Sonic disruption of Azotobacter vinelandil

Ballistic disruption of Penicillium chrysogenum cells

The use of glass beads in a high-speed mixing device to rupture organisms was applied to molds. The use of a mixer in which the propellor shaft enters from the top into a metal mixing chamber made it possible to immerse the whole device in a salt water and ice mixture so that the temperature of the glass-bead slurry could be kept below 5 C without difficulty. Mycelia, glass beads, and buffer in a 1:2:3 (w/w) ratio gave above 95% breakage in 15 min with Penicillium chrysogenum cells and in 4 min with Rhizopus nigricans. Some of the factors influencing breakage are discussed.

Effect of sonic treatment on pure cultures and aggregates of bacteria

Pure cultures of a variety of bacteria were treated with ultrasonic energy using a sonic probe. Fractions of organisms killed at different sonic energies were calculated, and Streptococcus mutans was 600 times more resistant than Fusobacterium nucleatum, the most sensitive organism tested. The effects of sonic treatment on aggregates of bacteria were examined, and the results were interpreted as a model of the events that probably occur during the sonic dispersion of dental plaque.

Inhibition of oxygen utilization and destruction of ubiquinone by ultraviolet irradiation of Thiobacillus thiooxidans

Ultraviolet (UV) irradiation inhibited sulfur oxidation by cells of Thiobacillus thiooxidans. Sulfur-oxidizing activity decreased as the exposure time to UV light increased. A loss of the ability of cells of fix CO(2) paralleled the loss of sulfur-oxidizing activity. UV light photoinactivated ubiquinone purified from T. thiooxidans. The same percentage of sulfur-oxidizing activity and ubiquinone was destroyed after 15 min of UV exposure. Both the photoinactivation of sulfur oxidation and ubiquinone followed first-order reaction kinetics. The specific rate constants for both photoinactivations were nearly equal. Cells completely inactivated by UV light contained no ubiquinone. Ubiquinone was found to be a component of the cell wall-membrane complex.

LOCATION OF PROTEINASE, PEPTIDASE, CATALASE, AND NADH OXIDASE IN CELLS OF STAPHYLOCOCCUS LACTIS

Cells of a strain of Staphylococcus lactis were disrupted by lysozyme treatment and fractionated by differential centrifugation. Proteinase and reduced nicotinamide adenine dinucleotide oxidase were found in the membrane fraction; peptidase and catalase were found in the cytoplasm. Similar results were obtained when cells were broken by sonic oscillation. Proteinase of this organism is considered to be a surface-bound enzyme.

LOCALIZATION OF CAROTENOID PIGMENT IN THE CYTOPLASMIC MEMBRANE OF XANTHOMONAS JUGLANDIS

Stephens, William L. (University of California, Davis), and Mortimer P. Starr . Localization of carotenoid pigment in the cytoplasmic membrane of Xanthomonas juglandis . J. Bacteriol. 86: 1070–1074. 1963.—The kinetics of release of carotenoid pigment from cells of Xanthomonas juglandis , disrupted by sonic or ballistic treatment, showed the pigment to be localized in the cell envelope. Cells subjected to ballistic disintegration released carotenoid at a rate identical to that of a membrane component (reduced nicotinamide adenine dinucleotide oxidase) and at a slightly higher rate than a wall component (hexosamine). Thus, the membrane portion of the cell envelope is the most probable locus of the unique carotenoid pigment of X. juglandis .

KINASES OF STREPTOCOCCUS FAECALIS I

Moore, L. Daneo (University of Pennsylvania, Philadelphia) and D. J. O'Kane . Kinases of Streptococcus faecalis . I. Enzyme localization. J. Bacteriol. 86: 766–772. 1963.—Cell-free extracts of Streptococcus faecalis 10C1 were found to contain a membrane-associated, particulate hexokinase with activity toward glucose, fructose, mannose, and, to a lesser extent, galactose, gluconate, and mannitol. In addition, the cell cytoplasm contained kinases specific for fructose, mannose, and galactose. No specific kinases were found for gluconate or mannitol, although in the presence of mannitol adenosine triphosphate was utilized by a cytoplasmic fraction. The possibility is discussed that the main pathways of gluconate and mannitol metabolism are oxidation followed by phosphorylation.

THE LYSIS OF ACETOBACTER XYLINUM

Lysis of about 90% of the cells of Acetobacter xylinum by lysozyme may be obtained after 2 hours at pH 8.1 in phosphate–citrate buffer. The cell population is heterogeneous since the remaining 10% of the cells do not lyse, even on repetition of the above treatment. The lysozyme does not cause the dissolution of all the bacterial wall, as in other lysozyme-sensitive species, but appears to attack only a limited, local area on the surface of the bacterium. Following the local weakening of the wall, the cell contents escape into the medium leaving a distinct "hull" with the same size and shape as the cell. The oxidative capacity of the lysed cells is the same as that of the whole cells. Reasons for the heterogeneity of the bacterial wall, both within and between cells, remain obscure.

LOCATION OF PROTEINASE IN CELLS OF A SPECIES OF MICROCOCCUS

Micrococcus sp. (ATCC No. 407) grown in tryptone yeast extract broth produced proteinase active against casein. In broth containing 2.0% sodium chloride, about 90% of the proteinase was in the culture supernatant; in broth without added salt, about 66% was associated with the cells. When such cells were washed with 2% sodium chloride, about one-half the associated proteinase was released. Presumably this saline-extractable portion of the proteinase is loosely held at the ceil surface, possibly by ionic linkages. A further yield of proteinase could be obtained from saline-washed cells by treatments that ruptured the cells or altered the permeability of the cell membrane. This so-called bound proteinase became accessible to the substrate, but was not liberated into the suspending medium on lysozyme treatment of saline-washed cells. When lysozyme-treated cells were fractionated, the proteinase was found with the cytoplasmic membrane fraction. During sonic treatment of saline-washed cells, the bound. proteinase was released without appreciable disintegration of the cell envelope suggesting that it may not be an integral part of the cell membrane.

Location of enzymes in Azotobacteragilis

Robrish, Stanley A. (University of California, Davis) and Allen G. Marr. Location of enzymes in Azotobacter agilis. J. Bacteriol. 83: 158-168. 1962.-If the cells of Azotobacter agilis are disrupted by osmotic shock, respiratory enzymes and the compounds characteristic of cell wall and cytoplasmic membrane are recovered almost completely in large particles. The large particles obtained by osmotic shock were found by electron microscopy to consist of cell wall, cell membrane, and an internal membrane appearing as either vesicles or tubules in section. These envelopes are free of all the soluble cytoplasmic material and are essentially free of ribosomes. Small particles obtained by osmotic shock are ribosomes; small particles obtained by sonic oscillation consist of both ribosomes and amorphous material, presumably fragments of the envelope.

THE OXIDATION OF SUCCINATE IN EXTRACTS OF XANTHOMONAS PHASEOLI

Succinoxidase and succinic dehydrogenase were found in cell-free extracts of Xanthomonas phaseoli, obtained by sonic oscillation, and remained largely in the supernatant solution after ultracentrifugation. The effect of time of exposure of the cells to sonic oscillation on cell breakage was found to follow first order reaction kinetics, as was the "solubilization" of succinic dehydrogenase and succinoxidase. It appears that the two enzymatic activities are released from the cell in a particulate form which is further fragmented on continued treatment in the sonic oscillator.The clear supernatant solution obtained after ultracentrifugation of the cell-free extract was found to contain those members of the electron transport chain which had previously been found in the intact cell, namely, flavoprotein and cytochromes b1, a1, and a2. These substances could be reduced by the addition of succinate. Malonate prevented this reduction. The effects of various inhibitors on the succinoxidase system and on succinic dehydrogenase are presented and discussed in relation to the operation of the electron transport chain in the oxidation of succinate by this organism.