Strategies and approaches in plasmidome studies, uncovering plasmid diversity disregarding of linear elements?

The term plasmid was originally coined for circular, extrachromosomal genetic elements. Today, plasmids are widely recognised not only as important factors facilitating genome restructuring but also as vehicles for the dissemination of beneficial characters within bacterial communities. Plasmid diversity has been uncovered by means of culture dependent or independent approaches, such as endogenous or exogenous plasmid isolation as well as PCR-based detection or transposon-aided capture, respectively. High-throughput-sequencing made possible to cover total plasmid populations in a given environment, i.e. the plasmidome, and allowed to address the quality and significance of self-replicating genetic elements. Since such efforts were and still are rather restricted to circular molecules, here we put equal emphasis on the linear plasmids which despite their frequent occurrence in a large number of bacteria are largely neglected in prevalent plasmidome conceptions.Fil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Wagenknecht, Martin. Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster.; AlemaniaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Meinhardt, Friedhelm. Institut für Molekulare Mikrobiologie und Biotechnologie, Westfälische Wilhelms-Universität Münster, Münster.; Alemani

Effect of stress factors associated with postharvest citrus conditions on the viability and biocontrol activity of Clavispora lusitaniae strain 146

Only quite recently, we have shown that yeast strains Clavispora lusitaniae 146 and Pichia fermentans 27 can act as efficient biocontrol agents for combating postharvest fungal diseases in lemons. During postharvest and storage conditions, microorganisms are subject to different stress factors that could affect both their survival and their protective capacity. Understanding the tolerance of yeasts to environmental stress factors could support the future development and commercial application of biological control formulations based on such organisms. Thus, the impact of different stressors on the viability and protection efficiency of C. lusitaniae strain 146 and P. fermentans strain 27 was evaluated, and the yeasts were subjected to oxidative stress, thermal treatments, exposure to NaOCl, osmotic stress, and ultraviolet irradiation. Candida oleophila strain O served as the reference control. C. lusitaniae 146 was more resistant to H2O2 in plate assays; however, in liquid media there was no significant difference to the other strains. Strain 146 was less affected by NaOCl, being able to survive with 300 ppm. P. fermentans 27 was the strain most heavily affected by osmotic pressure, while strains 146 and strain O showed a similar adaptation. UV-B irradiation severely affected C. oleophila and P. fermentans, while C. lusitaniae was the most resistant. Strains 146 and 27 were similarly tolerant to thermal shocks, compared to the reference strain, which was less viable. In in vivo tests, exposure to 10 mM H2O2, 45 °C or 200 ppm NaOCl prior to fruit inoculation, reduced the antagonistic activity against the pathogen Penicillium digitatum. However, in no case was the biocontrol efficiency reduced to less than 50%. As C. lusitaniae 146 demonstrated a great potential to combat P. digitatum under a wide range of conditions, the organism is a promising candidate as an effective and valuable alternative to toxic fungicides.Fil: Pereyra, Martina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Diaz, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Meinhardt, Friedhelm. Münster Universität; AlemaniaFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán; Argentin

Towards the sustainable production of lemons: native yeasts as biological control agents

The province of Tucumán is positioned as one of the main centers of production and processing of lemons. Among the problems associated with the production of lemons, the economic losses caused by postharvest fungal infections stand out. Chemical fungicides have traditionally been applied as control and preventive measures, but their use entails numerous problems such as environmental contamination, toxicity in humans and restrictions on international markets. However, efficient and sustainable alternatives to the use of such pesticides are not known so far. Thus, the aim of this research was to search for biological control alternatives based on native yeasts, understand the associated mechanisms of action, and formulate a sustainable biocontrol agent. Biocontrol yeasts were isolated from citrus plants and lemon packinghouses. The antagonism of the isolates against Penicillium digitatum in in vitro and in vivo assays as well as the possible mechanisms of action related to biological control were determined. In addition, both liquid and solid formulations were tested. Among the yeast isolates, Clavispora lusitaniae 146stood out as it was able to inhibit P. digitatum in vitro and also to control green mold onlemons with high efficiency, both in room temperature and cold storage. Yeast 146 was ableto resist stress factors associated with the packaging process and was compatible with carnauba wax. Among the mechanisms of action, the ability to colonize wounds and the competition for space and nutrients were evidenced. C. lusitaniae depicted a broad spectrum of action in controlling green mold on other citrus fruits, such as oranges, mandarins, and grapefruit. C. lusitaniae 146 did not negatively affect the aroma perception of fruits by consumers. Moreover, it was able to remove the mycotoxin patulin from a solution. Different liquid and solid formulations were tested; being the yeast dried by lyophilization in combination with sucrose and skimmed milk the most promising. The native yeast C. lusitaniae 146 is a promising biological control agent for the control of P. digitatum in lemons and other varieties of citrus fruits. A yeast-based formulation would replace the use of chemical fungicides and promote the organic production of lemons.Fil: Diaz, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pereyra, Martina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Rasuk, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaXVIII Congreso de la Sociedad Argentina de Microbiología GeneralChapadmalalArgentinaSociedad Argentina de Microbiología Genera

