Feeding laying hens with lactobacilli improves internal egg quality and animal health.

Feeding animals with lactobacilli strains is a biotechnological strategy to improve production, food quality, and animal health. Thus, this study aimed to select new lactic acid bacteria (LAB) able to improve laying hens health and egg production. Forty Bovans White layers (two days old) were randomly divided into four experimental groups that receive an oral gavage with saline solution (control group) or with one of the three lactobacilli selected (KEG3, TBB10, and KMG127) by their antagonistic activity against the foodborne pathogen Bacillus cereus GGD_EGG01. 16 S rRNA sequencing identified KEG3 as Lentilactobacillus sp., and TBB10 and KMG127 as Lactiplantibacillus sp. The data showed that feeding birds with LAB increased weight uniformity and improved the internal quality of the eggs (high yolk index and Haugh unit) compared with the control group (p < 0.05). Beta-diversity analysis showed that LAB supplementation modifies the cecal microbiota of laying hens. The prokaryotic families Bacteroidaceae, Ruminococcaceae, Rikenellaceae, and Lactobacillaceae were most important to the total dissimilarity of the cecal microbial community (calculated by SIMPER test). At end of in vivo experiments, it was possible to conclude that the feed of laying hens with Lentilactobacillus sp. TBB10 and Lentilactobacillus sp. KEG3 can be an important biotechnological tool for improving food quality and animal health.

Effects of probiotic supplementation on the gut microbiota composition of adults: a systematic review of randomized clinical trials.

Researchers have associated the therapeutic potential of probiotics with its ability to modulate gut microbiota, which is considered an "invisible organ" of the human body. The present study investigates the effects of probiotic supplementation on the gut microbiota composition of adults. The authors conducted a systematic review of the literature published in six different databases. The search followed PRISMA guidelines and aimed to identify randomized clinical trials on probiotic supplementation. All relevant publications indexed up to May 28, 2021, were retrieved. Then, the authors defined the inclusion and exclusion criteria. Two independent reviewers performed study screening, data extraction, and quality assessment. A total of 2,404 publications were retrieved, and eight studies met the eligibility criteria. The included randomized clinical trials were published between 2015 to 2020. The worldwide studies included adults aged from 18 to 79 years, most of whom were women (66.5%). Only one of the included studies observed significant effects on fecal microbiota composition in the relative abundance of Bacteroidetes and Firmicutes phyla in comparison with the placebo treatment. Overall, this systematic review could not draw consistent conclusions on the effects of probiotic supplementation on the gut microbiota composition of adults.

Biotechnological potential of Bacillus sp. S26 for alleviation of abiotic and biotic stresses in vine.

Grapevine (Vitis spp.) is one of the most cultivated fruit plants in the world. Vineyard growers apply copper-based products in these crops to prevent fungal diseases, generating worries about Cu contamination in soils and food. In this context, this study identifies prokaryotic communities associated with grapevine plants grown under different levels of Cu-contaminated soils. Moreover, the study isolates new bacteria to improve Cu resistance in plants. Soil Cu content correlated inversely with operational taxonomic units (OTUs) belonging to the groups Acidobacteria (SubGroup 2), Latescibacteria, Pedosphaeraceae, and Candidatus Udaeobacter. A total of 14 new bacterial isolates were obtained from copper-contaminated soils. These isolates produced Indolic Compounds (IC) in a range of 25 to 96 µg mL- 1, highlighting bacterial strains S20 and S26 as the highest producers. These new bacteria also produced siderophores, highlighting strains S19 and S26, which removed 58 and 59% of Fe ions from the CAS complex, respectively. From the in vitro antagonistic activity against Colletotrichum spp. strains, the authors identified some bacterial strains that inhibited phytopathogen growth. Bacterial strain Bacillus sp. S26 was chosen for inoculation experiments in grapevine plants. This bacterial isolate improved the growth of grapevine plants in Cu-contaminated soils. However, growth promotion did not occur in unstressed plants. More studies are necessary for developing a new bioinoculant containing S26 cells aiming to reduce biotic and abiotic stresses in grapevine.

