摘要:

AbstractA procedure described for the partial purification of suspensions of the organisms of psittacosis utilizes tryptic digestion, calcium chloridedextran sulfate precipitation, and centrifugation through a sucrose barrier. More than 40% of the organisms in the original suspension are recovered in 80% of the original volume, with approximately 95% of the lipids and 85% of the proteins removed. This method is suggested as a preliminary purification procedure in laboratories desiring relatively large amounts of purified agent for studies on metabolism, physical properties, or antigenicity of the organism. Significant aspects of the investigations leading to the selection of the procedures are included.

ISSN:0006-3592    

DOI:10.1002/bit.260070402

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe response of heterogeneous populations to shockloading was studied under a variety of operational conditions using synthetic wastes consisting of glycerol, glucose, and a mixture of glucose and glycerol. In all experiments, the cells were acclimated to glycerol. The addition of glucose as a shockloading at various times during the aeration period caused an immediate cessation of glycerol metabolism, and glycerol was not again actively metabolized until all glucose had been assimilated. Experiments conducted at various initial sludge concentrations showed that this effect was not dependent upon biological solids level. Glycerol metabolism was also blocked when glucose was applied as a shockloading to a system operating under severe nitrogen deficiency, further reenforcing the conclusion that there is a blockage mechanism for catabolic pathways which operates to suppress enzyme function rather than enzyme synthesis. It was also found that considerable amounts of metabolic intermediates or end products were released during glucose metabolism regardless of the presence or absence of glycerol. In systems containing a source of nitrogen, these products were metabolized after dissimilation of glucose. In resting cell suspensions, the metabolic intermediates were not subsequently removed, indicating that their metabolism depended upon the synthesis of new enzymes. Using old cell sludge, concurrent rather than sequential removal of glycerol and glucose was observed. The results using two component (C6C3) carbon sources were in general the same as for C6C6synthetic wastes. The results provide further evidence for the generality of sequential substrate removal, and suggest that the metabolite suppressing catabolism of glycerol lies below the triose le

ISSN:0006-3592    

DOI:10.1002/bit.260070403

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe growth ofThiobacillus Thiooxidans, utilizing sulfur in three media, was studied by observing changes in halfcell emf, bacterial cell count, and acid production, all as a function of time. A comparison of the biological halfcell emf with comparable control halfcells reveals thatT. thiooxidansmakes an electrochemical contribution to halfcell voltage. A change from the more complex medium of Skerman's mineral salts to ATCC allowed a clearer delineation of the ability ofT. thiooxidansto make an electrochemical contribution. Reproducible biological halfcell emf's were obtained when the ferrous sulfate was removed from the ATCC medium. One halfcell, consisting ofT. thiooxidansutilizing sulfur in ATCC, was observed over a 111‐day period. During this time, the initial halfcell voltage of −0.35 V. decreased to a value of −0.64 V. (hydrogen emf series).T. thiooxidans, in utilizing sulfur, produces only sulfate ion, thereby simplifying the identification of an electrochemical contribution during g

ISSN:0006-3592    

DOI:10.1002/bit.260070404

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

年代:1965

数据来源: WILEY

摘要:

AbstractThe electrochemical activity of the individual chemicals in the nutrient medium for growth ofThiobacillus thiooxidanswas studied along with the effect of the gases in equilibrium with their solutions. Several chemicals were active individually; however, the magnitudes, as measured by changes in half‐cell potential, were less than that observed whenT. thiooxidanswas present in their composite mixture. Sterilized Skerman's mineral salts and the American Type Culture Collection (without ferrous sulfate) media were not sensitive electrochemically to changes from pure oxygen to nitrogen atmospheres. WhenT. thiooxidanswas present in these media, the biological half‐cell emf became sensitive to changes in the oxygen content of the atmosphere in equilibrium with the organism and nutrient. The ability ofT. thiooxidansto make an electrochemical contribution, as registered by a platinum electrode, is substantiated further by these investigati

ISSN:0006-3592    

DOI:10.1002/bit.260070405

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

年代:1965

数据来源: WILEY

摘要:

AbstractA new type of mixer that utilizes the Bernoulli effect has been found highly useful for providing gentle agitation in suspension cultures of fragile mammalian cells in culture volumes up to 6 l.

ISSN:0006-3592    

DOI:10.1002/bit.260070406

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

年代:1965

数据来源: WILEY

摘要:

AbstractA substrain ofBacillus cereus569/H produced above 10,000 units of penicillinase/ ml. when grown in a pilot‐plant fermentor using a medium containing Casamino acids techn. (Difco) or N‐Z‐Amine type B (Sheffield), and salts. Simplified purification and concentration procedures give an overall yield of 50‐65% enzyme. The freeze‐dried enzyme preparation had a good storage stability in vacuumsealed ampules kept at 4, 30, and 37°C. In vials containing air in the head space, partial inactivation occurred in two months at 30 and 37°C. The freezedried preparation showed satisfactory performance in the production of yoghurt fer

ISSN:0006-3592    

DOI:10.1002/bit.260070407

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

年代:1965

数据来源: WILEY

摘要:

AbstractA 1‐l. fermentor was designed and tested for use as a tissue‐culture vessel. It features a temperature control device, impeller agitation without the necessity of a shaft seal, and a means of measuring, recording, and controlling both pH and oxidation‐reduction potential (ORP). Tests have shown the ORP to change fairly rapidly with impeller speed variations under conditions of a continuous carbon dioxide‐air overlay. Working with strain L mouse fibroblasts (Earle), cell counts of more than 1.25 ×106ml., without centrifugation and medium renewal, were achieved, and cell counts were maintained above 1 ×106for more than 30 hr. With the vessel studied, pH control was ±0.05, the ORP control was ±10 mV. Controlled environments for tissue‐cell metabolic studies are entirely feasible wit

ISSN:0006-3592    

DOI:10.1002/bit.260070408

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

年代:1965

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260070409

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

年代:1965

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260070401

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

年代:1965

数据来源: WILEY