Search

This review illustrates the relationships between additives in the diets of ruminants and the consequence for ruminant nutrition. Feed additives are used to improve animal performance and/or the quality of the products. There are several categories of additives available for ruminant nutrition, with emphasis on antibiotics, prebiotics, probiotics, plant extracts, and exogenous enzymes. Antibiotics, essential oils, and chitosan act by selecting sensitive bacteria, consequently modulating the ruminal fermentation pattern. Prebiotics favor microbial growth, providing greater digestion and the production of volatile fatty acids. Probiotics are living microorganisms that improve the ruminal environment, promoting microbial growth and resulting in increased digestion and the production of volatile fatty acids. Exogenous enzymes act synergistically with the enzymes secreted by the ruminal microorganisms, besides favoring microbial adhesion and colonization and facilitating feed degradation. Tannins, whether altering the fermentation standard and/or modifying the ruminal microbiota population, are effective in improving animal performance. However, the effects of additives on the quality of the products are linked to diet quality. Highlights • Exogenous enzymes act synergistically with the enzymes secreted by the ruminal microorganisms. • Exogenous enzymes favoring the microbial adhesion and colonization of the particles, aid in the degradation of the feed. • Tannins can altering the fermentation standard and/or modifying the ruminal microbiota population. • Essential oils and chitosan act by selecting sensitive bacteria and consequently modulate the ruminal fermentation.

ABSTRACT The objective of this study was to evaluate the growth performance and meat quality of feedlot Aberdeen Angus steers fed high-concentrate diets with or without a natural feed additive composed of a mixture of yeasts and essential oils (EO). A completely randomized design with two diets (with or without natural feed additive) and 12 replicates was used. Twenty-four steers with initial shrunk body weight of 402.62±48.2 kg and average age of 18±2.0 months were used. Steers were fed ad libitum a diet containing 777.3 g of concentrate/kg dry matter (DM) and 222.7 g of corn silage/kg DM for 74 days. The mixture of yeast and EO was supplied at the rate of 10.0 and 0.117 g/animal/day, respectively. Average daily weight gain and feed efficiency in the adaptation period was greater in animals fed natural feed additive; however, there was no difference for the total experimental period. Dry matter intake, carcass weight, carcass yield, proportion of carcass bone, carcass muscle + fat:bone ratio, round thickness, and arm length were not altered by treatments. The inclusion of a natural feed additive in the diet increased the cooling loss (0.98 vs. 1.25%), proportion of carcass muscle (51.32 vs. 54.56%), carcass muscle:fat ratio (1.70 vs. 2.11%), leg length (68.79 vs. 70.71 cm), and arm perimeter (36.70 vs. 37.88 cm) and reduced the proportion of carcass fat (30.17 vs. 25.92%). Carcass length was greater in animals fed the diet with a natural feed additive. Meat color, texture, and marbling were not altered by treatments. The addition of natural feed additive to high concentrate diets does not alter the productive performance of feedlot Aberdeen Angus steers, although it can increase the proportion of lean meat of carcasses.

Abstract The possibility of using agro-industrial residues in bioconversion processes advances with the development of biotechnology and the search for processes in which is possible to add commercial value to previously discarded products. These processes should be low cost, easy to control and chemical-free. The yeast Yarrowia lipolytica (YL) is widely used to produce lipids, enzymes, citric acid, and proteins, among others. This study aimed to evaluate the capacity of this yeast to use agro-industrial residues as a source of carbon without adding extra carbohydrate sources for the development of cells. The study evaluated the production of proteins and lipids from different carbon sources as well as the optimization of the process (agitation, temperature, and nitrogen source). Indeed, YL produced 22.3% of protein and 9.4% of lipids in dry biomass, a 179% of protein and 660% of lipid increase from raw material, respectively, when using cassava residues as a carbon source. However, lipase production was low, indicating that the strain had priority for cell growth.

To provide fruit throughout the whole year, maintain quality and reduce spoilage, apples and pears are stored at low temperature. However, the development of rots, caused mainly by Penicillium expansum, cannot be avoided. To prevent fruit losses, biological control has been proposed as a potential alternative. In this work, 16 psychrotrophic, non-pectinolytic Debaryomyces hansenii strains were evaluated in a bioassay for their potential biocontrol against P. expansum rots in apples and pears. Isolates with different degrees of biocontrol effectiveness were further investigated in vitro to elucidate mechanisms of antagonism that may have contributed to biocontrol. No correlation between any of the studied mechanisms and biocontrol activity could be established. One of the isolates, designated F9D, was selected due to its ability to reduce rot incidence in more than 95% in apples and 85% in pears. This strain could be a good candidate for the development of a yeast-based formulation to protect both types of fruit. An ISSR-PCR method was developed for typing the selected strain. This molecular marker could be a useful tool to follow the fate of the strain applied on fruit.

We evaluated the effects of urea addition on gas and effluent losses, fermentation profile, microbial populations, aerobic stability and chemical composition of corn silages. A completely randomised design with five levels of urea (0, 0.5, 1.0, 1.5, and 2.0% based on dry matter) and five replicates was used. A decreasing linear effect of urea levels on effluent losses in corn silages was observed. In parallel, an increasing linear effect of urea levels on pH, increasing from 3.49 to 4.12 in silages without urea in relation to silages with the maximum urea level, was also observed. Urea addition improved the aerobic stability of the silages, with 62 h for the silages without urea and from 90 to >96 h for the silages with urea. Based on the results of the principal components, two groups (I and II) could be distinguished. The most discriminating variables in group I were dry matter (-0.9), pH (-1.2) and lactic acid bacteria (-0.9), while in group II, effluent losses (1.0), ethanol (1.0), acetic acid (0.8) and gas losses (0.8) were most important. The use of urea at inclusion levels of around 2% in corn silage reduced gas losses, improved the nutritive value and promote the aerobic stability of silages. Highlights: The addition of urea in the corn silages increased the pH values from 3.49 (control) to 4.12 (2% of urea DM). The use of urea improved chemical composition of corn silages. The addition of urea reduced the moulds and yeast populations in the corn silages after exposure to air. Urea addition improved the aerobic stability of the corn silages.

The objective of this study was to evaluate the effect of bacterial inoculants at two inoculation rates on chemical and biological characteristics of maize silage. The treatments consisted of two inoculating rates (5 and 6 log cfu g-1 of forage) for each strain of lactic acid bacteria (LAB) identified as Lactobacillus buchneri, L. hilgardii, or L. plantarum. The maize was ensiled in experimental PVC silos. Samples were taken for the determination of the contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), water-soluble carbohydrates (WSC), organic acids and alcohols, for the evaluation of the populations of lactic acid bacteria, yeasts, filamentous fungi, and for the determination of pH values during ensilage and after 30 or 90 days of fermentation. The doses of inoculants did not promote significant differences on the evaluated characteristics. There was effect of inoculants on acetic acid, 1.2-propanediol, LAB population, filamentous fungi, and pH value. No significant influence of the treatments with inoculants was observed in the variables DM, WSC, CP, lactic acid concentrations, or ethanol. The maximum temperature, i.e., the time to achieve the maximum temperature (TMT) and aerobic stability (AS), was not influencied by treatments. However, a decrease in maximum temperature, an increase in TMT, and improvement in the AS were observed after 90 days of fermentation. These results proved the advantage of microbial inoculation. The treatments influenced LAB populations and filamentous fungi, but no effect was observed on the yeast population. The best inoculation dose is 6 cfu g-1 of forage because it provides higher reduction of filamentous fungi in maize silage, thereby decreasing the aerobic deterioration by these microorganisms.

