利用玉米酒精废糟液生产单细胞蛋白

玉米酒精废水中,含有丰富的有机物及大量的固形物,COD、BOD值极高(见表3),直接排放会对环境造成严重的污染。如果利用其有机物培养单细胞蛋白,不但减轻其对环境的污染,厂家还因而受益,从而促进了饲料工业和各种养殖业的发展。因此,我们从1987年开始对“利用玉米酒精废糟液生产单细胞蛋白”     

大豆与乳清蛋白协同释放必需氨基酸的动态模式研究

目的：探讨运动后摄入大豆与乳清混合蛋白,血液中必需氨基酸的动态变化模式。方法：健康洁净级Wistar系雄性大鼠18只随机分为3组：大豆蛋白组、乳清蛋白组和双蛋白组。运动模型采用大鼠静水游泳,建立一次性力竭运动模型。蛋白干预后每隔30min采集尾静脉血,检测9种必需氨基酸浓度的动态变化。结果：与单独补充大豆及乳清蛋白相比,运动后摄入双蛋白能够维持高浓度的色氨酸及支链必需氨基酸持续性释放,2种蛋白的单独摄入或混合摄入不影响除色氨酸外的其他非支链必需氨基酸的释放。结论：运动后及时补充“大豆+乳清”双蛋白能够发挥2种动植物蛋白的协同作用,维持血液中支链必需氨基酸的持续性供给。     

腐乳废水生物转化单细胞蛋白的研究

利用腐乳酿造过程中所排放的废水,以白地霉1315为菌种,采用液体深层发酵法培养,使白地霉菌体蛋白产率达到10 g/L左右,产品的蛋白质含量达41.6%。发酵前后废液中COD(化学耗氧量)平均降低71.1%,SS(悬浮物)含量平均降低73.4%,从而实现了腐乳生产废水资源化利用的目的。     

利用废水液体发酵生产单细胞蛋白的实验研究

利用工厂废水或动物血制作培养基,以液体发酵方式培养产朊假丝酵母NCTC3576菌及甘饲8501菌.离心分离菌体,测定菌体生物生长量,并观察蔗糖、温度、酸碱度、发酵时间、种子液接种量对生物生长量的影响.生化方法分析NCTC3576菌单细胞蛋白的品质,氨基酸分析仪分析单细胞蛋白的氨基酸组成.结果表明,玉米淀粉厂废水,不必调pH,不用添加其它任何组分,即可直接用于液体发酵产朊假丝酵母NCTC3576菌;pH4.0～7.0均对生长量无明显影响;24h培养已达到最好生长量,再延长时间已不能提高产量;28℃及37℃培养无明显差别,在3%～17%种子液接种量范围内,接种量与生长量有正相关关系.研究表明,玉米淀粉厂废水单一成分即可用于液体发酵产朊假丝酵母NCTC3576菌,原料成本低,且易于产品分离纯化和工业化生产中的连续培养,是单细胞蛋白生产的良好途径.     

人α-乳清蛋白基因的克隆及其在转基因小鼠中高效表达

从粘粒文库中筛选出人α-乳清蛋白基因,构建9.5 kb的转基因表达载体.利用显微注射的方法获得68只F₀代小鼠,经PCR检测和DNA印迹分析证实有8只小鼠（4♂,4♀）为整合人α-乳清蛋白基因的转基因阳性小鼠,整合率为11.7%,整合拷贝数在1至8之间.利用SDS-聚丙烯酰胺凝胶电泳检测和蛋白质印迹分析,4只雌性F₀代转基因阳性小鼠全部表达了人α-乳清蛋白.放射免疫测定法测定,含量分别为0.62 g/L、0.48 g/L、0.56 g/L、3.21 g/L;同时测定F₀代50号转基因公鼠的后代阳性母鼠（50-2号）乳样中人α-乳清蛋白含量也达到1.03 g/L,证明由原代转基因公鼠遗传给后代的人α-乳清蛋白基因亦获得了稳定的表达.所构建的人α-乳清蛋白转基因载体具有结构较小,表达量高,可以稳定遗传等优点.为利用人α-乳清蛋白基因改善牛乳成分和品质奠定了基础.     

