藏灵菇源干酪乳杆菌发酵剂分批发酵条件的优化

为了提高发酵液中筛选自藏灵菇产胆盐水解酶干酪乳杆菌KL1的活菌数量,通过采用5 L自动发酵罐进行三因素三水平[L₉(3⁴)]正交试验的方法,研究不同培养基与发酵条件对发酵剂活菌数的影响。结果表明：在发酵温度40℃、接种量3%、发酵液pH 6.5、发酵时间20 h的条件下,采用改良MRS培养基,发酵剂活菌数量最高,为8.2×10⁹ CFU/mL。在此优化条件下,发酵剂的活菌数是优化前的25.63倍。     

米汤发酵乳乳酸菌的筛选及其制备工艺

从贵州酸汤样品中分离筛选乳酸菌,并研究米汤的添加量、发酵时间、白砂糖添加量等工艺条件对米汤发酵乳感官特性的影响,最终确定米汤发酵乳的最佳工艺配方。结果表明,适合米汤发酵乳发酵的菌株为M-14-3-3和P-3-3-7;当米汤添加量20%,白砂糖添加量8%,两菌株的混合比例1∶1,并以4%的接种量,于37℃下发酵15 h时,米汤发酵乳的口感细腻、酸甜适口,具有米汤特有的清香,其酸度为94.8°T,黏度为1 236 cP,活菌数为1.5×10~8CFU/mL,理化及微生物指标均符合风味发酵乳产品标准;15 d内具有较好的贮藏特性,乳酸菌活菌数7.5×10~7CFU/mL,酸度117.3°T,黏度1670 cP。     

植物乳杆菌SC9直投式发酵剂的研究

采用50 L发酵罐对植物乳杆菌SC9进行培养,同时流加NaOH中和发酵过程产生的酸,培养至16 h时活菌数达到8.6×1012CFU/mL。确定植物乳杆菌SC9直投式发酵剂的制备工艺:收集发酵菌液并于4℃,7 000 r/min下离心10 min,用生理盐水洗涤菌体后重悬菌体,室温静置30 min,离心,向菌泥中添加11%脱脂乳、1%甘油、3%谷氨酸钠、2.5%海藻糖和2.5%果糖混合液作为保护剂,发酵剂菌粉中活菌数为4.3×1011CFU/g。     

一种新型发酵乳的工艺配方优化研究

对双歧杆菌和嗜酸乳杆菌发酵生产凝固型发酵乳的工艺配方进行研究。结果表明,二次发酵生产新型发酵乳中的最佳工艺配方为双歧杆菌和嗜酸乳杆菌混合发酵剂接种量5.5%,菌种比例1∶1.5,37℃条件下发酵4.0 h,二次加入4.0%混合发酵剂(保加利亚乳杆菌与嗜热链球菌比例为1∶1),发酵温度42℃,发酵时间2.5 h。采用该工艺生产的发酵乳凝乳状态良好、口感细腻、酸甜适中、奶香味纯厚,产品酸度88°T,活菌数可达3.88×10~(10)CFU/m L。     

一种产中性蛋白酶的凝结芽孢杆菌Liu-g1活菌制剂的制备方法

为提高发酵液中产中性蛋白酶凝结芽孢杆菌Liu-g1 的活菌数量,采用单因素和正交实验研究不同培养基配方和不同发酵条件对凝结芽孢杆菌Liu-g1 活菌数量的影响。结果表明：优化培养基配方为大豆粕1%、玉米淀粉1%、碳酸钙0.2%。选用最优培养基配方,在发酵温度为45℃、接种量2%、装液量50 mL、发酵液pH 7.5、发酵时间为48 h、发酵转速为180 r/min时,发酵剂活菌数量最高,为9.53×109 CFU/mL。在此优化条件下,发酵剂的活菌数量是优化前的28.88倍。,发酵剂的活菌数量是优化前的28.88倍。     

降解胆固醇和甘油三酯发酵酸豆奶的研制

以具有高效降解胆固醇、甘油三酯功能的植物乳杆菌为试验菌株,通过对发酵酸豆奶品质的影响因素研究,确定发酵酸豆奶的工艺参数.试验结果表明,蔗糖添加量、接种量、发酵温度及发酵时间对酸豆奶品质的影响显著,最佳发酵条件为接种量4％,蔗糖添加量4％,发酵温度40℃,发酵时间8h,在此条件下发酵酸豆奶为乳白色,口感细腻嫩滑,酸度为83.6°T,总活菌数为4.36×108 CFU/g,胆固醇和甘油三酯的降解率分别为50.01％和39.23％.     

