摘要:

AbstractAn interesting cholinergic compound has been isolated from the fungusRhizoctonia leguminicola grown on extracts of red clover hay. The compound was characterized as 1‐acetoxy‐8‐aminooctahydroindolizidine and given the name “slaframine.” It has been shown that slaframine is not the active compound but is converted to the active metabolite by liver microsomal enzymes. Physiological studies with slaframine point out that it is a potent stimulator of exocrine glands. In addition, its long duration of action and low toxicity suggest that it may have therapeutic value. Preliminary data suggest that slaframine is a potent stimulator of pancreatic activity, and its long duration of action results in a stimulation of protein synthesis by

ISSN:0006-3592    

DOI:10.1002/bit.260100402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractSubstances which cause emesis in pigeons were extracted from corn (Zea mays) artificially inoculated withFusarium graminearumand from liquid culture medium inoculated withF. moniliforme, F. roseum, F. poae, F. culmorum, andF. nivale. Emetic preparations were obtained also from infected wheat (Triticum aestivumL. em. Thell), (Hordeum vulgareL. em. Lam), and durum (Triticum durumDesf). Partial purification resulted from chromatography with columns of cellulose and DEAE cellulose and with thin layers of silica gel. Two active materials were obtained from liquid culture ofF. moniliformebut only one from infected cereals. Emetic preparations fromF. moniliformeand infected cereals contained a polypeptide as a minor component. Ultraviolet and infrared spectrums, elemental analyses, refractive indices, and amino acid composition of the emetic from corn and one of the emeties from liquid culture ofF. moniliformewere similar but not identical. Attempts to crystalline these emetics and to characterize them were unsuccessful.

ISSN:0006-3592    

DOI:10.1002/bit.260100403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractColisan has the formula Lys3Val4Leu3IleTyr and a molecular weight of approximately 1500. NeitherN‐terminal norC‐terminal group have been found. The peptide is highly resistant to hydrolysis by proteolytic enzymes (pepsin and trypsin). The ϵ‐amino groups of lysine are indispensable for biological activity, since either deamination or acetylation completely inactivates Colisan. A comparative study with basic peptides like polylysine demonstrated their similarity of action, on one hand, and an antagonistic effect to Colisan, on the other. The fast action of the antibiotic and the specific effect on the cell membranes of many different biological systems (Entameba, Paramecium, erythrocytes, smooth muscle, and others) support the hypothesis that the primary damage occurs in the membrane with consequent alteration of permeability. The leakage of intracellular material (histamine) from mast cells after application of Colisan is in accord with this hypothesis. The results strongly suggest that the biological activity of the peptide is based essentially, but not exclusively, on its basic cha

ISSN:0006-3592    

DOI:10.1002/bit.260100404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractMany hyphomyceteous fungi have been found to produce closely related toxic metabolites which form the class of compounds called scirpenes. The structures of those compounds are reviewed and current studies on their biological activity and possible implication in moldy corn poisoning are discussed.

ISSN:0006-3592    

DOI:10.1002/bit.260100405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractToxicological investigations were conducted on two new antibiotics, Muconomycin A and Muconomycin B. Thesenon‐nitrogenous antibiotics were found to be highly toxic and capable of inducing profound inflammation in the peritoneal cavity of male albino rats. Either antibiotic produced large volumes (10–20 ml) of inflammatory exudate even when injected intraperitoneally in quantities of 1.6 × 10−10moles. An extensive profile of the electrolytes and proteins found in inflammatory exudates was developed. Simultaneous assays of the blood serum of treated rats provided a basis for comparing the concentrations of constituents of serum with those of the exudate. The results of these assays showed that the exudate contained lower concentrations of sodium and proteins, and greater amounts of potassium, calcium, and phosphorus than the serum. Chloride ion concentrations were variable. Since previous work showed that one of the manifestations of toxicity of these substances was the production of creatinuria, further studies were carried out with ATP/Creatine Phosphotransferase. These studies show that these antibiotics are potentin vitroinhibitors of the enzyme ATP/Creatine Phosphotrans

