黄浆水发酵生产SCP的菌种选配

以黄浆水为原料,采用液态发酵方式,选配适合其发酵生产单细胞蛋白(SCP)的菌种,进行单因素及正交试验。结果表明:扣囊拟内孢霉(Endomycopsis fiburiger CICC31258)、解脂假丝酵母(Candida lipolytica CICC32457)、产朊假丝酵母(Candida utilis CICC31268)、白地霉(Geotrichum candidum link SH501)是适合发酵黄浆水生产单细胞蛋白的优良菌种;菌种间的最佳发酵配比为白地霉(SH501)∶扣囊拟内孢霉(CICC31258)∶解脂假丝酵母(CICC32457)∶产朊假丝酵母(CICC31268)为2∶1∶1∶2或者3∶1∶1∶2。     

传统黄酒淋饭酒母搭窝期生化过程的探讨

测定了传统黄酒酒药中微生物的数量,研究了淋饭酒母搭窝期微生物的变化,分析了搭窝期微生物生化过程,阐述了拟内孢霉酵母、乳酸球菌(糊精片球菌)、念珠霉、拟内孢霉以外的能同化淀粉和糊精的酵母(如糖化酵母、假丝酵母属中的有些酵母、丝孢酵母等)是搭窝期主要糖化、分解菌;而根霉、犁头霉等起次要作用;乳酸球菌是保障搭窝期顺利进行、正常完成的关键菌之一.     

利用废糖蜜生产SCP菌种性能的测定

分别以白地霉、热带假丝酵母、皮状丝孢酵母和产朊假丝酵母为研究对象,以糖蜜废液为培养基,通过恒温培养,测定活细菌数、细胞干重和菌体蛋白质含量等指标比较,从而选育生长快、蛋白质含量高的菌种生产SCP。结果表明,热带假丝酵母生长较快、粗蛋白含量较高,为生产SCP的最佳菌种。     

木醋杆菌生产纤维素凝胶过程中主要染菌调查及防护技术

为了保证纤维素凝胶生产的顺利进行,调查了纤维素凝胶生产过程中造成严重危害的污染杂菌,主要有裂殖酵母、假丝酵母、掷孢酵母、针孢酵母、克鲁弗氏酵母、白地霉、青霉、木霉、曲霉、青霉等等.提出了提高菌种质量,加强器具卫生,环境卫生、原料卫生、个人卫生、工艺过程卫生、药物防治等综合防护措施,应用于指导生产、并取得良好的效果.     

红麻亚铵法制浆废液发酵菌种的筛选

以热带假丝酵母菌、白地霉AS2.616和白地霉AS2.1035为菌种,发酵红麻业铵法制浆废液,在原废液浓度9°Be'、培养液pH值6.0、发酵温度30℃、摇床转速140r/min、接种量3%、摇瓶装液敏50mL/250 mL,发酵时间分別在48h、60h、60h的优化条件下,以每升废液中曲体绝于质量(以Q表示)和COD友除率为指标筛选菌种.结果表明白地霉AS2.1035优于热带假丝酵母和白地霉AS2.616,因此确定白地霉AS2.1035为发酵红麻亚铵法制浆废液优选菌种,在初选条件下,Q可达6.110g,发酵废液CODCr去除率达28.1%.     

曲酒丢糟生产单细胞蛋白的菌种初选

以白地霉、假丝酵母和根霉为菌种,以大曲丢糟为主要原料,通过添加适当辅料为培养基,经固态发酵方法生产单细胞蛋白。试验结果表明,白地霉对丢糟的转化较为理想,发酵后可使蛋白质含量高达18．6％。     

多菌种混合发酵大曲丢糟生产饲料的研究

以大曲丢糟为主要原料,以假丝酵母、白地霉、根霉为生产菌,采用正交试验,得到最佳工艺条件为∶丢糟∶麸皮=5∶1,假丝酵母∶白地霉∶根霉=1∶1∶2,在32℃下培养5 d,得到的饲料营养丰富,易被动物吸收,是一种新型的饲料蛋白来源.     

