Effect of 3,4,4 '-trichlorocarbanilide on growth of lactic acid bacteria contaminants in alcoholic fermentation

3,4,4'-trichlorocarbanilide (TCC) was rested as a new method of bacterial growth control for S. cerevisiae alcoholic fermentations of diluted high test molasses (HTM). Minimal inhibitory concentration (MIC) was tested to determine the necessary concentration of TCC to control bacterial growth. The fed-batch alcoholic fermentation process was used with cell recycle similar to industrial conditions and Lactobacillus fermentum CCT 1407 was mixed in the first inoculum to grow with the yeast. Yeast extract was added into the must to stimulate bacterial growth. The best results of TCC's MIC to bacterial growth of Lactobacillus fermentum and Leuconostoc mesenteroides (< 0.125-1.0 mu g/ml) and Saccharomyces cerevisiae (16 mu g/ml) occurred when it was combined with sodium dodecylsulphate (SDS) in a 1: 4 TCC/SDS ratio (wt/wt) in distilled water solution. 1.8 g/l TCC entrapped in calcium alginate added to the must with yeast extract inhibited the growth of Lactobacillus fermentum CCT 1407 maintaining a controlled acidity, higher yeast viability and up to 20.8% of improvement in the average of alcoholic efficiency. Addition of 0.075 g/l TCC entrapped in calcium alginate and 1.67 mg/l SDS in the wort with yeast extract (0-5.0 g/l), inhibited and controlled the extensive bacterial contamination for 19 cycles of fermentation. (C) 1998 Published by Elsevier B.V. Ltd.

An experimental inoculation system to study citrus-Xylella fastidiosa interactions

Difficulties in reproducing the citrus variegated chlorosis (CVC) disease symptoms in expertmental plants have delayed implementation of studies to better understand the essential aspects of this important disease. In an extensive Study, cultivars of sweet orange (Citrus sinensis) were inoculated with Xylella fastidiosa using procedures that included root immersion, and stein absorption, pricking, or infiltration of the inoculum into plants of different ages. Inoculum consisted of 5-day-old cultures or cell suspensions of CVC strain 9a5c diluted in phosphate-buffered saline. Inoculated plants and controls were grown, or transferred just after inoculation, to 5-liter pots or 72-cell foam trays. Approximately 4, 5, 9, and 12 months after inoculation, leaves were collected and processed for polymerase chain reaction analysis or X. fastidiosa isolation on BCYE agar medium. Root immersion and stem inoculation of 4- and 6-month-old plants resulted in low percentages of symptomatic (0 to 7%) and plants positive by isolation (0 to 9%). Pinpricked or injected stems of I-month-old seedlings resulted in high percentages of plants symptomatic (29 and 90% in Pera Rio, 75, 59, and 83% in Valencia, and 77% in Natal) or positive by isolation (26 and 93% in Pera Rio, 98, 96, and 83% in Valencia, and 77% in Natal), In foam trays, the seedlings grew less, the incubation period was shorter. and disease severity was higher than in pots. This system allows testing of higher numbers of plants in a reduced space with a more precise reproduction of the experimental conditions.

Effect of lesion age, humidity, and fungicide application on sporulation of Alternaria alternata, the cause of brown spot of tangerine

Alternaria brown spot, caused by Alternaria alternata, causes yield losses and fruit blemishes on many tangerines and their hybrids in most citrus areas of the world where susceptible cultivars are grown. Although the conditions affecting infection and disease severity are known, little information is available on inoculum production on infected tissue. We found that sporulation on leaves began about 10 days after symptoms developed, was abundant from 20 to 40 days, and declined thereafter. Conidial production was far greater on leaf than on fruit or twig lesions. Spore production per unit area of leaf lesion was greater on the more susceptible hybrids, Minneola and Orlando tangelos, than on the less susceptible Murcott tangor. At 74% relative humidity, conidial production on leaf lesions was low, but it was abundant at 85, 92.5, 96, and 100%. Application of Q(o)I or copper fungicides, but not ferbam, suppressed sporulation on leaf lesions for about 14 to 21 days after application. Additional applications did not appear to be more effective than a single spray in reducing inoculum production.

