Comunidades bacterianas implicadas en sistemas de producción aviar : factores de modulación e intervenciones sustentables

Tesis presentada para optar al título de Doctor de la Universidad de Buenos Aires en el área Ciencias Biológicas, 14 de octubre de 2021Las comunidades bacterianas presentes en el tracto gastrointestinal (TGI) de las aves son de vital importancia ya que contribuyen a su sanidad y nutrición. Además, cobran relevancia dado que las mismas pueden ser transferidas a suelos agrícolas cuando los residuos de la producción aviar son utilizados como enmiendas orgánicas. En la presente tesis se utilizaron técnicas de secuenciación masiva de amplicones del gen ARNr 16S con el objetivo de caracterizar estas comunidades bacterianas. Primeramente, se realizó un meta-análisis comparando la composición bacteriana del TGI de aves de diferentes países. Los resultados obtenidos mostraron el papel de la locación geográfica como modulador de la composición microbiana de ciegos permitiendo describir la "microbiota local" argentina. Además, se evaluaron los efectos de diferentes aditivos dietarios a escala experimental y comercial, encontrándose patrones diferenciales de modulación para cada aditivo, con un incremento en la relación Firmicutes/Bacteroidetes en los animales alimentados con taninos, debido a la mayor proporción de bacterias del orden Clostridiales. Finalmente, se describieron poblaciones de bacterias presentes en los residuos avícolas y el impacto que éstos producen en los agroecosistemas, particularmente en suelos agrícolas. Si bien la aplicación de guano y cama de pollo no mostró efectos significativos sobre la estructura de las comunidades bacterianas del suelo, se encontraron aumentos importantes en los valores de fósforo total y extractable, así como efectos fitotóxicos. Por este motivo, el guano fue tratado mediante compostaje y digestión anaeróbica encontrándose en cada enmienda obtenida, grupos taxonómicos y funcionales vinculados a cada tipo de tratamiento. Además, esto redujo el exceso de nutrientes y bacterias patógenas, permitiendo su utilización de forma segura, sin poner en riesgo la salud humana, animal ni vegetal, y disminuyendo el riesgo de contaminación de napas y cursos de agua.The bacterial communities present in the gastrointestinal tract (GIT) of birds are of vital importance as they contribute to their health and nutrition. In addition, they are relevant since can be transferred to agricultural soils when the waste of avian production are used as organic amendments. In the present study, metabarcoding of 16S rRNA gene was used in order to characterize these bacterial communities. First, a meta-analysis was carried out comparing the bacterial composition of the GIT of birds from different countries. The results obtained showed the role of the geographic location as a modulator factor of the microbial composition of cecum, allowing the Argentine "local microbiota" to be described. In addition, the effects of different dietary additives were evaluated on an experimental and commercial scale, finding differential modulation patterns for each additive, with an increase in the Firmicutes/Bacteroidetes ratio in animals fed with tannins, due to the higher proportion of bacteria of the order Clostridiales. Finally, bacteria communities present in poultry waste and the impact they produce on agroecosystems, particularly on agricultural soils, were described. Although the application of poultry manure and chicken litter did not show significant effects on the structure of the soil bacterial communities, significant increases were found in the values of total and extractable phosphorus, as well as phytotoxic effects. For this reason, the poultry manure was treated by composting and anaerobic digestion, finding in each amendment obtained, taxonomic and functional groups linked to each type of treatment. In addition, this reduced the excess of nutrients and pathogenic bacteria, allowing their use in a safe way, without putting human, animal, or plant health at risk, and reducing the risk of contamination of water courses.Instituto de BiotecnologíaFil: Pin Viso, Natalia Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pin Viso, Natalia Daniela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología y Biología Molecular y Celular; Argentin

Argentine Navy Icebreaker Ship “Almirante Irizar” Sludge Microbial Composition Analysis for Biohydrogen Production

