满意度函数-响应面法优化枯草芽孢杆菌发酵工艺

以枯草芽孢杆菌（Bacillus subtilis）为研究对象,优化其液态发酵工艺条件。在单因素试验基础上,运用Plackett-Burman（PB）试验方法,选择对试验结果有显著影响的因素,并结合满意度函数分析与响应面法,建立发酵工艺参数影响因素的二次回归方程模型。结果表明,得到总体满意度值93.95%,最佳发酵工艺条件为初始pH值为7.4,装液量75 mL/250 mL,接种量5.5 mL/100 mL,发酵温度37 ℃,转速250 r/min,发酵时间25 h。在此最佳发酵工艺条件下,发酵液中活菌量对数值为8.03±0.6,抑菌圈直径为（28.2±1.3） mm,分别较优化前提高了1.32倍、1.73倍。满意度函数-响应面法是优化枯草芽孢杆菌发酵工艺参数的有效方法。     

响应面法快速优化工程菌黑色素发酵生产条件

对工程菌E.colifss6产黑色素培养条件进行优化,以降低工程菌产黑色素的成本及提高产率。首先采用单因子实验筛选出最适氮源为工业酵母粉,在此基础上,然后用Plackett-Burman设计对影响产黑色素因素的效应进行评价,得出对产黑色素有显著影响的工业酵母粉、初始pH值和酪氨酸。用最速等高法逼近最大产色素区域后,利用响应面中心组合设计对显著因素进行优化,得出工程菌产黑色素的最佳培养基配方为:安琪酵母粉浓度0.7%、蛋白胨0.7%、氯化钠0.6%、磷酸氢二钾0.6%、硫酸镁0.04%、酪氨酸浓度为0.14%、培养基起始pH值为6.75。优化后的培养基产黑色素为4.90 g/L,比优化前的2.03g/L提高了2.41倍,效果显著。     

基于SVM-PSO的羰基还原酶产酶条件优化

构建优化模型对羰基还原酶的产酶培养条件进行优化,获得较优的发酵产酶条件。通过Plackett-Burman设计筛选出羰基还原酶产酶培养条件的4个显著影响因子;设计正交试验进一步探究显著影响因子对羰基还原酶产酶的影响;以正交试验结果为样本数据,采用支持向量机(SVM)模型对正交试验结果进行拟合回归;构建SVM-PSO优化模型对拟合函数进行全局寻优,寻优结果即为羰基还原酶较优产酶条件。实验结果表明在预测的最优产酶条件下培养菌体,羰基还原酶酶活达到299.19 U/L,比优化前提高了16.81%,证明构建的SVMPSO模型对于产酶条件优化问题有较好处理能力。     

毕赤酵母工程菌发酵木聚糖酶条件的响应面优化

通过单因素实验研究了诱导温度、种龄、p H、甲醇浓度以及诱导时间对毕赤酵母工程菌产木聚糖酶的影响。在此基础上进行响应面优化设计实验,并根据结果拟合小二乘二次项回归方程,探讨了各因素对木聚糖酶比酶活力的影响。确定了最优的发酵培养条件:种龄为31 h,诱导时间104 h,甲醇诱导浓度1%,发酵起始p H4.0,诱导温度为30℃,在此条件下对实验结果进行验证,得到木聚糖酶比酶活力为43526.3 U/mg。      

响应面法优化黑曲霉产单宁酶的固体发酵条件

通过固体发酵培养基单因素研究,确定了三个影响单宁酶产率的关键因素,对氮源用量、五倍子用量、培养温度采用响应面法的中心旋转实验设计原理,进行三因素三水平的响应面分析,以获得最佳产单宁酶的培养基及培养条件组成。结果表明,固体发酵黑曲霉最佳产酶条件为：五倍子含量为9％;氮源添加量为2．3％;温度为32℃。在此条件下进行发酵产酶重复实验,酶活力为219．4U／mL。     

响应面法优化产蛋白酶菌株的发酵条件

从新疆吐鲁番地区土样中分离筛选获得1株产蛋白酶菌株Bacillus tequilensis C9,采用Plackett-Burman(PB)设计法筛选出影响其产酶条件的主效应因素为葡萄糖含量、装液量和接种量.应用中心组合设计以及响应面分析,建立了以蛋白酶酶活为响应值的二次回归方程模型,得到最优发酵产酶条件为:葡萄糖含量1.3％,装液量45mL,接种量5％.此条件下蛋白酶活为86.17 U/mL,与优化前相比酶活提高2.1倍.     

