bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of the rate of ethanol production and accumulation on the viability of Saccharomyces cerevisiae in "rapid fermentation"
Authors: Nagodawithana T W , Steinkraus K H
Published: January 2020

Whereas "rapid fermentation" of diluted clover honey (25 degrees Brix) fortified with yeast nutrients using 8 X 10(8) brewers' yeast cells per ml resulted in an ethanol content of 9.5% (wt/vol; 12% vol/vol) in 3 h at 30 C, death rate of the yeast cells during this period was essentially logarithmic. Whereas 6 h was required to reach the same ethanol content at 15 C, the yeast cells retained their viability. Using a lower cell population (6 X 10(7) cells/ml), a level at which the fermentation was no longer "rapid," the yeast cells also retained their viability at 30 C. Ethanol added to the medium was much less lethal than the same or less quantities of ethanol produced by the cell in "rapid fermentation." It was considered possible that ethanol was produced so rapidly at 30 C that it could not diffuse out of the cell as rapidly as it was formed. The hypothesis was postulated that ethanol accumulating in the cell was contributing to the high death rate at 30 C. It was found that the intracellular ethanol concentration reached a level of approximately 2 X 10(11) ethanol molecules/cell in the first 30 min of fermentation at 30 C. At 15 C, with the same cell count, intracellular ethanol concentration reached a level of approximately 4 X 10(10) ethanol molecules/cell and viability remained high. Also, at 30 C with a lower cell population (6 X 10(7) cells/ml), under which conditions fermentation was no longer "rapid," intracellular ethanol concentration reached a similar level (4 X 10(10) molecules ethanol/cell) and the cells retained their viability. Alcohol dehydrogenase (ADH) lost its activity in brewers' yeast under conditions of "rapid fermentation" at 30 C but retained its activity in cells under similar conditions at 15 C. ADH activity was also retained in fermentations at 30 C with cell populations of 6 X 10(7)/ml. It would appear that an intracellular level of about 5 X 10(10) ethanol molecules/cell is normal and that this level does not damage either cell viability or ADH activity. Higher intracellular ethanol concentrations, such as 2 X 10(11) molecules ethanol/cell (a fourfold increase in intracellular ethanol concentration), are accompanied by inactivation of ADH and loss of cell viability.
Method for reproducible large-volume production and purification of Rauscher murine leukemia virus
Authors: Johnson R W , Perry A , Robinson O R , Shibley G P
Published: January 2020

Rauscher murine leukemia virus was produced in roller-bottle cultures of chronically infected JLS-V9 cells. Virus from this culture fluid was concentrated and purified by two semi-isopycnic bandings in sucrose gradients. Virus material obtained from young, nonconfluent cultures (early-harvest virus) yielded products characteristically containing endogenous ribonucleic acid-dependent deoxyribonucleic acid polymerase with high specific activity (400 to 1,000 pmol of [3H]thymidine 5'-triphosphate incorporated per milligram of protein per hour). Fluids obtained from older confluent cultures (late-harvest virus) yielded products with endogenous ribonucleic acid-dependent deoxyribonucleic acid polymerase with little or no specific activity (200 pmol or less of [3H]thymidine 5'-triphosphate incorporated per milligram of protein per hour), but with higher virus particle counts and greater amounts of protein and gs antigen than the early-harvest products.
Effect of sodium nitrite inhibition on intracellular thiol groups and on the activity of certain glycolytic enzymes in Clostridium perfringens
Authors: O'Leary V , Solberg M
Published: January 2020

Activities of glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) (GAP-DH) and aldolase (EC 4.1.2.13) in cells of Clostridium perfringens that had been inhibited with sodium nitrite were investigated. A complete loss in GAP-DH activity and a 67% decrease in aldolase activity were observed when growth of C. perfringens was inhibited. There was also a 91% decrease in the concentration of free sulfhydryl groups of soluble cellular components. Dithiothreitol restored some activity to inactive GAP-DH from sodium nitrite-inhibited cells, indicating that a loss of reduced sulfhydryl groups was involved in the inactivation of the enzyme. The evidence presented suggests that sodium nitrite inhibition of C. perfringens may involve an interaction of sodium nitrite as nitrous acid with sulfhydryl-containing constituents of the bacterial cell.
Detection of virus in water: sensitivity of the tentative standard method for drinking water
Authors: Hill W F , Jakubowski W , Akin E W , Clarke N A
Published: January 2020

The sensitivity of several microporous virus-adsorbent media for reliably detecting low levels of poliovirus from 380 and 1,900 liters of drinking water by use of the tentative standard method was investigated. The virus-adsorbent media tested were (i) nitrocellulose membrane filters, (ii) epoxy-fiber glass-asbestos filters, (iii) yarn-wound fiber glass depth filters, and (iv) epoxy-fiber glass filter tubes. Virus was adsorbed to the filter media at pH 3.5 and eluted with glycine buffer, pH 11.5. The results from 44 samples demonstrated that poliovirus was detected with a 95% reliability at mean virus input levels of 3 to 7 plaque-forming units/380 liters when 1,900 liters of water was sampled. At mean virus input levels of less than 1 to 2 plaque-forming units/380 liters, the detection reliability was 66% in 76 samples when 1,900 liters of water was sampled. No significant difference in virus detection sensitivity was observed among the various virus adsorbent media tested. Overall virus recovery efficiency ranged from 28 to 42%, with a grand average of 35%. Members of the coxsackievirus groups A and B, echovirus, and adenovirus were also detected when 380 and 1,900 liters of water were sampled. These experimental observations attest to the sensitivity of the tentative standard method for detecting low levels of virus in large volumes of drinking water.
Variation in colony counts of total viable anaerobic rumen bacteria as influenced by media and cultural methods
Authors: Grubb J A , Dehority B A
Published: January 2020

