Immobilization of trophic anaerobic acetogen for semi-continuous syngas fermentation

The massive consumption of fossil energy force s people to find new source s of energy.Syngas fermentation has become a hot research field as its high potential in renewable energy production and sustainable development.In this study,trophic anaerobic acetogen Morella thermoacetica was successfully immobilized by calcium alginate embedding method.The ability of the immobilized cells on production of acetic acid through syngas fermentation was compared in both airlift and bubble column bioreactors.The bubble column bioreactor was selected as the better type of bioreactor.The production of acetic acid reached 32.3 g·L^(-1) in bubble column bioreactor with a space-time yield of 2.13 g·L^(-1)·d^(-1).The immobilized acetogen could be efficiently reused without significant lag period,even if exposed to air for a short time.A semi-continuous syngas fermentation was performed using immobilized cells,with an average space-time acetic acid yield of 3.20 g·L^(-1)·d^(-1).After 30 days of fermentation,no significant decrea se of the acetic acid production rate was observed.

Optimization of Mycelial Biomass Production in Submerged Culture Fermentation of <i>Pleurotus flabellatus</i>Using Response Surface Methodology

The factors selected to optimize the productivity of Pleurotus flabellatus biomass in 250ml working volume Erlenmeyer flask were agitation rate, initial pH value and incubation temperature. The central composite design was applied to study the significant factors and the interactions between the chosen factors, if present. The Design Expert software generated 20 runs. The optimized conditions obtained were as follows: the agitation rate of 129.8 rpm, incubation temperature at 27.8&degC, and initial pH of 6.06. The optimized conditions tripled the productivity at the range of 980 - 1040 mg/litre/day compared to the initial rate productivity at 310 mg/litre/day. From the quadratic equation,the agitation rate, temperature and the interaction between agitation rate and temperature were found to be significant (p < 0.05). At optimum conditions, the experimental data supported the theoretical estimate.

The Optimization of Aspergillus sp.GM4 Tannase Production under Submerged Fermentation

Tannase is a hydrolytic enzyme that is involved in the biodegradation of tannins and it has biotechnological potential in the pharmaceutical, chemical, food and beverage industries. Microorganisms, especially filamentous fungi, are important tannase producers. The aims of this work were to find a potential tannase producer and to improve the cultivation conditions. Three Aspergillus species (A. japonicus 246A, A. tamarii 3 and Aspergillus sp. GM4) were investigated in different culture media (Adams, Czapeck, Khanna, M5 and Vogel) and inducers (1% and 2% tannic acid;1% green tea;1% methyl gallate;1% gallic acid). Aspergillus sp. GM4 and Adams medium were selected. The tannase production by Aspergillus sp. GM4 in Adams medium was induced in the presence of 2% (w/v) tannic acid and gallic acid as carbon sources, while green tea was not able to induce tannase production. The Plackett-Burman screening design was performed with the variables MgSO4, KH2PO4, yeast extract, tannic acid, agitation rate and salt solution. The variables MgSO4 and agitation rate were selected for the optimization of tannase production using a Central Composite Rotatable Design. Under optimized conditions, a 2.66-fold increase in the enzyme production was observed with small modifications in the medium composition.

Research of Submerge Fermentation Conditions on <i>Agaricus blazei</i>Murill

Rotational speed, temperature, inoculation amount and pH are the four factors that affect the submerge fermentation of Agaricus blazei Murill. The orthogonal experiment was on the basis of single factor experiments. And the optimal submerge fermentation condition of Agaricus blazei Murill was determined through orthogonal test. The results were as follows: temperature (25℃), rotational speed (150 r/min), inoculation amount (6%) and pH (7), in this condition the cell dry weight reached 1.32 g/100mL;temperature (25℃), rotational speed (150 r/min), inoculation amount (8%) and pH (6.5) in this condition the extracellular polysaccharide reached 6.95 mg/mL.

