳条件组合为A₂B₃C₂,即装液量80 mL/250 mL、酵母膏为唯一氮源、接种量(体积分数)为12%,其余因素选择单因素中最佳水平。经验证,该菌株合成胞外多糖的质量浓度达247.06 mg/L,较未优化前胞外多糖的产量23.67 mg/L提高了9.43倍。     

台湾虫草子实体人工培养条件的初步研究

目的研究人工培养条件对台湾虫草子实体形成的影响。方法通过黄山被毛孢的液体摇瓶培养,确定摇瓶种子的最佳培养时间,并研究了在人工诱导下台湾虫草子实体的形成条件,即子实体形成与营养液pH、营养液量、培养温度及光照时间之间的关系。结果黄山被毛孢液体摇瓶最佳培养时间为12 d,人工固体培养子实体所需营养液最佳pH为6.0,营养液量为40 mL,培养温度为25℃,菌丝培养阶段为完全黑暗培养,原基出现后给予光照,可获得较多的子实体。结论人工培养条件对台湾虫草菌丝体生长、原基形成、子实体产量具有显著影响。     

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.     

地衣芽胞杆菌培养条件的研究

应用单因素和正交试验设计试验法对地衣芽胞杆菌在摇瓶水平上进行了培养基配方和培养条件的研究。结果表明：最适培养基配方为山芋淀粉1．0％,豆粕0．6％,玉米芯粉0．8％,K2HPO4 0．1％,MgSO40．1％。最适培养条件为37℃,摇床转速150r／min,250mL三角瓶装液50mL,接种量5．0％,振荡培养48h,pH7．0。在20L自动发酵罐中进行了扩大培养试验,考察溶氧对菌体生长的影响,并根据试验结果进一步扩大至1m^3发酵罐,通过控制搅拌速度和通气量,1m^3发酵罐中地衣芽胞杆菌培养液菌浓为7．2×10^9efu／mL,芽胞率达到90％。     

冬虫夏草与韩芝液体发酵混合培养特性研究

平板培养基上比较了冬虫夏草、韩芝及树舌的菌丝生长速度和对淀粉的利用情况,结果显示三者的生长速度分别达到1.28、0.64和0.55 cm/d,且韩芝与树舌对淀粉的利用均优于冬虫夏草;混合培养结果得出菌种的最佳菌龄比为虫草:韩芝=3 d:5 d,最佳的接种比例为2:3;正交试验混合发酵最佳的培养基配方(%):葡萄糖1.0、淀粉2.0、黄豆粉2.0、酵母粉0.5,在此条件下,菌丝生物量达到最大值1.97 g/100 mL。     

Optimization of submerged culture requirements for the production of mycelial growth and exopolysaccharide by Cordyceps jiangxiensis JXPJ 0109

AIMS: The objective of the present study was to investigate the optimal culture requirements for mycelial growth and exopolysaccharide production by Cordyceps jiangxiensis JXPJ 0109 in submerged culture. METHODS AND RESULTS: The effects of medium ingredients (i.e. carbon and nitrogen sources, and growth factor) and other culture requirements (i.e. initial pH, temperature, etc.) on the production of mycelia and exopolysaccharide were observed using a one-factor-at-a-time method. More suitable culture requirements for mycelial growth and exopolysaccharide production were proved to be maltose, glycerol, tryptone, soya bean steep powder, yeast extract, medium capacity 200 ml in a 500-ml flask, agitation rate 180 rev min(-1), seed age 4-8 days, inoculum size 2.5-7.5% (v/v), etc. The optimal temperatures and initial pHs for mycelial growth and exopolysaccharide production were at 26 degrees C and pH 5 and at 28 degrees C and pH 7, respectively, and corresponding optimal culture age were observed to be 8 and 10 days respectively. According to the primary results of the one-factor-at-a-time experiments, the optimal medium for the mycelial growth and exopolysaccharide production were obtained using an orthogonal layout method to optimize further. Herein the effects of medium ingredients on the mycelial growth of C. jiangxiensis JXPJ 0109 were in the order of yeast extract > tryptone > maltose > CaCl2 > glycerol > MgSO4 > KH2PO4 and the optimal concentration of each composition was 15 g maltose (food-grade), 10 g glycerol, 10 g tryptone, 10 g yeast extract, 1 g KH2PO4, 0.2 g MgSO4, and 0.5 g CaCl2 in 1 l of distilled water, while the order of effects of those components on exopolysaccharide production was yeast extract > maltose > tryptone > glycerol > KH2PO4 > CaCl2 > MgSO4, corresponding to the optimal concentration of medium was as follows: 20 g maltose (food-grade), 8 g glycerol, 5 g tryptone, 10 g yeast extract, 1 g KH2PO4, and 0.5 g CaCl2 in 1 l of distilled water. CONCLUSIONS: Under the optimal culture requirements, the maximum exopolysaccharide production reached 3.5 g l(-1) after 10 days of fermentation, while the maximum production of mycelial growth achieved 14.5 g l(-1) after 8 days of fermentation. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report on the submerged culture requirements for mycelial growth and exopolysaccharide in C. jiangxiensis, and this two-step optimization strategy in this study can be widely applied to other microbial fermentation processes.     