富硒保健酸奶的研制

通过L9(33)正交试验,确定富硒乳酸菌制作酸奶生产用发酵剂的最佳发酵条件为:发酵温度42℃,加硒量7μg·mL-1,接种量4%。测得发酵剂的活菌数为9.45×108cfu·mL-1,硒的转化率达到84.15%,活力为0.65,符合酸奶发酵剂的质量要求。用此发酵剂生产富硒酸奶的最佳工艺条件为:富硒发酵剂接种量7%,加糖量6%,培养温度42℃,发酵时间4.5h。该酸乳的硒含量达0.49μg·mL-1,转化硒为0.4815μg·mL-1,转化率为98.25%。与普通乳酸菌发酵酸乳相比,该产品硒含量提高了约480倍。     

牛羊乳乳酸发酵过程中流变性变化比较

探讨牛羊乳乳酸发酵过程中流变特性。对牛羊乳分别发酵6 h,测定其乳酸发酵0、1、3和6 h的剪切粘度、酸度和蛋白质含量。结果表明：牛乳发酵0、1、3和6 h的剪切粘度和蛋白质含量均高于羊乳,而羊乳发酵酸度均高于牛乳。蛋白质是影响牛、羊乳乳酸发酵乳流变性的重要因素。     

云南传统腌制韭菜中一株乳酸菌的分离及发酵特性研究

从大理腌制韭菜中分离得到一株优势乳酸菌,经形态学特征观察和16S r RNA分子序列鉴定,确定C198-B-03为嗜热链球菌;通过生长曲线测定、活菌数计数,测定了其对低pH值和高胆盐培养条件的耐受性。结果表明,嗜热链球菌C198-B-03在pH值为2.5,胆盐质量分数0.3%条件下处理后其存活率可达50.98%,44.11%;通过双乙酰标准曲线法测得其产双乙酰含量为9.725 2 mg/L;发酵结果表明,在12%脱脂乳中发酵3 h后开始凝乳,38℃下发酵96 h内极限滴定酸度为120°T,且活菌数仍保持在1.5×108CFU/m L,揭示该菌株在酸性发酵乳中稳定性较好。     

贮藏温度对酸羊奶品质的影响

研究了不同贮藏温度对酸羊奶贮藏期间理化特性、乳酸菌活菌数和感官品质的影响。结果表明,在4℃和8℃下,可延缓酸羊奶贮藏期间酸度的上升和黏度的下降,而12℃贮藏酸羊奶的酸度增长较快,黏度下降明显;在4℃和8℃下,酸羊奶贮藏4d,酸奶中的保加利亚乳杆菌和嗜热链球菌活菌数基本保持稳定,随着贮藏时间的延长呈显著下降趋势(p<0.05);贮藏温度为4℃,在14d的贮藏期内酸羊奶感官品质保持良好,而12℃贮藏条件加速了酸奶品质劣化,保质期只有4d。分析认为,贮藏温度为4℃时,更有利于酸羊奶良好品质的保持。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.     

Disease resistance in protected crops and mushrooms

Summary Cultivars of tomatoes, cucumbers, lettuce and peppers have been bred for resistance to one or more pathogens. Some tomato and cucumber cultivars have resistance to a wide range of diseases. Resistance has been transient in many cases and a succession of cultivars with new genes or new combinations of resistance genes has been necessary to maintain control. There has been a number of notable exceptions and these have included durable resistance to such pathogens asFulvia fulva and tomato mosaic virus. With lettuce the resistance situation is complicated by the occurrence of fungicide resistant pathotypes. There are no strains ofAgaricus bisporus purposely bred for disease resistance.In protected flower crops only resistance to Fusarium wilt in carnations has been purposely bred but differences in disease resistance are apparent in cultivars of many ornamental crops. This is particularly so in chrysanthemums where there are cultivars with resistance to many of the major pathogens. Similar situations occur with other flower crops and pot plants. Cultivars of some species have not been systematically investigated for resistance.The need for genetic resistance will increase with the further reduction, in the limits on pesticide use and an increasing public awareness and importance of pesticide pollution.ADAS is an executive agency of the Ministry of Agiculture, Fisheries and Food and the Welsh Office.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Evolution under domestication involving disturbance of genic balance

Summary An hypothesis is developed that the rapid change from wild plants into domesticated crops principally involves the selection of alleles with non-functional gene products which leads to reduced control of the highly integrated metabolism and morphogenesis previously accumulated by lengthy natural selection. Such disturbance of the genome produces altered physiological and morphological development which, although deleterious in nature, serves mankind better and has been selected.