Combined effects of ultrahigh vacuum and temperature on the viability of some spores and soil organisms. (73/655)

Considerably fewer spores of Bacillus stearothermophilus, B. megaterium, and Clostridium sporogenes were recovered than were spores of B. subtilis var. niger and Aspergillus niger after 4 to 5 days at 53 and 60 C in ultrahigh vacuum. There were no significant differences in the recoveries of these five organisms at 25 C and atmospheric pressure, and after exposure to 25 and -190 C in vacuum. At 60 C, a far greater decrease in viability was demonstrated for B. stearothermophilus, B. megaterium, and C. sporogenes in ultrahigh vacuum than at atmospheric pressure. Viable B. subtilis var. niger spores were not detected in an initial 10(7) spores after retention at 90 C and ultrahigh vacuum, and 10(4) spores were viable after 5 days at 90 C and atmospheric pressure from an initial 10(6) spores. Molds and actinomycetes in soil were particularly resistant up to 69 C in vacuum. Actinomycetes were the only soil organisms recovered so far at 120 C.  (+info)

GROWTH OF CELLULAR FORMS IN CULTURES OF CHROMATIN BODIES ISOLATED FROM BACILLUS MEGATERIUM. (74/655)

Chatterjee, B. R. (Baylor University College of Medicine, Houston, Texas) and Robert P. Williams. Growth of cellular forms in cultures of chromatin bodies isolated from Bacillus megaterium. J. Bacteriol. 85:623-627. 1963.-Chromatin bodies isolated from old cultures of Bacillus megaterium were capable of growing into protoplastlike cells when cultured in broth enriched with horse serum, yeast extract, adenosine triphosphate, and penicillin. A tendency toward formation of rod forms of bacteria was observed in such cultures. Omission of penicillin from the medium resulted in development of short bacterial forms. In 3 of 29 experiments, actual bacillary forms indistinguishable from the parent B. megaterium organism were recovered. Culture of the chromatin bodies in plain nutrient broth did not produce any growth. Inoculation on serum-enriched agar medium of a culture of chromatin bodies, after they had begun multiplication in serum-enriched broth, resulted in development of large bodies characteristic of L forms. Ability of chromatin bodies to grow was not affected by heating for 2 hr at 80 C or by sonic treatment for up to 25 min. The possible role of such resistant chromatin bodies in the latency and persistence of infectious diseases was discussed.  (+info)

OXIDATIVE ASSIMILATION BY BACILLUS MEGATERIUM. (75/655)

Clifton, C. E. (Stanford University, Stanford, Calif.). Oxidative assimilation by Bacillus megaterium. J. Bacteriol. 85:1365-1370. 1963.-Washed suspensions of Bacillus megaterium oxidized to CO(2) about 39% of the U-C(14)-glucose supplied and incorporated about 37% of the label by the time a marked break in the rate of O(2) consumption was noted. Almost one-half of the label was lost from the cells on acidification of the suspension. The remainder of the C(14) was present in the supernatant fluid, primarily in forms as yet unidentified, but other than carbohydrate. Both the Embden-Meyerhof and hexose monophosphate pathways of oxidation were involved. Endogenous respiration appeared to be inhibited only to a slight extent in the presence of an exogenous substrate. C(14) appeared in all fractions of the cells; the highest percentage of firmly bound C(14) was present in hot 5% trichloroacetic acid-insoluble matter. A decrease in C(14) content of the various fractions was noted during endogenous respiration of cells labeled during growth. Pyruvate and acetate were oxidized very slowly by B. megaterium. The results indicate the complexity of oxidative assimilation and the dynamic state of cellular metabolism.  (+info)

SURVEY OF THE BACTERIOCINES OF ENTEROCOCCI. (76/655)

Brock, Thomas D. (Indiana University, Bloomington), Barbara Peacher, and Deborah Pierson. A survey of the bacteriocines of enterococci. J. Bacteriol. 86:702-707. 1963.-A survey has been made of bacteriocine production by a wide variety of well-characterized strains of group D streptococci. On the basis of spectrums and sensitivity to chloroform, heat, and proteolytic enzymes, five distinct bacteriocines can be defined. Type 1 is produced by all Streptococcus zymogenes (S. faecalis var. zymogenes) strains, is active against a wide variety of gram-positive bacteria, and is also a hemolysin. Type 2 is produced by some S. liquefaciens (S. faecalis var. liquefaciens) strains, and acts on many enterococci as well as on certain other lactic acid bacteria. Type 3 is produced by certain strains of both S. faecalis and S. faecium, and inhibits a wide variety of group D streptococci, but is inactive against all other lactic acid bacteria tested except Leuconostoc citrovorum. Type 4 is produced by certain S. faecium strains and resembles in certain ways the type 3 activity, but differs from it in other ways. Type 5 has been found to be produced by only one proteolytic strain of S. zymogenes, and this bacteriocine has a very narrow spectrum. The strain that produces this bacteriocine also produces type 1 activity. No strain is sensitive to a bacteriocine of the type it produces.  (+info)

