无花果曲霉（NRRL 3135）与黑曲霉（AsN 70）植酸酶产酶条件的研究

本文重点进行了无花果曲霉（Ａｓｐ．ｆｉｃｕｕｍＮＲＲＬ３１３５）和黑曲霉（Ａｓｐｎｉｇｅｒ７０）用固体培养法生产植酸酶的对比研究。结果表明：ＮＲＲＬ３１３５与ＡｓＮ７０均可以麸皮为主要原料，ＮＲＲＬ３１３５用缓冲液（ｐＨ４．８）控制ｐＨ，在３０℃±１℃培养８～９，产酶水平为５．２ｕ／ｇ干基；ＡｓＮ７０在不需要缓冲液控制ｐＨ的情况下，３０℃±１℃培养５～６天，其产酶水平可达４５．０ｕ／ｇ干基。     

酶促水解蔗糖生产果葡糖浆新工艺

以黑曲霉（Ａｓｐ．ｎｉｇｅｒ－ｗ１）为出发菌，经紫外诱变、亚硝基胍处理获得一蔗糖酶高产菌（Ａｓｐ．ｎｉｇｅｒ－ｗ３）。经固态发酵培养获高活力蔗糖酶。该酶在５０￣５５℃有较高活力，在ｐＨ５．５￣６．０范围内有较高稳定性。该菌种选育成功，可为果葡糖浆生产提出一种简易制备方法。     

蔗糖酶生产菌选育及其在果葡糖浆生产中的应用

本文以黑曲霉（Ａｓｐ．ｎｉｇｅｒ－ｗ１）为出发菌，经紫外诱变，亚硝基胍等方法处理获得－蔗糖酶高产菌（Ａｓｐ．ｎｉｇｅｒ－ｗａ）该菌经固态培养获得高活力蔗糖酶。该蔗糖酶在５０～５５℃有较高活力稳定性，在ｐＨ５．５～６．９范围内稳定，为生物酶法生产果葡糖提供了一种新方法。     

短小杆菌酶促合成二肽甜味剂Aspartame

研究多种因素对短小杆菌酶催化Ｌ－天冬氨酸（Ｌ－Ａｓｐ）和Ｌ－苯丙氨酸甲酯（Ｌ－ＰｈｅＯＭｅ）合成二肽甜味剂Ａｓｐａｒｔａｍｅ能力的影响。结果表明，反应最适ｐＨ为６．０，最适温度为４０℃，反应１０ｈ，催化能力为０．４７５ｇＡＰＭ／ｇ菌体，产率８０．５％，收率８１．０５％。     

国外文摘

国外文摘塑料印刷用水基油墨ＳｃｒｅｅｎＤｉｓｐ．ｎｏ．８３，Ｊｕｌｙ１９９２．ｐ．５（英）Ｓｅｒｉｃｏｌ公司生产的ＡｑｕａｐｌａｓｔＰＷ是一种在ＰＶＣ或类似塑料表面印刷用的亮光水基喷墨干燥丝网印刷油墨。它含有很低比例的有机溶剂，烘箱中基本不散发溶剂。...     

来稿摘刊

Ａｓ．３．４３０９菌株的分离选育在白酒生产中的作用张东林，王金兰山东太原酒厂（０３００１０）太原北郊种子公司（０３００２３）Ａｓ．３．４３０９是糖化酶生产的优良菌株，但连续多次传代后，产糖化酶能力减弱，故每年对此菌株进行单菌落分离筛选和糖化能力的测定...     

羟基脂肪酸聚酯产生菌选育

以特定方法筛得羟基脂肪酸聚酯（ＰＨＡＳ）产生株ＡＭＢ－００１，初步鉴定为产碱菌（Ａｌｃａｌｉｇｅｎｅｓ）属。经紫外线与亚硝基胍诱变，变异株ＡＵＮ－３９产聚羟丁酸（ＰＨＢ）和聚羟丁戊酸共聚物（ＰＨＢＶ）的产率分别为细胞干重的３５％和４７．５％．透射电镜观察表明ＡＵＮ－３９胞内积累的ＰＨＢ粒子可充满胞内空间。     

酶法生产L—天冬氨酸之研究

本文对利用Ｅ．ｃｏｌｉＡＳ１．８８１细胞内之Ｌ－Ａａｐ酶，以反丁烯二酸及氨为底物转化生产Ｌ－天冬氨酸进行了系统的研究，试验结果表明该酶反应转化率高，Ｌ－Ａｓｐ收率亦较高，Ｌ－Ａｓｐ对反丁烯二酸总收率可达９０％以上。     