Nutrient Requirements and Fermentation Conditions for Mycelia and Crude Exo-Polysaccharides Production by <i>Lentinus squarrosulus</i>

Lentinus squarrosulus Mont. is an emerging tropical white rot basidiomycete, with nutritional and medicinal benefits. Low levels of commercial cultivation of the mushrooms limit their availability for use as food and medicine. Mycelia from submerged fermentation are a suitable alternative to the mushroom from L. squarrosulus. Three strains, 340, 339 and 218, were studied to determine optimum growth conditions for mycelia mass and crude exo-polysaccharides (CEPS) production. The experiments were conducted in a completely randomized design (CRD) with a factorial structure. Nutrients involving 8 carbon and 8 nitrogen sources were screened, and concentrations of the best sources were optimized. Optimized nutrients, interaction between strains and other parameters such as agitation and medium volume were investigated to obtain optimum fermentation conditions for biomass and CEPS production. Biomass yield varied among strains depending on carbon or nitrogen nutrient sources. Starch and yeast extract at 30 and 25 g/L were identified as the most important nutrients in mycelia and CEPS production. Nutrient optimization resulted in a 3-fold increase in mycelia mass: 12.8, 10.0 and 15.3 g/L in strains 340, 339 and 218 respectively. There was a significant interaction between strain, agitation, and volume (p p = 0.02). Static conditions favored more polysaccharide production. Optimized fermentation conditions resulted in very high increase in biomass: 238.1, 266.9 and 185.0 g/L in strains 340, 339 and 218 respectively. Results obtained could be useful in modeling fermentation systems for large-scale production of mycelia mass, CEPS and other bio-products from L. squarrosulus.

Production of Xylanase and <i>β</i>-Xylosidase Enzymes by <i>Pseudozyma hubeiensis</i>in Solid State Fermentation

Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by yeast strains which have great potential in paper and pulp industry in removing the hemicellulose from the treated or untreated pulp. In this study, P. hubeiensis NCIM 3574 isolated in our laboratory produced significant levels of extracellular cellulase free xylanase (2480 IU/g DSS) in solid state fermentation (SSF) using wheat bran and xylan. It also produced high levels of β-xylosidase (198 IU/g DSS) when grown in SSF using ground nut oil cake and xylan. These highest activities were obtained when fermented Koji was extracted with 1% NaCl supplemented with 0.5% of Triton X-100. These are the highest activities reported so far from yeast strains in the available literature. The crude xylanase preparation of P. hubeiensis produced xylooligosaccharides (XOS) without xylose proving its potential for XOS production with no further requirement of downstream processing. The XOS as prebiotic show beneficial effect on gut microflora such as Lactobacilli and Bifidobacteria which suppress the activity of pathogenic organisms. This xylanase also has a potential application as a bio-bleaching agent in paper and pulp industry.

树舌灵芝深层发酵产物抑菌作用的研究

以分离自广西乐业天坑群的树舌灵芝的深层发酵产物(菌丝体、发酵液)为试材,采用滤纸片法、二倍稀释法,研究了树舌灵芝发酵产物提取物的抑菌作用,以期为开发防腐、食品保鲜产品提供参考依据。结果表明:树舌灵芝菌丝体提取物和发酵液提取物中均含有抗菌活性物质,发酵液乙酸乙酯提取物的抑菌能力最强,对10种供试菌均有较好的抑菌效果;发酵液乙酸乙酯提取物梯度洗脱、分离纯化后得到的30%乙酸乙酯组分(B5)的抑菌能力最高,对10种供试菌的抑菌圈直径基本上均最大;B5对藤黄微球菌的最低抑菌浓度(MIC)值为25 mg·mL^(-1),对大肠杆菌等5种菌的MIC值为50 mg·mL^(-1),对酿酒酵母的MIC值为200 mg·mL^(-1),对黑曲霉、米曲霉和绿色木霉的MIC值为400 mg·mL^(-1)。

