bluuebunny/crossref_metadata_2025 huggingface dataset:
Undecompressed microbial populations from the deep sea
Authors: Jannasch H J , Wirsen C O , Taylor C D
Published: January 2020

Metabolic transformations of glutamate and Casamino Acids by natural microbial populations collected from deep waters (1,600 to 3,100 m) were studied in decompressed and undecompressed samples. Pressure-retaining sampling/incubation vessels and appropriate subsampling/incubation vessels and appropriate subsampling techniques permitted time course experiments. In all cases the metabolic activity in undecompressed samples was lower than it was when incubated at 1 atm. Surface water controls showed a reduced activity upon compression. The processes involving substrate incorporation into cell material were more pressure sensitive than was respiration. The low utilization of substrates, previously found by in situ incubations for up to 12 months, was confirmed and demonstrated to consist of an initial phase of activity, in the range of 5 to 60 times lower than the controls, followed by a stationary phase of virtually no substrate utilization. No barophilic growth response (higher rates at elevated pressure than at 1 atm) was recorded; all populations observed exhibition various degrees of barotolerance.
Use of activated charcoal for the removal of patulin from cider
Authors: Sands D C , McIntyre J L , Walton G S
Published: January 2020

Penicillium urticae (NRRL 2159A) was grown in culture broth containing 1 muCi of [1-14C-A1acetate to produce [14C]patulin. [14C]patulin was purified from the broth and added to apple cider. After the patulin concentration of the cider was adjusted to 30 mug/ml with unlabeled patulin, the cider was subjected to various charcoal treatments. [14C]patulin was completely removed by shaking the cider with 20 mg of activated charcoal per ml and by eluting the cider through a 40- to 60-mesh charcoal column. Activated charcola at 5 mg/ml reduced patulin in naturally contaminated cider to nondetectable levels.
Oxidation of arsenite to arsenate by Alcaligenes faecalis
Authors: Philips S E , Taylor M L
Published: January 2020

Alcaligenes faecalis, resistant to the toxic effects of 0.01 M sodium arsenite, was isolated from raw sewage and shown to be capable of oxidizing arsenite to arsenate. When the organisms were grown in chemically defined medium, this conversion was due to the appearance at stationary phase of an intracellular, oxygen-sensitive, inducible enzyme and/or component of the electron transport system; when the organisms were grown in a nutrient broth-yeast extract medium, the enzyme appeared in the late exponential phase of growth. The presence of 0.02 M arsenite in the culture medium affected neither growth rate nor final cell yield.
Defined conditions for synthesis of Bacillus cereus enterotoxin by fermenter-grown cultures
Authors: Glatz B A , Goepfert J M
Published: January 2020

A strain of Bacillus cereus produced high levels of enterotoxin when grown in a semidefined medium in a laboratory scale fermenter. The optimum conditions for enterotoxin synthesis by cultures grown in this medium, which contained Casamino Acids and yeast extract, were found to be: inoculation of vigorously gorwing culture at the 1% level, addition of glucose at a concentration of 1%, control of culture pH at 8.0, incubation at 32 degrees C, use of a moderate stirring rate, and addition of air at low flow rates to minimize foaming. The enterotoxin yield in fermenter-grown cultures was approximately 20 to 50 times higher than the yield obtained in shake flask cultures.
Beneficial effect of catalase treatment on growth of Clostridium perfringens
Authors: Harmon S M , Kautter D A
Published: January 2020

Several common plating media were tested for their ability to support growth of Clostridium perfringens after storage of the plates for 1 to 10 days at 4 and 25 degrees C with and without subsequent addition of catalase. Liver-veal (LV) agar and brain heart infusion (BHI) agar quickly become incapable of supporting growth after storage without added catalase, whereas Shahidi Ferguson perfringens (SFP) agar and Brewer anaerobic (BA) agar were less affected. Plate counts of C. perfringens on untreated LV and BHI agars stored 3 days at 25 degrees C showed a reduction of 98.2%, whereas counts on SFP and BA agars were reduced by 13.6% and 46.2%, respectively. Addition of 1,500 U of beef liver catalase to the surface of the 3-day-old agars before incubation resulted in substantial restoration of their growth-promoting ability. Counts of colonies on LV, GHI, SFP, and BA agars with added catalase were usually 20 to 90% higher than untreated controls. Similar results were obtained using purified catalase, fungal catalase, and horseradish peroxidase. These results suggest that inhibition may be due to peroxide formed during storage and incubation and that additon of catalase provides near optimum conditions for growth of C. perfringens on these media.
Identification of Thiobacilli by Replica Plating on Thallous Sulfide Paper
Authors: Galizzi Alessandro , Ferrari Eugenio
Published: January 2020

Colonies of
Thiobacillus thioparus
and
T. thiooxidans
grown on thiosulfate medium can be identified by replica plating on thallous sulfide paper.
Comparison of different purification procedure for extraction of staphylococcal enterotoxin A from foods
Authors: Niskanen A , Lindroth S
Published: January 2020

Different procedures commonly used for extraction, purification, and concentration of staphylococcal enterotoxins from foods were investigated with 131I- and 125I-labeled staphylococcal enterotoxin A. Loss of labeled enterotoxin A was compared with loss of total nitrogen. The results showed that in most of the common procedures, such as gel filtration, ion exchange, and heat treatment, the percentage of loss of labeled enterotoxin A was greater than the loss of total nitrogen. Chloroform extraction and acid precipitation with hydrochloric acid had nearly the same effect on the purification of both labeled enterotoxin A and total nitrogen. Ammonium sulfate precipitation proved to be practical and was successfully used for purification of enterotoxin A from sausage extract. Simultaneous use of trypsin and Pseudomonas peptidase for treatment of food extracts considerably reduced food proteins capable of interfering with serological detection of enterotoxins but did not essentailly influence the loss of enterotoxin A.
Rhizobium japonicum derivatives differing in nitrogen-fixing efficiency and carbohydrate utilization
Authors: Kuykendall L D , Elkan G H
Published: January 2020