ISSN:0006-3592    

DOI:10.1002/bit.260100406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260100407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractThe effect of NaCl on the yield of biological solids and on the ability of continuously cultured heterogeneous microbial populations to remove substrate was assessed by changing the salt concentration in the inflowing synthetic waste. During the period of increasing the salt concentration to 30,000 mg/l the system could not maintain a high substrate removal efficiency. However, after an acclimation period the system regained its former efficiency. Upon diluting the salt out of the system, a significant rise in cell yield was noted as the salt level passed through the range 8,000–10,000 mg/l. It was found that steady operation at a salt level of 8,000 mg/l sustained the cell yield at a high leve

ISSN:0006-3592    

DOI:10.1002/bit.260100408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractAn analysis is presented of the effects on substrate utilization and cell growth of varying the volume distribution of and the input distribution to a model continuous‐culture unit consisting of three stirred tanks. The model is used to establish the best volume and input distributions and to indicate the effects of mixing imperfections. The Michaelis‐Menten rate expression is utilized, including an endogenous respiration term, and results are presented on unique triaxial charts. Of the distributions considered, maximum substrate utilization is achieved with 60% of the total volume in the first stage, 20% in the second stage, and 20% in the third stage and with all of the input to the first stage. At a constant fractional input to the third stage; variation in the ratio of inputs to the first and second stages has virtually no effect, except in the case that a critical dilution is exceeded. At a constant input ratio to the first two stages, an increase in the fractional input to the third stage always decreases efficiency. Three stages, regardless of relative size, are always better than one. Except for endogenous respiration effects, cell growth parallels substrate utilizat

ISSN:0006-3592    

DOI:10.1002/bit.260100409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractACandidasp. was grown on a fraction ofn‐alkanes (dodecane 22%, tridecane 48%, tetradecane 28%) as sole carbon source. The growth rate was increased most markedly by using high concentrations ofn‐alkanes (16.7% v/v). When grown in a 5 liter fermentor, the yeast reached its highest yield (60 g. of cell dry wt/l) with a concomitant high yield of fatty acids (21 g of fatty acids/l), by using a nitrogen‐deficient medium. To achieve good growth, it was essential to use an inoculum (1 part into 10) of rapidly growing cells and beneficial to increase the agitation rate gradually once growth had begun. After 108 hr maximum conversions of substrate to product were: 71.5% (w/w) for alkanes into cells and 24.8% (w/w) for alkanes into fatty acids. Of the, total fatty acids at the end of the fat‐accumulating phase of growth 54% were shorter in chain length than palmitic acid (C16H32O2). When grown on glucose, as sole carbon source, less than 2% of the total fatty acids were shorter than palmitic acid. Whenn‐alkanes were added to cells growing on glucose, short‐chain fatty acids (C10to C14) were synthesized immediately, indicating a derepressed enzyme system for hydrocarbon assimilation and the absence of diauxie. The production of these acids was at the apparent sacrifice of linoleic acid synthesis. In spite of the high conversion ratios, it is concluded that it would be uneconomical to produce fatty acids, even expensive ones such as lauric acid, by microbial transformation

ISSN:0006-3592    

DOI:10.1002/bit.260100410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY

摘要:

AbstractAn automatically working test arrangement for the permanent analysis of O2and CO2in microbiological cultures is described. The measuring principle is based on the paramagnetic properties of oxygen and on the absorption of infrared by carbon dioxide. The preparation of the gas for measuring and the correction of the recording are indicated. The formula of correction was programmed and the values were calculated for a range of 3%. The routine correction of analysis values is done with a nomogram established on the basis of these individual values. The advantages of the described test arrangement are illustrated by two examples of growth experiments onSaccharomyces cerevisiae.

ISSN:0006-3592    

DOI:10.1002/bit.260100411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1968

数据来源: WILEY