EARLY ACTIVATION OF SPLENIC MACROPHAGES BY TUMOR-NECROSIS-FACTOR-ALPHA IS IMPORTANT IN DETERMINING THE OUTCOME OF EXPERIMENTAL HISTOPLASMOSIS IN MICE

Experimental infection of animals with Histoplasma capsulatum caused a massive macrophage infiltration into the spleen and induced the production of tumor necrosis factor alpha (TNF-alpha) locally. The cytokine was also produced in vitro by peritoneal exudate macrophages exposed to a large inoculum of yeast cells. Depletion of the cytokine by injection of polyclonal sheep anti-TNF-alpha antibody was detrimental to sublethally infected mice. Fungous burdens in the spleens of TNF-alpha-depleted mice were higher than they were in the infected control mice at days 2, 7, and 9 after infection, and the antibody-treated animals succumbed to the infection. Histopathological study of spleen sections revealed that splenic macrophages were not able to control proliferation of intracellular yeasts as a result of TNF-alpha depletion. It seems that TNF-alpha plays a role in early activation of splenic macrophages which is important in controlling the outcome of an infection.

The effect of soil moisture and cabbage amendment on the thermoinactivation of Phytophthora nicotianae

The analysis of the effect of soil water matric potential and temperature regimes on the inactivation of chlamydospores of Phytophthora nicotianae in cabbage amended soils was evaluated using three matric potentials (0, -10, and -30 kPa), temperature regimes of 1.5 h at 44 degreesC, 5 h at 41 degreesC and 8 h at 35 degreesC, or 3 h at 47 degreesC, 5 h at 44 degreesC and 8 h at 35 degreesC, with a baseline temperature of 25 degreesC during the rest of the day. The results indicated that survival of P. nicotianae was lowest in saturated soil; and as temperature increased, survival of the pathogen decreased at all soil water matric potentials evaluated. Cabbage amendments can enhance the effect of the heat treatment, further decreasing the pathogen population. The soil water matric potentials evaluated represent optimum levels for the study of thermal inactivation. However, under field conditions lower potentials may be found. Extending the range of soil water matric potentials and the treatment time would allow better comparisons with the field data. There is a clear indication that one irrigation period prior to solarization would provide enough moisture to inactivate the primary inoculum of P. nicotianae in the top soil under field conditions; however, other factors may affect the effectiveness of solarization, reducing or enhancing its potential.

Saprophytic colonization of citrus twigs by Diaporthe citri and factors affecting pycnidial production and conidial survival

Melanose, caused by Diaporthe citri, produces reddish brown lesions on the fruit, leaves, and twigs of citrus trees, and greatly reduces the marketability of fresh fruit. Most of the inoculum is produced in pycnidia on dead twigs in the tree canopy, which exude large numbers of conidia in slimy masses. In this study, detached twigs inoculated with conidia were readily colonized and produced large numbers of pycnidia within 30 to 40 days when they were soaked 3 to 4 h on alternate days. Conidial production was measured by wetting twigs in a rain tower periodically and collecting the conidia in the runoff water. Production began after 80 days and continued for nearly 300 days. In other experiments, production of mature pycnidia on detached twigs was greatest at 94 to 100% relative humidity (RH) and at 28 degrees C. Low RH and temperature, however, favored survival of conidia in exuded masses on twigs. In the field, colonization of detached twigs by D. citri was high in rainy season, moderate in spring and early fall, and minimal in late fall and winter. Twig colonization was positively related to the number of rain days and average temperature, but not to total rainfall. In another experiment, inoculated twigs placed in the tree canopy developed pycnidia and then produced conidial masses for about 200 days. D. citri is a serious pathogen, but a weak parasite, that survives primarily by colonization and reproduction on dead twigs.