蜜环菌菌株M6的液体深层发酵工艺研究

目的:优化蜜环菌菌株M6的发酵工艺及提高其生产效率。方法:以蜜环菌菌株M6为供试菌株,通过摇瓶液体培养,筛选该菌株的最适液体发酵培养基;以摇瓶培养结果为基础,通过多级匀浆制备高活性种子液,进行液体深层发酵,优化发酵条件。结果:筛选出蜜环菌菌株M6最佳液体深层发酵条件为转速150 r/min、接种量5%、溶氧20%及温度28℃,在此条件下使用液体发酵培养基配方1发酵180 h所得蜜环菌菌株M6生物量干重高达18.39 g/L;使用液体发酵培养基2发酵120 h所得蜜环菌菌株M6生物量干重达23.83 g/L。结论:液体培养条件优化后,蜜环菌菌株M6生物量产出较高。本研究促进了蜜环菌菌株M6的快速生产,为应用于天麻种植业提供了技术参考。

灵芝菌株深层发酵及发酵饮料的配方优化

灵芝(Ganoderma lucidum)是一种营养和药用价值极高的真菌。为提高灵芝深层发酵效益和促进发酵液的开发利用,本研究采用可食用原料配制培养基,以菌丝生物量为评价指标,采用正交试验优化培养基组成。同时将灵芝发酵液用于饮料制备,并使用模糊数学综合评价法优化发酵饮料的配方。结果表明,蔗糖添加量为30 g·L^(-1)和玉米粉添加量为15 g·L^(-1)条件下配制的培养基效果最佳,菌丝生物量可达6.86 g·L^(-1),所得发酵液中胞外多糖含量为430.21μg·mL^(-1)、多酚含量为26.07μg·mL^(-1)、黄酮含量为8.16μg·mL^(-1)。发酵液体积分数为60%、柠檬酸添加量为0.5%、黄原胶添加量为0.30%、蔗糖添加量为6%和柠檬黄添加量为0.05%的工艺条件下制备的发酵饮料的感官评分最高。

牛樟树水提物中促进樟芝无性产孢的效应物鉴定及其添加量优化

为明确牛樟树水提物(aqueous extract of Cinnamomum kanehirae Hay,CWE)中促进樟芝(Antrodia cinnamomea)深层发酵无性产孢的效应物。首先,采用醇沉法及不同有机溶剂分级萃取法对CWE进行分离,并以产孢量为检测指标,考察不同组分对樟芝无性产孢的影响。结果表明,30μg/mL的CWE醇沉上清氯仿萃取物LFE和50μg/mL的醇沉上清乙酸乙酯萃取物YZE对樟芝无性产孢有明显的促进效果,且LFE的促进效果明显优于YZE,表明效应物主要存在于LFE和YZE中。随后,采用液相色谱-质谱联用仪对CWE不同萃取组分进行成分分析,并结合不同组分对樟芝产孢的影响效果,确定主要效应物为赤藓糖醇。最后,考察赤藓糖醇(纯度98%)对樟芝深层发酵性能的影响,结果表明,赤藓糖醇对樟芝无性产孢有显著促进效果,且在最佳添加量(1.0μg/mL)下,产孢量较对照组提高55.17%;同时,1.0μg/mL赤藓糖醇显著促进樟芝深层发酵菌丝体生长及胞内多糖的合成,生物量和胞内多糖产量较对照组分别提高18.65%和260.13%,但对三萜的合成无显著影响。

红色“野酿2号”毛葡萄醋饮料的配方优化

为拓宽罗城毛葡萄深加工产品的形式,利用可工业化全年供给的“野酿2号”毛葡萄汁和葡萄皮渣,开发一款色泽鲜红的毛葡萄果醋饮料。在实现毛葡萄皮色素提取和原醋深层发酵的基础上,以感官评分为评价指标,以原醋、蔗糖、色素、蜂蜜添加量为影响因素,进行果醋饮料配方的单因素和响应面试验,确定优化配方为色素添加量4.784%、蔗糖添加量5.836%、原醋添加量5.385%、蜂蜜添加量2.187%,该条件下感官评分可达91.49,花色苷含量62.07 mg/L,该毛葡萄果醋饮料色泽鲜红诱人、口感清爽、酸甜适饮,富含有机酸、花色苷等营养物质。