Levels of oxidized and reduced pyridine nucleotides in dormant spores and during growth, sporulation, and spore germination of Bacillus megaterium. (77/655)

Dormant spores of Bacillus megaterium contained no detectable reduced nicotinamide adenine dinucleotide (NADH) or reduced nicotinamide adenine dinucleotide phosphate (NADPH) despite significant levels of the oxidized forms of these nucleotides (NAD and NADP). During the first minutes of spore germination there was rapid accumulation of NADH and NADPH. However, this accumulation followed the fall in optical density that is characteristic of the initiation of spore germination. Accumulation of NADH and NADPH early in germination was not blocked by fluoride or cyanide, and it occurred even when germination was carried out in the absence of an exogenous source of reducing power. In addition to pyridine nucleotide reduction, de novo synthesis also began early in germination as the pyridine nucleotide levels increased to those found in growing cells. Midlog-phase cells grown in several different media had 20 to 35 times as much total pyridine nucleotide as did dormant spores. However, as growth and sporulation proceeded, the NADH plus NAD level fell four- to fivefold whereas the NADPH plus NADP level fell by a lesser amount. From min 10 of spore germination until midway through sporulation the value for the ratio of NADH/NAD is about 0.1 (0.03 to 0.18) while the ratio of NADPH/ANDP is about 1.4 (0.3 to 2.4). Comparison of these ratios in log-phase versus stationary phase (sporulation) growth in all three growth media tested did not reveal any common pattern of changes.  (+info)

SPORULATION IN PROTOPLASTS AND ITS DEPENDENCE ON PRIOR FORESPORE DEVELOPMENT. (78/655)

Fitz-James, Philip C. (University of Western Ontario, London, Ontario, Canada). Sporulation in protoplasts and its dependence on prior forespore development. J. Bacteriol. 87:667-675. 1964.-Phase-contrast and electron microscopy were used to decide whether cells from late growth or sporulating cultures could, where converted into protoplasts, complete the process of sporulation. The cell wall was found essential to the development of the forespore. Incomplete forespores formed a satellite protoplast. Completed forespores were enclosed by the sporangial protoplast, and only these or later forms were able to complete sporulation in protoplasts.  (+info)

USE OF CALCIUM DIPICOLINATE FOR ENUMERATION OF TOTAL VIABLE ENDOSPORE POPULATIONS WITHOUT HEAT ACTIVATION. (79/655)

A method, based on germination with 50 mm CaCl(2) and 40 mm sodium dipicolinate (Na(2)DPA), was developed for the determination of total viable counts of bacterial spores requiring heat activation. Incorporation of these germinating agents into Tryptone Glucose Extract Agar permitted plate-count enumeration of essentially 100% of Bacillus subtilis strain 5230 spores without a heat treatment. Other spore suspensions were surveyed for their response to CaCl(2) and Na(2)DPA, and for the subsequent removal of the heat-activation requirement for enumeration of maximal populations.  (+info)

ACCUMULATION OF RIBONUCLEIC ACID IN BACTERIAL NUCLEAR PREPARATIONS DURING TREATMENT OF WHOLE CELLS WITH 8-AZAGUANINE, TETRACYCLINES, AND OTHER INHIBITORS. (80/655)

Ezekiel, David H. (Albert Einstein Medical Center, Philadelphia, Pa.). Accumulation of ribonucleic acid in bacterial nuclear preparations during treatment of whole cells with 8-azaguanine, tetracyclines, and other inhibitors. J. Bacteriol. 87:755-760. 1964-Ribonucleic acid (RNA), synthesized in Bacillus megaterium KM during chloramphenicol treatment, accumulates in the chromatin-containing cell fraction obtained by lipase treatment of protoplasts. To determine whether this phenomenon is the cause or an effect of the inhibition of protein synthesis, or neither, other inhibitors of protein synthesis were studied. Chloramphenicol, tetracyclines, azaguanine, and, to a lesser extent, 7-azatryptophan permitted RNA synthesis while inhibiting protein synthesis. In each case, RNA accumulated in the chromatin body fraction. Azaguanine at 5 mug/ml causes more RNA accumulation than at 15 mug/ml, but allows some protein synthesis. Other inhibitors of protein synthesis inhibit RNA synthesis as well, and no accumulation is seen. The evidence favors the hypothesis that inhibition of protein synthesis causes the accumulation in the nuclear fraction. The possible nature and intracellular locus of the RNA accumulation are discussed briefly.  (+info)