Citrus and coffee strains of Xylella fastidiosa induce Pierce's disease in grapevine

Xylella fastidiosa causes citrus variegated chlorosis (CVC) disease in Brazil and Pierce's disease of grapevines in the United States. Both of these diseases cause significant production problems in the respective industries. The recent establishment of the glassy-winged sharpshooter in California has radically increased the threat posed by Pierces disease to California viticulture. Populations of this insect reach very high levels in citrus groves in California and move from the orchards into the vineyards, where they acquire inoculum and spread Pierce's disease in the vineyards. Here we show that strains of X. fastidiosa isolated from diseased citrus and coffee in Brazil can incite symptoms of Pierce's disease after mechanical inoculation into seven commercial Vitis vinifera varieties grown in Brazil and California. Thus, any future introduction of the CVC strains of X. fastidiosa into the United States would pose a threat to both the sweet orange and grapevine industries. Previous work has clearly shown that the strains of X. fastidiosa isolated from Pierce's disease- and CVC-affected plants are the most distantly related of all strains in the diverse taxon X. fastidiosa. The ability of citrus strains of X. fastidiosa to incite disease in grapevine is therefore surprising and creates an experimental system with which to dissect mechanisms used by X.,fastidiosa in plant colonization and disease development using the full genome sequence data that has recently become available for both the citrus and grapevine strains of this pathogen.

Chlorine dioxide against bacteria and yeasts from the alcoholic fermentation

The ethanol production in Brazil is carried out by fed-batch or continuous process with cell recycle, in such way that bacterial contaminants are also recycled and may be troublesome due to the substrate competition. Addition of sulphuric acid when inoculum cells are washed can control the bacterial growth or alternatively biocides are used. This work aimed to verify the effect of chlorine dioxide, a well-known biocide for bacterial decontamination of water and equipments, against contaminant bacteria ( Bacillus subtilis, Lactobacillus plantarum, Lactobacillus fermentum and Leuconostoc mesenteroides) from alcoholic fermentation, through the method of minimum inhibitory concentration ( MIC), as well as its effect on the industrial yeast inoculum. Lower MIC was found for B. subtilis ( 10 ppm) and Leuconostoc mesenteroides ( 50 ppm) than for Lactobacillus fermentum ( 75 ppm) and Lactobacillus plantarum ( 125 ppm). Additionally, these concentrations of chlorine dioxide had similar effects on bacteria as 3 ppm of Kamoran (R) ( recommended dosage for fermentation tanks), exception for B. subtilis, which could not be controlled at this Kamoran (R) dosage. The growth of industrial yeasts was affected when the concentration of chlorine dioxide was higher than 50 ppm, but the effect was slightly dependent on the type of yeast strain. Smooth yeast colonies ( dispersed cells) seemed to be more sensitive than wrinkled yeast colonies ( clustered cells/pseudohyphal growth), both isolated from an alcohol-producing unit during the 2006/2007 sugar cane harvest. The main advantage in the usage of chlorine dioxide that it can replace antibiotics, avoiding the selection of resistant populations of microorganisms.

Esporulação de Botryotinia ricini em diferentes meios de cultura

The castor bean plant is a tropical species and is subject to various diseases, which cause great losses. Among these diseases, the gray mold (Botryotinia ricini) is one of the most important. The fungus spore production was evaluated in the media of cultures BDA; Oats-Agar; Mazeina-Agar; Rice-Agar; castor-bean crushed leaves-agar (FM), FM-CaCO3; V8 juice to 5% (V8-5%); V8-10%; V8-20% and tomato juice at 5% (TJ-5%); TJ-10% and TJ-20%. The production of spore in different media of cultures was evaluated at 8(th) days of incubation. The data were analyzed using the comparison of means, through the test Tukey a 5% probability, and the data processed for (X + 1) (0.5). All means of crops tested were able to produce conidia, but the best results was obtained with the culture medium V8-20% (5.7 x 10(6) conidia/mL) and BDA (3.5 x 10(6) conidia/mL).