计算机模拟酶解制备驴乳清蛋白抗氧化肽的研究

本文选用驴乳清蛋白为原材料,以DPPH自由基清除率为指标,利用计算机模拟酶解驴乳清蛋白,筛选出能够产生抗氧化活性肽的最适蛋白水解酶,以pH、酶解温度、酶底比(质量比)为自变量,采用Design-Expert V8.0.6设计响应面试验,确定以α-胰凝乳蛋白酶酶解驴乳清蛋白制备抗氧化肽的最佳工艺条件。结果表明在底物浓度4%,酶解时间4 h的条件下,当温度达到39℃,pH 8,酶底比4%时得到的酶解肽抗氧化活性最强,10 mg/mL驴乳清蛋白酶解肽的DPPH自由基清除率最高可达46.23%。     

大豆分离蛋白基脂肪模拟物初步研究

以大豆分离蛋白为原料,对大豆分离蛋白溶液实施加热、高速剪切处理,从而获得与油脂相近的感官特征。在单因素试验基础上,利用二因素中心组合设计原理及响应面法分析建立二次回归模型。以加热温度、蛋白质浓度为考察因子,以大豆分离蛋白溶液粘度及乳化稳定性为响应值,确定大豆分离蛋白基脂肪模拟物的最佳工艺条件。研究结果表明,最佳工艺条件为蛋白质浓度9.10%,加热温度79.6℃,加热时间10 min,均质时间40 s,此条件下大豆分离蛋白溶液的粘度为46.8 mPa·s,乳化稳定性为49.15 min,与市售植物油相当。     

维生素D与乳清蛋白联合干预社区绝经期女性肌肉衰减综合症的研究

目的：探讨单独口服乳清蛋白、维生素D或两者联合补充促进绝经期女性骨骼、骨外健康效应及改善肌肉衰减综合征影响。方法：2015—2016年在北京市王佐镇50岁及以上绝经期女性中,筛选出肌肉衰减综合征的患者80名,并随机分4组,即对照组（普通膳食组）、维生素D组、乳清蛋白组和乳清蛋白联合维生素D干预组。随访半年,重点监测受试者口服维生素D以及乳清蛋白前后血清1,25-（OH）2D3、血生化指标以及上下肢肌力测定,握力、步速等变化的同时,应用ISCCWG诊断标准进行肌量测定,观察ASM指标的变化规律,对比分析4组间患者前述指标在基线以及给予乳清蛋白和维生素D后变化的差异。结果：通过连续6个月每日单独补充800 IU维生素D,可以使受试人群的体内血清1,25-（OH）2D3水平达到30 ng/mL,且恢复到了正常水平（P<0.05）。当同时联合每日30 g乳清蛋白进行干预,6个月以后其受试者体内的血清1,25-（OH）2D3水平也可达到30 ng/mL。通过干预实验的结果表明,受试人群体内的白蛋白水平、体内血清肌酐、四肢骨骼肌量、步速、握力都有了较为明显的提高,尤其在联合补充维生素D和乳清蛋白后,变化更为显著。结论：维生素D、乳清蛋白的干预对受试人群的四肢骨骼肌量、步速、握力都得到了较为明显的改善趋势,尤其在联合补充维生素D和乳清蛋白后,变化更为显著。.     

单细胞蛋白生产最佳接种混合比的研究*

以苹果渣混合菌发酵生产单细胞蛋白为例,利用3个和4个菌种分别探讨了多菌种发酵最佳接种混合比的选取问题,获得一种求取最佳接种混合比的有效方法,完善了发酵生产单细胞蛋白这类问题的研究。     

乳清蛋白生物活性肽研究进展

以乳清蛋白为原料,经过酶解或发酵等方法可以获得独特理化性质的生物活性肽。乳清蛋白生物活性肽来源广、活性强、分子量小,在食品和医药行业有很高的应用研究价值,已经成为研究热点。随着制备、分离纯化以及鉴定技术的不断发展和成熟,越来越多的乳清蛋白生物活性肽被发现。本研究主要综述了乳清蛋白生物活性肽的制备、分离纯化、鉴定方法以及生物功能,并展望了乳清蛋白生物活性肽应用前景,以期为功能性乳清蛋白生物活性肽产品的开发与应用提供参考。     