Sludge from the wastewater treatment plant of the Argentinean Navy icebreaker ship “Almirante Irizar” was used as inoculum for biohydrogen production. The bacterial community was monitored throughout the fermentation, by sequencing 16S rRNA amplicons, to establish the microbial dynamics of the bioreactor over time. The established operating procedure assured a hydrogen content, along the process, in the range of 59.2–70.0%. The predominant species found were Clostridium sensu stricto and Sporolactobacillus sp. Clostridium showed higher values in the beginning of the fermentation with more than 90% of relative abundance. Conversely, Sporolactobacillus reached values close to 20% at its end. Additional topics discussed are the role of lactic acid bacteria in fermentative biohydrogen production systems and a series of in-process parameters that would allow control of this population. The results obtained allow supporting the use of this type of sludge as a source of hydrogen-producing bacteria.Fil: García, Rodrigo Enrique. Ministerio de Defensa. Instituto de Investigaciones Científicas y Técnicas para la Defensa; ArgentinaFil: Pin Viso, Natalia Daniela. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Gerosa, Fernando Ariel. Ministerio de Defensa. Instituto de Investigaciones Científicas y Técnicas para la Defensa; ArgentinaFil: Nishinakamasu, Verónica Cecilia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Puebla, Andrea Fabiana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Farber, Marisa Diana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación En Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Lavorante, Maria Jose. Ministerio de Defensa. Instituto de Investigaciones Científicas y Técnicas para la Defensa; Argentin

Hacia la reutilización sustentable de residuos avícolas: evaluación integrada como enmienda orgánica

Poster y resumenLos residuos de la producción avícola (guano de gallinas ponedoras y cama de pollos de engorde) se han utilizado como fertilizantes o enmiendas orgánicas para disminuir el impacto y degradación que causan en los suelos la aplicación de fertilizantes químicos a largo plazo. Sin embargo, pocos estudios han evaluado condiciones de campo contrastantes donde estos residuos se hayan utilizado durante períodos prolongados de tiempo en sistemas de cultivos agrícolas. En este estudio se utilizaron parámetros fisicoquímicos, metabarcoding del gen ARNr 16S e índices de ecotoxicidad para caracterizar el guano de gallinas ponedoras y la cama de pollos de engorde y examinar el efecto de su aplicación en suelos agrícolas durante un período de 10 años (campos sometidos a rotación trigo/soja-maíz, utilizándose tres tratamientos: suelo control sin enmienda añadida, suelo + guano de ponedoras, suelo + cama de pollos). Los residuos avícolas mostraron altas concentraciones de nutrientes (N y P) y una alta conductividad eléctrica, lo que provocó efectos fitotóxicos al evaluar tanto la germinación de semillas como el alargamiento de la radícula de cinco especies vegetales (lechuga: Lactuca sativa variedad "Gallega", rabanito: Raphanus sativus variedad "Puntas blancas", zucchini: Cucurbita maxima variedad "Veronés", rúcula: Eruca sativa y achicoria: Cichorium intybus) en presencia de extractos acuosos de los residuos avícolas. Las comunidades bacterianas presentes en los residuos estuvieron dominadas por miembros típicos del tracto gastrointestinal de las aves, destacando la presencia de familias de bacterias patógenas (Xanthomonadaceae, Clostridiales, Staphylococcaceae, Flavobacteriaceae, Sphingobacteriaceae). Los suelos sometidos a aplicaciones de guano de ponedoras mostraron valores estadísticamente más altos de fósforo total y fósforo extraíble respecto del suelo control, aumentando el riesgo de eutrofización. Por su parte, las comunidades bacterianas de los suelos sometidos a aplicaciones prolongadas de residuos avícolas permanecieron dominadas por familias de bacterias involucradas en los ciclos biogeoquímicos de los nutrientes y en la promoción del crecimiento de las plantas (Gemmatimonadaceae, Sphingomonadaceae, Nitrosomonadaceae, Planctomycetaceae, Nitrospiraceae), destacando la capacidad de resiliencia del suelo. Sin embargo, no debe descartarse la persistencia de bacterias de importancia sanitaria. En conjunto, nuestro trabajo contribuye a comprender los efectos de las prácticas agrícolas locales y, por lo tanto, al apoyo de la adopción de procesos de biotransformación previos a la reutilización de los residuos, de acuerdo con las pautas de sostenibilidad ambiental.Instituto de Microbiología y Zoología Agrícola (IMYZA)Fil: Pin Viso, Natalia Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pin Viso, Natalia Daniela. Universidad Nacional de Hurlingham; ArgentinaFil: Rizzo, Pedro Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Young, Brian Jonathan. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Gabioud, Emmanuel Adrian. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: Bres, Patricia Alina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Riera, Nicolas Iván. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Microbiología y Zoología Agrícola; ArgentinaFil: Merino, Lina. Universidad Nacional de Hurlingham; ArgentinaFil: Farber, Marisa Diana. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnologia y Biologia Molecular; ArgentinaFil: Farber, Marisa Diana. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Farber, Marisa Diana. Universidad Nacional de Hurlingham; Argentin