Four derivatives of Rhizobium japonicum 110 were isolated on the basis of morphologically different colonies formed on yeast extract-mannitol-HM salts medium. All are able to nodulate Lee soybeans. The bacteria-plant associations formed by each clone have measurable acetylene-reducing activity, but those formed by two of these clones (designated L1-110 and L2-110) are 5- to 10-fold less efficient than those formed by the others (designated I-110 and S-110). These derivatives were not detectable with ordinary culture techniques since, because of cell adherence, genetically mixed colonies result. When a detergent (Tween 40 at 0.01%, vol/vol) was added to the dilution medium, separate clones resulted. The metabolic basis for the gross differences in colony morphology on yeast extract-mannitol-HM salts medium was found to be that L1-110 and L2-110 utilized p-mannitol for growth, whereas I-110 and S-110 did not. These clones differ analogously in ability to utilize D-arabitol. Clones I-110 and L1-110 were chosen for studies of growth rates on various carbohydrates. Although clone I-110 and clone L1-110 did not differ in growth rates on a number of sugars, such as gluconate, arabinose, glycerol, and mannose, they differed in growth rates on glucose and fructose. Although clone I-110 grew faster on glucose than did clone L1-110, clone L1-110 grew faster on fructose than did clone I-110. Clones I-110 and L1-110 showed identical responses to several antibiotics and deoxyribonucleic acid (DNA) synthesis inhibitors and identical susceptibility to some highly specific bacteriophages. Identical buoyant densities of their DNAs in isopycnic CsCl density gradients and identical thermal denaturation temperatures of their DNAs suggest that clones I-110 and L1-110 have the same DNA base composition. Preliminary DNA/DNA hybridization experiments show that strain I-110 DNA and strain L1-110 DNA have a high degree of common polynucleotide sequences.
Role of L-proline in the biosynthesis of prodigiosin
Authors: Scott R H , Qadri S M , Williams R P
Published: January 2020

Nonproliferating cells of Serratia marcescens, wild-type strain Nima, synthesized the pigment, prodigiosin, when saline suspensions were incubated with aeration at 27 degrees C in the presence of proline or alanine. Mutants PutS1 and PutS2 derived from strain Nima formed prodigiosin from alanine, but not from proline, unless alanine also was added. Strain Nima utilized proline as a sole source of carbon and of nitrogen for growth, whereas Put mutants did not. Investigation of enzymes degrading proline showed that the wild-type strain contained proline oxidase, which was absent in Put mutants. The wild type, as well as the mutants, utilized alanine as the sole source of carbon and nitrogen for growth. Although nonproliferating cells of Put mutants failed to synthesize prodigiosin from proline, addition of L-[U-14C]proline to suspensions metabolizing and synthesizing the pigment because of addition of alanine resulted in the incorporation of radioactive label into prodigiosin, as well as into cellular protein. Since Put mutants could not catabolize proline, the incorporation of [14C]proline into the prodigiosin molecule indicated that proline was incorporated directly into the pigment.
Hepatitis B surface antigen in saliva, impetiginous lesions, and the environment in two remote Alaskan villages
Authors: Petersen N J , Barrett D H , Bond W W , Berquist K R , Favero M S , Bender T R , Maynard J E
Published: January 2020

A study was conducted in an area of hepatitis B hyperendemicity to determin whether contact with infective bodily secretions or contaminated environmental surfaces could be involved in the transmission of the hepatitis B virus. Hepatitis B surface antigen was detected in gingival swab, saliva, and impetiginous lesion exudate samples from children. Hepatitis B surface antigen also was found in swab samples of surfaces frequently touched or placed in the mouth. In the absence of classical exposure to infectious blood or blood products, these findings suggested that, in a crowded home environment, saliva and cutaneous exudates containing hepatitis B virus may play a role in the transmission of hepatitis B.
Agar plate tests of enhanced sensitivity for detecting biologically active products of staphylococcal filtrates
Authors: Madler J J , Lee S H , Haque R U
Published: January 2020

Optimal conditions for detecting staphylokinase, phosphatase, protease, lipase, esterase, egg yolk factor, lysozyme, deoxyribonuclease, hyaluronidase, penicillinase, and alpha-, beta-, and delta-hemolysins in cell-free filtrates of selected strains of staphylococci by agar plate methods were established by studying the effect of factors such as buffer composition, pH, ionic strength, type of agar, nature and concentration of substrate, and certain metal ions. The final tests that evolved from this study are simple to perform, require only 6 mul of the sample per test, and are capable of detecting microgram and, in some cases, nanogram quantities of the product. The zones of reaction can also be quantitatively related to the amount of material present. The test may also be useful for the detection of extracellular products of other microorganisms.
Isoelectric focusing of mycoplasma proteins
Authors: Sayed I A , Hatten B A
Published: January 2020