The objective of this study was to evaluate the microbiological profile and aerobic stability of silage with Tifton 85 bermudagrass and different additives and wilting. The studied treatments were: pre-drying in the sun for two hours before ensiling; use of bacterial-enzymatic inoculant; addition of soybean peel; addition of corn grits and use of salt in the surface layer of the silo. The experimental design was completely randomized with six treatments and four replications. Plants of Tifton 85 bermudagrass with 38 days were ensiled in experimental silos with Bunsen valves, with compacting density of 236 kg silage per m³ for Tifton 85 bermudagrass, which was pre-dried in the sun; the average silage was 294 kg m-3 for the other treatments. The ratios between soybean hulls and corn grits, added to the silage, were calculated based on the initial DM content from Tifton 85 bermudagrass in order to obtain 320 g/kg DM of the material to be ensiled. There was an increase of lactic bacteria and Clostridium as well as an absence of enterobacteria after the silo opening. Fungi developed only in Tifton 85 bermudagrass and its treatments before the ensilage and yeasts developed in silages of Tifton 85 bermudagrass when they received soybean hulls or corn grits after silo opening. There was no breach regarding aerobic stability of silages during the studied period. The pH reached the highest values within 48 hours after opening the silos, but there were variations during this period.

The objective of this study was to evaluate the effects of feeding cattle with isoprotein and isoenergetic diets, with and without the addition of polyclonal antibody preparation (PAP), yeasts (YST) or monensin sodium (MON) on performance, carcass characteristics and gain cost in feedlot. Ninety-five 20-month old bullocks (323.3±21.8 kg) were distributed in 25 pens. The completely randomized experimental design had a 2 × 2 + 1 factorial arrangement and the treatments were replicated 5 times. There was no effect of MON for DMI throughout the feedlot period; however, MON reduced the dry matter intake (DMI) in g/kg of BW in the first 28 days when compared with the other treatments. The gain cost decreased with MON addition in relation to the other treatments. Inclusion of YST decreased average daily gain (ADG), final body weight, hot carcass weight, carcass weight, gain to feed ratio and DMI in g/kg body weight, worsening feed conversion and increasing the gain cost in the feeding periods. Inclusion of PAP increased ADG and decreased the gain cost, besides improving feed conversion. For MON and PAP, a difference was found for kidney-pelvic fat and kidney-pelvic fat per 100 kg of hot carcass weight. For MON and YST, there was a difference in ADG, feed conversion, gain cost and carcass yield and kidney-pelvic fat per 100 kg of hot carcass. Treatment YST worsened performance in relation to the non-supplemented treatments. Feeding PAP to animals did not influence performance and carcass characteristics of bullocks in feedlot negatively. Thus, PAP shows potential to substitute MON in cattle feeding using isoprotein and isoenergetic diets.

Fermentation and aerobic stability were evaluated in high-moisture corn (HMC) silage inoculated with different levels of Lactobacillus buchneri. The HMC composed of 654 g/kg dry matter (DM) was ensiled in quadruplicate laboratory silos (7 L) per treatment. L. buchneri 40788 was applied at 5 × 10(4); 1 × 10(5); 5 × 10(5); and 1 × 10(6) cfu/g to the ground corn. Silages with no additive were used as controls. After 140 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days in which the chemical parameters, microbiological parameters and silage temperature were measured to determine the aerobic deterioration. The lactic acid, acetic acid and propionic acid concentrations did not differ between silages. The fermentation parameters of HMC were not affected by L. buchneri. The HMC containing L. buchneri had a low number of yeast and mould colonies and a more stable pH until in the eighth measurement, which improved the aerobic stability without affecting gas loss. Doses of L. buchneri greater than or equal to 5 × 10(5) cfu/g applied to the HMC were the most efficient in control of aerobic deterioration.

The characteristics of fermentation and aerobic stability were evaluated in corn silage inoculated with different doses of Lactobacillus buchneri. The whole corn plant (300 g/kg DM) was ensiled in quadruplicate laboratory silos (7L). L. buchneri 40788 was applied at 5×10(4), 1×10(5), 5×10(5) and 1×10(6) cfu/g of fresh forage. Silages with no additive were used as controls. After 130 d of ensiling, the silages were subjected to an aerobic stability evaluation for 12 days, in which chemical and microbiological parameters as well as the temperature of the silage were measured to determine the aerobic deterioration. The addition of L. buchneri resulted in increased acetic acid concentrations. The number of yeast colonies was low in all treated silages. The pH, lactic and propionic acid concentrations did not differ between silages. Under aerobic conditions, all the treated silages showed a low number of yeasts and a great aerobic stability. Therefore, L. buchneri is effective against yeasts and improves the aerobic stability of corn silage in laboratory silos. However, doses equal or superior to 1×10(5) cfu/g of fresh forage were more efficient in the control of aerobic spoilage.

This research study was conducted to evaluate, by means of microbiological analyses, the preservation of wet brewery waste stored under aerobic and anaerobic conditions, regarding the development of filamentous fungi, yeasts and lactic-acid bacteria. The following treatments were used: untreated brewery waste, pre-dried brewery waste silage, brewery waste silage with effluent drainage and BW silage without effluent drainage. Silos made of PVC and equipped with Bunsen valves to allow gases to escape were used. Dry matter (DM), crude protein (CP), temperature (°C) and pH in the untreated BW, in the stored brewery waste and in the brewery waste silage upon silo opening, after 60 days of ensilage were analyzed. A completely randomized design was used. The data were subjected to analysis of variance, and the means were compared by the Tukey test at the 5% probability level. The preservation of brewery waste packaged under aerobic conditions was not appropriate due to the development of filamentous fungi and yeasts; however, storage under anaerobic conditions proved to be an effective conservation process.