Plant beneficial rhizobacteria community structure changes through developmental stages of peanut and maize

Our objective in this study was to analyze the structure of the rhizobacterial community during different growth stages of peanut and maize plants. Microcosm assays were performed using pots containing unsterile soil from the peanut growing area of Argentina in which peanut and maize plants were grown during 120 and 100 days, respectively. Four to five samples of rhizospheric soil were obtained at the beginning of the assay, at an early growth stage of each plant and at the end of the assay. Two replicate DNA extractions from rhizospheric soil samples were realized per treatment on both microcosm assays to analyze rhizobacterial community structure by high-throughput sequencing of 16S rRNA gene. We observed changes in rhizobacteria community structure with crop developmental stages. Community structure changes occurred at several bacteria taxonomic levels, and major changes were observed in later stages. In particular, plant growth promoting bacteria genera were promoted in later stages. Our results indicate plant rhizospheric selection for growth enhancing rhizobacteria during stages of high nutrient demand. In conclusion, the structure of the rhizobacterial communities of peanut and maize are influenced by plant phenological stages, and beneficial bacteria are favoured in late phenological stages.Instituto de BiotecnologíaFil: Anzuay, María Soledad. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Anzuay, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Pin Viso, Natalia Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ludueña, Liliana Mercedes. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Ludueña, Liliana Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Morla, Federico Daniel. Universidad Nacional de Río Cuarto. Facultad de Agronomía y Veterinaria. Departamento de Producción Vegetal; ArgentinaFil: Angelini, Jorge Guillermo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Angelini, Jorge Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Taurian, Tania. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas, Físico-Químicas y Naturales. Departamento de Ciencias Naturales; ArgentinaFil: Taurian, Tania. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Agrobiotecnológicas; Argentin

Evaluation of native bacteria and manganese phosphite for alternative control of charcoal root rot of soybean

Plant growth promoting rhizobacteria (PGPR) are potential agents to control plant pathogens and their combined use with biopesticides such as phosphites may constitute a novel strategy to incorporate in disease management programs. In the present study, 11 bacterial isolates were selected on the basis of their antagonistic activity against Macrophomina phaseolina in dual-culture tests, and their plant growth promoting traits. Selected isolates were characterised on the basis of auxin and siderophore production, phosphate solubilisation and rep-PCR genomic fingerprinting. Two of these isolates, identified as Pseudomonas fluorescens 9 and Bacillus subtilis 54, were further evaluated for their inhibitory capacity against M. phaseolina using in vitro (on soybean seeds) and in vivo (greenhouse assay) tests. Both bacteria were applied individually as well as in combined treatment with manganese phosphite as seed treatments. Damage severity on soybean seeds was significantly reduced, compared with the untreated control, by both bacterial strains; however, the individual application of phosphite showed to be least effective in controlling M. phaseolina. Interestingly, the phosphite treatment improved its performance under greenhouse conditions compared to the results from the in vitro assays. In the greenhouse trials, the greatest reductions in disease severity were achieved when strain P. fluorescens 9 was applied singly or when strain B. subtilis 54 was combined with manganese phosphite, achieving 82% of control in both cases. This work is the first to report the control of M. phaseolina using combined treatment with PGPR and phosphite under greenhouse conditions.Fil: Simonetti, Ester. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Pin Viso, Natalia Daniela. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Montecchia, Marcela Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Zilli, Carla Giannina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Balestrasse, Karina Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Carmona, Marcelo Anibal. Universidad de Buenos Aires. Facultad de Agronomía; Argentin