Volume and type of medium, carbohydrate concentration, carbohydrate ratios, and inoculum level were investigated as possible factors influencing total colony counts of anaerobic rumen bacteria obtained in roll tubes (18 by 150 mm). Colony counts were lower when the rumen fluid was clarified by centrifugation before inclusion in the medium; however, decreasing the volume of 40% rumen fluid glucose-cellobiose-starch-agar medium (RGCSA medium with 0.025% each of glucose and cellobiose and 0.05% starch, 4 ml per tube) was compared to the clarified rumen fluid medium and non-rumen fluid medium (medium 10) of Caldwell and Bryant (1966), 9 ml of each per tube. Total counts of rumen contents from sheep consuming four different types of rations were higher with the 4 ml of RGCSA medium than with the other two media. Dilution of the basal medium as a result of inoculum volume, as much as 1.5 ml per 4 ml of medium, did not appear to affect total counts. Colony counts and the simplicity of medium preparation and inoculation would favor the present method for routine use in estimating numbers of total viable anaerobic rumen bacteria, especially when large numbers of samples are involved.
Characteristics of bacteria isolated by the anaerobic roll-tube method from cheeses and ground beef
Authors: Gray W M , Johnson M G
Published: January 2020

In this study the methods of Hungate were used to quantitate the anaerobic bacteria present in commercially available ground beef, cheddar cheese, and German hand cheese. Of 235 anaerobic roll-tube isolates from ground beef and German hand cheese, all were facultative anaerobes. Of 213 anaerobic roll-tube isolates from cheddar cheese, 91% were facultative anaerobes and 9% were obligate anaerobes. Using results of biochemical tests, 14 or the 17 obligately anaerobic isolates from cheddar cheese were Propionibacterium acnes, two were strains of Propionibacterium that could not be speciated, and one was tentatively identified as a strain of Streptococcus evolutus. Obligate anaerobes were estimated to be present in the cheddar cheese at a level of about 10(6)/g. The possible significance of these levels of P. acnes in nonsterile foods is discussed.
Differences in destruction of cysts of pathogenic and nonpathogenic Naegleria and Acanthamoeba by chlorine
Authors: De Jonckheere J , van de Voorde H
Published: January 2020

The destructive action of chlorine on the pathogenic Naegleria fowleri and Acanthamoeba culbertsoni, the nonpathogenic N. gruberi, and an avirulent Acanthamoeba isolate was investigated. N fowleri is somewhat more sensitive to chlorine than N. gruberi, whereas the two Acanthamoeba strains are very resistant. This study yields information needed for the destruction of amoebic cysts in drinking water and swimming pools. It also gives some explanation for the occurence of Acanthamoeba strains in these waters.
Preservation of gastrointestinal bacteria and their microenvironmental associations in rats by freezing
Authors: Davis C P
Published: January 2020

The use of frozen rat gastrointestinal tissue samples for both the recovery of viable bacteria and for observation of microbial communities associated with the tissue was investigated. A decrease of 1 log in lactobacilli, bifidobacteria, and anaerobes was observed when the numbers of bacteria recoverable from frozen tissue (stored 7 to 9 days) were compared to those recoverable from fresh nonfrozen tissue (zero time control). However, freezing did not appear to decrease the numbers of recoverable coliforms. Tissues, cleaved with razor blades after being frozen and stored for 7 to 9 days, showed bacterial communities situated on the mucosa and in the lumen of gastrointestinal specimens. This freezing technique preserved structures not previously observed in the gastrointestinal tract. This indicates that freezing is a good method to use to study such fragile microenvironments.
Demonstration of solids-associated virus in wastewater and sludge
Authors: Wellings F M , Lewis A L , Mountain C W
Published: January 2020

Data presented demonstrate the relatively high multiplicity of solids-associated virus in field samples, i.e., wastewater, sludge, and soils. Influent, effluent, and chlorinated effluent samples showed 16.1 to 100% of the total virus demonstrated in samples to be solids associated. Three techniques for freeing solids-associated virus are described and compared. Using sonication of solids and polyethylene glycol concentration, virus was demonstrated in fully digested sludge (60 days at 34 C), sand at the site of a sewer leak, and dried sludge cake and mud 900 m downstream from a sewage disposal site. These data emphasize the inadequacy of virus concentration techniques that do not include the processing of solids. In situ elution failed to free solids-associated virus.
Human fecal flora: variation in bacterial composition within individuals and a possible effect of emotional stress
Authors: Holdeman L V , Good I J , Moore W E
Published: January 2020