响应面法优化木聚糖酶发酵培养基的研究

采用响应面法对毕赤酵母发酵产木聚糖酶的培养基进行了优化。首先利用Plackett Burman试验设计筛选出影响产酶的3个主要因素,即麸皮水解液浓度、酵母水解液浓度和甲醇添加量。在此基础上用最陡爬坡路径逼近最大响应区域,再利用Box-Behnken试验设计及响应面分析法确定最佳条件。结果表明,麸皮水解液402.5g/L、酵母水解液49.9 g/L和甲醇添加量为28.1mL/L时,木聚糖酶最大理论酶活为6566.79U/mL。经3次试验验证,实际平均酶活与预测酶活相近,比优化前木聚糖酶酶活提高了23.7%。     

响应面法优化隐甲藻LS1057产二十二碳六烯酸发酵条件

为了提高一株隐甲藻藻株LS1057的二十二碳六烯酸产量,对发酵培养基进行了优化。采用Plackett-Burman实验设计法考察发酵培养基中各组分对二十二碳六烯酸产量的影响,结果表明:葡萄糖、酵母膏、KH2PO4的浓度对二十二碳六烯酸的产量影响显著。再用最陡爬坡路径逼近最大响应区域,并结合Box-Behnken实验设计和响应面分析法对3个显著因素进行回归分析,得到优化的发酵培养基组成:葡萄糖79.76g/L、酵母膏14.0g/L、KH2PO40.5g/L、海盐20.0g/L、MgSO4·7H2O 5.0g/L、KNO38.0g/L、FeSO4·7H2O 0.2g/L和M液(M液:V B10.6g/L,V B120.1mg/L)1%(V/V)。采用该法优化培养基,经摇瓶发酵实验供试藻株的二十二碳六烯酸产量达到了1.811g/L,较优化前提高了71.33%。利用70L发酵罐的分批补料发酵实验对优化后的结果做了进一步的验证,发酵结束后二十二碳六烯酸终产量为2.112g/L。实验结果表明经响应面法优化得到的发酵培养基利于隐甲藻LS1057发酵生产二十二碳六烯酸。     

响应面法优化黑曲霉HQ-1产纤维素酶固体发酵条件

采用单因素试验和响应面法对黑曲霉(Aspergillus niger) HQ-1产纤维素酶的固体发酵条件进行了优化并以滤纸酶活力作为响应值.首先通过单因素试验确定最适碳源为玉米秸秆粉/麦麸(1/1)及其最适含量为12.0g;最适氮源为(NH4)2SO4及其最适含量为1.5g.再利用Plackett-Burman设计筛选出影响滤纸酶活力的显著因素:含水量、培养温度和起始pH值.通过最陡爬坡试验逼近最大酶活力区域.最后用Box-Behnken设计及响应面分析确定产酶的最佳发酵条件为玉米秸秆粉6.0g、麦麸6.0g、(NH4) 2SO4 1.5g、KH2PO41.6g、MgSO4· 7H2O 0.8g、含水量73.5%、起始pH值为3.91、培养温度和培养时间分别为33.9℃和96h.经过优化,滤纸酶活力最高为59.432U/g,比未优化的酶活力最高值(13.511U/g)提高了3.40倍.     

响应面法优化马奶酒发酵条件的研究

以新鲜马奶为原料,通过考察接菌量(乳酸菌/酵母菌)、发酵温度、发酵时间、糖添加量单因素试验对马奶酒发酵的影响,并借助响应面设计,研究接菌量(乳酸菌/酵母菌)、发酵温度、发酵时间对马奶酒品质的影响。结果表明,最佳发酵条件分别为接菌量(乳酸菌/酵母菌)3%∶5%、发酵温度32℃、发酵时间80h、糖添加量6%。马奶酒酒香清雅,微酸爽口。     

Optimization of d-lactic acid production by Lactobacillus coryniformis using response surface methodology

New low-cost media for lactic acid fermentation are desired to enhance the economics of the d-lactic acid production by Lactobacillus coryniformis. The aim of this work was to optimize the production of d-lactic acid from glucose by L. coryniformis in a reduced nutritional medium composed of corn steep liquors (CSL), yeast extract (YE) and peptone (P). Response surface methodology has been successfully used to modelling and optimizes the d-lactic acid production at variable fermentation times (20, 31, 44, 53, 72 and 96 h). The models predicted a maximum d-lactic acid concentration (58.9 g/l) at 96 h using 5 g CSL/l, 3.6 g YE/l and 10 g P/l. However, the maximum economic yield (10.14 $/$) was obtained at 96 h using 5 g CSL/l as a sole nutrient and the maximum economic productivity (0.22 $/h$) was obtained by reducing the fermentation time at 44 h.     

Optimisation of osmotic dehydration process of guavas by response surface methodology and desirability function

Response surface methodology was used to assess the effects of osmotic solution concentration (40–60°Brix), process temperature (20–40 °C) and vacuum pulse application time (0–20 min) at 100 mbar on water loss (WL), weight reduction (WR), solid gain (SG), water activity (a_w), colour parameters and mechanical properties of guava slices. Optimal process conditions were determined through the desirability function approach and quality characteristics of osmotically dehydrated guavas were analysed. Only models obtained for WL, WR and a_w were suitable to describe the experimental data. The desirability function showed that optimal conditions for osmotic dehydration of guavas were: osmotic solution concentration at 60°Brix, process temperature at 32 °C and 20 min of vacuum pulse application. Under optimal conditions, colour and mechanical properties of treated guavas were similar to fresh fruit, presenting WL of 29.01 g/100 g, WR of 25.91 g/100 g, SG of 3.10 g/100 g and a_w of 0.979.     

Optimization of fermentation conditions for ting production using response surface methodology

This study investigated the effect of fermentation conditions (time and temperature) of sorghum on the composition of ting, using the Doehlert design of response surface methodology (RSM). Fermentation temperature and time were optimized and pH, titratable acidity (TTA), total viable bacteria count (TBC), total lactic acid bacteria count (TLABC), total fungal and yeast count (TFYC), tannin content (TNC), total phenolic content (TPC), total flavonoid content (TFC), and antioxidant activities (AA) were determined. Experimental and predicted values obtained were similar, with statistical indices indicating the validity of the models generated (R² between 93.45 and 99.71%, AAD values close to 0, B_f and A_f values close to 1). Numerical multi‐response optimization of parameters suggested optimal fermentation conditions to be 34 °C for 24 hr. Physicochemical characterization of ting samples using scanning electron microscopy (SEM), X‐ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) showed slight changes in morphology, similarity in diffraction patterns and presence of different functional groups, respectively. Results of this study could provide information for the commercialization of quality ting.

Practical applications

Response surface methodology was used to study the influence of fermentation conditions on the quality of ting and optimal fermentation conditions were obtained at 34 °C for 24 hr. The findings in this study will be useful for ting processors to obtain a product with maximal beneficial composition and traits.     

Optimization of isoflavone production from fermented soybean using response surface methodology

This study was conducted to investigate the interaction effects among process variables during isoflavone production and optimized the yield of isoflavone. A response surface methodology (RSM) was employed to study the relationships of fermentation temperature, time, and starter culture on daidzin and daidzein as an isoflavone product. The experiments were designed using central composite by applying 2⁴ factorial designs with 2 center points. Fermented soybean produced a maximum of 1,284.14 μg/g daidzin at an optimum temperature of 29.39°C, fermentation duration at 32.06 h and starter culture content of 0.96%(w/w). Meanwhile, an optimum daidzein (1,663.85 μg/g) was obtained at 35°C and 48 h fermentation process with 0.5%(w/w) starter culture. Validation study showed the observed and predicted values were in compliance with 5% level of significance. The RSM was successful in identifying the optimum conditions for the isoflavone production.     