The Mycology Department of the Instituto Nacional de Enfermedades Infecciosas "Dr. C. Malbrán", conducted the Second National Multicenter Survey on Fungemia due to Yeasts in Argentina. The aim was to obtain updated data of the frequency of the causative species encountered and their in vitro susceptibility to seven antifungal agents. Yeast species were identified by micromorphological and biochemical studies. Antifungal susceptibility testing was performed by the reference microdilution method E.Def 7.1 of the European Committee on Antibiotic Susceptibility Testing (EUCAST). A total of 461 viable yeasts were identified. The most frequent species were: Candida albicans (38.4 %), Candida parapsilosis (26 %), Candida tropicalis (15.4 %) and Candida glabrata (4.3 %). Other uncommon species, such as Candida viswanathii (0.6 %), Candida haemulonii (0.4 %), Candida inconspicua (0.2 %) and Candida fermentati (0.2 %) were also isolated. Among the Candida spp., 5.4 % and 1.6 % were resistant to fluconazole and voriconazole, respectively. Itraconazole and caspofungin were the most efficient agents against all Candida spp. tested (MIC < 1 mg/l). For anidulafungin, 21.6 % of C. parapsilosis showed a MIC value of 4 mg/l. Fluconazole was less active against 53.1 % of Cryptococcus neoformans (MIC > 8 mg/l), 75 % of Trichosporon spp., and 100 % of Rhodotorula spp., Geotrichum candidum, Saccharomyces cerevisiae. The global percentage of mortality was 20 %. The presence of uncommon species reinforces the need for performing continuous laboratory surveillance in order to monitor possible changes, not only in the epidemiological distribution of species, but also in the resistance to antifungal drugs.Distribución de especies y perfil de sensibilidad de levaduras aisladas de hemocultivos: resultados de un estudio multicéntrico de vigilancia de laboratorio en Argentina. El Departamento Micología del Instituto Nacional de Enfermedades Infecciosas "Dr. Carlos G. Malbrán" condujo el segundo estudio multicéntrico nacional sobre funge- mias debidas a levaduras. El objetivo fue obtener datos actualizados sobre la distribución de especies y la sensibilidad in vitro frente a siete antifúngicos. Las levaduras fueron identificadas mediante el estudio de la micromorfología y la realización de pruebas bioquímicas. La determinación de la sensibilidad se realizó según el método de referencia E.Def 7.1 del European Committee on Antibiotic Susceptibility Testing (EUCAST). Se identificaron 461 levaduras. Las especies más frecuentes fueron Candida albicans (38,4 %), Candida parapsilosis (26 %), Candida tropicalis (15,4 %) y Candida glabrata (4,3 %). Se aislaron otras especies menos comunes, como Candida viswanathii (0,6 %), Candida haemulonii (0,4 %), Candida inconspicua (0,2 %) y Candida fermentati (0,2 %). Entre las especies del género Candida, el 5,4 % y el 1,6 % fueron resistentes al fluconazol y al voriconazol, respectivamente. El itraconazol y la caspofungina fueron los antifúngicos más eficaces in vitro frente a las especies de Candida evaluadas (CIM < 1 mg/l). Para la anidulafungina, el 21,6 % de los aislamientos de C. parapsilosis mostraron una CIM de 4 mg/l. El fluconazol fue menos activo para el 53,1 % de los aislamientos de Cryptococcus neoformans (CIM > 8 mg/l), el 75 % de los aislamientos de Trichosporon spp. y el 100 % de los aislamientos de Rhodotorula spp., Geotrichum candidum y Saccharomyces cerevisiae. El porcentaje de mortalidad fue del 20 %. La presencia de especies infrecuentes refuerza la necesidad de realizar la continua vigilancia de laboratorio con el fin de monitorear posibles cambios, no solo en la epidemiología de las especies causantes de fungemia, sino también en la resistencia a los antifúngicos.

Los métodos de referencia E. Def 7.1 y M27-A3, que detectan resistencia in vitro a los antifúngicos, son onerosos y muy laboriosos, por lo que su implementación en los laboratorios hospitalarios es limitada. Existen técnicas comerciales de simple realización, que permitirían obtener resultados comparables a los que se obtienen con los métodos estándares. Los objetivos de esta investigación fueron: a) comparar los resultados de concentración inhibitoria mínima obtenidos según el método de referencia E.Def 7.1 con los obtenidos mediante el empleo del equipo comercial ATB® Fungus 3 en un conjunto de 82 aislamientos clínicos de Candida spp. frente a los siguientes antifúngicos: anfotericina B, 5-fluorocitosina, fluconazol e itraconazol; b) comparar en ese mismo conjunto de aislamientos los resultados del estudio de sensibilidad al fluconazol por difusión en agar empleando tabletas Neo-SensitabsTM o discos Malbrán con los que se obtienen por el método de referencia. La concordancia general entre el método de referencia y el ATB® Fungus 3 fue del 90,2 %, mientras que la concordancia del método de referencia con los métodos por difusión con discos y con tabletas alcanzó el 96,3% y el 92,7 %, respectivamente. El ATB® Fungus 3 fue eficaz para determinar la sensibilidad a la anfotericina B y a la 5-fluorocitosina, pero se observaron discrepancias al evaluar la sensibilidad a los azoles. Los métodos por difusión resultaron útiles para determinar la sensibilidad al fluconazol; sin embargo, observamos 3 discrepancias muy mayores, 1 mayor y 2 menores con el método de difusión con tabletas, mientras que con los discos solo se produjeron 3 discrepancias menores.Reference methods E.Def 7.1 and M27-A3 detect in vitro resistance; however, they are expensive and very laborious. Thus, their actual use in hospital laboratories is limited. There are commercial techniques available, having easier accessibility and development, which would yield results comparable to those of the reference methods. The objectives of this study were: a) to compare the results of minimal inhibitory concentration of 82 Candida spp. clinic isolates according to reference method E.Def 7.1 and ATB® Fungus 3; b) to compare the results of fluconazole susceptibility testing by disk diffusion in agar with Neo-SensitabsTM tablets and Malbrán disks with those of the reference methods. Minimal inhibitory concentration for amphotericin B, 5-flucytosine, fluconazole and itraconazole was performed according to the E.Def 7.1 and the ATB Fungus 3 methods and diffusion was carried out with fluconazole disks and tablets. General concordance between the reference method and ATB Fungus 3 was 90.2 % and 96.3 and 92.7% for diffusion with disks and tablets. The ATB Fungus 3 method was effective to determine susceptibility against amphotericin B and 5-flucytosine; however, discrepancies were observed with azole drugs. Disk diffusion methods are useful to determine susceptibility to fluconazole; however, 3 very major, 1 major and 2 minor errors were observed with the tablets, whereas only 3 minor errors were observed with the disks.

Descreve-se aqui o caso de infecção fúngica mista por leveduras em paciente de UTI: por Saccharomyces cerevisae - levedura conhecida e de larga utilização na panificação e produção de vinhos - e Candida albicans. As infecções fúngicas mistas possuem alta mortalidade em terapia intensiva. Discutimos neste artigo o caso de paciente idoso portador de doença pulmonar obstrutiva crônica, portador de tumor não tratado de bexiga, tabagista, admitido no Hospital com quadro diarréico, evoluindo para choque séptico, com isolamento em hemoculturas das duas leveduras supracitadas. Quadro grave, de evolução letal, possibilitando a discussão de um dos germes emergentes em unidade de terapia intensiva e apresentação atípica em terapia intensiva.A case of a mixed fungal yeast infection involving Saccharomyces cerevisiae - well known for its use in the bread and wine industries - and Candida albicans, is described in an intensive care unit patient. Mortality due to mixed fungal infections in the intensive care unit is high. An elderly smoker patient with chronic pulmonary obstructive disease and untreated bladder neoplasm was admitted to the hospital with diarrhea and progressed to septic shock. The above-mentioned yeasts were identified in blood cultures. This case with fatal outcome provides an opportunity to discuss one of the emergent germs found in the intensive care unit, in a case with an atypical presentation.