Associação micorízica em espécies arbóreas, atividade microbiana e fertilidade do solo em áreas degradadas de cerrado

The recuperation of areas used during the construction of the hydroelectric plant, especially in 'borrowed areas', is a difficult and long process since all vegetation and the fertile layer of soil were removed. Interventions in these degraded areas could accelerate the revegetation process. The objective of this research was to evaluate the association of arbuscular mycorrhizal fungi (AMF) in tree species, microbial activity (basal respiration) and fertility of 'cerrado' degraded areas. Soil from two areas, pasture soil and exposed subsoil, were utilized. Organic and mineral fertilization, and liming, were added to the pit for better seedlings' initial growth, where 50 mL of preserved cerrado soil was applied as inoculum of microorganisms. Seedlings of 11 tree species were planted: Anadenanthera falcata (Benth.) Speg ('angico-preto'), Acacia polyphylla D. C. ('monjoleiro'), Stryphnodendron adstringens (Mart.) Coville ('barbatimao'), Dimorphandra mollis Benth ('faveiro'), Hymenaea stigonocarpa Mart. ex Hayne ('jatoba-de-cerrado'), Dipteryx alata Vog. ('baru'), Machaerium acutifolium Vogel ('jacaranda-do-campo'), Schinus terebinthifolia Raddi ('aroeirapimenteira'), Magonia pubescens St. Hil. ('tingui'), Lafoensia pacari St. Hil. ('dedaleira') and Tabebuia aurea (Manso) Benth. & Hook ('ipe-amarelo'). Twelve months later, root samples were colleted at the depth of 0-0.10 m and used for evaluations. The subsoil, as compared to pasture soil, was poor in organic matter and presented less microbial activity. The highest mycorrhizal colonization was seen in the species Acacia polyphylla D. C. (monjoleiro), Magonia pubescens St. Hil. (tingui), Hymenaea stigonocarpa Mart. ex Hayne (jatoba-de-cerrado) and Schinus terebinthifolia Raddi (aroeira-pimenteira). These species could be indicated in revegetation projects in 'cerrado' degraded areas. Plants from both areas showed seedlings form high mycorrhizal colonization and low numbers of spores.

Use of fungal inocula and pumice for decomposing coffee pulp

A study of decomposition of coffee pulp (from Guatemala City, Guatemala) was carried out with several inocula. Fresh and pressed pulps were studied in field and laboratory experiments. Results showed that the best inoculum among the eight examined in the experiments was the fungus Trichoderma viride, the only one not isolated from the coffee pulp itself. This inoculum, together with pumice, accelerated the decomposition of coffee pulp at ambient temperature during a 45-day test period. © 1985.

In vitro evaluation of the antimicrobial activity of a castor oil-based irrigant

The antimicrobial activity of irrigating solutions - Endoquil (castor oil detergent), 2% chlorhexidine gluconate solution, and 0.5% NaOCI solution - was evaluated against Gram-positive cocci (Micrococcus luteus, Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus mutans, and Streptococcus sobrinus), Gramnegative rods (Escherichia coli and Pseudomonas aeruginosa), and the yeast Candida albicans. Activity was evaluated using the two-layer agar diffusion technique. The base layer was obtained by pouring 10.0 ml of Muller Hinton Medium or 10.0 ml of Brain Heart Infusion agar in a Petri dish. After solidification a 5.0 ml seed layer of Muller Hinton Medium or Brain Heart Infusion agar with inoculum (106/ml) was added. Absorbent paper disks (6.0 mm in diameter) immersed in the solutions were placed at equidistant points. Plates were maintained at room temperature for 2 h for prediffusion of the solutions and incubated at 37°C for 24 h. The candle jar system was used for the Brain Heart Infusion agar plates. All tests were performed in duplicate. After incubation the medium was optimized with 0.05 g% triphenyltetrazolium chlorate gel and inhibition halos were measured. All bacterial strains were inhibited by 2.0% chlorhexidine gluconate. Endoquil was effective against Grampositive microorganisms, and 0.5% NaOCI was effective only against S. aureus. Copyright © 2001 by The American Association of Endodontists.