豆腐酸浆中高产蛋白微生物的氨基酸营养分析

对豆腐酸浆中假丝酵母和白地霉的蛋白质中氨基酸进行了研究，测得其含有18种氨基酸，8种必需氨基酸齐全，还含有组氨酸。根据模式蛋白质，应用模糊识别分析法与化学分析法对假丝酵母和白地霉蛋白质营养价值进行了评价。     

响应面法优化黄浆水发酵生产单细胞蛋白的工艺参数研究

以大豆黄浆水为原料,选用白地霉、扣囊拟内孢霉、解脂假丝酵母和产朊假丝酵母（2∶1∶1∶2）作为发酵菌株发酵黄浆水。在单因素试验的基础上,通过响应面设计法,对黄浆水发酵生产单细胞蛋白（SCP）的工艺进行研究。结果表明,影响SCP产量的因素大小顺序为初始pH、发酵时间、装液量;最佳发酵工艺参数为碳氮比5、初始pH 6、装液量140 mL/250 mL、接种量6%、发酵温度28 ℃、发酵时间42 h;经过优化后的SCP产量达到3.28 g/100 mL。     

荆州地区霉豆渣真菌多样性研究

采用高通量测序技术,对采集自湖北省荆州地区下辖的监利市和石首县的霉豆渣样品真菌多样性进行解析。结果发现,子囊菌门(Ascomycota)平均相对含量57.77%、担子菌门(Basidiomycota)33.54%和毛霉门(Mucoromycota)8.00%,为荆州地区霉豆渣中主要真菌门,且各菌门在2个县市霉豆渣样品中含量差异不显著(P>0.05)。镰刀霉属(Fusarium)34.60%、丝孢酵母属(Trichosporon)28.96%、篮状菌属(Talaromyces)12.51%、放射毛霉属(Actinomucor)7.27%和枝孢属(Cladosporium)1.55%为主要真菌属,且镰刀霉属在2个县市霉豆渣样品中含量差异极显著(P<0.01),其在监利市和石首县样品中的平均相对含量分别为56.74%和12.45%。10个分类操作单元矩阵(operational taxonomic units,OTU)存在所有样品中,其中OTU1366和OTU963分别被鉴定为丝孢酵母属和镰刀霉属,平均相对含量分别为27.50%和29.08%。经聚类分析、主坐标分析和多元方差分析发现,采集自荆州地区下辖2个县市的霉豆渣样品真菌群落结构存在显著差异(P<0.05),且采集自石首县的霉豆渣真菌类群的组间差异性大于监利市(P<0.05);经LEfS e(linear discriminant analysis effect size)分析发现,导致2个县市霉豆渣样品存在差异的类群为耐碱酵母属(Galactomyces),其在监利市和石首县样品中的相对含量分别为1.46%和0.62%。由此可见,虽然共有大量的核心类群,但荆州地区不同县市制作的霉豆渣其真菌群落结构存在显著的差异,而该差异主要由耐碱酵母属导致。     

Antifungal activities of anthocyanins from purple sweet potato in the presence of food preservatives

Food Science and Biotechnology - Effects of anthocyanins from purple sweet potato (APSP) against the fungal growth of Geotrichum candidum and Candida albicans were assessed. Response surface...     

微生物固态发酵法提升冷榨菜籽饼粕营养价值的研究(Ⅰ)——菌种的选择与复配

主要利用冷榨提油后的菜籽饼粕,辅以少量麸皮为培养基,以产朊假丝酵母、白地霉、植物乳杆菌为微生物菌剂,进行单菌和混菌发酵实验,以提高其营养价值。实验结果表明,以8%为总接种量,接种比例白地霉:产朊假丝酵母:植物乳杆菌=2:1:2条件下,菜籽饼的营养价值最高,相对未发酵的菜籽饼,硫甙降解率为74.85%,体外消化率提高59.93%,植酸和单宁降解率分别为43.14%和14.50%。     