Data are presented on the distribution of 101 bacterial species and subspecies among 1,442 isolates from 25 fecal specimens from three men on: (i) their normal diet and normal living conditions, (ii) normal living conditions but eating the controlled metabolic diet designed for use in the Skylab simulation and missions, and (iii) the Skylab diet in simulated Skylab (isolation) conditions. These bacteria represent the most numerous kinds in the fecal flora. Analyses of the kinds of bacteria from each astronaut during the 5-month period showed more variation in the composition of the flora among the individual astronauts than among the eight or nine samples from each person. This observation indicates that the variations in fecal flora reported previously, but based on the study of only one specimen from each person, more certainly reflect real differences (and not daily variation) in the types of bacteria maintained by individual people. The proportions of the predominant fecal species in the astronauts were similar to those reported earlier from a Japanese-Hawaiian population and were generally insensitive to changes from the normal North American diet to the Skylab diet; only two of the most common species were affected by changes in diet. However, one of the predominant species (Bacteroides fragilis subsp. thetaiotaomicron) appeared to be affected during confinement of the men in the Skylab test chamber. Evidence is presented suggesting that an anger stress situation may have been responsible for the increase of this species simultaneously in all of the subjects studied. Phenotypic characteristics of some of the less common isolates are given. The statistical analyses used in interpretation of the results are discussed.
Microbial formation and degradation of dimethylamine
Authors: Tate R L , Alexander M
Published: January 2020

Dimethylamine was formed from trimethylamine in soils of different pH values. The rate of disappearance of the secondary amine from soil was affected by pH and was markedly reduced under anaerobiosis. The accumulation of dimethylamine in cultures of Micrococcus sp. provided with trimethylamine depended on the nitrogen sources available to the bacterium but was not greatly influenced by the C-N ratio of the medium. Dimethylamine and nitrite accumulated in large amounts at pH 6.0 to 8.0 in cultures containing the tertiary amine and nitrate, but dimethylnitrosamine was apparently not produced.
In situ morphology of nitrifying-like bacteria in aquaculture systems
Authors: Johnson P W , Sieburth J M
Published: January 2020

The in situ microbiota from several aquaculture facilities with active nitrification was examined by transmission electron microscopy of thin sections for the presence of bacteria that contained intracytoplasmic membranes characteristic of the nitrifying bacteria. Colonies of bacteria with the cellular morphology of a species of Nitrosomonas were found to be present in both the culture water and in the biological filter slime of a freshwater chinook salmon (Oncorhynchus tshawytscha) culture system. bacteria in the water possessed the normal nitrosomonas type of ultrastructure, whereas similar bacteria in the slime had an aberrant morphology due to multiple invaginations of the cell wall and cyto-membranes and a significantly greater number of ribosomes. These nitrosomonas-like bacteria lysed during enrichment in commonly used media. Bacteria with the morphology of species of Nitrosomonas and Nitrosococcus were also observed in colonies in the surface slimes of marine culture systems for striped bass (Morone saxatilis) and quahaug (Mercenaria mercenaria).
Method for estimating the decomposition of hexadecane in the marine environment
Authors: Seki H
Published: January 2020

A method, based on quantitating 14CO2 produced from [14C]hexadecane, has been developed for estimating the rate of hexadecane decomposition in seawater of Tokyo Bay during the summer stagnation period. The rate of hexadecane decomposition was from 0.1 to 1.3 mug/h per liter of seawater at the surface layer in the polluted gyre of the inner part of Tokyo Bay during the summer of 1974. A similar horizontal distribution pattern was seen for the density of hexadecane-decomposing bacteria.
Improved Method of Assay for Choline
Authors: Tanguay A. E. , Blanchard M. H.
Published: January 2020

A modified assay for choline is described which is shorter, yields more consistent responses, and requires considerably less time, space, and equipment than the existing assays.
Microbial Models of Mammalian Metabolism: Aromatic Hydroxylation of Isomeric Xylenes
Authors: Smith Robert V. , Humphrey David W. , Engel Kenneth O. , Rosazza John P.
Published: January 2020

The ability of 11 microorganisms to convert
o
-,
m
-, and
p
-xylene to monophenolic metabolites was evaluated. Four organisms were found to produce qualitatively identical products to those observed with mammalian systems.
Enterobacteriaceae
and
Pseudomonas aeruginosa
Recovered from Vegetable Salads
Authors: Wright Charles , Kominos Spyros D. , Yee Robert B.
Published: January 2020

Klebsiella, Enterobacter
, and
Serratia
were recovered frequently in high counts from vegetable salads.
Pseudomonas aeruginosa
, although isolated frequently, was in lower counts.
Comparative studies on the microbiological vitamin B12 assay at two laboratories
Authors: Berg T M , de Vries J A , van Gasteren C J , Meeuwissen H , Stevens G A , Verbon F J
Published: January 2020

The turbidimetric methods in routine use at two laboratories for the microbiological assay of vitamin B12 have been compared. Attempts were made to standardize some major parts of the method, i.e., assay design, test strain (Lactobacillus leichmannii), test medium, and reference standard. The laboratories used different approaches to achieve efficient assay procedures. During a 6-year period four comparative experiments were carried out. In these experiments the vitamin B12 content of five different products was determined in a series of independent assays at each laboratory. A satisfactory degree of agreement (difference less than 5%) was found for four of these products.
Influence of specific growth rate on biomass yield, productivity, and compostion of Candida utilis in batch and continuous culture
Authors: Paredes-López O , Camargo-Rubio E , Ornelas-Vale A
Published: January 2020

Candida utilis was grown in batch and continuous culture on prickly pear juice as sole carbon and energy source. In batch culture the maximum specific growth rate (mum) and the substrate yield coefficient (Yps) varied according to sugar concentration. When the fermentation was carried out with 1% sugar, mum and Ys were 0.47/h and 42.6%, respectively. The best yields occurred in a chemostat at the pH range of 3.5 to 4.5 and temperature of 30 C. A beneficial effect on Ys was observed when the dilution rate (D) was increased. At a D of 0.55/h, the productivity was 2.38 g/liter per h. The maintenance coefficient attained a value of 0.09 g of sugar/g of biomass per h. Increases of D produced higher protein contents of the biomass. The information obtained indicates that protein production with Candida utilis, using prickly pear juice, should be carried out a high dilution rates where the Ys and protein content of the cell mass are also higher.
Poliovirus survival and movement in a sandy forest soil
Authors: Duboise S M , Moore B E , Sagik B P
Published: January 2020