The aim of this research was to evaluate the effect of microbial additives containing heterofermentative or homofermentative bacteria on the chemical and microbiological characteristics of sugar cane (Saccharum spp) silages. Sugar cane was inoculated with Lactobacillus plantarum, L. paracasei, L. brevis or L. buchneri previously isolated from sugar cane silages or commercial inoculants containing L. buchneri or L. plantarum. Silages were produced in laboratory silos (10 × 60 cm PVC tubes) and evaluated 90 days after ensiling. A randomized complete design was used with eight treatments (seven inoculants and control - without inoculant) and three replications. The inoculation with bacteria affected lactic acid bacteria, yeast populations, volatile fatty acids and ethanol contents in the silages. Inoculation with different strains of the same species of bacteria result in silages with different chemical and microbiological characteristics. Two of the L. buchneri strains show the best results in relation to silage quality.Objetivou-se avaliar o efeito de aditivos microbianos contendo bactérias heterofermentativas ou homofermentativas sobre as características químicas e microbiológicas de silagens de cana-de-açúcar (Saccharum spp.). A cana-de-açúcar foi inoculada com Lactobacillus plantarum, L. paracasei, L. brevis ou L. buchneri, previamente isolados de silagens de cana-de-açúcar, ou inoculantes comerciais contendo L. buchneri ou L. plantarum. As silagens foram produzidas em silos laboratoriais (tubos de PVC - 10 × 60 cm) e avaliadas 90 dias após a ensilagem. O delineamento utilizado foi o inteiramente casualizado com oito tratamentos (sete inoculantes e um controle, sem inoculante) e três repetições. A inoculação influenciou as populações de bactérias ácido-láticas e leveduras e também as concentrações de ácidos graxos voláteis, ácido lático e etanol nas silagens. A inoculação com cepas diferentes da mesma espécie de bactéria resulta em silagens com características químicas e microbiológicas diferentes. Duas cepas de L. buchneri promovem melhores resultados de qualidade das silagens.

Avaliou-se a eficácia de aditivo químico e inoculantes microbianos nas alterações fermentativas que inibem a produção de etanol e diminuem as perdas de matéria seca em silagens de cana-de-açúcar. A ensilagem foi realizada em baldes plásticos de 20 litros (minissilos) adaptados com válvulas tipo Bunsen para eliminação dos gases e dispositivo para coleta de efluentes. Utilizou-se uréia (1% na matéria verde) como aditivo e os inoculantes microbianos Lalsil cana® contendo a bactéria heterolática Lactobacillus buchneri (cepa NCIMB 40788) na razão de 3,65 × 10(5) ufc/g massa verde (MV) e um inoculante não comercial contendo a combinação de bactérias homo e heteroláticas Pedioccocus pentosassus e Lactobacillus buchneri (1 × 10(6) ufc/g de massa verde). As amostragens foram realizadas após 110 dias de fermentação. A utilização de uréia e principalmente do aditivo Lactobacillus buchneri + Pediococcus foi eficaz em diminuir a produção de etanol (1,30 e 2,75% vs 8,27% na silagem controle), as perdas de matéria seca (47 e 60%) e o consumo de carboidratos solúveis (22 e 56%) e em aumentar a digestibilidade in vitro da matéria seca (14,7 e 12,4%) quando comparados à silagem controle, respectivamente. Apesar dos altos teores de ácido acético em todas as silagens, principalmente nas silagens acrescidas da combinação de bactérias homo e heteroláticas, não foram verificados efeitos dos inoculantes sobre a população de leveduras. Os valores de pH e ácido lático da silagem com uréia foram maiores que os obtidos na silagem controle. As silagens com L. buchneri apresentaram neste estudo maior produção de etanol (11,53% vs 8,27%, silagem controle), o que refletiu em perdas significativas e baixa recuperação de matéria seca, além de baixa digestibilidade pela perda de carboidratos solúveis e pelo acúmulo de FDN, que foram similares aos das silagens sem aditivo.The objective of this study was to evaluate chemical additive and microbial inoculants effectiveness on fermentative changes that lead to the inhibition of the ethanol production and reduction of dry matter losses in sugarcane silages. Silos were made in 20 liter plastic buckets provided with a Bunsen type valve that allows gas to escape and a device to collect effluents. The applied additives were urea (1% of fresh forage); microbial additive Lalsil cana®, that has heterolactic bacteria Lactobacillus buchneri (NCIMB 40788), 3.65 × 10(5) CFU g-1 of fresh forage, and a non-commercial additive with homolactic bacteria Pedioccocus pentosassus and Lactobacillus buchneri (1 × 10(6) CFU g-1 FM) supplied by Lallemand Inc. (Montreal, Quebec). Sampling occurred after 110 days of fermentation. Urea and mainly the additive Lactobacillus buchneri and Pediococcus were efficient on the reduction of ethanol production (1.30 and 2.75% versus 8.27% in the control treatment), on the reduction of dry matter losses (47 and 60%) and soluble carbohydrates (22 and 56%), and increase in vitro dry matter digestibility (14,7 and 12,3%) when compared to the control silages, respectively. Despite the high values of acetic acid in all silages, mainly in silages inoculated with homo and heterolactic bacteria, it was not verified effects on yeast population. The silage with urea had greater values of pH and lactic acid compared to control silage. Silages with L. buchneri had, in this experiment, the largest ethanol production (11.53% vs 8.27% from control silage), resulting in greater losses and lower dry matter recovery. In addition, these silages also showed lower digestibility because of soluble carbohydrates losses and NDF accumulation, similar to the silages without additive.

Avaliaram-se o pH, a relação nitrogênio amoniacal/nitrogênio total (N-NH3), a composição química e a digestibilidade in vitro da MS (DIVMS) e as populações microbianas de silagens de capim-elefante produzidas ou não com inoculantes enzimo-bacterianos, em seis períodos de fermentação (1, 3, 7, 14, 28 e 56 dias), utilizando-se silos laboratoriais. Foi usado um arranjo fatorial 6 x 3 (seis períodos de fermentação x três inoculantes), em um delineamento inteiramente casualizado, com três repetições. Avaliaram-se os seguintes inoculantes microbianos: controle (sem inoculante), Sil All C4 (Alltech do Brasil) e Bacto Silo C Tropical (Katec). Os teores de PB, FND e FDA, foram influenciados apenas pelo período de fermentação, enquanto para a DIVMS observou-se efeito da interação inoculante × período.Para o pH observou-se efeito de inoculante e de período, estimando-se reduções de 0,5769; 0,62327 e 0,80218 unidades/dia de fermentação para as silagens controle e tratadas com Sil All e Bacto Silo, respectivamente. Para o teor de N-NH3, observou-se efeito da interação inoculante × período. A população de bactérias ácido lático no capim antes da ensilagem foi de 10(4) ufc/g de forragem fresca, atingindo valor máximo da ordem de 10(8) ufc/g de silagem, para a silagem controle, aos 14 dias de fermentação, e para as silagens tratadas com inoculantes, aos 7 dias. As enterobactérias não foram detectadas a partir do terceiro dia, apresentando valor máximo de 10(4), < 10 e 10³ ufc/g para as silagens controle, Sil All e Bacto Silo C Tropical, respectivamente.Values of pH, ammonia nitrogen/total nitrogen (NH3-N), chemical composition, in vitro DM digestibility (IVDMD) and microbial populations of elephantgrass silages produced with enzymatic-bacterial inoculants, were evaluated in six fermentation periods (1, 3, 7, 14, 28, and 56 days), using laboratory silos. A 6 x 3 (six fermentation periods x three inoculants) factorial arrangement of treatments in a completely randomized design, with three replicates, was used. The following bacterial inoculants were evaluated: control (without inoculant), Sill All C4 (Alltech of Brazil) and Bacto Silo Tropical C (Katec). The CP, NDF and ADF contents were affected only by the fermentation period. The IVDMD, however, was affected by the inoculant × fermentation period interaction.The IVDMD concentration, however, was affected by the interaction between inoculant and fermentation period. There was a significant effect of inoculant and period on pH value, being observed reduction of 0.5769; 0.62327, and 0.80218 units/day of fermentation for the control silage, silage treated with Sil All, and Bacto Silo, respectively. It was observed inoculant × fermentation period interaction for NH3-N. The lactic acid bacteria population in the grass before ensiling was 10(4) cfu/gram of fresh forage, reaching maximum value of 10(8) cfu/gram of fresh silage at 14 days of fermentation to the control silage, and at 7 days of fermentation to the silages treated with inoculant. The enterobacter were not detected after the third day of fermentation and the maximum values of 10(4),