The heart microbiome of insectivorous bats from Central and South Eastern Europe

Host associated microbiome not only may affect the individual health-status or provide insights into the species- or group specific bacterial communities but may act as early warning signs in the assessment of zoonotic reservoirs, offering clues to predict, prevent and control possible episodes of emerging zoonoses. Bats may be carriers and reservoirs of multiple pathogens such as viruses, bacteria and parasites, showing in the same time robust immunity against many of them. The microbiota plays a fundamental role on the induction, training and function of the host immune system and the immune system has largely evolved in order to maintain the symbiotic relationship of the host with these diverse microbes. Thus, expanding our knowledge on bat-associated microbiome it can be usefully in understanding bats’ outstanding immune capacities. The aim of this study was to investigate the presence of different bacterial communities in heart tissue of insectivorous bats, Nyctalus noctula, Pipistrellus pipistrellus and Rhinoplophus hipposideros, from Central and Eastern Europe using high-throughput sequencing of variable regions of the 16S rRNA. In addition, species-specific PCRs were used to validate the presence of the vector-borne pathogens Bartonella spp. and Rickettsia spp. In this study we identified a wide variety of bacterial groups, with the most abundant phyla being Proteobacteria and Firmicutes. The results showed that at individual level, the year or location had no effect on the diversity and composition of the microbiome, however host species determined both structure and abundance of the bacterial community. We report the presence of vector-borne bacteria Bartonella spp. in samples of N. noctula and indications of Rickettsia spp. in R. hipposideros. Our results provide a first insight into the bacterial community found in heart tissue of bats from Central and South Eastern Europe.Instituto de BiotecnologíaFil: Corduneanu, Alexandra. University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca. Department of Parasitology and Parasitic Diseases; RumaniaFil: Mihalca, Andrei Daniel. University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca. Department of Parasitology and Parasitic Diseases; RumaniaFil: Sandor, Attila D. University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca. Department of Parasitology and Parasitic Diseases; RumaniaFil: Sandor, Attila D. University of Veterinary Medicine. Department of Parasitology and Zoology; HungríaFil: Hornok, Sándor. University of Veterinary Medicine. Department of Parasitology and Zoology; HungríaFil: Malmberg, Maja. Swedish University of Agricultural Sciences. Department of Biomedical Sciences and Veterinary Public Health. Section of Virology; SueciaFil: Malmberg, Maja. Swedish University of Agricultural Sciences. Department of Animal Breeding and Genetics. SLU Global Bioinformatics Centre; SueciaFil: Pin Viso, Natalia Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bongcam-Rudloff, Erik. Swedish University of Agricultural Sciences. Department of Animal Breeding and Genetics. SLU Global Bioinformatics Centre; Sueci

Argentine navy icebreaker ship “Almirante Irizar” sludge microbial composition analysis for biohydrogen production

Sludge from the wastewater treatment plant of the Argentinean Navy icebreaker ship “Almirante Irizar” was used as inoculum for biohydrogen production. The bacterial community was monitored throughout the fermentation, by sequencing 16S rRNA amplicons, to establish the microbial dynamics of the bioreactor over time. The established operating procedure assured a hydrogen content, along the process, in the range of 59.2–70.0%. The predominant species found were Clostridium sensu stricto and Sporolactobacillus sp. Clostridium showed higher values in the beginning of the fermentation with more than 90% of relative abundance. Conversely, Sporolactobacillus reached values close to 20% at its end. Additional topics discussed are the role of lactic acid bacteria in fermentative biohydrogen production systems and a series of in-process parameters that would allow control of this population. The results obtained allow supporting the use of this type of sludge as a source of hydrogen-producing bacteria.Instituto de Biotecnologí

Biological inoculants and chemical fertilizers application produce differential effects on rhizobacterial community structure associated to peanut (Arachis hypogaea L.) and maize (Zea mays L.) plants