Evolution of the scientific literature on esophageal cancer from 1945 to 2020: a bibliometric analysis.

The aim of this study was to use bibliometric techniques to provide a longitudinal view of the evolution over more than 50 years of the literature on esophageal cancer without focusing on a specific area. The Web of Science Core Collection database was searched for published articles on esophageal neoplasm. Different aspects of the articles were analyzed - country, journal, authors, keywords, and topics. The search returned 24,215 articles - the journal Diseases of the Esophagus present the most number of manuscripts (n = 858), followed by Annals of Surgical Oncology (n = 475).The most cited article was one by van Hagen et al. (2012) (2,807 citations). The most prevalent topic was oncology (n = 10,448), followed by surgery (n = 4,944). Most articles were original research (n = 22,697), mainly with the basic science study design and published by institutions in China. The analysis of the variables chosen, identified China as the country with the highest number of articles and showed that authors and institutions in Asia stand out when it comes to production of scientific information on esophageal cancer.

Diversity and phylogenetic affinities of Bradyrhizobium isolates from Pampa and Atlantic Forest Biomes.

In this work, we investigated Bradyrhizobium strains isolated from soils collected from the rhizosphere of native and exotic legumes species inhabiting two ecoclimatic zones - asubtropical-lowland pasture (Pampa Biome) and a volcanic plateau covered by Araucaria Moist Forests (Atlantic Forest Biome). The rhizobial strains were isolated from the nodules of seven native and one exotic legume species used as rhizobium traps. Single-gene (recA, glnII, dnaK) and combined-gene MLSA analyses (dnaK-glnII-gyrB-recA-rpoB) revealed that nearly 85% of the isolates clustered in B. elkanii supergroup, while the remaining (except for two isolates) in B. japonicum supergroup, albeit, in most cases, separately from the type strains of Bradyrhizobium species. As a symbiotic gene marker, a portion of nifD gene was sequenced for 194 strains. In the nifD-tree, an American branch III.3D (104 isolates), was the most numerous among the isolates. A significant portion of the isolates clustered in American groups; subclade III.4 (40 strains), Clade VII (3 strains), and a new Clade XX (4 strains). Most of the remaining strains belonged to a pantropical III.3C branch (39 isolates). On the other hand, identification of isolates belonging, respectively, to Clade I and Clade II may result of spreading of the Australian (Clade I) and European (Clade II) bradyrhizobia following the introduction of their legume hosts. Our study indicated that the American groups predominated in the symbiotic Bradyrhizobium communities in southern Brazil. However, there is a significant component of exotic lineages, resulting from the dispersal of pantropical Fabaceae taxa and the introduction of exotic legumes.

Use of Mineral Weathering Bacteria to Enhance Nutrient Availability in Crops: A Review.

Rock powders are low-cost potential sources of most of the nutrients required by higher plants for growth and development. However, slow dissolution rates of minerals represent an obstacle to the widespread use of rock powders in agriculture. Rhizosphere processes and biological weathering may further enhance mineral dissolution since the interaction between minerals, plants, and bacteria results in the release of macro- and micronutrients into the soil solution. Plants are important agents in this process acting directly in the mineral dissolution or sustaining a wide diversity of weathering microorganisms in the root environment. Meanwhile, root microorganisms promote mineral dissolution by producing complexing ligands (siderophores and organic acids), affecting the pH (via organic or inorganic acid production), or performing redox reactions. Besides that, a wide variety of rhizosphere bacteria and fungi could also promote plant development directly, synergistically contributing to the weathering activity performed by plants. The inoculation of weathering bacteria in soil or plants, especially combined with the use of crushed rocks, can increase soil fertility and improve crop production. This approach is more sustainable than conventional fertilization practices, which may contribute to reducing climate change linked to agricultural activity. Besides, it could decrease the dependency of developing countries on imported fertilizers, thus improving local development.

Microbial communities in anaerobic digesters change over time and sampling depth.