Polyacrylamide gel isoelectric focusing (PAGIF) in thin layer was used to resolve proteins of Mycoplasma spp., Acholeplasma spp., and eight strains of Ureaplasma urealyticum (T-strain). A mixture of urea, Triton X-100, and dithioerythritol was used to solubilize sonically disrupted cells. PAGIF was performed in the range of pH 3 to 10. Protein patterns were carefully compared, demonstrating resolved and distinguishable species-specific protein bands. The eight serotypes of U. urealyticum (T-strain) gave identical protein patterns in the pH 3 to 10 range. The characteristic "fingerprints" of a species appeared to correlate with the biochemical nature and not the habitat in each case. Arginine-hydrolyzing species seemed to show more diverse focusing than those that ferment glucose, or prefer an acid environment. Characterization and identification of highly resolved species-specific proteins, ease of performance, and reproducibility of this method suggest that PAGIF might be employed as a taxonomic aid.
Morphological characterization of small cells resulting from nutrient starvation of a psychrophilic marine vibrio
Authors: Novitsky J A , Morita R Y
Published: January 2020

Upon starvation, Ant-300, a psychrophilic marine vibrio, was observed to decrease in size and change in shape from a rod to a coccus. After 3 weeks of starvation 50% of the starved population was able to pass through a filter with a pore size of 0.4 mum. Electron microscopy of thin sections of the small cells revealed normal cell structure except for an enlarged periplasmic space. When inoculated into a fresh medium, starved cells growth without a significant lag and regained "normal" size and shape within 48 h.
Simplified Thermonuclease Test for Rapid Identification of
Staphylococcus aureus
Recovered on Agar Media
Authors: Lachica R. V. F.
Published: January 2020

A simplified thermonuclease test that identifies colonies of
Staphylococcus aureus
5 h after recovery on various agar media is described.
Electrochemical sterilization of beer
Authors: Wagener R E , Helbert J R , Chicoye E
Published: January 2020

Electrochemical inactivation of microorganisms was not achieved in beer but was achieved in physiological saline. Addition of carbohydrates or proteins to physiological saline prevented inactivation in this medium.
Microbiological hazard from the exhaust of a high-vacuum sterilizer
Authors: Barbeito M S , Brookey E A
Published: January 2020

Data are presented which show the potential for release of viable microorganisms into the atmosphere from high-vacuum steam sterilizers during the evacuation cycle preceding application of steam under pressure. Bacillus subtilis var. niger spores, Serratia marcescens cells, and T1 coliphage disseminated into the sterilizer chamber as small particles from liquid suspensions, and dried spores of B. subtilis var. niger distributed on bulk discard materials were recovered from the atmosphere around pipes venting steam from the steam ejectors used to create chamber vacuum. Evaluation of the hazard involved is discussed, and the design, fabrication, and installation of a valved filter system for preventing release of viable microorganisms are presented. The filtration system utilized an F-700 water-resistant filter and was shown to eliminate the release of viable airborne microorganisms from a high-vacuum sterilizer. A method is presented for determining size requirements for an atmospheric vent filter in relation to the volume of a sterilizer.
Bacteria within ovules and seeds
Authors: Mundt J O , Hinkle N F
Published: January 2020

Surface-sterilized ovules and seeds of 27 species of plants were cultured in the water of syneresis of a nutrient medium low in agar content. Bacteria were obtained from 30% of the ovules, 15% of the seeds of herbaceous plants, 16% of the seeds of woody plants, 5.4% of the overwintered noncereal seeds, and 13.5% of overwintered cereal seeds. In no instance did every ovule or seed of a plant species contain bacteria. No bacteria were obtained from the hard, waxy seeds of mimosa or yellowwood. They were not obtained from ovules with unbroken coats or from seeds with coats that were not ruptured during the swelling of the seed. Only one species of bacteria was recovered in 93% of the instances in which bacteria were obtained. Bacteria were obtained from seeds that were embedded in the acidic parenchyma of the lemon or surrounded by the thickened flesh of the cucurbits. The bacteria were distributed among 19 genera and 46 species. The species isolated in greatest numbers were Bacillus megaterium, B. cereus, Erwinia herbicola, Flavobacterium devorans, and Pseudomonas fluorescens. Bacteria recovered less frequently were in the genera Achromobacter, Acinetobacter, Alcaligenes, Brevibacterium, Corynebacterium, Cytophaga, Leuconostoc, Micrococcus, Nocardia, Proteus, Streptococcus, Streptomyces, and Xanthomonas. Members of 11 genera and 15 species of bacteria were isolated once.
Chamber for Bacterial Chemotaxis Experiments
Authors: Palleroni Norberto J.
Published: January 2020

A design for a chemotaxis chamber and its use in bacterial chemotaxis experiments are described. Some of the advantages of the new design are discussed.
Effect of zinc on adenine nucleotide pools in relation to aflatoxin biosynthesis in Aspergillus parasiticus
Authors: Gupta S K , Maggon K K , Venkitasubramanian T A
Published: January 2020

The adenylic acid systems of Aspergillus parasiticus were studied in zinc-replete and zinc-deficient media. The adenosine 5'-triphosphate levels of the fungus were high during exponential phase and low during stationary phase in zinc-replete cultures. On the other hand, the levels of adenosine 5'-diphosphate and adenosine 5'-monophosphate were low during exponential phase of growth and high during stationary phase. The adenosine 5'-triphosphate levels during exponential phase may indicate higher primary metabolic activity of the fungus. On the other hand, high adenosine 5'-monophosphate levels during stationary phase may inhibit lipid formation and may enhance aflatoxin levels. The inorganic phosphorus content was low in a zinc-replete medium throughout the growth period, thereby favoring aflatoxin biosynthesis. The energy charge during the exponential phase was high but low during the stationary phase. In general the energy charge values were lower because of high adenosine 5'-monophosphate content.
New approach to the cultivation of methanogenic bacteria: 2-mercaptoethanesulfonic acid (HS-CoM)-dependent growth of Methanobacterium ruminantium in a pressureized atmosphere
Authors: Balch W E , Wolfe R S
Published: January 2020