大豆乳清中蛋白质和异黄酮的超滤分离技术

研究了用超滤技术分离大豆乳清中的蛋白质和异黄酮的工艺条件. 结果表明,大豆乳清在超滤之前要进行预处理以减轻膜污染;通过2因素3水平正交试验,确定了最佳的预处理工艺：按大豆乳清中固形物含量的5%,向其中加入CaCl₂,并在85 ℃下加热15 min,在此条件下,蛋白质的沉淀率为49.8%,异黄酮的保留率为90.4%;通过单因素试验,确定了比较合适的超滤条件：选择切割分子量（MWCO）为10000的聚醚砜膜,超滤压力选择51～68 kPa,超滤温度选择30 ℃～40 ℃.在此条件下,大豆乳清中蛋白质的截留率为83.9%,而异黄酮的截留率为7.6%.     

Production of Fungal Mycelial Protein in Submerged Culture of Soybean Whey

Various soybean whey media were tested as substrate for seven species of fungi in submerged culture. Very little mycelial growth was obtained with Morchella hybrida, Collybia velutipes, Cantharellus cibarius, and Xylaria polymorpha. Agaricus campestris failed to grow. Tricholoma nudum and Boletus indecisus showed the greatest rate of growth and production of mycelial protein and the best utilization of soybean whey solids, with much shorter incubation times compared with those of the other species. T. nudum developed as spheres having diameters of about 5 to 8 mm, instead of the usual slurry or yeastlike form, in the presence of added ammonium acetate. B. indecisus always developed as spheres. Mycelial yields and production of protein by T. nudum greatly decreased with the addition of more than 1% glucose to soybean whey, whereas with B. indecisus the yield of protein almost doubled when up to 3% glucose was added. The effect of minerals on mycelial growth was determined. With soybean whey concentrated to 50%, the rate of mycelial growth of T. nudum was nearly doubled, but protein content of mycelia was greatly reduced. Mycelial growth and yield of protein of B. indecisus grown in concentrated whey were increased greatly. About 4 to 6 g of mycelial protein per liter can be obtained from fermentation in soybean whey, depending upon the medium used. Utilization of soybean whey by fungal fermentation may have economic value in whey disposal and in the production of products of high protein content.     

Biodegradable biocomposite films based on whey protein and zein: barrier, mechanical properties and AFM analysis

Whey and zein protein are byproducts of the food industries and have good film making properties. Single and laminated films were produced from zein protein and whey protein and their film properties were studied. Glycerol and olive oil were used as plasticizer for the single and laminated films. The laminated films exhibited higher ultimate tensile strength (UTS) than the single whey protein films (260% and 200% in the whey-zein-glycerol and whey-zein-olive oil films, respectively). The UTS of the whey protein films increased 2-3-fold after lamination. The laminated films showed higher barrier properties than the single whey protein films (180% in the whey protein-zein-glycerol films and 200% in the whey protein-zein-olive oil films in comparison to single whey protein films) and lower than the single zein films.     

Conversion of cheese whey to single-cell protein

Thirteen yeast species belonging to nine genera were screened for the production of single-cell protein (SCP) using cheese whey as the substrate. Cheese whey supplemented with minerals and yeast extract proved to the best medium for yield, lactose utilization, biomass production, and conversion efficiency. Production of beta-galactosidase was studied in Brettanomyces anomalus, Kluyveromyces fragilis, Trichosporon cutaneum, and Wingea robertsii; the last proved to be the best strain combining high yield with shorter incubation period.     

HPLC法分析乳清蛋白对糖尿病模型小鼠血浆氨基酸组分的影响

为寻求有效的氨基酸分离方法并探讨乳清蛋白对2型糖尿病防治的作用机制,采用HPLC法分析乳清蛋白中氨基酸组分及含量;分别以0％、10％、20％和40％的乳清蛋白(WP)灌胃1型、2型糖尿病模型组、正常组小鼠,4周后观察各组血浆氨基酸的变化.乳清蛋白中亮氨酸、异亮氨酸、缬氨酸分别占氨基酸总量的14.40％、5.93％和5....     