Activity of benomyl for control of postbloom fruit drop of citrus caused by Colletotrichum acutatum

Postbloom fruit drop (PFD) of citrus caused by Colletotrichum acutatum produces orange-brown lesions on petals and induces the abscission of young fruitlets and the retention of the calyces. Despite the fact that C. acutatum is not highly sensitive to benomyl in culture, this fungicide provides good control of the disease under field conditions. This study was undertaken to determine the effect of benomyl on various stages of disease development to understand the basis for its effectiveness in the field. We found that benomyl at 1.0 μg/ml reduced colony area of C. acutatum by about 75% and completely inhibited growth of C. gloeosporioides. Benomyl did not prevent conidial germination even at 100 μg/ml, but reduced germ tube elongation at 10 and 100 μg/ml. When benomyl was applied to flower clusters on screen-house-grown plants before inoculation, disease severity was greatly reduced. Applications at 24 and 48 h, but not at 72 h, after inoculation reduced PFD severity. Application of benomyl to symptomatic petals not bearing conidia did not prevent or reduce production of inoculum. Application to petals bearing conidia reduced viability of these fungal propagules by only about 50%. The viability of appressoria on mature leaves was not affected by benomyl application. Even when appressoria on mature leaves were stimulated to germinate by treatment with flower extracts, subsequent application of benomyl did not reduce propagule numbers below original levels. Benomyl appears to act by preventing infection and early development of the fungus in petals. However, once symptoms have developed, this fungicide has only minimal effects on further disease development and spread.

Assessment of anaerobic sewage sludge quality for agricultural application after metal bioleaching

The effects of metal bioleaching on nutrient solubilization, especially nitrogen and phosphorous, from anaerobically-digested sewage sludge were investigated in this work. The assessment of the sanitary quality of the anaerobic sludge after bioleaching was also carried out by enumerating indicator (total coliforms, fecal coliforms, and fecal streptococci) and total heterotrophic bacteria. The experiments of bioleaching were performed using indigenous sulphur-oxidizing bacteria (Thiobacillus spp.) as inoculum and samples of anaerobically-digested sludge. Nitrogen and phosphorous solubilization from sewage sludge was assessed by measuring, respectively, the concentration of Total Kjeldahl Nitrogen, ammonia, nitrate/nitrite, and soluble and total phosphorous before and after the bioleaching assays. At the end of the experiment, after 4 days of incubation (final pH of 1.4), the following metal solubilization yields were obtained: zinc, 91%; nickel, 87%; copper, 79%; lead, 52%; and chromium, 42%. As a result of sludge acidification, the viable counts of selected indicator bacteria were decreased to below the detection limit (4 × 103 cfu 100 ml-1), followed by an increase in the mineral fraction of nitrogen (from 6 to 10%) and in the soluble fraction of phosphorous (from 15 to 30%). Although some loss of sludge nutrients can occur during solid-liquid separation following bioleaching, its beneficial effects as metal removal and reduction of pathogenic bacteria are sufficient to consider the potential of this treatment before sludge disposal onto agricultural fields.

Experimental infection of commercial layers using a Salmonella enterica serovar Gallinarum strain: Leukogram and serum acute-phase protein concentrations

The aim of the present study was to evaluate white blood cell counts and serum protein profiles of commercial layers experimentally infected with Salmonella Gallinarum (SG) in order to better understand the pathophysiology of the disease caused by this bacterium. 180 five-day-old commercial layers were divided into 3 groups (G); G1 and G2 received 0.2 mL of inoculate containing 3.3x10 8 CFU or 3.3×10 5 CFU SG resistant to nalidix acid (Nal r)/mL, respectively, directly into their crops. G3 group did not receive the inoculum. Birds were sacrificed 24 hours before (T1) and 24 hours after the infection (T2), and three (T3), five (T4), seven (T5), and ten (T6) days after the administration of the inoculum. White blood cell counts were carried out in a Neubauer hemocytometer and in blood smears. Serum protein concentrations, including acute-phase proteins, were determined using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Data were submitted to analysis of variance, and means were compared by Tukey's test (P <0.05). G1 and G2 groups presented higher leukocyte counts on T4 and T5, respectively, due to the increase of circulating lymphocytes and heterophils, with a significant difference relative to G3. In electrophoresis, an increase in the serum levels of ceruloplasmin, haptoglobin, and hemopexin and a decrease in transferrin, which are acute-phase proteins, was verified. IgA serum levels did not change; however, IgG concentration increased during the infection. In conclusion, the results provide information for the better understanding of the pathophysiology of fowl typhoid.