摘要:

By two methods of genetic manipulation, the ability to use dextrin was introduced intoSaccharomyces uvarumandS. cerevisiae.Both methods obtained the genetic information for dextrin utilization fromS. diastaticus.With the fusion technique, spheroplasts were formed by the enzymatic digestion of the cell walls of the species to be fused. Fusion took place in polyethylene glycol; complete cells were then regenerated in a hypertonic media containing 3% agar. Successful fusion products were capable of using dextrin and melibiose as carbohydrate sources. The transformation procedure involved the extraction and purification of DNA fromS. diastaticus.TheS. uvarumandS. cerevisiaerecipients were spheroplasted and then incubated with the extracted DNA. Complete cells were subsequently regenerated in hypertonic media containing 3% agar. The transformants were selected by their ability to utilize and ferment dextrin.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0001

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Two possibilities for efficient use of spent brewer's yeast (Saccharomyces uvarum) are: 1) using yeast cells that have incorporated various essential elements as a feed and 2) using cell ingredients, especially intracellular components of yeast, as antitumor agents. Spent yeast was reincubated aerobically in 5™P wort at 26™C in the presence of various elements. Good growth and good incorporation were found for Mg, K, Ca, Cr, Fe, Zn, Ge, Se, Mo, and I. Good growth with almost no incorporation was found for Mn and As. Poor growth with good incorporation was found for Co and Cu. Yeast incorporated with selenium prevented selenium-deficiency disease in chicks and showed much lower toxicity than inorganic selenium. Intracellular components of spent yeast were obtained by destroying yeast cells directly or by destroying their spheroplasts. Antitumor activity was measured by the total packed cell volume method using ICR mice and Sarcoma-180A cells. One of these components inhibited the growth of tumors by more than 90% when administered intraperitoneally at a daily dose of 30 mg/kg for five days. Immunological tests on ICR mice suggested that the antitumor activity of these components was caused by immunological potentiation.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0005

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Four kinds of apparatus for vicinal diketone determination by the improved micro method were developed in our laboratory. Procedures for renewing sample beers and distillate collectors in the multiple gas-stripping apparatus sets connected in series were simplified by the introduction of a ball joint connector between the generator and the water-cooled condenser and by a screw cap connector for the trap. A space-saving model was developed by arranging the gas-stripping apparatus sets around a rotating table. In this apparatus, a rotating connector prevented twisting of the tubes used for stripping-gas supply, cooling-water supply, and discharge. To permit sample charges to be made without removing the generator from its mount, a sample charge and discharge system was constructed, using a three-way stopcock, a sample dosimeter with a removable cap, a multi-way valve, and additional three-way stopcocks leading to the generators. The gas-stripping apparatus was then automated by automating these valves. Finally, an automatic color development unit was devised by connecting the required number of reaction units in a series in which the flow mechanism of the gas and the reaction mixture was the same as that in the sample charge and discharge system.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0008

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

The possibility that free fatty acids (C6-C24) are excreted during the course of yeast autolysis was studied. Lager yeast was suspended in 0.1Mcitrate buffer, and autolysis was induced by heat, alteration of pH, and treatments with ethanol and other organic solvents. The fatty acids released in the media were extracted with chloroform/methanol (3:1), methylated, and then analyzed by high performance gas-liquid chromatography. Results indicated that varying amounts of fatty acids were released, depending upon the conditions under which the autolysis was initiated. The most prominent fatty acids released in the autolyzate were octanoic and decanoic acids, which are two of the main contributors to the“caprylic”(also called“yeast, fatty”) flavor of beer. Under normal conditions, fatty acid contents of beer in primary storage do not change appreciably. However, when storage temperature increases, or when contact between the beer and relatively large amounts of yeast cells is prolonged, autolysis may occur, with fatty acids being released as a consequence.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0013

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Lin's wild yeast medium was modified to be specific for wildSaccharomyces.The addition of 0.6% ET80 (ergosterol, 4.2 mg/ml, in 50% v/v Tween 80 and ethanol) to Lin's medium allowed wildSaccharomycesto grow when plates were incubated under anaerobic conditions and effectively suppressed non-Saccharomycesyeast. To maintain effective suppression of pitching yeast, the crystal violet concentration was raised to 6 mg/L; equivalent suppression in unmodified Lin's medium incubated aerobically required a concentration of 1.2 mg/L. Adjustment of basic fuchsin did not improve selectivity. With the exception ofSaccharomyces bayanus, all pure cultures of wildSaccharomycescould be differentiated, although the growth response ofS. diastaticuswas weak. All spoilage yeasts isolated from filled containers during two investigations grew well on crystal violet agar, suggesting that these media are well suited for routine use in the brewery. The modified media were suitable for use with polycarbonate membrane filters. Selective media containing ET80 could also be used with cellulose acetate membrane filters but not with any membrane filter containing cellulose nitrate.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0018

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

The effect of adding enzymes to a mixture of malt and sorghum during the brewing process was studied according to the following criteria: presence of soluble nitrogen-containing compounds and sugars, filterability, physical stability of the finished product, amount of extract yielded by raw materials in the malting process, and taste. Addition of Neutrase to the malt gave a significant increase in the nitrogen content of the wort and the beer. These low molecular weight nitrogen compounds (α-amino nitrogen, amino acids, albumose, and peptides) are decisive in determining the taste, foam, stability, and chill sensitivity qualities of beer. The advantages of adding enzymes such as Neutrase and the carbohydrases Termamyl and Cereflo in the brewing process are seen in the increased amounts of soluble nitrogen-containing compounds and carbohydrates, a decreased viscosity leading to higher filtration rates, an increased yield, and the possibility of using larger amounts of cheaper unmalted adjuncts to obtain a similar product.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0023

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Formulas and a calculator program that accurately calculate alcohol, real extract, original gravity, and calories from either refractive index or immersion refractometer scale readings and either specific gravity or apparent extract are explained. Two alternate computational approaches are compared and contrasted with the use of tables. One such program has been successfully used with a programmable printing calculator for routine quality control for more than nine months. This has resulted in increases in speed, operator convenience, and accuracy.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0027

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

ISSN:0361-0470    

DOI:10.1080/03610470.1980.11960130

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor

摘要:

Two new hop products, stabilized pellets and isomerized pellets, present analytical problems because of the low solubility of the magnesium (or calcium) salts of theα-acids and iso-a-acids formed during processing. An acidified extraction procedure that has given good results is described.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-38-0034

出版商:Taylor&Francis    

年代:1980

数据来源: Taylor