La identificación rápida de levaduras de origen ambiental o clínico es de importancia para el estudio de la biodiversidad de estos microorganismos y para la detección de posibles patógenos. Rhodotorula mucilaginosa es una levadura ubicua y pigmentada, capaz de producir infecciones en pacientes inmunocomprometidos. En este trabajo se evaluó la utilidad de la técnica de fingerprinting conocida como MSP-PCR (Micro/Minisatellite-Primed PCR) en la caracterización e identificación de aislamientos ambientales de R. mucilaginosa provenientes de la Patagonia noroccidental. Sobre la base de sus caracteres fenotípicos, de un total de 200 levaduras pigmentadas se seleccionaron 110 aislamientos que presuntamente corresponderían a la especie R. mucilaginosa. Se evaluaron los iniciadores (GTG)5, (GAC)5 y M13 en aislamientos representativos, y se seleccionó el iniciador (GTG)5 por ser el que permitió una mejor agrupación de los aislamientos pertenecientes a R. mucilaginosa y una mejor diferenciación de éstos con los de especies filogenéticamente próximas. Utilizando dicho iniciador, el 87% de los aislamientos de R. mucilaginosa presentó un perfil de MSP-PCR similar (> 60%) al de la cepa de referencia CBS 316T de R. mucilaginosa. La técnica de MSP-PCR resultó efectiva, tanto para caracterizar e identificar un número elevado de aislamientos ambientales de R. mucilaginosa como para detectar polimorfismos en la especie.The rapid identification of environmental or clinical yeast isolates is important for biodiversity studies and the detection of probable pathogens. Rhodotorula mucilaginosa is a ubiquitous and pigmented yeast capable of infecting immunocompromised patients. In this study, we evaluated the Micro/mini satellite-primed PCR (MSP-PCR) fingerprinting method for the characterization and identification of R. mucilaginosa isolates from natural environments in northwestern Patagonia. There were selected 110 putative R. mucilaginosa isolates from 200 environmental pigmented yeast isolates on the basis of phenotypic criteria. (GTG)5, (GAC)5 and M13 primers were initially evaluated in representative R. mucilaginosa isolates. (GTG)5 allowed a good grouping of these isolates and, at the same time, a good differentiation among closely related species, and thus was selected for subsequent studies. R. mucilaginosa isolates (87%) presented similar (> 60%) MSP-PCR profiles to those of the reference strain CBS 316T. The MSP-PCR technique was effective, both, for the characterization and identification of a large number of R. mucilaginosa environmental isolates as well as for the detection of polymorphisms within the species.

Se estudió la biodiversidad de levaduras presente en el ambiente acuático ácido del Río Agrio y el Lago Caviahue. En todas las muestras de agua analizadas se encontraron levaduras en concentraciones variables (25 - 1192 UFC L-1). Fueron aisladas un total de 202 cepas de levaduras, las cuales en base a estudios morfológicos y fisiológicos fueron asignadas a cinco géneros: Candida, Cryptococcus, Cystofilobasidium, Rhodotorula y Sporobolomyces. Los géneros Cryptococcus y Rhodotorula fueron los más abundantes, correspondiendo ambos al 98% del total de las levaduras aisladas. Asimismo, los resultados de las pruebas antes mencionadas sugieren la existencia de al menos dieciocho especies. Este trabajo representa el primer registro cuantitativo y cualitativo de levaduras de un ambiente acuático ácido de origen natural de la Argentina.Yeast biodiversity at the acid aquatic environment of the Agrio River and Caviahue Lake was studied. All water samples analyzed contained yeasts in variable concentrations (25 - 1192 UFC L-1). 202 yeasts strains were isolated and on the basis of morphological and physiological studies were assigned to five genera: Candida, Cryptococcus, Cystofilobasidium, Rhodotorula and Sporobolomyces. Cryptococcus and Rhodotorula were the most abundant genera, comprising the 98% of the isolated yeast strains. The results of the tests mentioned above suggested the existence of at least eighteen different yeast species. This work provides the first quantitative and qualitative data on yeasts from an aquatic acid environment of natural origin in Argentina.

The microflora of naturally fermented green olives produced in Western Algeria was studied over 15, 60 and 90 day fermentation periods. Different microorganisms (aerobic bacteria, coliforms, staphylococci, lactic acid bacteria, lactobacilli, enterococci, yeasts, psychrotrophs and lipolytic bacteria) were recorded at 15 and 60 days of fermentation. After 90 days (pH 4.40) of fermentation, the lactic acid bacteria population became dominant and persisted together with yeasts throughout the fermentation period. The lactic acid bacteria isolated (343 isolates) were identified as L. casei, L. rhamnosus, L. paracasei, L. plantarum, L. lactis subsp. lactis, E. faecalis, E. faecium and E. durans. The dominant species was L. plantarum. Yeasts were isolated from all samples (32 isolates) and were identified as Saccharomyces cerevisiae or Candida parapsilosis. Also, in this study we reported that brine solutions obtained at the end of olive fermentation were able to stimulate the growth of several L. plantarum strains

Se estudiaron 1193 aislamientos clínicos para estandarizar y evaluar un método de difusión con discos de fluconazol de lectura visual, que permita detectar levaduras sensibles al antifúngico. Las especies analizadas fueron: Candida albicans (n=584), Candida parapsilosis (n=196), Candida tropicalis (n=200), Candida glabrata (n=113), Candida krusei (n=50), Candida spp. y otras levaduras oportunistas (n=50). Los discos fueron manufacturados en el INEI-ANLIS "Dr. Carlos G. Malbrán". Se midieron los halos de inhibición del crecimiento producidos por fluconazol y la concentración inhibitoria mínima (CIM) por el método de referencia M27-A2 modificado por EUCAST. Se establecieron los valores de corte del método de difusión en: ≥16 mm para levaduras sensibles a fluconazol (CIM ≤ 8 µg/ml), entre 9 y 15 mm para sensibles dependientes de la dosis (CIM = 16-32 mg/ml) y ≤ 8 mm para resistentes (CIM ≥ 64 µg/ml). El método de difusión tuvo 94,7% de concordancia con el de referencia, con 0,2% de errores very major y 0,3% de errores major. La reproducibilidad inter e intralaboratorio fue muy buena. Para detectar aislamientos sensibles a fluconazol, este método resulta confiable y de bajo costo; sin embargo, es conveniente que los aislamientos con halos ≤ 15 mm sean reevaluados por el método de referencia.In order to standardize and evaluate a disk diffusion method with visual reading to detect in vitro fluconazole susceptibility of yeast, 1193 clinical isolates were tested. These included 584 Candida albicans, 196 Candida parapsilosis, 200 Candida tropicalis, 113 Candida glabrata, 50 Candida krusei and 50 Candida spp. and other opportunistic yeasts. The disks were manufactured in the INEI-ANLIS "Dr. Carlos G. Malbrán". The disk diffusion method results were compared to MIC results obtained by the reference CLSI M27-A2 broth microdilution method modified by EUCAST. The interpretative breakpoints for in vitro susceptibility testing of fluconazole were established at: zone diameter ≥ 16 mm for MIC ≤ 8 µg/ml (susceptible isolates), between 9 and 15 mm for MIC = 16-32 mg/ml (susceptible dose-dependent isolates), and ≤ 8 mm for MIC ≥ 64 µg/ml (resistant isolates). Overall agreement between the two methods was 94.7%, with 0.2% very major errors, and 0.3% major errors. Inter - and intralaboratory agreement was good. The disk diffusion method for drug susceptibility testing of Candida spp. isolates is inexpensive, reliable and reproducible. However, when the inhibition zone diameter is ≤ 15 mm, it is advisable to test the isolate by the reference microdilution method.