Fermentative Production of Mycelial Chitosan from Zygomycetes: Media Optimization and Physico-Chemical Characterization

The present study focused on production of mycelial chitosan from fungal mycelium by submerged fermentation with ecologically more balanced process. Different fungal strains were screened and Absidia butleri NCIM 977 was found to produce the highest mycelial chitosan. The one-factor-at-a-time method was adopted to investigate the effect of batch time, environmental factors (i.e. initial pH and temperature) and medium components (i.e. carbon and nitrogen) on the yield of mycelial chitosan. Among these variables, the optimal condition to increase in yield of mycelial chitosan was found to be batch time (72 h), pH (5.5), temperature (30°C), carbon source (glucose) and nitrogen source (tryptone and yeast extract). Subsequently, a three-level Box– Behnken factorial design was employed combining with response surface methodology (RSM) to maximise yield of mycelial chitosan by determining optimal concentrations and investigating the interactive effects of the most significant media components (i.e. carbon and nitrogen sources). The optimum value of parameters obtained through RSM was glucose (1.58%), tryptone (1.61%) and yeast extract (1.11%). There was an increase in mycelial chitosan yield after media optimization by one-factor-at-a-time and statistical analysis from 683 mg/L to 1 g/L. Mycelial chitosan was characterized for total glucosamine content (80.68%), degree of deacetylation (DD) (79.89%), molecular weight (8.07 × 104 Da) and, viscosity (73.22 ml/g). The results of this study demonstrated that fungi are promising alternative sources of chitosan with high DD and high purity.

灵芝发芽糙米蒲公英复合饮料研制

为了提高灵芝、发芽糙米和蒲公英的附加值,以发芽糙米灵芝液体发酵液为原料,采用单因素试验和正交试验方法对灵芝发酵液、蒲公英提取物、木糖醇和柠檬酸的添加量及海藻酸钠与羧甲基纤维素钠形成的复配稳定剂添加量进行研究。结果表明,灵芝发酵液添加量40%,蒲公英提取物添加量0.35%,木糖醇添加量4%,柠檬酸添加量0.005%,复配稳定剂添加量0.3%(羧甲基纤维素钠与海藻酸钠之比为1∶2)时,得到了品质符合相关标准、感官最佳、稳定性较好的灵芝发芽糙米蒲公英复合饮料,具有良好的保健功能,符合消费者对保健饮料的需求。

长根菇液体深层发酵制备多糖条件优化及体外抗氧化活性研究

目的优化长根菇液体深层发酵产胞外多糖的培养基成分,考察其基本结构特征和体外抗氧化活性。方法以长根菇液体深层发酵胞外多糖质量浓度为评价指标,先分别筛选出液体培养基最适碳源、氮源、生长因子,再通过单因素、响应面实验对最佳发酵培养基条件进行优化,对胞外多糖进行分离和纯化后,利用红外光谱扫描法分析其基本结构,最后通过羟基自由基(OH·)、1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2-picrylhydrazyl free radical,DPPH·)清除能力和铁离子(Fe^(3+))还原能力等考察其体外抗氧化活性。结果长根菇液体培养基最佳培养条件为:可溶性淀粉24 g/L、牛肉粉1.9 g/L、维生素B10.03 g/L,在此条件下长根菇液体深层发酵胞外多糖质量浓度为384.72μg/mL;红外光谱表明:胞外多糖含有主要官能团O-H、C-H、C=O、C-O,另外还存在吡喃环结构;体外抗氧化研究表明:长根菇液体深层发酵胞外多糖具有较好的体外抗氧化活性,但其抗氧化能力均低于维生素C,胞外多糖对OH·、DPPH·的清除能力和Fe^(3+)还原能力的半抑制浓度(half maximal inhibitory concentration,IC_(50))分别为0.68、1.00和8.46 mg/mL。结论本研究确定了长根菇液体深层发酵产多糖的最佳培养基,且制备的多糖具有较好的体外抗氧化活性,可为长根菇进一步研究和利用提供理论参考。

