制麦白地霉的筛选及其初步应用

对40株白地霉产β-葡聚糖酶、木聚糖酶、中性蛋白酶和纤维素酶的酶活情况进行研究,以加权评分对这些酶活进行分析评价,从中选出4株白地霉菌株(3号、12号、18号和39号)作为制麦用微生物。通过大麦制麦试验证明:这4株白地霉均对麦芽的溶解具有促进作用,其中12号白地霉的效果最好。与空白对照相比,制得的白地霉麦芽中,β-葡聚糖质量分数降低了17.8%,60min的滤液体积提高了35.4%,糖化力增加了10.3%,α-氨基氮质量分数增加了7.3%,其他理化指标也均符合QB1686-2008。将12号白地霉麦芽与对照麦芽分别进行了啤酒酿造实验,结果表明:白地霉麦芽的酿造性能优于空白对照麦芽,两种麦芽所酿啤酒的理化指标均符合GB 4927-2008。     

利用白地霉提高低发芽率大麦溶解性能的研究

采用恒温和升温两种发芽工艺,研究了第一次浸麦过程中添加NaOH和接种5株具有高水解酶活力的白地霉菌株对低发芽率大麦溶解性能的影响。结果表明:在不同工艺下添加NaOH和接种白地霉菌株均能提高低发芽率大麦的溶解性能,特别是在升温发芽工艺下接种白地霉菌株G4能更好地改善麦芽的溶解指标,与对照样品相比,其成品麦芽β-葡聚糖酶酶活提高了6.2倍,木聚糖酶酶活提高了8.9倍,糖化力提高了21.5%,其它理化指标也均符合QB1686-93的标准。      

利用白地霉提高低发芽率大麦溶解性能的研究

采用恒温和升温两种发芽工艺,研究了第一次浸麦过程中添加NaOH和接种5株具有高水解酶活力的白地霉菌株对低发芽率大麦溶解性能的影响.结果表明:在不同工艺下添加NaOH和接种白地霉菌株均能提高低发芽率大麦的溶解性能,特别是在升温发芽工艺下接种白地霉菌株G4能更好地改善麦芽的溶解指标,与对照样品相比,其成品麦芽β-葡聚糖酶酶活提高了6.2倍,木聚糖酶酶活提高了8.9倍,糖化力提高了21.5%,其它理化指标也均符合QB1686-93的标准.     

白地霉水解茶油的研究

<正> 近年来国外已报导用酶法制备脂肪酸。酶有三个特殊性能,首先是专一性:酶通常是在分子的特定部位变更专一的化学键,而普通化学反应是按照热力学规律随机发生这种变更,正确选择酶就可以控制生成的产品,使付反应降至最小。     

果香风味导向白地霉M5的分离鉴定及生物学特性研究

通过嗅闻技术从清香型白酒新鲜酒醅中分离、筛选产香酵母,获得一株能够产生愉悦水果香气的菌株M5。采用HS-SPME-GC-MS技术对其风味物质进行检测,发现该菌株在不同的培养基中产香能力不同。在糖化酶与高粱组合的固体培养基中,产生果香味、清香味、并夹杂奶香味,香气最佳,主要的香气物质为酯类和醇类,其中玫瑰花香的β-苯乙醇占风味物质的28.14%,酯含量高达26.5 g/L。通过形态学,生理生化试验和26S rDNA序列系统发育分析,确定该菌株属于地霉属的白地霉,命名为白地霉M5。通过对菌株M5的酸碱、温度、酒精度、糖度耐受性研究发现,该菌株可在pH 3~6、酒精度(体积分数)0%~18%、糖度5%~35%、温度25~40℃条件下生长,最适生长温度25℃,糖度10%,pH 4。本研究为该菌株的开发利用奠定基础,也为清香型白酒及风味导向的中国白酒发酵调控提供理论基础及优质菌种资源。     

白地霉的培养与核糖核酸工业化生产的研究

利用淀粉厂生产过程中排放的废水可培养白地霉，以达到改善环境污染的目的。进而采用白地霉，通过物理，化学等方法可将核糖核酸提取出来，并使纯度进一步提高，对提取的工业化生产作了探讨。     

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。     

白地霉的应用研究进展

白地霉在食品、香料、饲料、环境治理等领域具巨大的开发价值.主要概述了近年来白地霉在脂肪酶、香气化合物、奶酪制作、污水处理以及饲料蛋白生产等方面的应用研究进展.     

白地霉Cryytococcus neo formans ch-3冷冻干燥保护剂的选择

以海藻糖、乳糖、麦芽糖、半乳糖、蔗糖、甘露糖、山梨糖、山梨醇、木糖作为1株产低温脂肪酶的白地霉ch-3的冷冻干燥保护剂。研究表明,海藻糖为最佳保护剂,菌体存活率可达75%以上,其次是蔗糖、乳糖、麦芽糖、山梨糖。对冻干前后及未加保护剂的菌体作电镜观察表明,海藻糖对菌体有很好的保护作用。     

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.     

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.     

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。      

Enzymatic and molecular characteristics of Geotrichum candidum strains as a starter culture for malting

Geotrichum candidum yeasts are proposed as a starter culture during malting. They have a double positive effect on the process. They eliminate the fungal pathogenic microflora and improve the technological properties of the finished product, malt. Among published research little or no information can be found considering the biosynthesis of hydrolytic enzymes. Most of the data is related to the production of lipases, proteases and cellulases. This paper examines the enzymology of a number of G. candidum strains. The main focus within the evaluation process was placed on whole cell barley grain cultivation. Hydrolase, which is present in cell wall degradation, was found at a satisfactory level. All tested strains produced both β‐1,3‐glucanases and β‐1,4‐glucanases capable of hydrolysing barley β‐glucan and reducing the amount of this polysaccharide in the wort. Molecular analysis of the tested strains with the use of restriction fragment length polymorphism–polymerase chain reaction and randomly amplified polymorphic DNA confirmed not only the species affiliation, but also the genetic similarity between the tested strains. Copyright © 2014 The Institute of Brewing & Distilling     

在小麦淀粉废水中培养白地霉的研究

将白地霉分别培养在液化及液化后再糖化的小麦淀粉废水中，对培养过程中的降糖，生物量，蛋白酶和糖化酶活力，所态氮，ｐＨ值的变化进行了研究。结果表明：在液化后再糖化的小麦淀粉废水中，白地霉能良好生长，生物量得率高。同时对白地霉在糖化淀粉废水中生长的动力学进行了初步研究。     

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     

酱香型白酒大曲中白地霉产蛋白酶液态发酵条件优化

从茅台镇酱香型白酒生产样品中分离得到1株白地霉MTBD,对其液态发酵条件下的不同原料比、料水比、pH值、发酵温度、发酵时间对菌株产蛋白酶酶活力影响进行了研究。结果表明,白地霉MTBD液态发酵产蛋白酶的最适条件为：原料高粱∶小麦∶麸皮为5∶4∶1;料水比为1∶8;pH值为5;发酵时间为6 d;发酵温度为30℃。在此条件下发酵测定蛋白酶活力为3387.61 U/mL。     

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。