被孢霉菌菌丝体在贮存过程中油脂的变化

报导了花生四烯酸生产菌被孢霉菌（Ｍｏｒｔｉｅｒｅｌａｓｐ．Ｍ１０）菌丝体在贮存过程中油脂的变化。研究结果表明，不同培养时间的菌丝体（３～７ｄ）在室温下贮存１５ｄ，菌丝体中总脂含量由１８％～３０％上升至３６％～４１％；菌丝体中ＡＡ含量由１．１％～２．６％上升至２．６％～３．７％。但菌丝体油脂中ＡＡ含量在贮存过程中根据不同培养时间显示出不同变化规律。不同贮存温度（５～２５℃）对菌丝体中ＡＡ含量没有显著影响。在ｐＨ为８．０时贮存更有利于菌丝体中花生四烯酸含量的提高。     

国外近期食品工业文献题录

国外近期食品工业文献题录１文献名ＴｈｅＢｅｎｅｆｉｔｓｏｆＧｒｅｅｎＴｅａ译名绿茶的益处出处ＦｏｏｄＩｎｇｒｅｄｉｅｎｔｓａｎｄＡｎａｌｙｓｉｓＩｎｔｅｒｎａ－ｔｉｏｎａｌ，１９９７，（１）ｐ１６２文献名ＷａｓｔｅＮｏｔＷａｎｔＮｏｔ译名食品残料变废...     

发酵血粉菌株的优化选育

从霉变猪血中筛选到产蛋白酶菌株 16株 ,研究了各菌株产复合酶的性能 ,并对其进行组合优化 ,从中筛选出一组兼产蛋白酶、淀粉酶、糖化酶、羧甲基纤维素酶、植酸酶及果胶酶的优化菌株 ,初步鉴定并命名为米曲霉 (AspergillusOryzae )AS10 0、AS10 2 ,酿酒酵母 (Sac charomycescerevisiae)Y113 ,芽孢杆菌 (Bacillussp .)Asp0 0 7。经血粉发酵试验 ,发酵产品香味浓郁 ,营养丰富 ,蛋白质含量高达 69% ,且富含游离氨基酸和无机元素 ,证实了该组合菌株是发酵血粉的优化菌种。     

Purification and properties of a low-molecular-weight phytase from Cladosporium sp. FP-1

A fungus producing high levels of phytase was isolated from air and identified as Cladosporium sp. The phytase production was stimulated by phytate in the medium used. The maximum production of phytase (108 U/ml) occurred in a medium containing 1.0 g of phytate per 100 ml. The phytase was purified to electrophoretic homogeneity by ion-exchange chromatography and gel filtration. Based on SDS-PAGE analysis, the molecular weight of the purified phytase was calculated to be approximately 32.6 kDa, and the narrow protein band indicated that this phytase is not glycosylated. The phytase has an optimum pH of 3.5, and an optimum temperature of 40 degrees C. The phytase activity was stimulated by 2-mercaptoethanol and dithiothreitol, and inhibited by Ba2+, Pb2+, iodoacetate, p-chloromercuribenzoate and phenylmethylsulfonyl fluoride. The phytase displayed high affinity for phytate and the Km was 15.2+/-3.1 microM. NMR analyses (1D and 2D) indicated that the end hydrolysis product of phytate was myo-inositol 1,2,5-triphosphate.     

响应面法优化芽孢杆菌发酵生产植酸酶

对实验室自行分离得到的芽孢杆菌ZJ0702发酵生产植酸酶的条件进行优化,以提高植酸酶的产量。利用2-level Factorial试验筛选出对产酶显著影响的3个因素,通过最陡爬坡试验确定中心点,再采用Central Composite设计对重要因子进行优化。结果发现麸皮、蛋白胨和KH2PO4的添加量是影响植酸酶产量的显著因素,经优化后的培养基组分为3.7%麸皮,2.27%蛋白胨,0.5%硝酸铵0,.008 63%无机磷0,.2%CaCl2,0.05%KCl,0.03%MgSO4,0.003%FeSO4,0.003%MnSO4,0.03%NaCl;培养条件为:34℃,接种量7%,pH7.0,摇瓶装液量75 mL/250 mL,在上述条件下该芽孢杆菌84 h产酶达到最高值13 625.8 U/mL,与优化前菌株产酶活力相比,酶活提高了19.6%。     

Production of phytase in a low phosphate medium by a novel yeast Candida krusei

A yeast strain producing high levels of phytase was isolated from soil and identified as Candida krusei. The phytase was located on the yeast cell wall and was a glucanase-extractable protein. The phytase production was controlled by the phosphate concentration in the medium used. The maximum production of phytase occurred in a medium containing 0.5 mg of phosphorus per 100 ml, and most of the cells were ellipsoid-shaped and did not exhibit budding. Increasing the concentration of phosphorus in the medium to more than 5 mg of phosphorus per 100 ml caused inhibition of phytase production and 90% of the cells exhibited budding. On the other hand, transferring cells grown in the high-phosphate medium into a phosphate-free one derepressed the phytase production. For example, transferring cells grown in 2 mg of phosphorus per 100 ml into the phosphate-free medium, enhanced the total phytase activity up to 5.5-fold that in the medium containing 0.5 mg of phosphorus per 100 ml. The phytase showed two optimum pHs of 2.5 and 5.5, an optimum temperature of 40 degrees C and the K(m) value for Na-phytate was 0.03 mM. Using in vitro experiments that simulated the conditions of the digestive tract, 50-80% phosphorus was liberated from different plant samples (wheat bran, rice bran and feeds) by the strain.     