Complete Genome Sequence of pAP13, a Large Linear Plasmid of a Brevibacterium Strain Isolated from a Saline Lake at 4,200 Meters above Sea Level in Argentina

pAP13 is an 89 kb-linear plasmid hosted by Brevibacterium sp. Ap13, an actinobacterium isolated from the feces of a flamingo from an extremely high-altitude lake in Argentina. Because of the ecological importance of the genus Brevibacterium, the absolute lack of information concerning Brevibacterium linear plasmids, as well as the as the possible ecological significance of this unusual plasmid, pAP13 was completely sequenced, including the inversely oriented termini.Fil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Schuldes, Jörg. Georg August Universität; AlemaniaFil: Thürner, Andrea. Georg August Universität; AlemaniaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Daniel, Rolf. Georg August Universität; AlemaniaFil: Meinhardt, Friedhelm. No especifíca

Killer yeasts for the biological control of postharvest fungal crop diseases

Every year and all over the world the fungal decay of fresh fruit and vegetables frequently generates substantial economic losses. Synthetic fungicides, traditionally used to efficiently combat the putrefactive agents, emerged, however, as the cause of environmental and human health issues. Given the need to seek for alternatives, several biological approaches were followed, among which those with killer yeasts stand out. Here, after the elaboration of the complex of problems, we explain the hitherto known yeast killer mechanisms and present the implementation of yeasts displaying such phenotype in biocontrol strategies for pre-or postharvest treatments to be aimed at combating postharvest fungal decay in numerous agricultural products.Fil: Díaz, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pereyra, Martina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Picón Montenegro, Ernesto. Universidad Nacional de Tucumán; ArgentinaFil: Meinhardt, Friedhelm. Universidad Nacional de Tucumán; ArgentinaFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán; Argentin

First Complete Sequence of a Giant Linear Plasmid from a Micrococcus Strain Isolated from an Extremely High-Altitude Lake

Micrococcus sp. V7, an actinobacterial strain adapted to the extreme conditions of the Laguna Vilama, an extremely high-altitude (4,600mabove sea level) lake in the Argentinian Puna, was found to carry the giant linear plasmid pLMV7. We determined its sequence (92,815 bp) as a prerequisite to the investigation of its role for survival in such a harsh environment.Fil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Schuldes, Jörg. Georg August Universität Göttingen; AndorraFil: Thürner, Andrea. Georg August Universität Göttingen; AndorraFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Daniel, Rolf. Georg August Universität Göttingen; AndorraFil: Meinhardt, Friedhelm. No especifíca

Новый вид нематод из пресноводных строматолитов Андского плоскогорья

The recently discovered "living" stromatolites in the Argentinean Puna are considered one of the most extreme stromatolites found so far. A rich biodiversity of bacteria, archaea and algae were previously reported in such stromatolites. As nematodes are the most numerous multicellular animals on Earth, the aim of this work was to investigate their presence in the stromatolites from Socompa lake at 3570 meters above sea level (masl). Nematodes were extracted and identified as belonging to the Monhysteridae family, with 91-92% homology to Diplolaimella dievengatensis. The phylogenetic analysis suggested they are novel species and probably belong to a new genus. This study represents the first report related to the presence of novel nematodes in such peculiar stromatolites. Knowing their functions and genetic features involved in the adaptation to these harsh conditions could help to elucidate important aspects about the ecological impact of these organisms in hostile environments.Недавно обнаруженные живые строматолиты Андского плоскогорья считаются самыми необычными из всех известных ранее. Богатство разнообразия бактерий и архей было ранее отмечено для строматолитов. Поскольку нематоды — самые многочисленные многоклеточные на планете Земля, то задачей работы было обнаружение нематод в строматолитах озера Сокомпа, расположенного на 3570 метров над уровнем моря. В ходе работы нематоды были обнаружены и определены как принадлежащие семейству Monhysteridae и с вероятностью 91–92% отнесены к виду Diplolaimella dievengatensis. В то же время филогенетический анализ показал, что обнаруженный вид представляет собой новый для науки вид, принадлежащий неописанному ранее роду нематод. Настоящая работа представляет собой краткое информационное сообщение о первой находке нематод в необычных пресноводных строматолитах. Новые знания о функциональных и генетических особенностях, приведших к адаптации в необычных условиях среды, позволят понять экологическую роль нематод в сообществах пресноводных строматолитов.Fil: D'almeida, Romina Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Investigaciones Biológicas. Universidad Nacional de Tucumán. Instituto Superior de Investigaciones Biológicas; ArgentinaFil: García, Marcia Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Perez, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentin

Impact of biocontrol yeast clavispora lusitaniae 146 on the lemon microbiome

The use of biocontrol agents has been proposed as an effective alternative to reduce citrus decays for promoting sustainable agriculture based on organic fruit production. Among the different microbial biocontrol agents, Clavispora lusitaniae 146 stands out as it is able of effectively controlling green mold in lemons. Although there is growing recognition of the role that the microbiome plays in the health and physiology of many plant species, to date, the composition of the lemon microbiome is unknown, nor is the effect of yeast 146 on it. Thus, the aim of this research was to study the impacts of biocontrol yeast Clavispora lusitaneae 146 on the composition of the lemon microbiome. Lemons were harvested, and then divided into two treatments: untreated and treated lemons with biocontrol yeast C. lusitaneae 146. Fruits were then stored at room temperature for 7 days. DNA was extracted from a pool of 3 pieces of peel per sample, and used for PCR that amplified the bacterial hypervariable V3-V4 region of the 16S rRNA gene. Paired-end sequencing of amplicons was done on an Illumina MiSeq sequencer. To assess the effects of postharvest treatment and storage on the diversity of the lemon microbiome, we used a series of ANOVA and adonis (~PERMANOVA) models with Shannon diversity and community composition as the response variables, respectively. There was no statistically significant difference (KruskalWallies, p > 0.05) in bacterial diversity between the treated and untreated fruits. In this sense, the application of Clavispora lusitaneae 146 did not produce significant changes on bacterial communities of lemons during storage, including alpha diversity, community composition and structure. The bacterial community was dominated by roteobacteria,followed by Firmicutes and Actinobacteria. Specific bacterial taxa were only identified for untreated lemons: Methylobacteriaceae (Alphaproteobacteria) and unclassified bacteria, however in a low abundance. Here, we presented the first lemon microbiome and we showed that the microbial abundance, diversity, and community structures were not significantly different for both treatments, revealing that Clavispora lusitaniae 146 didn´t modify the native bacterial population of the fruit microbiome. The present study is part of larger project whose objectives are to define the complete lemon microbiome, assess the effects of the postharvest biocontrol agents on the composition of the lemon microbiome to develop a science-based strategy for manipulating this microbiome to prevent postharvest decay and physiological disorders.Fil: Rasuk, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pisa, José Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Chacón, Florencia Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Pereyra, Martina María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaXVIII Congreso de la Sociedad Argentina de Microbiología GeneralChapadmalalArgentinaSociedad Argentina de Microbiología Genera

Prevalence of intestinal parasitic infection among children from a shanty town in Tucuman, Argentina

A parasitological survey was conducted in children living in a poor area next to a drainage channel, in Tucumán province, Argentina. Stool specimens from 115 children were collected and samples were analyzed by direct microscopy examination and concentration techniques. The prevalence rate of intestinal parasites infection was high (78.3%) and Blastocystis hominis was the most frequent protozoan parasite found (68.9%) followed by Giardia intestinalis (33.3%), Entamoeba coli (24.4%), Endolimax nana (12.2%), Chilomastix mesnili (5.6%) and Iodamoeba bütschlii (2.2%). Ascaris lumbricoides was the most prevalent intestinal helminth, with an infection frequency of 38.9%, followed by Trichuris trichiura (13.3%), Strongyloides stercoralis (13.3%), Hymenolepis nana (7.8%) and Enterobius vermicularis (3.3%). Multiple parasitic infections were also high, affecting 71.1% of infected population. These results indicate that sanitary policies, including health care and sanitary education have been inadequate for the control of intestinal parasitism in this high-risk population. Implementation of sanitation programs is a basic need and a joint collaboration between public servant and health professionals should be a priority.Fil: Dib, Julian Rafael. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Fernandez Zenoff, Maria Veronica. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Oquilla, Juana del Valle. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Lazarte, S.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; ArgentinaFil: Gonzalez, Silvia Nelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Microbiología; Argentin

Parasitological Survey of Schoolchildren from a High-Altitude Community from Tucumán Province, Argentina. Remarkable Low Detection of Soil-Transmitted Helminths in Comparison with Coastal Communities

The prevalence of intestinal parasitic infections among schoolchildren in Colalao del Valle, a high-altitude community in Tucumán province, Argentina, was investigated. The data revealed a high prevalence of parasitism (79.7%) with no significant differences in distribution by sex or age. Protozoa infections were the most common with Blastocystis hominis being the most prevalent (62.5%), followed by Giardia lamblia (29.7%), Endolimax nana (15.6%), Entamoeba coli (12.5%) and Iodamoeba bustchili (3.1%). Interestingly, there was an absence of soil-transmitted helminths among the studied population which could be related to climate (variable temperatures, moderate rainfall) and soil type (clay).Fil: Dib, Julian Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Fernandez Zenoff, Maria Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Oquilla, Juana del Valle. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Rudelli, M.. Ministerio de Salud de la Nación; ArgentinaFil: Lazarte, S.. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Gonzalez, Silvia Nelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentin