酱香大曲中白地霉产蛋白酶固态发酵条件及其优化

从酱香型酒大曲中分离得到一株白地霉MTBD,对其进行发酵实验,检测蛋白酶活力,测定其在不同原料比、不同培养时间、不同pH值、不同接种量、不同培养温度、不同料水比条件下产蛋白酶的情况,同时对其产酶条件进行优化,获得最佳产酶条件为：培养温度为45℃、pH值为3.5、料水比为1∶1、培养时间为6d。     

豆腐酸浆中白地霉发酵条件的探讨

从酸浆中分离筛选出白地霉FL44菌株,对该菌株产单细胞蛋白的发酵条件进行了初步研究,并对其发酵过程作了动态分析.结果表明:在优化的培养基组成(废糖蜜5%、(NH4)2HPO41%)和培养条件(培养基初始pH5.5,装量40mL/250mL摇瓶,摇瓶转速为220r/min,30℃培养48h)下,菌体生物量及蛋白产量分别为15.2g/L和7.42g/L.     

米根霉液态发酵产糖化酶工艺条件研究

米根霉具有较强的产淀粉糖化酶能力。本研究通过对米根霉液态发酵工艺条件的研究来提高其产糖化酶能力,为红曲黄酒纯种酿造技术奠定基础。以米根霉为出发菌株,大米液化液作为碳源进行摇瓶发酵,通过正交试验优化液态培养基配方,并通过单因素试验得出米根霉的培养条件。优化的摇瓶发酵最佳培养基为:液化液浓度50%,NH4Cl 5 g/L,KH2PO41 g/L,MgSO4·5H2O 0.3 g/L,FeSO4·7H2O 0.4 g/L,CaCO38 g/L;发酵条件为:初始pH6.0,装液量50 mL,摇床转速150r/min,接种量6%,发酵温度为32℃。该发酵条件下,菌株摇瓶发酵液的糖化酶活力达到196.6 U/mL±8.1 U/mL。     

产香白地霉发酵无醇绿啤饮料研究

以产香白地霉菌株发酵麦芽汁制得无醇绿啤饮料。确定了白地霉菌株58A、45B的最适发酵条件,分别于最适生长温度(28℃和27℃)、最适转速(120 r/min和80 r/min)和最佳接种量为5%的条件下,摇瓶发酵48 h,发酵饮料感官指标较佳,不含甲醇、乙醇和甲醛。食用安全性试验结果显示,菌株45B的发酵液对小鼠无毒无害,发酵饮料饮用安全。     

大曲发酵液态白酒工艺优化研究

以高粱、小麦、玉米为主要原料,以糖化酶添加量、大曲添加量、发酵温度、发酵时间作为研究因素,在单因素实验的基础上,采用响应面试验设计方法,建立相应的响应面模型并开展数据分析。获得最高大曲发酵液态白酒产酒率的工艺条件为糖化酶添加量0.8%、大曲添加量24.6%、发酵温度32℃、发酵时间5 d。在此条件下,大曲发酵液态白酒产酒率为（87.24±0.041）%,酒精度与风味物质含量符合最新国家标准中高度酒一级理化要求,对于大曲发酵液态白酒生产具有一定的理论指导作用。     

酱香大曲中Geotrichum candidum MTBD菌株筛选及发酵产物研究

对从酱香大曲中分离的白地霉菌株Geotrichum candidum MTBD进行了鉴定,并对该菌株的固态发酵和液态条件下产蛋白酶及其产酶条件进行了研究,以及该菌株利用酿酒原料的固态和液态发酵产物分析。结果表明,该菌株能产较高活力的蛋白酶,发酵代谢产物包括酸类、酯类、芳香族化合物、醛酮类、含氮化合物等多种成分,与茅台地区酱香型白酒的风味成分分析结果进行比较分析,结果表明,该菌株也是酱香型白酒生产的主要功能菌株,对提供发酵动力和风味形成具有重要的贡献。     

豆腐酸浆中高产蛋白的白地霉发酵条件的研究

本文对从酸浆中分离筛选出的白地霉FL44菌株在以黄浆水为主的培养基的条件下生产单细胞蛋白的发酵条件进行了初步研究,并对其发酵过程作了动态分析。结果表明培养基组成、初始pH值、摇瓶装量与培养时间等,均对该菌株细胞生物量和蛋白产量有影响,优化培养基组成为废糖蜜5%、(NH4)2HP041%);培养条件为培养基初始PH5.5,装量40mL/250mL,摇瓶,摇瓶转速为220rpm,30培养48h;菌体生物量及蛋白产量分别为15.2g/L和7.42g/L。     

高产纤维素酶的里氏木霉液态发酵培养基条件优化

以天然原料作为培养基主要成分,采用Plackett-Burman(PB)、最陡爬坡和Box-Behnken(BB)试验设计及响应面(RSM)分析,对高产纤维素酶的里氏木霉液态发酵培养基进行优化.结果表明:最优发酵培养基条件为豆饼粉添加量2.140％,麸皮添加量1.88％,蛋白胨添加量0.30％,在此条件下,里氏木霉发酵...     

豆腐酸浆中高产蛋白的白地霉发酵条件的研究

本文对从酸浆中分离筛选出的白地霉FL44菌株在以黄浆水为主的培养基的条件下生产单细胞蛋白的发酵条件进行了初步研究，并对其发酵过程作了动态分析。结果表明：培养基组成、初始pH值、摇瓶装量与培养时间等，均对该菌株细胞生物量和蛋白产量有影响，优化培养基组成为：废糖蜜5％、(NH4)2HPO4 1％)；培养条件为：培养基初始PH5．5，装量40mL／250mL，摇瓶，摇瓶转速为220rpm，30℃培养48h；菌体生物量及蛋白产量分别为：15．2g／L和7．42g／L。     

豆腐废水发酵生产白地霉的研究

利用豆腐废水从酸浆中分离筛选出的白地霉FL44菌株进行了摇瓶培养研究，通过正交试验确定了FL44生产单细胞蛋白的最适发酵条件，并对其发酵过程作了动态分析。结果表明：培养基组成、初始pH值、摇瓶装量与培养时间均对该菌株细胞生物量有影响。优化培养基组成为：废糖蜜5％，(NH4)2HPO4 1％；培养条件为：培养基初始pH5．5，摇瓶装量40ml／250mL，摇瓶转速为220rpm，30℃培养48h；菌体生物量可达到15．08g／L。     

天然白地霉菌株发酵产品的毒理安全性评价

研究产香白地霉菌株发酵产品的食用安全性。采用小鼠急性毒性试验、骨髓细胞微核试验、小鼠精子畸形试验和30d喂养试验进行毒理学研究。急性毒性试验表明,白地霉发酵产品的小鼠LD50〉10．0g／kg体重,说明该受试物属于无毒级物质。骨髓细胞微核试验和小鼠精子畸形试验的结果为阴性,未显示出致突变性。30d喂养试验中各实验组（2．5、5．0、10．0g／kg体重）小白鼠生发育良好,体重、食物利用率,以及血常规、血液生化指标与对照组之间无显著差异,小白鼠组织解剖检查均未见病变,产香白地霉菌株发酵产品具有较好的饮用安全性,可作为饮料供消费者饮用。     

白地霉发酵过程中菌体量检测方法的研究

探讨了白地霉发酵过程中菌体量的检测方法,对白地霉的细胞组分麦角固醇和氨基葡萄糖,能否作为菌体量检测指标的可行性进行了比较分析。结果表明:氨基葡萄糖在白地霉细胞中的含量较为稳定,在不同的培养时间、培养条件和培养基中都有较好的稳定性,可以作为白地霉菌体量的检测指标;麦角固醇受培养时间和培养基成分的影响较大,含量不稳定,不太适合作为白地霉菌体量的检测指标。用氨基葡萄糖法测得的白地霉生长曲线与用干重法测得的生长曲线变化一致,能够较为准确地反映白地霉菌体量变化。将此方法应用到白地霉固态发酵中,可快速得到白地霉固态发酵过程中的菌体量变化,为以后固态发酵菌体量的测定提供了依据。      

Energy substrate efficiency during batch cultures of Geotrichum candidum

BACKGROUND: Metabolisation of carbon and nitrogen substrates is a key factor during the ripening process of white soft cheeses but has not previously been examined in terms of energy substrate efficiency. Such work could be useful to improve physiological knowledge concerning Geotrichum candidum, a yeast involved in the neutralisation of curd during ripening. Its behaviour was therefore examined during batch cultures on simple (glutamate) or complex (peptones) substrates as nitrogen and carbon sources and lactate as a second carbon source. RESULTS: In addition to their assimilation as carbon and nitrogen sources, G. candidum used peptides and amino acids as energy sources during growth in preference to lactate. Contrarily, during stationary state, lactate was preferred over peptides and amino acids for carbon dissimilation for energy supply, allowing the avoidance of ammonium production. Indeed, lactate dissimilation theoretically yields 15 adenosine triphosphates (ATPs), while only nine ATPs are theoretically yielded during the dissimilation of an amino acid such as glutamate. CONCLUSION: This behaviour can be considered as an energy‐saving response. Indeed, the use of peptides and amino acids as energy sources in addition to being used as carbon and nitrogen sources during G. candidum growth can be related to its deaminating activity and was in agreement with the better energy efficiency expected from utilisation of the same substrate as both carbon and energy source. Contrarily, the better efficiency of lactate dissimilation led to its use during stationary state instead of peptides and amino acids. Copyright © 2008 Society of Chemical Industry     

清香型白酒生产中白地霉的分离鉴定

从清香型二锅头酿酒车间分离到1株酵母属微生物.经传统形态学分析法结合利用26SrDNA D1/D2区序列对其进行鉴定,鉴定结果为白地霉.该白地霉是酿酒生产中的常见菌种,无酒精发酵力,但能产生良好的清香气味.从其发酵代谢产物中检测出:有机酸4种,酯类20种,醛类8种,醇类15种,芳香族化合物4种,酚类5种,含氮化合物1种.     

地衣芽孢杆菌在麸曲中产中性蛋白酶发酵工艺条件的研究

对地衣芽孢杆菌在细菌麸曲培养过程中的最佳培养基和最佳培养条件进行了研究。结果表明,地衣芽孢杆菌麸曲产中性蛋白酶的最佳培养基为:玉米粉8g/L,黄豆粉2g/L,麸皮10g/L;最佳培养条件为:温度40℃,pH7.0,接种量10%,培养60h时,产中性蛋白酶活力达到最大,为192U/mL。     

中国拟青霉液体深层发酵条件的优化

中国拟青霉(Paecilomyces sinensis sp nov,PS)属于冬虫夏草中的一个无性型菌株,研究表明其与冬虫夏草在生物活性成分方面十分接近。该文通过单因素和正交试验对中国拟青霉液体深层发酵进行条件优化。对中国拟青霉进行发酵培养,选取菌丝体生物量为指标,确定碳源、氮源和无机盐的最佳比例和最优发酵条件。中国拟青霉液体深层发酵的最佳培养基配比为:玉米粉4.0%、葡萄糖1.5%、黄豆粉2.0%、酵母粉0.3%、KH2PO40.2%、MgSO40.1%、CaSO40.1%、ZnSO40.03%。优化后的菌丝体生物量比优化前提高了1.22倍,而胞内糖肽产量与优化前相比提高了54.0%。     

产辅酶Q_(10)白地霉菌的罐发酵条件优化

以白地霉菌(Geotrichum candidum)为出发菌株,根据摇瓶发酵结果控制pH值进行罐发酵。采用间歇补料分批发酵的方法,考察溶氧量、搅拌转速、空气流量及补糖因素对菌体生物量及辅酶Q10产量的影响。确定发酵罐发酵的最适条件为控制溶氧在35%～40%,补糖控制在发酵液糖质量浓度为2g/L,该发酵条件下辅酶Q10产量从分批发酵的78.75mg/L提高到106.26mg/L,较摇瓶发酵提高了69.8%。     

Differences in hydrolytic abilities of two crude lipases from Geotrichum candidum 4013

The fungus Geotrichum candidum 4013 produces two types of lipases (extracellular and cell‐bound). Both enzymes were tested for their hydrolytic ability to p‐nitrophenyl esters and compounds having a structure similar to the original substrate (triacylglycerols). Higher lipolytic activity of extracellular lipase was observed when triacylglycerols of medium‐ (C12) and long‐ (C18) chain fatty acids were used as substrates. Cell‐bound lipase preferentially hydrolysed trimyristate (C14). The differences in the abilities of these two enzymes to hydrolyse p‐nitrophenyl esters were observed as well. The order of extracellular lipase hydrolysis relation velocity was as follows: p‐nitrophenyl decanoate > p‐nitrophenyl caprylate > p‐nitrophenyl laurate > p‐nitrophenyl palmitate > p‐nitrophenyl stearate. The cell‐bound lipase indicates preference for p‐nitrophenyl palmitate. The most striking differences in the ratios between the activity of both lipases (extracellular : cell‐bound) towards different fatty acid methyl esters were 2.2 towards methyl hexanoate and 0.46 towards methyl stearate (C18). The Michaelis constant (K_m) and maximum reaction rate (V_max) for p‐nitrophenyl palmitate hydrolysis of cell‐bound lipase were significantly higher (K_m 2.462 mM and V_max 0.210 U/g/min) than those of extracellular lipase (K_m 0.406 mM and V_max 0.006 U/g/min). Copyright © 2010 John Wiley & Sons, Ltd.