利用蛋白酶产生菌固态发酵去除豆粕中抗原蛋白

从实验室保藏的菌种中,筛选出固态发酵所需的高产蛋白酶菌株,进行豆粕发酵。以抗源蛋白去除情况作为考察指标,通过条件优化发现,在豆粕水分质量分数为45%,颗粒直径在1.0-2.0 mm,发酵温度35℃,发酵时间为50 h时,抗原蛋白的去除率在90%以上。通过十二烷基磺酸钠（SDS）聚丙烯酰胺凝胶电泳,发现抗源蛋白得到有效降解,分解为相对分子质量小于10 000的肽类物质。     

Production of a white wine and a protein-rich soy flour by yeast fermentation of soybean slurry,soybean milk and the whey from tofu production

A dry white wine with an alcoholic content of 10 to 14% v/v was produced by yeast fermentation of slurried ground soybeans, soybean milk and whey from tofu production. Wines from whey and soybean milk were judged by a 20 member taste panel to be acceptable and comparable to a commercial chablis control. Chemical analysis indicated that the high fat and protein contents of soybeans do not cause a problem in the production of wines from soybeans as the lipids and proteins are precipitated by the acid and alcohol formed during the fermentation. The less recovered following fermentation were dehydrated and ground to a flour having an enriched protein content due to the yeasts and an improved flavor resulting from the yeast fermentation.     

Treatability of cheese whey for single-cell protein production in nonsterile systems: Part I. Optimal condition for lactic acid fermentation using a microaerobic sequencing batch reactor (microaerobic SBR) with immobilized Lactobacillus plantarum TISTR 2265 and microbial communities

Cheese whey contains a high organic content and causes serious problems if it is released into the environment when untreated. This study aimed to investigate the optimum condition of lactic acid production using the microaerobic sequencing batch reactor (microaerobic SBR) in a nonsterile system. The high production of lactic acid was achieved by immobilized Lactobacillus plantarum TISTR 2265 to generate an acidic pH condition below 4.5 and then to support single-cell protein (SCP) production in the second aerobic sequencing batch reactor (aerobic SBR). A hydraulic retention time (HRT) of 4 days and a whey concentration of 80% feeding gave a high lactic acid yield of 12.58 g/L, chemical oxygen demand (COD) removal of 62.38%, and lactose utilization of 61.54%. The microbial communities in the nonsterile system were dominated by members of lactic acid bacteria, and it was shown that the inoculum remained in the system up to 330 days.     

利用纤维质原料生产高酶活单细胞蛋白

以蒸汽爆破处理的玉米秸秆为主要原料,接种木霉菌和酵母菌,进行混合发酵生产高酶活单细胞蛋白,在优选的条件下,产品蛋白质含量达31．82％,较原料提高49．69％,纤维素降解率达56．88％,产品纤维素酶活性达105U/g。     

New aspects of sterol carrier protein 2 (Nonspecific lipid-transfer protein) in fusion proteins and in peroxisomes

Sterol carrier protein 2 (SCP2) is a 13-kDa peroxisomal protein, identical to nonspecific lipidtransfer protein, and stimulates various steps of cholesterol metabolism in vitro. Although the name is reminiscent of acyl carrier protein, which is involved in fatty acid synthesis, SCP2 does not bind to lipids specifically or stoichiometrically. This protein is expressed either as a small precursor or as a large fusion (termed SCPx) that carries at its C-terminal the complete sequence of SCP2. SCPx exhibits 3-oxoacyl-CoA thiolase activity, as well as sterol-carrier and lipid-transfer activities. The N- and C-terminal parts of SCPx are similar to the nematode protein P-44 and the yeast protein PXP-18, respectively. P-44, which has no SCP2 sequence, thiolytically cleaved the side chain of bile acid intermediate at a rate comparable to that of SCPx. This, together with the properties of other fusions with SCP2-like sequence, suggests that the SCP2 part of SCPx does not play a direct role in thiolase reaction. PXP-18, located predominantly inside peroxisomes, is similar to SCP2 in primary structure and lipid-transfer activity, and protects peroxisomal acyl-CoA oxidase from thermal denaturation. PXP-18 dimerized at a high temperature, formed an equimolar complex with the oxidase subunit, and released the active enzyme from the complex when the temperature went down. This article attempts to gain insight into the role of SPC2, and to present a model in which PXP-18, a member of the SCP2 family, functions as a molecular chaperone in peroxisomes.