玫烟色拟青霉最适液体培养条件的研究

通过对不同营养和不同培养条件下玫烟色拟青霉菌丝生物量和产孢量的研究,结果表明:葡萄糖为玫烟色拟青霉液体培养的最适碳源,蛋白胨为该菌生长的最适氮源,C/N为10∶1~20∶1最适于玫烟色拟青霉菌丝生长和产孢;25℃2、4 h全光照条件,对该菌生长和产孢均有利。接种后144~168 h时,菌丝生物量和产孢量均达到高峰,分别为31.72 mg/mL、24.62孢子/mL,为黑暗条件下的1.5倍和18.3倍,因此玫烟色拟青霉液体发酵终点应选择在接种后144~168 h为最好。     

脂肪酶抑制剂产生菌Bacillus sp.LF深层发酵条件研究

随着生活水平的不断提高 ,肥胖在中国也开始成为影响人们健康的主要危险之一。目前市场上常见的减肥产品主要是作用于大脑 ,通过抑制食欲减少食物的摄入 ,由于这类药可能产生大脑、心血管及神经系统的副作用 ,不宜长期使用。瘦素 (Leptin)是一种肥胖基因表达的多肽激素 ,也是通过食欲中枢发挥作用 ,可以抑制食欲 ,提高代谢率 ,达到减肥的目的。因而另一类减肥药品脂肪酶抑制剂近年来受到国内外重视。脂肪酶抑制剂可直接阻断人体对脂肪的吸收 ,它不需要通过影响中枢神经系统来抑制人体的食欲 ,而是阻止脂肪在胃肠道的吸收。文献报道脂肪酶抑…     

Nutritional requirements of mycelial growth of Cordyceps sinensis in submerged culture

AIMS: The nutritional requirements for mycelial growth of Cordyceps sinensis in semi-synthetic liquid media were investigated. The results provide a basis for further physiological study and industrial fermentation of the fungus. METHODS AND RESULTS: Nutritional requirements, including 17 carbohydrates, 16 nitrogen compounds, nine vitamins, four macro-elements, four trace-elements and eight ratios of carbon to nitrogen, were studied for their effects on the mycelial growth in submerged cultures of C. sinensis by using one-factor-at-a-time and orthogonal matrix methods. Among these variables, sucrose, peptone, folic acid, calcium, zinc and a carbon to nitrogen ratio 12 : 1 were identified as the requirements for the optimum mycelial growth. The concentrations of sucrose, peptone and yeast extract were optimized and the effects of medium composition on mycelial growth were found to be in the order sucrose > yeast extract > peptone. The optimal concentration for mycelial growth was determined as 50 g l(-1) sucrose, 10 g l(-1) peptone and 3 g l(-1) yeast extract. CONCLUSIONS: Under optimal culture conditions, over 22 g l(-1) of mycelial biomass could be obtained after 40 days in submerged cultures. SIGNIFICANCE AND IMPACT OF THE STUDY: Cordyceps sinensis, one of the most valued medicinal fungi, is shown to grow in axenic culture. This is the first report on nutritional requirements and design of a simplified semi-synthetic medium for mycelial growth of this psychrophilic species, which grows slowly below 20 degrees C. The results of this study will facilitate research on mass production of the fungus under defined culture conditions.     

Optimum Culture Conditions for Production of Exfoliative Toxin by Staphylococcus hyicus

Optimum culture conditions for the production of exfoliative toxin by Staphylococcus hyicus (shET) were examined. High shET activity was obtained from the culture filtrate of HI and TY broth inoculated with S. hyicus. The pH in these two media ranged from 7 to 8.5 during bacterial culture, while the lowest pH in TS and BHI broth was less than 6. shET activity in the culture filtrate from TY broth inoculated with 10⁷ CFU of S. hyicus per ml was higher than that in TY broth inoculated with 10⁶ and 10⁸ CFU of bacteria per ml. When shET activity in the culture filtrate was measured under various shaking conditions, the culture filtrate shaken at 75 oscillations per min had the highest shET activity of the five shaking conditions. shET activity of the culture filtrate of TY broth to which protease inhibitor had been added was the same as that of TY broth without inhibitor. shET activity in a shaking culture in an Erlenmeyer flask was also the same as that in sac culture and that in shaking culture using a shaking (Sakaguchi) flask. shET activity in TY broth supplemented with 100 mM glucose was significantly lower than that in TY broth without glucose. Based on the above results, the optimum culture conditions for the production of shET were as follows: inoculation of 3 × 10⁹ CFU of S. hyicus strain P-1 into 300 ml of TY broth in a 2,000-ml Erlenmeyer flask, and incubation at 37 C with shaking at 75 oscillations per min. Then shET activity of the culture filtrate under appropriate culture conditions was measured after various incubation periods. shET activity was detected 6 hr after inoculation, reached the maximum (2⁵³ exfoliative unit/0.1 ml) at 16 hr and decreased between 20 and 48 hr. Thus, the optimum incubation period was determined to be 16 hr. Then the optimum concentration of ammonium sulfate for isolation of shET from the culture filtrate under appropriate culture conditions was examined. The greatest shET activity was obtained from the fraction salted out with 90% saturated ammonium sulfate. Thus, the optimum concentration of ammonium sulfate for the isolation of shET was determined to be 90% saturation.     

用正交试验法筛选樟芝菌适宜发酵培养基

用正交试验法对樟芝菌 (AntrodiacamphorataZang&Su)的发酵培养基进行了研究。选取马铃薯淀粉、葡萄糖、麦芽糖、酵母膏、蛋白胨、麸皮、KH2 PO4 、MgSO4 ·7H2 O等作为试验因素 ,采用L2 7(31. 3)正交表设计五因素、三水平的正交试验 ,对所选各因素的添加量分别作了试验 ,对菌丝干重和发酵液多糖含量结果作了方差分析 ,确定了合适的发酵培养基。试验结果表明 :樟芝菌的深层发酵适宜培养基是 :马铃薯淀粉 1 .0 0 % ,葡萄糖2. 0 0 % ,酵母膏 0 . 10 % ,蛋白胨 0 . 10 % ,麸皮 1 .0 0 % (或 0. 5 0 % ) ,KH2 PO4 0 . 10 % ,MgSO4 ·7H2 O 0 . 0 5 %。