粗毛纤孔菌产胞外黑色素发酵条件优化及其抗氧化活性研究

为提高天然黑色素的产量,本研究通过探索碳氮源、转速、pH、温度等单因素对粗毛纤孔菌产黑色素的影响,并利用正交试验筛选产胞外黑色素的最适发酵培养基配方和发酵条件。结果表明,优化后的最佳发酵培养基配方为甘露醇20 g·L^(-1)、牛肉浸膏5 g·L^(-1)、碳氮比4∶1、维生素B110 mg·L^(-1),最适发酵条件为发酵温度25℃、发酵初始pH值6、转速180 r·min^(-1)、发酵时间10 d。在此培养条件下,粗毛纤孔菌胞外黑色素(IHEM)含量高达3.29 g·L^(-1),较优化前提高了17.32倍。IHEM体外化学抗氧化活性检测结果显示,IHEM具有良好的抗氧化活性,其对ABTS自由基的清除效果较佳,半最大效应浓度(EC50)为0.019 mg·mL^(-1)。本研究结果为深层发酵高产黑色素的开发提供了技术支持。

金属离子促进樟芝深层发酵无性产孢

樟芝(Antrodia cinnamomea)是一种珍稀药食两用蕈菌,其目前最主要的人工培养方式是基于无性孢子接种的深层发酵。为了提高樟芝深层发酵的产孢量及产孢速度,进而提高其种子制备效率及工业化生产效益,该文首先采用单因素法筛选出能显著促进樟芝无性产孢的金属离子,再采用响应面法优化金属离子组合的最佳添加浓度。结果表明,在培养基中单独添加1.0 mmol/L的Ca^(2+)、0.1 mmol/L的Fe^(2+)及0.1 mmol/L的Zn^(2+)可使樟芝最大产孢量较对照组分别提高87.21%、72.39%及35.05%;同时添加0.149 mmol/L的Fe^(2+)、2.01 mmol/L的Ca^(2+)及0.135 mmol/L的Zn^(2+)可使樟芝深层发酵最大产孢量达8.67×10^(7)个/mL,较对照组提高133.62%,同时使樟芝无性孢子产量达到最大值的时间缩短24 h。该研究操作方便、成本低廉、效果显著,具有较好的开发价值及应用前景。

樟芝深层发酵多糖对抗生素相关性腹泻小鼠肠道菌群的调节作用

为了研究樟芝(Antrodia cinnamomea)深层发酵产生的多糖对抗生素相关性腹泻小鼠肠道菌群的影响,开发樟芝在功能食品领域的应用价值和潜力,本实验首先采用水提醇沉法从樟芝深层发酵菌丝体及发酵液中提取樟芝胞内多糖(Antrodia cinnamomea intracellular polysaccharides,AIPS)及胞外多糖(Antrodia cinnamomea exopolysaccharides,AEPS)并进行结构表征,结果表明,AIPS和AEPS的主要组成单糖均为葡萄糖、半乳糖及甘露糖;AEPS的平均分子质量为4.16×10^(5) Da,AIPS的平均分子质量为3.52×10^(6) Da;AEPS是吡喃环结构多糖,而AIPS则具有—C≡C—H及C—O官能团;随后进行体外抗α-淀粉酶消化能力和抗模拟胃液消化能力实验,结果表明,AIPS和AEPS均具有较强的抗消化能力;最后进行抗生素盐酸林可霉素(lincomycin hydrochloride,LIH)相关性腹泻小鼠体内实验,结果表明,灌胃樟芝多糖可明显增加小鼠肠道菌群中部分有益微生物(如Lactobacillus)的相对丰度,同时明显降低部分有害微生物(如Enterococcus、Staphylococcus、Parasutterella及Shigella)的相对丰度,其中AEPS的调节效果明显优于AIPS。本研究可为开发新型多功能益生元提供新思路及依据。

