摘要:

AbstractA procedure for sterilization of microbiological media with β‐propiolactone has been developed. Special attention was paid to the maintenance of mild conditions to enable the treatment of media sensitive to high temperature or low pH. The maximum temperature allowed was 40°C. and automatic neutralization of acid produced during hydrolysis was effected by the use of titration unit. The apparatus could be used for several successive sterilization cycles without disconnect

ISSN:0006-3592    

DOI:10.1002/bit.260070122

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

年代:1965

数据来源: WILEY

摘要:

AbstractIn a study of fermentation methods of producing amphotericin B‐14C, a variety of C‐14 labeled precursors were added to cultures of the amphotericin‐B producing streptomycete growing in a glucose‐cottonseed meal medium. Acetate‐14C and propionate‐14C were efficiently incorporated into the amphotericin‐B while formate‐14C, glucose‐U‐14C and methi

ISSN:0006-3592    

DOI:10.1002/bit.260070123

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

年代:1965

数据来源: WILEY

摘要:

AbstractA small fraction, about 0.05%, of the microorganisms in milk are resistant to pressure to at least 150,000 p.s.i. The pressure‐resistant microorganisms were shown to be mainly bacterial spores. Some of the pressure‐resistant organisms were identified. The lethal effect of pressure is more pronounced in the solid phase than in the liquid phase of water.B. subtiliswas found to be capable of surviving solid‐phase transitions from Ice II, III, and V to Ice I. The lethal effect of high pressure in the liquid phase of water was found not to be counteracted by an increase in temperature. The pressure resistance ofB. subtiliswas found to be maximum around neutral or slightly basic pH. The damaging effect of low and high pH are counteracted by sodium chloride and glucose. It is suggested that the primary mechanism of protein denaturation by pressures above 30,000 p.s.i. is ionization and formation of ionic bonds between charged groups on proteins, altering their solub

ISSN:0006-3592    

DOI:10.1002/bit.260070124

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

年代:1965

数据来源: WILEY

摘要:

AbstractA method to make purified polysaccharide synthesized exocellularly from cereal carbohydrates by the bacteriumXanthomonas campestrisNRRL B‐1459 and a characterization of its properties have been reported previously by this Laboratory. Because of increasing commercial interest in a less purified polymer, we have extended our work to include production of a lower cost industrial‐grade product. Fermentation of media containing 2.25% corn sugar, seeded with 5% inoculum ofX. campestrisNRRL B‐1459 and cultured aerobically at 82°F., is complete in 96 hr. The viscous fermented broth contains about 1.5% polymer. A tan product containing approximately 60% polymer and having good viscosity characteristics is obtained by drum drying the fermented broth at steam pressures below 40 p.s.i.g, 287°F. Drying at higher temperatures adversely affects viscosity. A good product is also obtained by spray drying. Cost estimates indicate that 5 million lb./yr. of dried crude solids could be produced for 37 cents/lb. by drum drying or for 41 cents a pound by spray

ISSN:0006-3592    

DOI:10.1002/bit.260070125

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

年代:1965

数据来源: WILEY

摘要:

AbstractA method is described for the isolation of bacterial polysaccharide B‐1459 from aqueous dispersion as a calcium hydroxide complex. The polysaccharide is liberated in fibrous form from the complex by means of hydrochloric acid in methanol solution. Overall recovery of the polysaccharide from aqueous dispersion is 85%. Direct conversion of the insoluble calcium hydroxide complex to aqueous polysaccharide solution appears to be a low‐cost procedure for preparing viscous solutions for industrial

ISSN:0006-3592    

DOI:10.1002/bit.260070126

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

年代:1965

数据来源: WILEY

摘要:

AbstractSteam corrosion and steam corrosion inhibition of dental and surgical instrument materials during autoclave sterilization have been investigated. The corrosion tests were performed on carbon steel test samples and on round dental burrs. Cyclohexylamine or decylamine were used as corrosion inhibitors, added to the “feed water,” i.e., deionized water, to a concentration of 0.1%. Before the corrosion experiment the surfaces of the test materials were standardized and calibrated by means of ultrasonic treatment. After the experiment the corrosion products were removed from the test samples or burrs using the same ultrasonic cleaning. Deionized water was used as cleaning liquid, and was then analyzed for the amount of Fe dissolved. The amount of corrosion was expressed as μg. Fe/cm.2sample surface area or μg. Fe/burr. The results show that considerable corrosion occurs when carbon steels are exposed to steam during autoclaving, but if cyclohexylamine or decylamine is added to the steam under the otherwise unchanged experimental conditions the total corrosion was reduced by 96–99%. No cytotoxic effect on HeLa cells could be detected with surface products possibly containing traces of amine and/or amine salts—nor with corrosion products alone—when these products were removed from the test materials by means of ultrason

ISSN:0006-3592    

DOI:10.1002/bit.260070127

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.260070101

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

年代:1965

数据来源: WILEY