The sensitivity of the requirement of Methanobacterium ruminantium strain M1 to a new coenzyme, 2-mercaptoethanesulfonic acid (HS-CoM) was examined by use of new techniques that were developed for rapid and efficient handling of large numbers of cultures of methanogenic bacteria. The system uses sealed tubes that contain a gas mixture of 80% hydrogen and 20% carbon dioxide under a pressure of 2 to 3 atm. This modification of the Hungate technique reduces variability among replicate cultures and simplifies the dispensing, sterilization, and storage of liquid media as well as the transfer and maintenance of methanogenic bacteria. Results indicate a limit of sensitivity of the assay at 5 nM HS-CoM, with half-maximal growth at 25 nM HS-CoM. Coenzyme activity could be replaced by 2,2'-dithiodiethanesulfonic acid at a half-molar equivalent of the HS-CoM concentration, or by 2-(methylthio)ethanesulfonic acid on an equimolar basis. These data reveal a very sensitive and precise requirement for HS-CoM in the nutrition of this fastidious anaerobe.
Growth of Aureobasidium pullulans on straw hydrolysate
Authors: Han Y W , Cheeke P R , Anderson A W , Lekprayoon C
Published: January 2020

Growth characteristics and cell properties of Aureobasidium (Pullularia) pullulans were studied. The organism grew well on an acid hydrolysate of ryegrass straw over a wide range of pH and temperature. The optimum temperature and pH for the growth of the organism were 32 degrees C and 5.5, respectively. A cell yield of 1.5 g/liter of straw hydrolysate was obtained. The dried cell mass contained 42.6% crude protein, 0.4% crude fat, and 6.4% nucleic acids. The essential amino acid profile of the microbial protein was comparable to that of Candida utilis. A rat feeding study indicated that the A. pullulans cells were not toxic and that the feed intake, weight gain, and protein efficiency ratio values were superior to those obtained with C. utilis. Once the question of mathogenicity is resolved, A. pullulans could be useful for production of single-cell protein from cellulosic wastes.
"Phoenix phenomenon" in the growth of Clostridium perfringens
Authors: Shoemaker S P , Pierson M D
Published: January 2020

The "Phoenix phenomenon" was observed with Clostridium perfringens Hobbs' serological type 9 (HT9) in a cooked-meat medium at 81.7 degrees C by a decrease in plate count (phase I), followed by an increase in count to the intiial level (phase II) and a continued increase above the initial count (phase III). The effects of sporulation, age of inoculum, assay medium, anaerobiosis, diluent, and growth inhibitor were studied. This phenomenon was reproduced in experiments with sporulation-negative mutants derived from HT9 inocula of various cell ages, and different assay media (sulfite-iron agar, tryptose-soytone-yeast extract agar, prereduced peptone-yeast extract agar, prereduced veal agar, and veal agar). When strict anaerobic conditions were employed, it was necessary to increase the heating temperature to 52.3 degrees C to observe the phenomenon. The phenomenon was eliminated at 52.3 degrees C when a combination of strict anaerobic conditions, prereduced media, and prereduced veal diluent was employed. The addition of nalidixic acid at the minimum point of the growth curve (end of phase I) had no effect on the appearance of phase II; however, phase III was completely inhibited. This indicated that phases I and II were an injury-recovery process.
Persistence of poliovirus 1 in soil and on vegetables grown in soil previously flooded with inoculated sewage sludge or effluent
Authors: Tierney J T , Sullivan R , Larkin E P
Published: January 2020

Land disposal of sewage sludge and effluent is becoming a common practice in the United States. The fertilizer content and humus value of such wastes are useful for agricultural purposes, and the recycling of sewage onto the land eliminates many of our stream pollution problems. The potential exists for crops grown in such irrigated soil to be contaminated by viruses that may be present in the sewage. Studies were initiated to determine viral persistence in soil and on crops grown under natural conditions in field plots that had been flooded to a depth of 1 inch (2.54 cm) with poliovirus 1-inoculated sewage wastes. Lettuce and radishes were planted in sludge- or effluent-flooded soil. In one study, the vegetables were planted 1 day before flooding, and in another they were planted 3 days after the plots were flooded. Survival of poliovirus 1 in soil irrigated with inoculated sewage sludge and effluent was determined during two summer growing seasons and one winter period. The longest period of survival was during the winter, when virus was detected after 96 days. During the summer, the longest survival period was 11 days. Poliovirus 1 was recovered from the mature vegetables 23 days after flooding of the plots had ceased. Lettuce and radishes are usually harvested 3 to 4 weeks after planting.
Hydrogen production by nitrogen-starved cultures of Anabaena cylindrica
Authors: Weissman J C , Benemann J R
Published: January 2020

