scholarly journals Studies on the cell-free biosynthesis of β-lactam antibiotics

1977 ◽  
Vol 162 (3) ◽  
pp. 681-687 ◽  
Author(s):  
P E Bost ◽  
A L Demain

Cell walls of Cephalosporium acremonium mycelia were lysed by enzyme preparations from either Helix pomatia (snail) digestive juice or Cytophaga. The yield of protoplasts depended on the lytic-enzyme preparation and the age of the culture, and it increased after the mycelia were pretreated with dithiothreitol. A cell-free preparation, obtained by osmotic lysis of protoplasts, synthesized labelled penicillin N from L-[14C]valine. Approx. 0.03-0.06% of the amino acid was incorporated into penicillin N. Under conditions of penicillin N synthesis, the broken-protoplast preparation failed to produce significant amounts of cephalosporin C or its precursors, deacetylcephalosporin C and deacetoxycephalosporin C.

1987 ◽  
Vol 33 (2) ◽  
pp. 123-127 ◽  
Author(s):  
Malcolm A. J. Finkelman ◽  
Alex Vardanis

A cell-free system catalysing the synthesis of β-glucan from uridine-diphosphoglucose was prepared from Aureobasidium pullulans. The activity was stable in the presence of 1 M sucrose and 10 mM MgSO4. The polymer produced was insoluble in H2O or acetic acid (0.5 M) and soluble in NaOH (0.5 M). Several enzyme preparations containing β-glucanase activity degraded the polymer to various extents. Synthesis of the polymer was enhanced by the presence of cellobiose and bovine serum albumin, but not by NaF or ATP. A Lineweaver–Burke plot of enzyme activity versus substrate concentration revealed biphasic kinetics. The enzyme preparation was subject to partial activation by trypsin and chymotrypsin.


1981 ◽  
Vol 194 (2) ◽  
pp. 645-647 ◽  
Author(s):  
G S Jayatilake ◽  
J A Huddleston ◽  
E P Abraham

In a cell-free system prepared by osmotic lysis of protoplasts of Cephalosporium acremonium, isopenicillin N is converted into penicillin N. The epimerase activity of the system is labile.


1990 ◽  
Vol 51 (1) ◽  
pp. 201-207 ◽  
Author(s):  
D. Pettersson ◽  
H. Graham ◽  
P. Åman

ABSTRACTThe efficacy of an enzyme preparation added to barley and rye-based diets given to broiler chickens and containing both β-glucanase and arabinoxylanase activities, was investigated and compared with a well characterized commercial enzyme preparation containing predominantly P-glucanase activity.Both enzyme preparations significantly improved body weight, cumulative food intake and food conversion efficiency for chickens given both barley- and rye-based diets. For the barley-fed chickens, on average a notable increase in body weight of 171 g at day 13 and 477 g at day 24 was noted, for both enzyme preparations. However, the preparation containing high amounts of both β-glucanase and arabinoxylanase activities was more effective in reducing the incidence of sticky droppings for rye-fed chickens, and, in comparison with previously published data, gave an optimal response at a lower supplementation rate. The results indicate that it is possible to reduce the protein content in enzyme-supplemented broiler chicken diets.


1987 ◽  
Vol 100 (4) ◽  
pp. 373-384 ◽  
Author(s):  
Yoshihiro Matsuda ◽  
Alan Musgrave ◽  
Herman Ende ◽  
Keith Roberts
Keyword(s):  

1982 ◽  
Vol 47 (5) ◽  
pp. 1530-1536 ◽  
Author(s):  
Ladislav Bilisics ◽  
Štefan Karácsonyi ◽  
Marta Kubačková

The presence of UDP-D-glucose 4-epimerase (EC 5.1.3.2) in the culture tissue of white poplar was evidenced. As found, the partially purified enzyme preparation contained UDP-D-glucose glucosyltransferase, UDP-D-galactose galactosyltransferase and non-specific enzymes able to cleave the uridine-diphosphate saccharides into the appropriate hexose monophosphates. The activity change of UDP-D-glucose 4-epimerase in tissue culture cells during the growth was in accord with changes in D-galactose content in cell walls and indicated the possibility to regulate the formation of polysaccharides containing D-galactose at the level of production of UDP-D-galactose in cells.