Movement of poliovirus I (Chat) through nonsterile core samples of a sandy forest soil was monitored, using several regimens of loading with either dechlorinated final effluent from an operating activated sludge treatment plant or distilled water. Stimulated cycles of rainfall and effluent applications, resulting in ionic gradients, were shown to affect virus movement. Such studies indicate that poliovirus applied in effluents may move considerable distances through this soil after rainfall. Survival of poliovirus in the soil at 4 and 20 C has been monitored for 84 days. During this period, the capacity of the virus to migrate is unchanged.
Colonization of soil by Arthrobacter and Pseudomonas under varying conditions of water and nutrient availability as studied by plate counts and transmission electron microscopy
Authors: Labeda D P , Liu K C , Casida L E
Published: January 2020

Arthrobacter globiformis and a Pseudomonas soil isolate were incubated separately and in combination in soil that had been presterilized by autoclaving. Growth and other responses of the cells in situ in this soil were monitored by plate counts and transmission electron microscopy examinations of cell sections. During the soil incubations, some of the samples were first allowed to dry and then were remoistened with water or with a dilute or a concentrated nutrient solution. Based on plate counts and ultrastructural analysis. Arthrobacter seemed to be in a non-multiplying coccoid-rod resting state and to be virtually immune to soil drying. Addition of a dilute nutrient solution helped maintain cell ultrastructure and prevent a low level of lysing that occurred in the absence of nutrient addition. Addition of a concentrated nutrient solution brought on cell multiplication as both coccoid-rods and long rods, but the ultimate form with further incubation was the coccoid-rod. The Pseudomonas strain suffered death and ultrastructural deterioration as water became less available. It responded by cell multiplication to an equal extent when either water or dilute nutrients were added, but possibly was able to give a growth response to nutritive amendment when a concentrated nutrient addition was made. The Arthrobacter was not affected by the presence of Pseudomonas in dual culture. The Pseudomonas, however, possibly suffered a nutritive deficiency under these conditions.
Lipolytic fermentations of stickwater by Geotrichum candidum and Candida lipolytica
Authors: Green J H , Paskell S L , Goldmintz D
Published: January 2020

Stickwater, a by-product of the fish meal and oil industry, is an aqueous suspension of fish proteins, lipids, and other materials, and also contains soluble nonprotein nitrogen but not carbohydrate. It is usually partially evaporated by heat to a marketable form called "fish solubles," which is sold with an acid preservative as an animal feed supplement. However, fish solubles are only used to a limited extent in feeds, because the lipids of solubles (averages 11%) are relatively prone to oxidative rancidity development. An investigation was undertaken to digest and/or stabilize lipids in stickwater by lipolytic fermentations and, at the same time, to attempt to increase the protein content as single cell protein. Strains of the yeast Candida lipolytica and the yeast like mold Geotrichum candidum were employed for these investigations. Stickwater fermentations were performed in a laboratory bench top fermentor. Respirometric studies of lipid metabolic activity and microbial observations were periodically performed during these fermentations. Rapid microbial growth and metabolic activity were observed in well aerated cultures. Fermented products were evaluated for chemical composition. Lipid residues were characterized by thin-layer chromatographic procedures. There was evidence of abundant microbial growth, increased lipolytic activity, and decreased lipid content. However, evidence was lacking to show that the protein content of stickwater was actually increased.
Electron microscopy of virulent phages for Streptococcus lactis
Authors: Tsaneva K P
Published: January 2020

Electron microscopic studies were made on eight virulent Streptococcus lactis bacteriophages. These phages were taken as representative of eight host range groups established in a study of 75 phage isolates and 253 hosts (213 S. lactis, 22 S. cremoris, 18 S. diacetilactis). The phages studied were shown to have an isometric hexagonal head and noncontractile tails, usually several times longer than the head diameter. The virus heads were octahedral. The phages investigated represented three morphological types on the basis of head diameter , tail thickness, and tail length. These dimensions were approximately: for type I phages, 63, 172, and 11 nm, respectively; type II, 73, 200, and 20 nm, respectively; and type III, represented here by a single phage, 98, 551, and 12 nm, respectively. The tail surface revealed a different arrangment of the structural subunits which lent a helical appearance to the tails of type I and II phages and a guaffered tube appearance to the tail of type III phage. The number of turns along the tail axis, turn length, axial pitch, and helix angle were: type I, 32, 12 to 13 nm, 7.14 nm, and 11 degrees 43', respectively; type II, 24, 24, to 28 nm, 40.00 nm, and 32 degrees 30', respectively; and type III, 120, 12 nm, and no visible slope towards the axis. The morphology types showed complete correlation with serological groups, but not with groups based on host range pattern.
Continuously variable amplitude contrast microscopy for the detection and study of microorganisms in soil
Authors: Casida L E
Published: January 2020