Anaerobic digestion (AD) is a process resulting from the anaerobic metabolism of specific microorganisms that produce an eco-friendly type of energy and a stabilized soil fertilizer. We described the microbial communities and their changes in three depths of BioKöhler® biodigester, fed with cattle manure for 18 days, under anaerobic incubation at the psychrophilic temperature range (~ 20 °C). During the experiment, the maximum methane content in the raw biogas was 79.9%. Non-metric multidimensional scaling (MDS) showed significant differences among microbial communities in the bottom, medium, and upper depths. Considering all the periods of incubation, the microbial communities changed until the eighth day, and they remained stable from eighth to seventeenth days. Bacteroidetes, Firmicutes, and Synergistetes were the most abundant phyla in samples, representing approximately 41% of the total OTUs. The relative abundance of the phyla Euryarchaeota, Actinobacteria, Firmicutes, and Verrucomicrobia changed from bottom to medium sampling points. Moreover, Crenarchaeota differed in frequencies from medium to upper, and Acidobacteria from bottom to upper samples. Lentisphaerae, Chloroflexi, and LD1 were different solely at the bottom, whereas OP9 and Tenericutes only in the medium. Psychrophilic AD performed in this work removed pathogens like Salmonella and Escherichia, as observed at the digestate analyzed. This type of treatment of raw manure besides producing eco-friendly energy efficiently also generates a stabilized and safe biomass that can be used as fertilizer in soils.

Acid lactic lactobacilli as a biotechnological toll to improve food quality and human health.

The genus Lactobacillus has been widely used in food industry as starter or adjunct culture due to its probiotic features. Its biotechnological features improve the spectrum of uses of lactobacilli, which can affect its applicability directly. In this sense, this literature review gathers information and discusses the biotechnological potential of technological/probiotic lactobacilli aiming to improve food quality and human health. The primary and secondary metabolism generates specific substances, such as organic acids, carbon dioxide, hydrogen peroxide, diacetyl, fatty acids, and bacteriocins, which are determinant due to their probiotic potential, antimicrobial activity, and the development of new food flavors. In order to become industrially and commercially attractive, it is necessary develop a large-scale process with lower production costs.

Use of biotechnological approaches to add value to rice hulls.

One of the most common agricultural wastes generated in rice producing countries, rice hull (RH) is considered an environmental problem due to increased rice production and RH accumulation, especially because natural degradation in the environment is very difficult and time-consuming. Currently, RH is mostly used as bed for broiler chickens or burned for energy generation, two processes that prevent environmental accumulation in a sustainable way, without adding value to the RH. To diversificate its use and effectively add some value to the RH, a pretreatment is frequently needed, allowing the application of several biotechnological approaches. In this review, we gather information about biotechnological uses of crude and processed RH, including their use as fertilizers, filler material in natural rubber and incorporation in cement for civil construction purposes, along with their use in processes as silica extraction and adsorption/removal of environmental contaminants as heavy metals and dyes. Finally, we critically evaluate the data published in the literature, and based on our own findings, we point future directions related to RH biodegradation and further methane production.

Bacterial and Archaeal Communities Change With Intensity of Vegetation Coverage in Arenized Soils From the Pampa Biome.

Arenization occurs in regions that present sandy soils with normal rainfall levels. Predatory use of environmental sources, the dissolution of arenitic rocks and reworking of non-consolidated surface sands intensify this degradation scenario. Thus, this work aimed to evaluate the impact of the arenization process in the Brazilian Pampa Biome and how this phenomenon affects the soil microbial and plant communities. For this purpose, three arenized areas in Southern Brazil (Pampa Biome) were selected and, in each one, three sampling points were studied: arenized (ARA), arenized to grassland transition (AGT), and grassland (GRA) areas. In the three sampling points, soils presented low levels of nutrients, organic matter, mud and pH acidic in all regions but, the presence of vegetation coverage in AGT and GRA areas preserved the topsoil structure. Our study related ARA with bacterial families Alcaligenaceae, Pseudomonadaceae, and Xanthomonadaceae. AGT with bacterial families Bacillaceae and Burkholderiaceae, and plant species Melinis repens (Willd.) Zizka and Paspalum stellatum Humb. and Bonpl. ex Flüggé, and GRA with bacterial families Koribacteraceae, Hyphomicrobiaceae, and Chthoniobacteraceae, and plant species Croton subpannosus Müll.Arg. ex Griseb., Piptochaetium montevidense (Spreng.) Parodi and Elyonurus sp. The three studied areas (as well as sampling points) present soils extremely poor in nutrients with sandy texture, and the bacterial and plant composition well known to be resistant to environmental stresses were dominant. The vulnerability of these areas causes a degradation scenario, which is worsened by agricultural activities. However, in general, this phenomenon is a natural process that occurs mainly due to soil characteristics (poor soils) and climatic variations.