2008 ◽  
Vol 145 (1-4) ◽  
pp. 109-121 ◽  
Author(s):  
M.J. Ranilla ◽  
M.L. Tejido ◽  
L.A. Giraldo ◽  
J.M. Tricárico ◽  
M.D. Carro

2001 ◽  
Vol 48 (2) ◽  
pp. 443-451 ◽  
Author(s):  
P Wojtaszek

Cell walls are at the basis of a structural, four-dimensional framework of plant form and growth time. Recent rapid progress of cell wall research has led to the situation where the old, long-lasting juxtaposition: "living" protoplast--"dead" cell wall, had to be dropped. Various attempts of re-interpretation cast, however, some doubts over the very nature of plant cell and the status of the walls within such a cell. Following a comparison of exocellular matrices of plants and animals, their position in relation to cells and organisms is analysed. A multitude of perspectives of the biological organisation of living beings is presented with particular attention paid to the cellular and organismal theories. Basic tenets and resulting corollaries of both theories are compared, and evolutionary and developmental implications are considered. Based on these data, "The Plant Body"--an organismal concept of plants and plant cells is described.


Author(s):  
G. V. Agafonov ◽  
A. E. Chusova ◽  
A. V. Zelenkova ◽  
V. E. Plotnikov

One of the effective ways to increase the malt capacity of existing plants is the use of complex enzyme preparations. The enzyme preparation of complex action, penetrating into the grain during soaking or germination, affect its powdery body, contributing to the loosening of the cell membranes and the endosperm itself, thereby accelerating the process of malting. A purpose of researches is development of technology of fermented oat malt with the use of enzyme drug Ceramics 6ХМG. This enzyme preparation with complex action, has ?-amylase, protease, ?-glucanase, pentosanase, cellulose activities. As the object of study was taken oats Kozyr’ variety. Amylolytic ability of malt was determined by colorimetric method, proteolytic-refractometric method (according to Petrov). It was established that as a result of the use of Ceremix 6XMG in an amount of 0.1–0.5 kg per ton of grain, a more pronounced increase in amylolytic and proteolytic ability compared to the control (without the use of an enzyme preparation) occurs at a dosage of 0.5 kg per ton of grain. It is impractical to introduce Ceremix 6HMG in the amount of 0.5 kg per ton of grain, because the enzymatic activity of oat malt is only 6.4–6.6% higher than that of malt treated with an enzyme preparation in the amount of 0.3 kg per ton of grain. It was found that the use of the enzyme preparation Ceremix 6HMG allows to improve the quality of oat malt by improving organoleptic characteristics, increasing the mass fraction of extractives, as well as to intensify the process by reducing the drying time by 10-12 hours, which is important for the preservation of biologically active substances and energy resources.


1999 ◽  
Vol 65 (12) ◽  
pp. 5431-5435 ◽  
Author(s):  
Patricia M. McCabe ◽  
Neal K. Van Alfen

ABSTRACT Cryparin is a cell-surface-associated hydrophobin of the filamentous ascomycete Cryphonectria parasitica. This protein contains a signal peptide that directs it to the vesicle-mediated secretory pathway. We detected a glycosylated form of cryparin in a secretory vesicle fraction, but secreted forms of this protein are not glycosylated. This glycosylation occurred in the proprotein region, which is cleaved during maturation by a Kex2-like serine protease, leaving a mature form of cryparin that could be isolated from both the cell wall and culture medium. Pulse-chase labeling experiments showed that cryparin was secreted through the cell wall, without being bound, into the culture medium. The secreted protein then binds to the cell walls ofC. parasitica, where it remains. Binding of cryparin to the cell wall occurred in submerged culture, presumably because of the lectin-like properties unique to this hydrophobin. Thus, the binding of this hydrophobin to the cell wall is different from that of other hydrophobins which are reported to require a hydrophobic-hydrophilic interface for assembly.


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