六种中草药提取物对羊肚菌深层发酵麦角甾醇的影响

探究了6种甘肃道地中草药提取物对羊肚菌液体发酵生物量及麦角甾醇产量的影响。采用单因素试验结合响应面法,筛选适宜羊肚菌发酵产麦角甾醇的中药材种类,并重点考察了添加红芪提取物对羊肚菌液体发酵麦角甾醇的影响,优化了其发酵工艺参数,建立了羊肚菌在中草药液体环境中的发酵体系。结果表明,党参、红芪、柴胡对羊肚菌生物量和麦角甾醇产量均有明显促进作用,其中红芪效果最佳,在100 g/L的添加剂量下,生物量干重和麦角甾醇产量最大,达到了10.57 g/L和47.69 mg/L,分别是对照组的2.83倍、2.50倍;甘草、当归、板蓝根在50 g/L的剂量下,对羊肚菌菌丝体生长有一定的促进作用,当超过50 g/L剂量时,对其生长均有强抑制作用。响应面分析结果表明,影响麦角甾醇含量的因素顺序为发酵时间>红芪剂量>发酵温度;最佳工艺参数为红芪剂量97.60 g/L,发酵温度26℃,发酵时间11 d,接种量8%,转速180 r/min,在此条件下麦角甾醇产量达到59.16 mg/L,比工艺优化前提高了21.95%。该研究结果可为相关产业利用中草药提取物促进羊肚菌液体发酵麦角甾醇提供理论依据和参考。

蜜环菌液体培养基配方优选及其活性成分和抗氧化活性研究

目的从4种蜜环菌液体培养基配方中筛选出最佳液体培养基配方,并测量其菌丝提取物和发酵液提取物的活性成分含量及抗氧化活性。方法采用目前4种较常用的液体培养基配方在相同温度、转速、时间条件下对蜜环菌进行液体发酵,制备菌丝提取物和发酵液提取物,通过紫外分光光度法测量其主要活性成分含量和抗氧化活性。结果4种配方菌丝生物量、生物活性物质含量及抗氧化能力差异显著。其中配方1菌丝生物量最高,为1.21 g/L,显著高于其余3种配方(P<0.01,P<0.001)。4种配方菌丝提取物总黄酮、总三萜、总酚含量差异显著,均为配方2最高且显著高于子实体(P<0.001,P<0.01);发酵液提取物主要活性物质含量,配方4总黄酮和总酚含量最高,配方2总三萜含量最高,均显著高于子实体(P<0.01,P<0.001)。抗氧化能力方面,配方1菌丝提取物·OH清除率及总还原力最高;配方4发酵液提取物总还原能力表现最佳,且抗氧化能力表现更为稳定。结论针对不同目标产物筛选出了具体的最佳蜜环菌液体培养基配方,对后续蜜环菌的研究提供参考借鉴意义,也为今后蜜环菌的开发利用奠定基础1。

樟芝菌液态发酵多糖富硒条件优化及其抗炎活性研究

为提高樟芝菌液态发酵硒多糖产量,探究樟芝菌多糖富硒后活性方面的变化。以生物量、多糖含量、硒含量和富硒率为评价指标,利用单因素试验和正交试验对发酵条件进行优化,综合得出最佳发酵条件。同时在脂多糖(lipopolysaccharide,LPS)诱导小鼠腹腔巨噬细胞(RAW264.7)建立炎症模型的基础上,评价樟芝菌硒多糖与无硒多糖的抗炎活性。通过发酵优化得到最佳发酵条件为Na_(2)SeO_(3)添加量2 mg/L、麦芽糖24 g/L、可溶性淀粉16 g/L、玉米浆干粉9 g/L,硫酸铵9 g/L,装液量75 mL/250 mL、初始pH值7,24℃、150 r/min发酵9 d。体外细胞实验结果表明,二者均能够显著降低促炎介质NO、TNF-α、IL-6和IL-1β的释放量,提高细胞内超氧化物歧化酶(superoxide dismutase,SOD)活性,起到有效抑制炎症反应的作用。而且,硒多糖在提高SOD活性、抑制IL-1β释放方面效果要优于无硒多糖。综上,樟芝菌硒多糖在富硒的同时,能够具有高于无硒多糖的抗炎活性,具备一定的开发前景。