Nitrogen-starved cultures of the alga Anabaena cylindrica 629 produced hydrogen and oxygen continuously for 7 to 19 days. Hydrogen production attained a maximum level after 1 to 2 days of starvation and was followed by a slow decline. The maximum rates were 30 ml of H2 evolved per liter of culture per h or 32 mul of H2 per mg of dry weight per h. In 5 to 7 days the rate of H2 evolution by the more productive cultures fell to one-half its maximum value. The addition of 10(-4) to 5 X 10(-4) M ammonium increased the rate of oxygen evolution and the total hydrogen production of the cultures. H2-O2 ratios were 4:1 under conditions of complete nitrogen starvation and about 1.7:1 after the addition of ammonium. Thus, oxygen evolution was affected by the extent of the nitrogen starvation. Thermodynamic efficiencies of converting incident light energy to free energy of hydrogen via algal photosynthesis were 0.4%. Possible factors limiting hydrogen production were decline of reductant supply and filament breakage. Hydrogen production by filamentous, heterocystous blue-green algae could be used for development of a biophotolysis system.
Hydrolysis of lactose by immobilized microorganisms
Authors: Ohmiya K , Ohashi H , Kobayashi T , Shimizu S
Published: January 2020

Cells of Lactobacillus bulgaricus, Escherichia coli, and Kluyveromyces (Saccharomyces) lactis immobilized in polyacrylamide gel beads retained 27 to 61% of the beta-galactosidase activity of intact cells. Optimum temperature and pH and thermostability of these microbial beta-galactosidases were negligibly affected by the immobilization. Km values of beta-galactosidase in immobilized cells of L. bulgaricus, E. coli, and K. lactis toward lactose were 4.2, 5.4, and 30 mM, respectively. Neither inhibition nor activation of beta-galactosidase in immobilized L. bulgaricus and E. coli appeared in the presence of galactose, but remarkable inhibition by galactose was detected in the case of the enzyme of immobilized K. lactis. Glucose inhibited noncompetitively the activity of three species of immobilized microbial cells. These kinetic properties were almost the same as those of free beta-galactosidase extracted from individual microorganisms. The activity of immobilized K. lactis was fairly stable during repeated runs, but those of E. coli and L. bulgaricus decreased gradually. These immobilized microbial cells, when introduced into skim milk, demonstrated high activity for converting lactose to monosaccharides. The flavor of skim milk was hardly affected by treatment with these immobilized cells, although the degree of sweetness was raised considerably.
Incidence and properties of temperate bacteriophages induced from lactic streptococci
Authors: Huggins A R , Sandine W E
Published: January 2020

Sixty-three strains of lactic streptococci isolated from commercial lactic streptococcal starter cultures were examined for lysogeny by treatment with ultraviolet light or mitomycin C. After treatment with the inducing agent, all strains, whether or not they lysed, were examined for evidence of phage release by electron microscopy. Thirty-eight strains yielded intact phages or phage particles of varying morphology. All the temperate phages had isometric heads and noncontractile tails; some had collars and structurally distinctive baseplates. Indicator host strains were found for phages induced from seven different strains. Three strains that released phages spontaneously yielded titers of 10(3) to 10(4) plaque-forming units per ml. When strains that spontaneously released phages were grown in mixed culture with indicator strains, increased phage titers of 10(6) to 10(7) plaque-forming units per ml were observed. These findings indicate that lysogenic lactic streptococcal strains may serve as a reservoir for phages that attack sensitive strains in mixed- or multiple-strain lactic starter cultures.
Production of cyclopiazonic acid by Aspergillus flavus Link
Authors: Luk K C , Kobbe B , Townsend J M
Published: January 2020

Production of cyclopiazonic acid by Aspergillus flavus is reported for the first time. A procedure for its production by agitated solid substrate fermentation on red wheat is described along with the isolation procedure and physical and chemical properties of this indole derivative. The compound has been found to exert antibacterial activity.
Two plating media modified with Tween 80 for isolating Yersinia enterocolitica
Authors: Lee W H
Published: January 2020

MacConkey agar modified with Tween 80, and deoxyribonuclease agar modified with Tween 80 plus sorbitol were used in differentiating Yersinia enterocolitica colonies from other lactose-negative bacterial colonies.
Microbial transformation of 8-chloro-10,11-dihydrodibenz(b,f)(1,4)oxazepine by fungi
Authors: Jiu J , Mizuba S , Hribar J
Published: January 2020

The microbial transformation of 8-chloro-10,11-dihydrodibenz(b,f)(1,4)oxazepine (compound I) was undertaken to obtain new derivatives. Compound I was transformed by Hormodendrum sp. (NRRL 8133) to 8-chloro-10,11-dihydrodibenz(b,f)(1,4)oxazepine-11-one (compound II) and 2-(2-amino-4-chlorophenoxy)benzyl alcohol (compound IV). Microbial cleavage of the nonaromatic ring to form compound IV was accomplished by several other fungi. Compound I was transformed to 8-chlorodibenz(b,f)(1,4)oxazepine (compound III) by Hormodendrum cladosporioides (NRRL 8132).
Amorphous ferrous sulfide as a reducing agent for culture of anaerobes
Authors: Brock T D , Od'ea K
Published: January 2020

Amorphous ferrous sulfide, prepared by reacting ferrous ammonium sulfate and sodium sulfide, is an excellent reducing agent for the culture of anaerobes. It reduces resazurin and reacts much more rapidly with O2 than does either soluble sulfide (HS)- or cysteine. One of the end products of the oxidation of ferrous sulfide with O2 is red and serves as an indicator for the oxygen contamination of a culture medium. Amorphous ferrous sulfide served as a suitable reducing agent for the growth of species of Methanobacterium or Clostridium. Its use is recommended for enrichment or culture of anaerobes (e.g. autotrophs, fermentative organisms) from sediments and other habitats were organic reducing agents are undesirable and where soluble sulfide might be toxic.
Inactivation of polioviruses and coxsackieviruses in surface water
Authors: O'Brien R T , Newman J S
Published: January 2020