Evaluation of in vitro probiotic potential of phytase‐producing bacterial strain as a new probiotic candidate

Sixty‐three phytase‐producing bacterial strains were isolated from natural sources, and their probiotic potential was evaluated. Of these, only fifteen strains were selected on the basis of confirmatory plate assay. Among these, five phytase‐producing strains exhibiting potent probiotic properties were identified as Bacillus cereus P1, Bacillus subtilis P6, B. subtilis P7, Pseudomonas aeruginosa P12 and P. aeruginosa P15 on the basis of morphological, biochemical and molecular characteristics. Maximum phytase activity (2.74 EU mL^?1) with potential probiotic properties, that is more than 70% survivability at pH 2.0, up to 2.0% bile salt tolerance, sporulation efficiency of more than 80% and survival in anaerobic condition (94.31%), was revealed by B. subtilis P6 as compared to the well‐established commercial probiotic strains Lactobacillus sporogenes and Lactobacillus casei. Thus, phytase‐producing B. subtilis P6 with promising probiotic features can be used in food and animal feed applications for betterment of mankind after further validation.     

诱导激活剂对不同曲霉菌株淀粉酶组分的激活作用

以活性电泳比较了不同酱油生产菌株的淀粉酶组分,研究了激活酿造时淀粉酶组分表达及活性的变化.结果表明,不同菌株淀粉酶组分数量各不相同,其中黑曲霉沪酿3350、黑曲霉3.324、米曲霉3.362和米曲霉HL均含有4个淀粉酶组分,而米曲霉3.042和米曲霉3042KG含有3个淀粉酶组分,米曲霉ZH含有2个淀粉酶组分.经诱导激活剂作用后,所有菌株的淀粉酶总活力提高,5株米曲霉的激活作用明显,米曲霉3.042的淀粉酶总活力提高15.55％.     

Degradation of phytate by Pichia kudriavzevii TY13 and Hanseniaspora guilliermondii TY14 in Tanzanian togwa

The fermented cereal-based gruel togwa is used as weaning food for children in Tanzania. Togwa is rich in minerals but these are often not available for uptake in the human intestine due to natural inhibitors, such as phytate (IP(6)). The yeasts Pichia kudriavzevii TY13, Hanseniaspora guilliermondii TY14 and TY20, isolated from Tanzanian togwa, and selected for high phytase activity in complex yeast medium YPD, were now studied regarding their ability to degrade IP(6) in maize-based model togwa. A modified constitutively high-phytase producing Saccharomyces cerevisiae BY80 and commercial Aspergillus ficuum phytase were included for comparison. In addition, a strain of Lactobacillus plantarum was included in the model-togwa set-up. All yeasts in the study grew and reached final cell density 1.5-2 log units higher than the start value. S. cerevisiae BY80 degraded 85% of the IP(6) in 48 h; the same degradation level as with A. ficuum phytase (89%). Of the togwa-isolated yeasts, P. kudriavzevii TY13 and H. guilliermondii TY14 showed strong phytate degradation in the model-togwa; 95% or more of the initial IP(6) was degraded after 48 h. This corresponds to a remaining level of 0.4 and 0.3μmol IP(6)/g dw. Co-inoculation with L. plantarum did not increase IP(6) degradation. Moreover, fermentation with P. kudriavzevii TY13 yielded a successive increase in inorganic phosphate (P(i)), from 0.7 to 5.4 mM, suggesting a phytase production in TY13 which is fairly insensitive to P(i) repression. The study shows that phytate in a model togwa is available for yeast phytase enzymes, and addresses the importance of strain selection for effectively degrading the phytate. Certain yeasts originating from togwa seem to have developed a natural high phytase production, and P. kudriavzevii TY13 and H. guilliermondii TY14 seem particularly well adapted to phytate degradation in togwa, and is our choice for further studies and strain improvement.     

发酵法生产衣康酸技术的研究——衣康酸生产菌株的选育(Ⅰ)

以实验室保藏菌种土曲霉No .2 0 1为出发菌株 ,经紫外线、亚硝基胍 (NTG)、高温、硫酸二乙酯 (DES)诱变处理和多次分离获得一支性能稳定的衣康酸高产突变株土曲霉HAT418,36℃摇瓶发酵 72h ,衣康酸产量 72 1g/L ,糖酸转化率 60 0 8%。发酵条件优化后 ,在含糖 12 0～ 160 g/L的培养基上 ,产酸 81 4～ 10 1 1g/L ,糖酸转化率 63 18%～ 67 83%。发酵液经高压液相色谱分析 ,衣康酸占总酸的 98 6%。     

植酸酶基础与应用研究概况

全面对植酸酶作用机理、植酸酶在饲料工业中的作用、国内外研究现状以及以后植酸酶更深层次的开发研究的趋势作了较系统的介绍。