Characterization of technological and probiotic properties of indigenous Lactobacillus spp. from south Brazil.

In this study, we isolated Lactobacillus spp. from bovine raw milk and artisanal cheese from southern Brazil, and evaluated their technological and probiotic potential to select new isolates for producing healthy fermented dairy foods with differentiated tastes and flavours. We obtained 48 new lactobacilli isolates, which were isolated from raw milk (38) and cheese (10). These bacterial isolates were closely related with ten species: Lactobacillus paracasei (50% of the isolates), L. parabuchneri (15%), L. pentosus (13%), L. zeae (4%), L. plantarum (4%), L. otakiensis (4%), L. casei (4%), L. harbinensis (2%), L. diolivorans (2%), and L. rhamnosus (2%). Isolates CH112 and CH131 showed the greatest acidification potential, reducing the pH of milk to below 5.3 after incubation for 6 h at 32 °C. Considering proteolytic activity and diacetyl production, isolates ML88a, ML04, and ML12 showed the most promising results. Isolate ML12 showed 100% survival rate when inoculated in gastric juice at pH 2.5. The evaluation of antibacterial activity of the lactobacilli showed that the pathogens Listeria monocytogenes, Staphylococcus aureus, Salmonella enteritidis, and Salmonella Typhimurium were strongly inhibited by the pure lactobacilli cultures. Five Lactobacillus isolates (ML01, ML04, ML12, ML88, and CH139) showed both technological and probiotic characteristics. Principal Component Analysis (PCA) was used to investigate correlations among technological and probiotic characteristics, and identified new promising lactobacilli isolates for exploring their characteristics. This study reveals the importance of selecting new microorganisms with potential applicability in the food industry for developing functional foods with differentiated aromas and flavours.

The genomes of three Bradyrhizobium sp. isolated from root nodules of Lupinus albescens grown in extremely poor soils display important genes for resistance to environmental stress.

Lupinus albescens is a resistant cover plant that establishes symbiotic relationships with bacteria belonging to the Bradyrhizobium genus. This symbiosis helps the development of these plants in adverse environmental conditions, such as the ones found in arenized areas of Southern Brazil. This work studied three Bradyrhizobium sp. (AS23, NAS80 and NAS96) isolated from L. albescens plants that grow in extremely poor soils (arenized areas and adjacent grasslands). The genomes of these three strains were sequenced in the Ion Torrent platform using the IonXpress library preparation kit, and presented a total number of bases of 1,230,460,823 for AS23, 1,320,104,022 for NAS80, and 1,236,105,093 for NAS96. The genome comparison with closest strains Bradyrhizobium japonicum USDA6 and Bradyrhizobium diazoefficiens USDA110 showed important variable regions (with less than 80% of similarity). Genes encoding for factors for resistance/tolerance to heavy metal, flagellar motility, response to osmotic and oxidative stresses, heat shock proteins (present only in the three sequenced genomes) could be responsible for the ability of these microorganisms to survive in inhospitable environments. Knowledge about these genomes will provide a foundation for future development of an inoculant bioproduct that should optimize the recovery of degraded soils using cover crops.

Phylogeny and Phylogeography of Rhizobial Symbionts Nodulating Legumes of the Tribe Genisteae.