A new type of phase microscope was used to detect and observe the microflora in soil and to differentiate cells and spores from soil debris. This microscope provides a continuous variation in the amplitude ratios between undeviated and deviated beams of light, and the microbial cells, spores, and debris in soil change in appearance to a differing degree in response to the changes in amplitude ratio.
Microapplicator and micropipette for inoculation of the embryonated chicken egg
Authors: Stearman W C , Norman J O , Del var Petersen H
Published: January 2020

Aflatoxin G2 was used to test the speed and accuracy of the microapplicator and the micropipette. The 50% lethal dose of both assay systems was approximately the same, and 4.0 mug of G2 had an 85% lethal effect in both systems. The 50% lethal dose of the microapplicator and the micropipette was lower than that of the syringe but, of these, only the micropipette can combine the accuracy of the microapplicator and the speed of the syringe.
Microbial degradation of oil spills enhanced by a slow-release fertilizer
Authors: Olivieri R , Bacchin P , Robertiello A , Oddo N , Degen L , Tonolo A
Published: January 2020

The improved cleanup of marine oil spills by stimulating biodegradation through the use of a slow-release fertilizer is reported. A paraffin-supported fertilizer containing MgNH4PO4 as active ingredient was developed and evaluated in laboratory and field experiments using quantitative infrared spectrometry and chromatographic techniques. The biodegradation of Sarir crude oil in the sea was considerably enhanced by paraffin-supported fertilizer. After 21 days 63% had disappeared as compared to 40% in the control area.
Use of a quantitative oxidase test for characterizing oxidative metabolism in bacteria
Authors: Jurtshuk P , McQuitty D N
Published: January 2020

It was possible to quantitate the terminal oxidase(s) reaction using bacterial resting-cell suspensions and demonstrate the usefulness of this reaction for taxonomic purposes. Resting-cell suspensions of physiologically diverse bacteria were examined for their capabilities of oxidizing N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD) using a manometric assay. For organisms having this capability, it was possible to calculate the conventional TMPD oxidase Q(O2) value (microliters of O2 consumed per hour per milligram [dry weight]). All cultures were grown heterotrophically at 30 C, under identical nutritional conditions, and were harvested at the late-logarithmic growth phase. The TMPD oxidase Q(O2) values showed perfect correlation with the Kovacs oxidase test and, in addition, it was possible to define quantitatively that point which separated oxidase-positive from oxidase-negative bacteria. Oxidase-negative bacteria exhibited a TMPD oxidase Q(O2) value (after correcting for the endogenous by substraction) of less than or equal 33 and had an uncorrected TMPD/endogenous ratio of less than or equal 5. The TMPD oxidase Q(O2) values were also correlated with the data obtained for the Hugh-Leifson Oxferm test. In general, bacteria that exhibited a respiratory mechanism had high TMPD oxidase values, whereas fermentative organsims had low TMPD oxidase activity. All exceptions to this are noted. This quantitative study also demonstrated that organisms that (i) lack a type c cytochrome, or (ii) lack a cytochrome-containing electron transport system, like the lactic acid bacteria, exhibited low or negligible TMPD oxidase Q(O2) values. From the 79 bacterial species (36 genera) examined, it appears that this quantitative oxidase test has taxonomic value that can differentiate the oxidative relationships between bacteria at the subspecies, species, and genera levels.
Growth of Fusarium moniliforme on carob aqueous extract and nutritional evaluation of its biomass
Authors: Drouliscos N J , Macris B J , Kokke R
Published: January 2020

Fusarium moniliforme was cultured semicontinuously on a carob medium in a 14-liter fermentor (8.5-liter working volume). The growth medium provided 2.4% carob sugar, 0.72% NH4H2PO4, and 0.03% MgSO4-7H2O. The biomass harvest was 8.8 g/liter per day. Ninety percent of the sugars were consumed, and the pH dropped from 5.9 to about 3.7. The crude protein (N X 6.25) of the spray-dried mycelium was 380 g/kg, 300 g/kg for the true protein (Lowry), and 4.8 g/kg for the (Folin-Denis) tannic acid. The mycelium was evaluated nutritionally with the weanling rat as experimental animal. The protein efficiency ratio and net protein utilization values for the unsupplemented mycelium were 1.15 and 0.42, respectively, and for the mycelium supplemented with DL-methionine (5 g/kg) they were 2.31 and 0.72, respectively. No growth depression was observed in the experimental rats, and on dissection of the carcasses the internal organs were found to be normal.
Estimation of viable airborne microbes downwind from a point source
Authors: Lighthart B , Frisch A S
Published: January 2020

Modification of the Pasquill atmospheric diffusion equations for estimating viable microbial airborne cell concentrations downwind form a continuous point source is presented. A graphical method is given to estimate the ground level cell concentration given (i) microbial death rate, (ii) mean wind speed, (iii) atmospheric stability class, (iv) downwind sample distance from the source, and (v) source height.
Concentrations of nitrifying bacteria in sewages, effluents, and a receiving stream and resistance of these organisms to chlorination
Authors: Strom P F , Matulewich V A , Finstein M S
Published: January 2020