La aparición esporádica de alteraciones en algunos envases dentro de lotes de aguas carbonatadas y de bebidas con zumos frutales (carbonatadas y no carbonatadas) motivó la presente investigación, en la que se determinaron los microorganismos causantes del deterioro observado. También se estudiaron los contaminantes del azúcar utilizado en la elaboración de una de las bebidas analizadas. Se emplearon los métodos de Déak y Beuchat y de Pitt y Hocking para la identificación de levaduras y de mohos, respectivamente. Las levaduras causantes del deterioro de las bebidas fueron Debaryomyces hansenii, Debaryomyces polymorphus, Galactomyces geotrichum, Metschnikowia pulcherrima, Mucor circinelloides, Pichia anomala, Pichia jadinii, Pichia subpelliculosa, Rhodotorula glutinis y Zygosaccharomyces bailii. Los mohos y las levaduras encontrados en el azúcar fueron Aspergillus niger, Aspergillus penicilloides, Aspergillus versicolor, Cladosporium sphaerospermum, Mucor racemosus, Pichia anomala y Rhizopus stolonifer. En el agua carbonatada se encontraron los mohos Paecilomyces fulvus y Penicillium glabrum.Some damaged cartons of soft drinks and carbonated water were analyzed to detect the microorganisms that caused the damage. The contaminants of sugar used in the production of one of the drinks were also studied. The methods of Déak & Beuchat and Pitt & Hocking were used for the identification of yeasts and moulds, respectively. The agents of the spoilage of soft drinks were Debaryomyces hansenii, Debaryomyces polymorphus, Galactomyces geotrichum, Metschnikowia pulcherrima, Mucor circinelloides, Pichia anomala, Pichia jadinii, Pichia subpelliculosa, Rhodotorula glutinis and Zygosaccharomyces bailii. The microorganisms found in sugar were Aspergillus niger, Aspergillus penicilloides, Aspergillus versicolor, Cladosporium sphaerospermum, Mucor racemosus, P. anomala and Rhizopus stolonifer. Paecilomyces fulvus and Penicillium glabrum were observed in carbonated water.

O objetivo deste trabalho foi identificar 50 leveduras isoladas a partir de diferentes substratos da Região Amazônica e selecionar uma espécie de maior atividade proteolítica. Entre as 26 espécies identificadas predominaram Candida aquatica (12%) e Candida tropicalis (10%). A fermentação submersa foi realizada em Extrato de Malte suplementado com gelatina 1%, Candida intermedia foi a que expressou maior atividade proteolítica, halo = 25 mm e 273 U/mL, crescimento máximo a 30 ºC, viabilidade celular 6,2 x 10(6) UFC, em 48 horas, não demonstrou características de patogenicidade e a melhor densidade do inóculo foi 3%, utilizando-se culturas com 24 horas de crescimento em ágar Malte.The objective of this work was to identify 50 yeasts isolates obtained from differents substracts from Amazon Region and to select one species of higher proteolytic activity. Among the 26 identified species it had predominance of Candida aquatica (12%) and Candida tropicalis (10%). The submerged fermentation was carried out in Malt Extract supplemented with gelatin 1%, Candida intermedia exhibited higher proteolytic activity, halo = 25 mm and 273U/mL, the maximum growth 30 ºC, the cellular viability 6.2 x 10(6) UFC, in 48 hours, did not demonstrate pathogenicity characteristics and the best inoculum density tested was 3%, using 24 hours Malt agar cultures.

Sugar cane silages are characterized by extensive yeast activity, alcohol production and great dry matter - DM - losses. Better knowledge of the fermentation process is fundamental to the development of efficient ensilage techniques for this forage. This study evaluates temporal changes in chemical composition, DM losses and epiphytic microflora in sugar cane silage. Mature sugar cane, variety RB835486 (12 months of vegetative growth), was hand harvested, processed in a stationary chopper and ensiled in 20-L plastic buckets provided with valves for gas release and a device for effluent collection. Laboratory silos were kept at ambient temperature and sampled after ½, 1, 2, 3, 7, 15, 45, 90, 120 and 180 days. Ethanol concentration reached 6.4% in DM after 15 days of ensilage, followed by 71% water soluble carbohydrates - WSCs - disappearance. Gas and total DM losses reached a plateau on day 45 (16% and 29% of DM, respectively). Yeast count was higher on the second day (5.05 log cfu g-1). Silage pH declined to below 4.0 on the third day. Effluent yield was negligible (20 kg t-1). DM content in the forage decreased (35% to 26%) from day 0 to day 45. The increase in ethanol concentration showed an opposite trend to WSCs and true in vitro dry matter digestibility reductions in the silage. Developing methods to control yeasts, most probably through the use of additives, will enable more efficient production of sugar cane silage by farmers.

OBJETIVO: Monitorar e caracterizar fungos anemófilos e leveduras de fontes bióticas e abióticas de uma unidade hospitalar. MÉTODOS: As coletas foram realizadas mensalmente e em dois períodos, do centro cirúrgico e unidades de terapia intensiva adulto e neonatal em hospital de Araraquara, Estado de São Paulo. Para coleta de fungos anemófilos foi utilizado amostrador tipo Andersen de simples estágio. A pesquisa de leveduras foi feita das mãos e de orofaringe de profissionais de saúde, bem como de superfícies de leitos e de maçanetas das áreas críticas. RESULTADOS: Foram recuperados do centro cirúrgico 32 gêneros de fungos anemófilos e 31 das unidades de terapia intensiva. Os gêneros mais freqüentemente isolados foram Cladophialophora spp., Fusarium spp., Penicillium spp., Chrysosporium spp. e Aspergillus spp. Durante o período de estudo, houve reforma e implantação de uma unidade dentro do hospital, que coincidiu com o aumento na contagem de colônias de Cladophialophora spp., Aspergillus spp. e Fusarium spp. Leveduras foram encontradas em 39,4% dos profissionais de saúde (16,7% das amostras dos espaços interdigitais, 12,1% do leito subungueal e 10,6% da orofaringe) e, em 44% das amostras do mobiliário, com predomínio do gênero Candida (C. albicans, C. guilliermondii, C. parapsilosis e C. lusitaniae) seguido por Trichosporon spp. CONCLUSÕES: Observou-se número relativamente elevado de fungos anemófilos (potencialmente patogênicos) em áreas especiais e níveis expressivos de leveduras em fontes bióticas e abióticas. O monitoramento microbiológico ambiental deve ser realizado, principalmente em salas especiais com pacientes imunocomprometidos, sujeitos à exposição de patógenos do meio ambiente, assim como, advindos de profissionais de saúde.OBJECTIVE: To monitor and characterize airborne filamentous fungi and yeasts from abiotic and biotic sources within a hospital unit. METHODS: Collections were carried out on a monthly basis, at two different time periods, from the adult and pediatric intensive care units and surgical center of a hospital in Araraquara, Southeastern Brazil. Collection of airborne fungi was carried out using a simple-stage Andersen sample. The presence of yeasts was investigated in samples taken from the hands and oropharynx of staff members as well as from the surface of beds and doorknobs inside the critical areas. RESULTS: Thirty-two genera of airborne fungi and were recovered from the surgical center and 31 from the intensive care units. Genera most frequently isolated were Cladophialophora spp., Fusarium spp., Penicillium spp., Chrysosporium spp. e Aspergillus spp. During the study period, a new unit was built in the hospital, which coincided with an increase in Cladophialophora spp., Aspergillus spp., and Fusarium spp. colony counts. Yeasts were found in 39.4% of samples obtained from healthcare staff (16.7% from interdigital spaces, 12.1% from nailbeds, and 10.6% from oropharynx) and in 44% of furniture samples, with a predominance of the Candida genus ((C. albicans, C. guilliermondii, C. parapsilosis e C. lusitaniae), followed by Trichosporon spp. CONCLUSIONS: We found a relatively high number of airborne fungi (potentially pathological) in special areas and expressive levels of yeasts in both biotic and abiotic samples. Microbiological and environmental monitoring should be conducted, especially in special areas which include immunocompromised patients, who are more susceptible to the exposure to environmental and staff-derived pathogens.