响应面法优化里氏木霉产木聚糖酶发酵培养基

采用响应面法对里氏木霉产木聚糖酶的发酵培养基进行了优化。首先利用Plackett-Burman实验设计筛选出影响产酶的3个主要因素:乳糖、玉米浆和KH2PO4。在此基础上运用最陡爬坡路径法逼近最大响应值区域,最后利用响应面分析法确定主要因子之间的交互作用及最佳条件。结果表明,乳糖45.13g/L,玉米浆15.94g/L,（NH4）2SO43g/L,KH2PO42.73g/L,MgSO4·7H2O0.8g/L,无水CaCl20.6g/L,吐温-801mL/L时,木聚糖酶最大理论酶活为855.01U/mL。经5次平行实验验证,实际平均酶活与预测酶活相近,比优化之前的酶活提高了24.1%。      

响应面法优化厌氧细菌产纤维素酶发酵培养基

通过单因素试验确定了厌氧纤维素降解细菌—溶纤维丁酸弧菌WHQ产纤维素酶的最佳培养条件,结果表明,最适产酶条件为培养时间48h,接种量10％,初始pH值8.5,温度37℃.在此基础上,应用响应面法优化该菌株产纤维素酶培养基.在初期研究中,葡萄糖和尿素确定为最佳的碳氮源,利用Plackett-Burman设计从10种培养基成分中筛选出对WHQ产内切纤维素酶有重要性的因素,结果表明葡萄糖、NaHCO,和MgSO4·7H2O对WHQ产内切纤维素酶有重要影响,利用Box-Behnken设计研究这3种因素对WHQ产内切纤维素酶的综合效应,结果表明3种因素的最佳值为MgSO4·7H2O 0.14g/L、葡萄糖14.3g/L、NaHCO3 6.92g/L,此时的内切酶酶活力最大值为206.548μg/(mL.min),与实验值相接近199.324μg/(mL·min),比未优化前的内切纤维素酶活力71.254μg/(mL·min)提高179％.     

利用响应面法优化枯草芽孢杆菌产尿苷发酵培养基

采用响应面法对枯草芽孢杆菌产尿苷发酵培养基进行优化,以期提高尿苷的产量。首先利用PlackettBurman实验设计筛选出影响尿苷产量的3个显著因素:酵母粉,谷氨酸钠,豆粕水解液;在此基础上利用最陡爬坡实验逼近响应值的最佳区域;最后通过中心复合实验和响应面分析确定了影响产苷主要因素的最佳浓度,分别为酵母粉25.6 g/L,谷氨酸钠25.2 g/L,豆粕水解液40.9 m L/L,此时尿苷产量的预测值为13.76 g/L。通过模型的验证实验发现,尿苷的实际产量为13.52 g/L,与模型预测值非常接近,并且比初始培养基提高了164.1%。     

利用响应面法优化海洋细菌YDX-1产纤维素酶的发酵条件

采用响应面法对海洋细菌YDX-1产纤维素酶的发酵条件进行了优化。首先用Plackett-Burman法从8个因子中筛选出3个主要影响YDX-1产酶的因素,然后进行最陡爬坡实验逼近最佳响应面区域,最后通过Box-Behnken响应面设计实验得到最适条件为温度31℃、羧甲基纤维素钠(CMC-Na)41g/L、(NH4)2SO44.7g/L。在最适条件下测得的酶活为273.20U/mL,较优化前的150.13U/mL提高了81.97%。     

响应面——满意度函数优化复合酶法提取野木瓜汁工艺的研究

为了提高野木瓜出汁率和野木瓜汁含糖量,采用复合酶法提取野木瓜汁,用响应面——满意度函数分析法进行优化.结果表明,最佳酶解工艺参数为每100g果肉打浆加水80mL,复合酶(纤维素酶与果胶酶添加比例为4∶1)添加量0.170％,调整pH值为4.0,在45℃处理4h,野木瓜出汁率为76.0％,野木瓜汁含糖量达到7.77％,均高于空白样.     

响应面法优化皮状丝孢酵母产油脂发酵培养基

以皮状丝孢酵母（Trichosporon cutaneum）为出发菌株,对其产油脂的发酵培养基进行研究。以油脂产量为评价指标,通过单因素试验研究发酵培养基中的碳源、氮源、外源因子对油脂产量的影响,然后利用响应面试验对培养基进行优化。结果表明,最佳培养基配方为葡萄糖97.6 g/L、玉米浆干粉4.4 g/L、乙酸钠0.09 g/L。在该优化条件下,皮状丝孢酵母的油脂产量达到了14.4 g/L。