Inactivation rates of polioviruses 1 and 3 and coxsackieviruses A-13 and B-1 were determined in situ in the Rio Grande in southern New Mexico, using membrane dialysis chambers. Inactivation of the viruses was exponential, and the rates of inactivation were apparently affected principally by the water temperature. Stability of the viruses in river water differed, with poliovirus 1 and coxsackie B-1 being most stable. Typically 1-log reductions of infectivity at water temperatures ranging between 23 and 27 degrees C required 25 h for poliovirus 1, 19 h for poliovirus 3, and 7 h for coxsackie virus A-13. At water temperatures of 4 to 8 degrees C, the log reduction times for poliovirus 1 and coxsackievirus B-1 were 46 and 58 h, respectively. Results obtained with labeled poliovirus 1 and coxsackievirus B-1 and with infectious ribonucleic acid indicate that inactivation was due to damage to viral ribonucleic acid. Virus-inactivation rates were also affected by heat sterilization of river water, indicating the presence of a heat-labile or volatile inactivating factor. The inactivating factor in Rio Grande water was apparently present at a constant concentration over a 1-year period.
Nitrogen-fixing Enterobacter agglomerans isolated from guts of wood-eating termites
Authors: Potrikus C J , Breznak J A
Published: January 2020

Two strains of facultatively anaerobic, N2-fixing bacteria were isolated from guts of Coptotermes formosanus and identified as Enterobacter agglomerans. The deoxyribonucleic acid base composition of isolates was 52.6 and 53.1 mol% guanine plus cytosine. Both isolates and a known strain of E. agglomerans carried out a mixed acid type of glucose fermentation. N2 fixation by E. agglomerans was inhibited by O2; consequently, N2 served as an N source only for cells growing anaerobically in media lacking a major source of combined N. However, peptone, NH4Cl, or KNO3 served as an N source under either aerobic or anaerobic conditions. It was estimated that 2 x 10(2) cells of E. agglomerans were present per termite gut. This value was 100-fold lower than expected, based on N2 fixation, low recoveries of E. agglomerans may be related to the marked decrease in N2 fixation rates observed when intact termites or their extracted guts were manipulated for the isolation of bacteria. It was concluded that the N2-fixing activity of E. agglomerans may be important to the N economy of C. formosanus.
In situ morphology of the gut microbiota of wood-eating termites [Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shiraki]
Authors: Breznak J A , Pankratz H S
Published: January 2020

Light microscopy and scanning and transmission electron microscopy were used to examine the in situ morphology of the gut microbiota of Reticulitermes flavipes and Caoptotermes formosanus. Laboratory-maintained termites were used and, for R. flavipes, specimens were also prepared immediately after collection from a natural infestation. The latter endeavor enabled a study of different castes and developmental stages of R. flavipes and revealed differences in the microbiota of field versus laboratory specimens. The termite paunch microbiota consisted of an abundance of morphologically diverse bacteria and protozoa. Thirteen bacterial morphotypes in the paunch were described in detail: seven were observed only in R. flavipes, three were observed only in C. formosanus, and three were common to both termite species. The paunch epithelium was densely colonized by bacteria, many of which possessed holdfast elements that secured them tightly to this tissue and to other bacterial cells. Besides bacteria, the protozoan Pyrsonympha vertens adhered to the paunch epithelium of R. flavipes by means of an attachment organelle. Cuplike indentations were present on the paunch epithelial surface and were sites of bacterial aggregation. Ultrastructural features of cups suggested their involvement in ion absorption. In addition to the paunch, the midgut was also colonized by bacteria that were situated between epithelial microvilli. Results suggest that bacteria are an integral part of the gut ecosystem.
Media for identification of Gibberella zeae and production of F-2-(Zearalenone)
Authors: Bacon C W , Robbins J D , Porter J K
Published: January 2020

Media are described for the isolaton of Fusarium graminearum in the perithecial state, Gibberella zeae, and for the production of F-2 (zearalenone) by Fusarium species. On soil extract-corn meal agar isolated medium, G. Zeae produced perithecia in 9 to 14 days under a 12-h photoperiod. Species of Fusarium were screened for F-2 production on a liquid medium. From strains that produced F-2, the yields, from stationary cultures of G. zeae and F. culmorum after 12 days of incubation, ranged from 22 to 86 mg/liter. Three strains produced no F-2. Glumatic acid, starch, yeast extract,and the proper ratio of medium volume-to-flask volume were necessary for F-2 synthesis.
Plating Medium for Differentiating
Salmonella arizonae
from Other Salmonellae
Authors: Littell Allan M.
Published: January 2020

A differential plating medium developed for isolation of
Salmonella arizonae
produces a uniform reaction for both lactose-negative and -positive
S. arizonae
and differentiates
S. arizonae
from other salmonellae.
Factors Affecting the Cellulolytic Activity of Rumen Contents
Authors: Stewart Colin S.
Published: January 2020

The cellulolytic activity of rumen contents was assayed by measuring losses in weight and tensile strength of cotton yarn incubated in rumen contents in the presence of dietary additives (barley, tallow) and at different pH values. The addition of barley depressed cellulolysis and the titer of filter paper-degrading bacteria only if the pH was allowed to fall. Lowering the pH from 7.0 to 6.0 by addition of HCl almost completely inhibited attack of cotton and greatly reduced the titer of filter paper-degrading bacteria. The layering of tallow on cotton inhibited attack of cotton but did not decrease the titer of filter paper-degrading bacteria. The results are discussed with special reference to the importance of the study of cellulosic substrates, which require a known enzyme or mixture of enzymes for attack.
Limax Amoebae in Public Swimming Pools of Albany, Schenectady, and Rensselaer Counties, New York: Their Concentration, Correlations, and Significance
Authors: Lyons Thomas B. , Kapur Ramesh
Published: January 2020