Estimates of NH4+-and NO2-oxidizers in samples from four activated sludge plants treating mainly domestic sewage were obtained using a most-probable-number (MPN) technique. Ranges of concentrations per milliliter of each, respectively, were 1,010 to 3,880 and 79 to 145 in settled sewages, 32 to 7,420 and 2 to 1,010 in secondary effluents, and less than 0.1 to 622 and 0.1 to 70 in chlorinated secondary effluents. The results of this field study indicated that nitrifiers were more resistant to chlorination than fecal streptococci, which were also enumerated. In laboratory studies the survivals of these bacterial groups in secondary effluents were determined after exposure to chlorine residuals of up to 2 mg/liter for 0 to 60 min. The nitrifiers proved considerably more resistant than fecal streptococci, with NO2-oxidizers showing greater resistance than NH4+-oxidizers. Below the outfall of one of the plants that discharges heavily chlorinated unnitrified effluent, NH4+-oxidizers amounted to approximately 200 X 10(5) per g of slime scraped from stream-bed rocks. Upstream of the outfall this was approximatley 3 X 10(5)/G.
Incorporation of proline into prodigiosin by a Put mutant of Serratia marcesens
Authors: Lim D V , Qadri S M , Williams R P
Published: January 2020

A Put mutant of Serratia marcescens, deficient in proline oxidase and therefore unable to degrade proline, was used to assay for an enzymatic reaction responsible for incorporation of proline into prodigiosin. The reaction had a pH optimum of 7.5 and a Km of 1.1 X 10(-4) M at 27 C. At temperatures above 27 C, the velocity of the reaction decreased with increasing temperature and little activity was detected at 42 C. Activity of the enzyme was directly proportional to the quantity of pigment formed and was inhibited by thioproline, a substrate analog. These data suggested the presence of a unique and specific enzyme in the biosynthetic pathway for prodigiosin.
N
2
Fixation Associated with Decaying Leaves of the Red Mangrove (
Rhizophora mangle
)
Authors: Gotto John W. , Taylor Barrie F.
Published: January 2020

N
2
(C
2
H
2
) fixation was associated with decaying leaves of
Rhizophora mangle
. The process was predominantly anaerobic, with about two-thirds of the nitrogenase activity being light dependent. Average N
2
fixation rates in the light were 11 μg of N per g (dry weight) per h for leaves that had decayed for 2 to 3 weeks. This nitrogen input is probably significant in the estuarine, detrital food chains linked to
R. mangle
.
Patchiness in the Distribution of Planktonic Heterotrophic Bacteria in Lakes
Authors: Palmer F. E. , Methot R. D. , Staley J. T.
Published: January 2020

By using conventional dilution plating procedures, the heterotrophic planktonic bacteria in Lake Washington were found to be distributed in small-scale (<1.0 ml) and large-scale (>1 m in horizontal distance) patches. Recommendations are made on sampling and enumeration procedures to minimize the effect of patchiness on obtaining an accurate estimate of bacterial numbers.
Production of extracellular alpha-glucosidase by a thermophilic Bacillus species
Authors: Suzuki Y , Kishigami T , Abe S
Published: January 2020

Production of extracellular alpha-glucosidase was studied with strain KP 1006 of a new species of thermophilic Bacillus, which was isolated from soil samples by enrichment at 65 C. alpha-Glucosidase production was maximum at 60 C and at an initial pH of 6.5. The final enzyme yield was increased by starch, maltose, glycerol, peptone, and yeast extract but reduced by acetate and gluconate, alpha-Glucosidase was formed in the cytoplasm and accumulated as a large pool during the logarithmic growth phase. At a midpoint of this period, the enzyme appeared in the culture broth, and its level increased until the end of the stationary phase.
Bacteriological quality and shelf life of ground beef
Authors: Emswiler B S , Pierson C J , Kotula A W
Published: January 2020

The bacteriological quality of unfrozen raw ground beef was evaluated after 0, 3, 6, 9, 12, 15, and 18 days of storage at 29 +/- 1 F (-1.7 +/- 0.6 C). At the time of fabrication, all of the ground beef samples contained 10(6) or fewer total aerobic and psychrotrophic bacteria/g; 81% contained 100 or fewer coliforms/g; 94% contained 100 or fewer Escherichia coli/g; and all of the samples contained 100 or fewer coagulase-positive Staphylococcus aureus and Clostridium perfringens/g. Total aerobic and psychrotrophic bacteria increased by 1 log between 3 and 18 days of storage. Coliform and E. coli counts decreased during storage, whereas coagulase-positive S. aureus and C. perfringens counts did not change significantly. These data indicate that meat processors, wholesalers, and retailers could improve the bacteriological quality and prolong the shelf life of ground beef packaged in oxygen-impermeable film if the temperature of product never exceeded 29 +/- 1 F (-1.7 +/- 0.6 C).
Improved method for preparing anaerobic bacteroid suspensions of Rhizobium leguminosarum for the acetylene reduction assay
Authors: Van Straten J , Roelofsen W
Published: January 2020

A method using ethylenediaminetetraacetate (EDTA) and toluene-treated pea bacteroid suspensions for the acetylene reduction assay is described. The high level of acetylene reduction by these bacteroids is comparable to that of intact plants. Reproducibility of the EDTA-toluene treatment is, on the average, within 5%. Preliminary experiments with soybeans indicate that the EDTA-toluene method might be applicable to other legumes as well.
Macromolecule synthesis in Escherichia coli BB under various growth conditions
Authors: Chohji T , Sawada T , Kuno S
Published: January 2020