El objetivo de este trabajo fue determinar la acción inhibitoria in vitro e in vivo de algunas cepas de levaduras de la zona citrícola jujeña sobre el crecimiento de los mohos patógenos post-cosecha y seleccionarlas para elaborar un producto de biocontrol. Se aislaron de frutos cítricos cepas de los mohos patógenos post-cosecha Penicillium digitatum, P. italicum,P. ulaiense, Phyllosticta sp. y Galactomyces geotrichum, así como de levaduras saprófítas de los géneros Brettanomyces, Candida, Cryptococcus, Kloeckera, Pichia y Rhodotorula. También se obtuvieron algunas levaduras de otras fuentes. Se identificaron las levaduras por las características macro y micromorfológicas y las pruebas fisiológicas. La actividad in vitro e in vivo de las diferentes cepas fue diferente según se enfrentaran a P. digitatum o P. ulaiense. Candida cantarellii y una cepa de Pichia subpelliculosa produjeron una reducción significativa del área de las lesiones provocadas por estas especies de Penicillium, y podrían ser empleadas en la formulación de un producto para biocontrol.The objective of this work was to establish the in vitro and in vivo inhibition of post-harvest pathogenic moulds by yeasts in order to make a biocontrol product. Post-harvest pathogenic moulds Penicillium digitatumP. italicum, P. ulaiense, Phyllosticta sp., Galactomyces geotrichum and yeasts belonging to genera Brettanomyces, Candida, Cryptococcus, Kloeckera,Pichia, Rhodotorula were isolated from citrus fruits. Some yeasts strains were also isolated from other sources. The yeasts were identified by their macro and micro-morphology and physiological tests. The in vitro and in vivo activities against P. digitatum or P. ulaiense were different. Candida cantarellii and one strain of Pichia subpelliculosa produced a significant reduction of the lesion area caused by the pathogenic moulds P. digitatum and P. ulaiense, and could be used in a biocontrol product formulation.

The behaviour of Picchia anomala, Picchia membranaefaciens, Pichia minuta, Saccharomyces cerevisiae, Candida diddensii, Candida famata y Debaryomyces hansenii, isolated form olive fermentations at low temperature was studied. The response, growth rate, at increasing time intervals, was studied by means of a General Linear Model (GLM) repeated measures, paying special attention to interactions. The most vigorous yeasts in YMGP were P. anomala, C. diddensii, y Deb. hansenii, who were able to grow at 7ºC and 8% salt. In brine, in addition to the main effects, the interactions salt-yeast, time-pH, time-yeast-species were also significant. P. membranaefaciens showed greater salt tolerance in brine than in YMPG. S. cerevisiae, P. minuta and C. famata were inhibited of both pH 3,5 and pH 4 at 7ºC. A sinergistic effect of salt and pH can inhibit yeast growth at 7ºC.

Fermented green olives of the variety “Picholine” were brined in 5% NaCl solutions, which were adjusted to pH 4.00 and 5.00 with lactic acid. Potassium sorbate was added to the brine at 0.05 % and the assays were inoculated with Lactobacillus plantarum strain I159, and Pichia anomala strains S18 from our collection. The pH values and microbial counts including Gram negative bacteria, yeasts and moulds, and lactic acid bacteria were followed during 6 months of storage. Results showed that even if the olives were inoculated with a high gas producing yeast (P. anomala S18), the attack of the fruits by the “bloater” spoilage was drastically reduced in the assays adjusted to pH4, added with potassium sorbate and inoculated with L. plantarum, without affecting the organoleptic characteristics of the product.

Se estudió el tiempo de reducción decimal (D) de Rhodotorula rubra (R. rubra) y Candida intermedia (C. intermedia) a diferentes concentraciones de sólidos solubles 12, 36 y 52 ºBrix, en jugo de naranja. Las temperaturas utilizadas fueron 63, 64, 65, 66 y 67 ºC. Los D obtenidos siguiendo el método de tubo de Stumbo modificado, para R. rubra fueron desde un mínimo de 3,1 seg para 36 ºBrix a 67ºC hasta un máximo de 209 seg para 52 ºBrix a 63ºC. Para C. intermedia, el D mínimo obtenido fue 3,2 seg. a 12 ºBrix a 64ºC y el máximo D obtenido fue de 6 seg a 52 ºBrix a 64ºC. Se evidenció que a medida que aumenta la concentración de sólidos solubles aumenta la resistencia térmica de las levaduras estudiadas, presentando R. rubra la mayor resistencia térmica a 52 ºBrix. C. intermedia es más osmotolerante que R. rubra pero más sensible al calor en altas concentraciones de azúcaresThermal resistance of yeasts in orange juice at different concentrations of soluble solids. Thermal decimal reduction time (D) of Rhodotorula rubra (R. rubra) and Candida intermedia (C. intermedia) at 63, 64, 65, 66 and 67ºC was studied, at soluble solids concentrations of 12, 36 and 52 ºBrix in orange juice. Experiments were conducted according to Stumbo method. D values for R. rubra were obtained in a range of 3.1 s for D 67ºC at 36 ºBrix as a minimum to 209 s at 64ºC and 52 ºBrix as a maximum. For C. intermedia, the minimum D value was 3.2 s at 64ºC and 12 ºBrix and the maximum was 6 s at 64ºC and 52 ºBrix. It can be noticed that as the concentration of soluble solids increases, the thermal resistance of the yeasts increases. R. rubra exhibits its highest thermal resistance at 52 ºBrix for all temperatures. C. intermedia shows more osmotolerancy that R. rubra but it is more sensitive to heat at high sugar concentrations