The use of biological inoculants in replacement of the application of chemical fertilizers is a desirable strategy taking into account it is more sustainable and economically less costly. Considering that agricultural practices can produce effects on soil microbial communities associated to the plant crops, the objective of this study was to analyze and compare the effect of these two practices on the structure of the rhizobacterial community of peanut and maize plants. For this purpose, microcosm assays were performed in which peanut and maize plants were inoculated individually with native peanut phosphate solubilizing strains or chemical fertilized with phosphorus, nitrogen, zinc and sulphur. At the beginning and at the end of the assays, samples of rhizospheric soil DNA were obtained and the structure of the rhizospheric bacterial community was analyzed by high-throughput sequencing of the 16S rRNA gene by using Illumina MiSeq platform. The results obtained indicated that the structures of the rhizospheric bacterial communities were different depending on plant type. It was possible to observe changes with respect to the initial bacterial structure in all taxonomic levels analyzed of all treatments. The more notorious structural changes of bacterial community were observed in those rhizospheres exposed to chemical fertilizers, mainly in soil samples associated to maize plants. The rhizospheric bacterial community of peanut showed to change mainly with plant growth. In conclusion, the rhizobacterial community structure is highly dynamic and influenced by different factors such as type of plant, the fertilizer input and bio-inoculant applied.Instituto de BiotecnologíaFil: Anzuay, María Soledad. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Anzuay, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pin Viso, Natalia Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Pin Viso, Natalia Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ludueña, Liliana Mercedes. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Ludueña, Liliana Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morla, Federico Daniel. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Morla, Federico Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Dalmasso, Romina Yanet. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Dalmasso, Romina Yanet. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Angelini, Jorge Guillermo. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Angelini, Jorge Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Taurian, Tania. Universidad Nacional de Río Cuarto. Instituto de Investigaciones Agrobiotecnológicas; ArgentinaFil: Taurian, Tania. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Tannins and Bacitracin Differentially Modulate Gut Microbiota of Broiler Chickens

Antibiotic growth promoters have been used for decades in poultry farming as a tool to maintain bird health and improve growth performance. Global concern about the recurrent emergence and spreading of antimicrobial resistance is challenging the livestock producers to search for alternatives to feed added antibiotics. The use of phytogenic compounds appears as a feasible option due to their ability to emulate the bioactive properties of antibiotics. However, detailed description about the effects of in-feed antibiotics and alternative natural products on chicken intestinal microbiota is lacking. High-throughput sequencing of 16S rRNA gene was used to study composition of cecal microbiota in broiler chickens supplemented with either bacitracin or a blend of chestnut and quebracho tannins over a 30-day grow-out period. Both tannins and bacitracin had a significant impact on diversity of cecal microbiota. Bacitracin consistently decreased Bifidobacterium while other bacterial groups were affected only at certain times. Tannins-fed chickens showed a drastic decrease in genus Bacteroides while certain members of order Clostridiales mainly belonging to the families Ruminococcaceae and Lachnospiraceae were increased. Different members of these groups have been associated with an improvement of intestinal health and feed efficiency in poultry, suggesting that these bacteria could be associated with productive performance of birds

Impact of Chestnut and Quebracho Tannins on Rumen Microbiota of Bovines

The use of phytogenic dietary additives is being evaluated as a means to improve animal productivity. The effect of tannins seems to be the influence not only directly on the digestive process through binding of dietary proteins but also indirectly over their effects on gastrointestinal microbiota. High-throughput sequencing of 16S rRNA gene was used to analyze the impact of dietary supplementation with a blend of chestnut and quebracho tannins on the rumen microbiota of Holstein steers. Bacterial richness was lower in tannins treated animals, while the overall population structure of rumen microbiota was not significantly disturbed by tannins. The ratio of the phyla Firmicutes and Bacteroidetes, a parameter associated with energy harvesting function, was increased in tannins supplemented animals, essentially due to the selective growth of Ruminococcaceae over members of genus Prevotella. Fibrolytic, amylolytic, and ureolytic bacterial communities in the rumen were altered by tannins, while methanogenic archaea were reduced. Furthermore, ruminal pH was significantly higher in animals supplemented with tannins than in the control group, while urease activity exhibited the opposite pattern. Further work is necessary to assess the relation between tannins impact on rumen microbiota and alteration of rumen fermentation parameters associated with bovine performance