The kinetic behavior of the macromolecule synthesis of Escherichia coli during balanced growth in various media at different temperatures as investigated. The results indicate that macromolecule contents per cell can be expressed as exponential functions of the specific growth rate at a given temperature. It was shown that the content per cell at the zero growth rate was constant in each macromolecule component, irrespective of the growth temperature. The rate of ribonucleic acid (RNA) synthesis per unit weight of deoxyribonucleic acid and that of protein synthesis per unit weight of RNA were taken as efficiencies of RNA and protein synthesis, respectively; both of them were found to be dependent on the growth rate and temperature. The efficiency of RNA synthesis was found to be very high at a high growth rate, whereas that of protein synthesis was found to decrease above certain growth rate. At the same growth rate, an increase in the growth temperature resulted in a decrease in the efficiency of RNA synthesis but an increase in that of protein synthesis.
Predation of Escherichia coli by Colpoda steinii
Authors: Drake J F , Tsuchiya H M
Published: January 2020

A study of single-stage chemostat cultures of Colpoda steinii. Escherichia coli, and glucose is reported here. Two levels of glucose were fed as the limiting nutrient to the chemostat cultures. The cultures were studied at three holding times. Oscillations developed at short holding time and damped oscillations developed a long-residence times that approached steady-state conditions of populations of C. steinii and E. coli and concentrations of glucose. The experimental data are fitted to and compared with Jost's model.
Co-metabolism of fluorobenzoates by natural microbial populations
Authors: Horvath R S , Flathman P
Published: January 2020

Co-metabolic degradation of monofluorobenzoates was carried out by a mixed soil population in a basal salts medium. The monofluorobenzoates did not support growth of microorganisms but were shown to be subject to ring cleavage as a result of microbial activity. Rate of ring cleavage was increased by use of the co-substrate enrichment technique using glucose as the co-substrate. Results indicate that the monofluorobenzoates were subject to an initial co-metabolic attack with glucose, providing the energy necessary for co-metabolism to proceed to a point where complete metabolism became possible.
N-Nitrosamine formation by cultures of several microorganisms
Authors: Mills A L , Alexander M
Published: January 2020

Of 38 pure cultures of microorganisms tested, only one, Pseudomonas stutzeri, was capable of forming dimethylnitrosamine from dimethylamine and nitrite during growth. Resting cells of P. stutzeri, Cryptococcus terreus, Escherichia coli, and Xanthomonas campestris formed dimethylnitrosamine, although no nitrosamine was found in growing cultures of the latter three organisms. No nitrosamine was produced by either growing cultures or resting-cell suspensions of Pseudomonas fragi or Proteus mirabilis. Boiled cells of P. stutzeri, but not those of C. terreus, E. coli, and X. campestris, formed dimethylnitrosamine, and this nitrosamine was also produced by extracts of E. coli cells at pH 5.0.
Effect of antimicrobial soap containing chlorhexidine on the microbial flora of skin
Authors: Aly R , Maibach H I
Published: January 2020

The qualitative and semiquantitative changes in the aerobic microbial flora of normal skin with the prolonged use of a chlorhexidine scrub (6 months) were investigated. More samples in the chlorhexidine scrub group had gram-negative bacilli in their axilla (63 of 96, 66%) and groin (36 of 96, 38%) than the controls (32 of 66, 49%, for axilla and 7 of 66, 11%, for groin; P = 0.01). Klebsiella and Enterobacter were the predominant organisms in the control and chlorhexidine groups, respectively. The chlorhexidine scrub produced a reduction in the total aerobic counts in the axilla, groin, and between the toes and the fingers. Fewer samples from the chlorhexidine-treated areas revealed the presence of lipophilic diphtheroids than did the controls. Lipophilic diphteroids were also reduced quantitatively in the groin and axilla with chlorhexidine treatment. No consistent pattern for the other major groups of bacteria was noted between the treatments.
Cultivation of mycoplasmas in a modified tissue culture medium
Authors: Gabridge M G , Singer S E , Esposito R A
Published: January 2020

A new medium, which contained a chemically defined tissue culture base ("medium 199"), was developed for the cultivation of mycoplasmas. When supplemented with albumin, glucose, serum, and yeast extract, the new medium adequately supported the growth of Mycoplasma and Acholeplasma species.
Production of Infectious Epstein-Barr Virus by Using an Intermittent Culture Collection System
Authors: Klein Frederick , Rosensteel John F. , Hummer Raymond , Charamella Leigh J.
Published: January 2020

Procedures were developed to produce infectious Epstein-Barr virus in large glass fermentors with limited mechanical agitation by using an intermittent culture collection system. The system appears quite suitable for use in fermentation vessels of 50 liters or larger.
Stability of Bacillus pumilus spore strips used for monitoring radiation sterilization
Authors: Prince H N
Published: January 2020

Dried Bacillus pumilus spore strips had a stable D-value of 0.17 to 0.18 Mrad after 1 year at 5 or 25 C, but resistance was lost at 35 C. Refrigeration did not have an adverse effect on resistance to irradiation. The presence of water at the time of initial preparation increased this resistance to 0.23 to 0.25 Mrad. Proper drying is essential to achieve reproducible results in sterility tests using USP-type biological indicators.
Influence of Organic Solvents on Chalcopyrite Oxidation Ability of
Thiobacillus ferrooxidans
Authors: Torma Arpad E. , Itzkovitch Irwin J.
Published: January 2020

It has been shown that organic solvents used primarily for the extraction of metals from aqueous leach liquors decrease both the surface tension of the aqueous phase and the chalcopyrite oxidation ability of
Thiobacillus ferrooxidans
. For the reagents and modifiers investigated, the order of inhibition was found to be LIX 70 < LIX 73 < LIX 71 < LIX 64N < LIX 65N < TBP ∼ isodecanol ∼ nonylphenol < LIX 63 <<< D
2
EHPA ∼ Kelex 100 < Kelex 120 <<< Alamine 336 ∼ Alamine 308 ∼ Alamine 310 < Alamine 304 < Adogen 381 ∼ Aliquat 336 < Adogen 364. To avoid limitation in bacterial activity, organic matter should be removed from the recycling liquor prior to leaching.
Effect of sediments on the survival of Escherichia coli in marine waters
Authors: Gerba C P , McLeod J S
Published: January 2020