The brewing activity in Andean Patagonia plays a very important role in the region's economy, being microbial contamination one of the main problems in terms of quality. The presence of contaminant bacteria and wild yeasts in beer generate microbiological, physical and chemical changes that impact on its sensory attributes. However, few breweries establish criteria and policies to guarantee the quality of their products in a microbiological sense. The purpose of this work was to study for the first time the incidence of microbial contaminants in bottled craft beers from Andean Patagonia, identify the main microorganisms involved and establish relationships between contamination and the physicochemical variables of beer. We analyzed 75 beers from 37 breweries from 12 different Patagonian cities. Our results showed that 69.3% of the analyzed beer exhibited contaminant microorganism growth. Bacteria Levilactobacillus brevis and wild yeasts of Saccharomyces were the main microorganisms responsible for these contaminations. In addition, we found that microbial contamination had an impact on beer sensory profile and also that pH was correlated with the presence of lactic acid bacteria in beer, being an indicator of contamination for these bacteria. In conclusion, we observed that 8 out of 10 breweries studied showed contamination problems, highlighting the need to design prevention and control strategies in microbreweries., (Copyright © 2022 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)

Lipid extract and fatty acid composition of cane molasses and yeasts (Saccharomyces cerevisiae M-300-A and Saccharomyces uvarum IZ-1904) grown in molasses medium were determined. In molasses, linoleic acid was found in higher levels (around 42%) and was followed by palmitic, oleic and linolenic acids. The lipid extract varied from 1.02 to 3.13 gkg-1. In yeasts, the level of lipid extract varied from 16.65 to 31.12 g.kg-1 (dry matter basis) depending on the molasses type and yeast species. Both yeasts were able to incorporate fatty acids from molasses' and therefore linoleic and palmitic acids were the major fatty acids found in them.Foram determinados o extrato lipídico e a composição em ácidos graxos de melaço de cana-de-açúcar e das leveduras (Saccharomyces cerevisiae M-300-A e Saccharomyces uvarum Iz-1904) multiplicadas em meio fermentativo de melaço. Nos melaços, o ácido linoleico foi encontrado em maiores quantidades (cerca de 42% do total) e foi seguido pelos ácidos palmitic o, oleico e linolênico. O extrato lipídico variou de 1,02 até 3,13 g.Kg-1. Em leveduras, o nível do extrato lipídico variou de 16,65 até 31,12 g.kg-1(com base na matéria seca) e foi afetado pelo tipo de melaço e da espécie de levedura. Ambas as leveduras foram capazes de incorporar ácidos graxos presentes no melaço e portanto os ácidos linoleico e palmítico foram os principais ácidos graxos encontrados nessas leveduras.

A study was carried out in order to determine the effect of vitamins (biotin, thiamine, pantotheniic acid and pyridoxal) and micronutrient (zinc, boron, manganese and iron) deficiencies on higher alcohol production during alcoholic fermentation with the industrially used yeast Saccharomyces cerevisiae M-300-A. Zinc deficiency induced a reduction on the levels of isobutyl and isoamyl alcohols. An increase on isobutyl alcohol (fivefold) and a reduction of isoamyl alcohol (two fold) and n-propyl alcohol (three fold) contents resulted from pantotheiiic acid deficiency, whereas pyridoxal deficiency caused an increase on the levels of isobutyl and isoamyl alcohols. Biotin was not essential for the growth of this strain.Foi estudado o efeito da deficiência das vitaminas (biotina, ti amina, ácido pantotênico e piridoxal) e de micronutrientes (boro, zinco, manganês e ferro) sobre a produção de álcoois superiores durante a fermentação alcoólica com a levedura industrial Saccharomyces cerevisiae M-300-A. Com a deficiência de zinco ocorreu redução na formação dos álcoois isobutílico e isoamílico enquanto que a deficiência de pantotenato provocou aumento no nível de álcool isobutflico (cerca de cinco vezes) e redução dos álcoois isoamílico (duas vezes) e n-propílico (três vezes). Na deficiência de piridoxina ocorreu aumento nos teores de isobutílico e de isoamflico. A biotina não foi essencial para o crescimento dessa linhagem de levedura.

En los últimos años, la emergencia de infecciones por hongos se ha dado en parte por el aumento en las infecciones por microrganismos que normalmente no son patógenos. El siguiente reporte describe la fungemia y meningoencefalitis por Sporobolomyces salmonicolor, una levadura frecuente en el medio ambiente y las plantas, en un paciente sin factores de riesgo conocidos, con desenlace fatal a pesar del manejo con antifúngicos. Este caso nos recuerda que dentro de las infecciones micóticas emergentes se encuentra el S. salmonicolor y se debe tener en cuenta dentro del diagnóstico diferencial de levaduras en sangre, como causa infrecuente, potencialmente mortal.The emergence of pathogens, mainly fungi, in recent years has been partly due to overappearance of organisms that normally are not pathogenic in humans. The following report describes Sporobolomyces salmonicolor fungaemia and proven meningoencephalitis in a patient not showing risk factors who suffers a fatal outcome despite management with antifungal agents. The said yeast lives mainly in tree environments and plants. This case reminds us that there is S. salmonicolor within the emerging fungal infections, and this fact should be taken into account in the differential diagnosis of yeasts in blood as a rare and lifethreatening cause.

Otitis externa is a multi-factorial etiology disease commonly affecting canines. It represents a complex pathology associated to infections caused by bacteria and yeasts, many times not responding to treatments. The goal of this study was to isolate and identify the pathogenic and non-pathogenic micro-organisms existent in otitis externa patients. This research was performed on 53 canine patients which were attended at the Outpatient Consult Service of the University Veterinary Policlinic at Zulia State University (UVP), and which showed clinical signs such as: auditory canal erythema, increased secretion, pain, continuous head shaking and pruritus, purulent secretions and pruritus being the most frequent. Samples were recollected from auditory canal horizontal portion exudates. Different bacteria groups were isolated in culture media, the most frequent were Pseudomona aeruginosa (22.22%), Proteus mirabilis (13.89%), Staphylococcus aureus (12.50%), Staphylococcus epidermidis (8.33%), Escherichia coli (5.56%) and Staphylococcus coagulase-negative (5.56%). In the control group, Bacillus spp. (16.67%), Staphylococcus epidermidis (16.67%) and Staphylococcus coagulase-negative (16.67%) were the most frequently isolated. Cytological examination showed Malassezia pachydermatis to be present in 69.8% of the cases studied. The most affected breeds were Poodles (30.19%), Mongrels (26.42%), Cocker Spaniels (16.98%) and German Shepherd Dogs (9.49%); likewise, a higher incidence of otitis was evidenced in dogs between 2 and 5 months of age (43.40%).

Introduction. Sixty-five percent of human infections are caused by bacteria or yeasts able to form biofilms. This feature makes them more resistant to antimicrobials and antifungals. Objective. To determine biofilm formation capacity of bacterial and fungal isolates by quantitative crystal violet microtiter and qualitative Congo red agar methods. Materials and methods. Brain-heart infusion, trypticase soy broth and Müeller‑Hinton culture media were used in bacterial isolates for the quantitative method; brain-heart infusion broth and Sabouraud dextrose were used for yeasts. The same culture media plus 3% Congo red and 10% dextrose were used to apply the qualitative method in agar. The proposal by Stepanovic, et al. was used as a reference method. Results. We evaluated 103 bacterial isolates and 108 yeasts isolates. We did not recommend substitute brain-heart infusion broth for trypticase soy and Müeller-Hinton broths for biofilm formation assessment in bacterial isolates using the quantitative method. Sabouraud dextrose medium, both broth and agar, can replace brain-heart infusion to assess biofilm formation in yeasts, quantitatively and qualitatively. Conclusion. The study of biofilms in the microbiology laboratory, using Congo red agar qualitative method, is a simple, fast, and inexpensive procedure that provides precise information for the diagnosis and treatment of persistent infections caused by bacteria and yeasts.