A survey was conducted on 30 halogenated public swimming pools, located in Albany, Schenectady, and Rensselaer counties, to determine their open-water limax amoeba densities. Six were outdoor pools. Other variables measured were the standard plate count, total seston, free residual chlorine or bromine, total alkalinity, total hardness, orthophosphate, total soluble phosphorus, specific conductance, pH, temperature, and several engineering parameters including the rate and type of filtration as well as a saturation index. Amoebae were isolated on agar plates at 37°C using heat-killed bacterial suspensions of
Enterobacter cloacae
or
Escherichia coli.
Most probable number estimates of amoebic densities ranged from not detectable (<0.01) to 110 amoebae per liter. The median concentration of amoebae was 0.9/liter. Eighty percent of the pools examined had less than 5 amoebae per liter. Significant correlations (
P
< 0.05) were found between amoebic densities and the log
10
of the standard plate count, orthophosphate, and total soluble phosphorus. No significant difference was found between amoebic densities in outdoor and indoor pools. Preliminary tests for the presence of the human pathogen
Naegleria fowleri
were inconclusive.
Relationship of Vaginal Cytology to Alterations of the Vaginal Microflora of Rats During the Estrous Cycle
Authors: Larsen Bryan , Markovetz A. J. , Galask R. P.
Published: January 2020

The influence of cyclic changes occurring in the vaginal tract during the estrous cycle upon the indigenous microflora of the vagina has been investigated by semiquantitative techniques in virgin female rats. By plate counts performed on material lavaged daily from the vaginal tract of several rats, it is apparent that bacterial counts are elevated in the proestrus and estrus phases of the cycle to values several orders of magnitude greater than those observed during metestrus or diestrus phases. Increases in vaginal bacterial counts were associated with the presence of cornified epithelial cells in the vagina; these cells were predominantly nonviable. Decreases in the vaginal bacterial content were related to the influx of leukocytes into the vagina after estrus. When leukocytes were present in the vaginal tract, they were 90 to 100% viable. From these observations it has been concluded that the female vaginal tract and the bacteria which colonize it represent a dynamic ecosystem which is responsive to cyclic events occurring in the estrous cycle. The changing cellular content of the vaginal tract may have relevance to the observed cyclic changes in the bacterial content of the vagina.
Lipid Accumulation in an Oleaginous Yeast (
Candida
107) Growing on Glucose Under Various Conditions in a One- and Two-Stage Continuous Culture
Authors: Hall Michael J. , Ratledge Colin
Published: January 2020

Lipid accumulation and fatty acid composition in
Candida
107 have been studied using a two-stage continuous culture system in which the first vessel was run under carbon-limited conditions and then the entire output was passed into a second vessel, where lipid accumulation was stimulated by adding only glucose. Maximum lipid accumulation (28% of yeast [dry weight]) occurred for a volume ratio of vessel 1 to vessel 2 of 3:5, with 30 g of glucose per liter being added to vessel 2 operated at 25°C with an aeration rate of between 0.1 and 1.0 volume of air/volume of medium per min. Although the maximum specific rate of lipid formation (0.05 g of lipid/g of yeast per h) was higher than in a nitrogen-limited, single-stage system, the efficiency of lipid formation was much less and never exceeded 14 g of lipid produced per 100 g of glucose consumed. The fatty acid composition was not significantly altered in either the two-stage or single-stage culture (nitrogen-limited) systems by changes in growth temperature (from 19 to 33°C) or aeration rates (0.05 to 1.0 volume of air/volume of medium per min); or, in the two-stage system, by changes in the residence time of the yeast in the second vessel (from 3.2 to 24.4 h), or, in the single-stage system, by changes in pH (from 3.5 to 7.5). Only when the concentration of glucose entering vessel 2 of the two-stage system was less than 30 g/liter did significant changes in the fatty acids occur. Thus, although a two-stage continuous culture system allows lipid accumulation to be separated from the growth phase, it offers no practical advantages over a single-stage system as a means of producing microbial oils and fats.
Effects of Varying Concentrations of Novobiocin Incorporated into Two
Salmonella
Plating Media on the Recovery of Four
Enterobacteriaceae
Authors: Restaino L. , Grauman G. S. , McCall W. A. , Hill W. M.
Published: January 2020

Hydrogen sulfide-producing strains of salmonellae,
Escherichia coli, Citrobacter freundii
, and
Proteus mirabilis
were isolated from fresh pork sausage. All the strains produced black-centered colonies on Hektoen enteric agar (HE). On xylose lysine deoxycholate agar (XLD),
C. freundii
produced yellow colonies, and the strains of the other three genera formed black-centered colonies. The selectivity of HE and XLD for salmonellae was improved by the addition of novobiocin to both media. With increasing concentrations of novobiocin, the degree of growth inhibition for the four genera was less on HE than on XLD. Novobiocin concentrations of 80 μg/ml in HE and 5 μg/ml in XLD did not affect the growth or colonial morphology of salmonellae. When 80 μg of novobiocin per ml was incorporated into HE,
P. mirabilis
strains were not recovered, 40% of
C. freundii
strains failed to form black-centered colonies, and growth of
E. coli
strains was not affected but colonies were altered without eliminating the black centers. When novobiocin at 5 μg/ml was incorporated into XLD, colonies of
P. mirabilis
strains were not recovered,
C. freundii
formed yellow colonies, and the colonies of the H
2
S-producing
E. coli
strains were unaffected.
Comparison of Nitrogen Fixation Activity in Tall and Short
Spartina alterniflora
Salt Marsh Soils
Authors: Hanson Roger B.
Published: January 2020