Escherichia coli, a fecal coliform, was found to survive for longer periods of time in unsterile natural seawater when sediment material was present than in seawater alone, and at least on one occasion growth was observed to occur. This enteric bacterium was found to increase rapidly in number in autoclaved natural seawater and autoclaved sediment taken from areas receiving domestic wastes, even when the seawater had salinities as high as 34 g/kg. However, in autoclaved seawater, growth was always more gradual and never reached numbers as high as those observed when sediment was present. It was found that nutrients were easily eluted from the sediment after autoclaving or upon addition to artificial seawater, but little elution occured during mixing of the sediments with unsterile natural seawater. The longer survival of E. coli in the sediment is attributed to the greater content of organic matter present in the sediment than the sweater. These laboratory results, in part, could explain why on a volume basis larger numbers of coliforms and fecal coliforms and fecal coliforms were found in estuarine sediments than the overlaying water at field sites.
Study of plating efficiency of bacteriophages of thermophilic lactic acid bacteria on different media
Authors: Sozzi T , Maret R , Poulin J M
Published: January 2020

The qualitative and quantitative abilities of phages of 13 strains of thermophilic lactic bacteria (lactobacilli and streptococci) to produce plaques on six different media were studied. The influence of the addition of calcium on the one hand, and of incubation conditions (aero-anaerobiosis), on the other hand, was also examined. For the phages of lactobacilli, the best results were obtained with the medium of de Man, Rogosa, and Sharpe (1960), whereas for the phages of streptococci the medium of Hogg and Jago (1970) appeared to be the best. Calcium and incubation conditions play a role which is variable in importance, but rarely negligible.
Isolation and characterization of an enzyme with esterase activity from Micropolyspora faeni
Authors: Bannerman E N , Nicolet J
Published: January 2020

The isolation and the characterization of one of the enzymes of Micropolyspora faeni that hydrolyzes the substrate N-benzoyl-DL-phenylalanine-beta-naphthyl ester and that seems to be of medical importance are described. This enzyme (enzyme 1) was isolated with an 86-fold purification by using the following seven steps: ammonium sulfate precipitation, gel filtration through Sephadex G-150, heat treatment, chromatography on diethylaminoethyl-cellulose, rechromatography on diethylaminoethyl-Sephadex, gel filtration through Sephadex G-200, and affinity chromatography. Enzyme 1 has a molecular weight of approximately 500,000 and maximum activity at pH 7.8 to 8.0 and at 20 degrees C. The enzyme is stable between pH 7.5 and 10.5 and at temperatures up to 60 degrees C. Its activity is not inhibited by ethylenediaminetetraacetic acid. It is, however, sensitive to diisopropyl phosphofluoride and phenylmethyl sulfonyl fluoride. These properties and the ability to hydrolyze the esters of phenylalanine, tyrosine, and tryptophan without endopeptidasic activity and no marked proteolytic activity suggest that the enzyme is an esterase.
Observations on bacteriophages of Clostridium botulinum type C isolates from different sources and the role of certain phages in toxigenicity
Authors: Hariharan H , Mitchell W R
Published: January 2020

Twenty strains of Clostridium botulinum type C, including 12 isolates from avian sources with varying toxigenic properties, were examined by electron microscope for the presence of bacteriophages. All toxigenic strains were infected with one or two types of phages. Three types of phages designated large, small, and intermediate were observed. Most of the strains carried the large and small phage, with the large phage being present in much greater numbers. Since there is evidence that highly toxigenic strains of C. botulinum type C are responsible for large outbreaks of botulism in wild birds, the phenomenon of toxigenic variation among the type C strains was investigated. Experiments were carried out employing a broth medium on a phagefree nontoxigenic strain for elucidating the role of bacteriophages in toxigenicity. All phage suspensions contained large phages, with the exception of one that caused conversion. The exception was a preparation containing an intermediate type of phage. Phages from different strains produced cultures of varying toxigenic characteristics. By employing a tube-lytic test and an agar-overlay-phage assay technique, it was determined that whenever the phage-bacterium relationship resulted in an initial high degree of lysis, the potency of toxin in the culture was weak. It appeared that in highly toxigenic strains, the phage-bacterium relationship is characterized by a stable lysogenic type of association. It was also found that in a highly toxigenic converted culture the percentage of toxigenic cells was 100, whereas in hypotoxigenic culture the percentage was only 20.
Detection of Thiobacillus ferrooxidans in acid mine environments by indirect fluorescent antibody staining
Authors: Apel W A , Dugan P R , Filppi J A , Rheins M S
Published: January 2020

An indirect fluorescent antibody (FA) staining technique was developed for the rapid detection of Thiobacillus ferrooxidans. The specificity of the FA stain for T. ferrooxidans was demonstrated with both laboratory and environmental samples. Coal refuse examined by scanning electron microscopy exhibited a rough, porous surface, which was characteristically covered by water-soluble crystals. Significant numbers of T. ferrooxidans were detected in the refuse pores. A positive correlation between numbers of T. ferrooxidans and acid production in coal refuse in the laboratory was demonstrated with the FA technique.