Safety assessment of dairy microorganisms: Geotrichum candidum

Geotrichum candidum is a ubiquitous filamentous yeast-like fungus commonly isolated from soil, air, water, milk, silage, plant tissues, digestive tract in humans and other mammals. This species is widely used as adjunct culture in the maturation of cheese. The genus Geotrichum is composed of 18 species. A recent taxonomic revision concluded that the old Galactomyces geotrichum/G. candidum complex contained four separate species of which Galactomyces candidus sp. nov./G. candidum. M13 primer can be used for identifying species of the Geotrichum genus. Used in combination, RAPD-PCR and RAM-PCR permit strains to be differentiated. The species can be unambiguous differentiated from the two species most frequently described in human pathology: Geotrichum clavatum (reclassified Saprochaete clavata) and Geotrichum capitatum (reclassified Magnusiomyces capitatus/Saprochaete capitata). Sources of exposure are food ingestion--cheese consumption playing a major role--inhalation and contact. A bibliographic survey was conducted to assess corresponding hazards and risks. G. candidum infections (mainly pulmonary or bronchopulmonary, but also cutaneous, oral, disseminates) are very rare: fewer than 100 cases reported between 1842 and 2006. Moreover, cases were not all confirmed by repeated isolations and demonstration of the fungus' presence in tissues, a prerequisite to establish a true diagnosis of geotrichosis. Immunocompromised population was recently shown as a target for opportunistic infection. The most effective treatments include either azole drogs as ketonazole, iconazole and clotrimazole, or polyene antibiotics as amphotericin B, nystatin and pimaricin, or voriconazole-amphotericin B association. Less than 1 case/year of disease was possibly caused by G. candidum and it never included dairy products or foodborne infection. The risk of developing an infection due to G. candidum in connection with its technological use and consumption of dairy products is virtually nil. For these reasons, G. candidum should be proposed for QPS status.     

生物制麦中白地霉的筛选及其特性的研究

以甘啤3号大麦为原料,从中分离得到了2株生长能力较强的菌株,通过对该菌产生的β－葡聚糖酶、木聚糖酶、纤维素酶和糖化酶的酶活情况进行研究及生理生化鉴定得出该菌株为白地霉,分别为白地霉GQG28．1和白地霉GQG28．2。对筛选到的白地霉GQG28生长特性的初步研究表明,该菌最适生长温度为25℃,生长温度范围为5℃～37℃,其最适生长pH5．6,最低生长pH值为3．2,最高生长pH值为11．0,利用该白地霉制得麦芽综合指标为206．15,所制麦芽糖化力为308．5WK、α-氨基氮为186mg／100g、浸出物相对质量分数为87．1％。     

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。     

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。     

潜力工业催化剂——白地霉脂肪酶

白地霉脂肪酶因具有独特的底物特异性,在油脂改性等领域有着广泛应用。文中概述了白地霉脂肪酶的发酵生产、分离纯化、克隆与表达、底物特异性分子机理及应用等,并展望其未来发展方向,为该工业催化剂的研发与广泛应用提供参考。     

Viili中霉菌的分离纯化与鉴定

为了解Viili中的发酵菌种组成以及产生多糖的主要菌种,通过分离培养,分别用纯培养物对牛奶进行发酵,通过对多糖层的观察,产生多糖的主要是一种霉菌,经鉴定为白地霉(Geotrichum candidum Lk)。     

Aroma compound production in cheese curd by coculturing with selected yeast and bacteria.

The microorganisms involved in cheese ripening produce various volatile compounds and induce typical flavors that contribute to cheese variety. To investigate aroma compound generation of cheese microflora, we used a dynamic headspace-gas chromatography-mass spectrometry analysis. To obtain good sensitivity and repeatability of quantification, dynamic headspace conditions and sample preparation were first optimized and led to an extraction set up in which samples were heated at 60 degrees C and diluted with water without pH adjustment. Then three different yeasts and three Geotrichum candidum commonly used in mold surface ripened cheeses were studied in pure culture in a cheese model medium. Thirty-nine cocultures of these three yeasts, the three G. candidum, and five bacteria were studied in the same medium to assess the interaction between microorganisms on aroma compound production. Twenty-four volatile compounds belonging to different chemical classes (alcohols, aldehydes, esters, sulfides, terpenes) were identified and quantified. Yeasts and especially Kluyveromyces lactis produced large amounts of alcohols, aldehydes, esters, and terpenes when cultured alone or in association. Geotrichum candidum and especially G. candidum strain G3 generated the largest amount of sulfides when cultured alone or in association. Finally, bacteria also produced aroma compounds but, except for Brevibacterium linens strain B5, which produced dimethyl trisulfide and ketones, no specific trend in the production of particular aroma compounds could be evidenced.