A comparison of the N
2
fixers in the tall
Spartina alterniflora
and short
S. alterniflora
marsh soils was investigated. Zero-order kinetics and first-order kinetics of acetylene reduction were used to describe the activity of the N
2
fixers in marsh soil slurries. It was found that the
V

max

values were approximately 10 times greater for the N
2
fixers in the tall
Spartina
than in the short
Spartina
marsh when raffinose was used as the energy source. In addition, the (
K
s
+
S
n
) values were approximately 4 to 15 times lower for the N
2
fixers in the tall
Spartina
than in short
Spartina
marsh. First-order kinetics of nitrogen fixation for several substrates indicate that the N
2
fixers in the tall
Spartina
marsh were two to seven times more active than those in the short
Spartina
marsh. Ammonium chloride (25 μg/ml) did not inhibit nitrogen fixation in the tall
Spartina
marsh, but there was a 50% inhibition in nitrogen fixation in the short
Spartina
marsh. On the other hand, sodium nitrate inhibited nitrogen fixation almost 100% at 25 μg/ml in both soil environments. Amino nitrogen (25 to 100 μg/ml) had little or no effect on nitrogen fixation. The results indicate that the N
2
fixers in the tall
Spartina
marsh were physiologically more responsive to nutrient addition than those in the short
Spartina
marsh. This difference in the two populations may be related to the difference in daily tidal influence in the respective areas and thus provide another explanation for the enhanced
S. alterniflora
production in the creek bank soil system.
Virus and Bacteria Removal from Wastewater by Rapid Infiltration Through Soil
Authors: Schaub Stephen A. , Sorber Charles A.
Published: January 2020

A rapid infiltration land wastewater application site, composed of unconsolidated silty sand and gravel, which has been in continuous operation for over 30 years was examined for the accumulation and/or migration of a tracer virus (coliphage f2), indigenous enteroviruses, and enteric indicator bacteria in the soils and underlying groundwater. Tracer f2 penetrated into groundwater together with the front of percolating primary effluent and was not observed to concentrate on the upper soil layers. The tracer virus concentration in a 60-foot (about 18.3-m)-deep observation well directly beneath the wastewater application area began to increase within 48 h after application to the soil. The tracer level in this well stabilized after 72 h at a level of approximately 47% of the average applied concentration. Indigenous enteroviruses and tracer f2 were sporadically detected in the groundwater at horizontal distances of 600 feet (about 183 m) from the application zone. Laboratory soil adsorption studies confirmed the poor virus adsorption observed at the site. This was especially true on surface soils when contained in wastewater. Enteric indicator bacteria were readily concentrated on the soil surface by filtration on the soil surface mat. However, during tracer f2 virus tests, comparison studies with fecal
Streptococcus
revealed that bacteria capable of penetrating the surface were able to migrate into the groundwater. They were detected at the same locations as tracer and enteric viruses.
Acetylene Reduction by Soil Cores of Maize and Sorghum in Brazil
Authors: Tjepkema John , Van Berkum Peter
Published: January 2020

Nitrogenase activity was measured by the C
2
H
2
reduction method in large soil cores (29 cm in diameter by 20 cm in depth) of maize (
Zea mays
) and sorghum (
Sorghum vulgare
). The activity was compared to that obtained by a method in which the roots were removed from the soil and assayed for nitrogenase activity after an overnight preincubation in 1% O
2
. In a total of six experiments and 28 soil cores, the nitrogenase activity of the cores was an average of 14 times less than the activity of roots removed from the same cores and preincubated. Nitrogenase activity in the cores was very low and extrapolated to an average nitrogen fixation rate of 2.8 g of N/hectare per day. It was shown that inadequate gas exchange was not a reason for the lower activity in the soil cores, and the core method gave satisfactory results for nitrogenase activity of soybeans (
Glycine max
) and
Paspalum notatum.
Dietary Effects on the Composition of Fecal Flora of Rats
Authors: Chung King-Thom , Fulk George E. , Silverman Sidney J.
Published: January 2020

A long-term animal feeding experiment was conducted to compare the effect of meat and Wayne laboratory chow diets on the composition of rat fecal flora. Fecal bacteria were enumerated on selective media under both aerobic and anaerobic conditions. Intrarectal administration of
N
-methyl-
N′
-nitro-
N
-nitro-soguanidine (MNNG) affected the count only on the phenylethylalcohol and veillonella-neomycin agars, whereas a slightly higher number of anaerobes appeared in the feces of rats that were treated with MNNG as compared with those obtained in the feces of untreated rats on the meat diet. In the absence of MNNG, feces of meat-fed rats yielded higher bacterial counts on aerobically incubated MacConkey agar, deoxycholate agar, and Pfizer selective enterococcus agar as well as higher numbers of clostridia on anaerobic egg yolk agar than did feces of rats on the Wayne diet. Feces of the group fed the Wayne diet produced more colonies on aerobic mitis-salivarius agar and lactobacillus agar as well as on anaerobically incubated phenylethylalcohol agar, veillonellaneomycin agar, bifidobacteria agar, fusobacterium (Nissui) agar, and kanamycin-vancomycin blood agar. These differences were consistent throughout the 1-year feeding period.