The legume tribe Genisteae comprises 618, predominantly temperate species, showing an amphi-Atlantic distribution that was caused by several long-distance dispersal events. Seven out of the 16 authenticated rhizobial genera can nodulate particular Genisteae species. Bradyrhizobium predominates among rhizobia nodulating Genisteae legumes. Bradyrhizobium strains that infect Genisteae species belong to both the Bradyrhizobium japonicum and Bradyrhizobium elkanii superclades. In symbiotic gene phylogenies, Genisteae bradyrhizobia are scattered among several distinct clades, comprising strains that originate from phylogenetically distant legumes. This indicates that the capacity for nodulation of Genisteae spp. has evolved independently in various symbiotic gene clades, and that it has not been a long-multi-step process. The exception is Bradyrhizobium Clade II, which unlike other clades comprises strains that are specialized in nodulation of Genisteae, but also Loteae spp. Presumably, Clade II represents an example of long-lasting co-evolution of bradyrhizobial symbionts with their legume hosts.

Inoculation of new rhizobial isolates improve nutrient uptake and growth of bean (Phaseolus vulgaris) and arugula (Eruca sativa).

BACKGROUND: In the current agricultural model, the massive use of chemical fertilizer causes environmental and economic losses. Inoculation of plant-growth-promoting (PGP) nitrogen-fixing bacteria is an alternative to the use of nitrogen, phosphorus and potassium fertilizers. In this study, rhizobia strains isolated from common bean (Phaseolus vulgaris) root nodules were evaluated in an effort to identify an efficient nitrogen-fixing rhizobia strain able to improve bean germination and growth. RESULTS: Common bean plants were collected from seven sites in southern Brazil, and 210 native rhizobia isolates were obtained. Evaluation of PGP traits showed that most of the rhizobia isolates were non-siderophore producers and weak indolic compounds producers. Under laboratory conditions, rhizobia isolates E15 (Rhizobium leguminosarum) and L5 (Rhizobium radiobacter) increase germination percentage, length, and dry weight of common bean and arugula (Eruca sativa) seedlings. Under greenhouse conditions, common bean plants inoculated with the rhizobia isolates VC28 and L15 (both Rhizobium fabae) presented the highest nodule number and shoot dry matter, while VC28 also presented the highest values of shoot nitrogen and potassium. Isolate L17 presented highly effective N fixation, even with reduced nodulation. CONCLUSION: These new rhizobia isolates are attractive PGP alternatives to chemical fertilizers. © 2015 Society of Chemical Industry.

Screening of plant growth promoting bacteria associated with barley plants (Hordeum vulgare L.) cultivated in South Brazil / Seleção de bactérias promotoras de crescimento vegetal associadas com plantas de cevada (Hordeum vulgareL.) cultivadas no Sul do Brasil

The occurrence of associations between bacteria and plant roots may be beneficial, neutral or detrimental. Plant growth promoting (PGP) bacteria form a heterogeneous group of beneficial microorganisms that can be found in the rhizosphere, the root surfaces or in association with host plant. The aim of this study was to isolate and characterize PGP bacteria associated to barley plants (Hordeum vulgare L.) aiming a future application as agricultural inoculant. One hundred and sixty bacterial strains were isolated from roots or rhizospheric soil of barley based on their growth in nitrogen-free selective media. They were evaluated for their ability to produce indolic compounds (ICs) and siderophores, and to solubilize tricalcium phosphate inin vitro assays. Most of them (74%) were able to synthesize ICs in the presence of the precursor L-tryptophan, while 57% of the isolates produced siderophores in Fe-limited liquid medium, and 17% were able to solubilize tricalcium phosphate. Thirty-two isolates possessing different PGP characteristics were identified by partial sequencing of their 16S rRNA gene. Strains belonging to Cedecea andMicrobacterium genera promoted the growth of barley plants in insoluble phosphate conditions, indicating that these bacteria could be used as bioinoculants contributing to decrease the amount of fertilizers applied in barley crops.

A ocorrência de associações entre bactérias e raízes de plantas pode ser benéfica, neutra ou prejudicial. Bactérias promotoras de crescimento vegetal (BPCV) formam um grupo heterogêneo de micro-organismos benéficos que pode ser encontrado na rizosfera, superfícies de raízes ou em associação com plantas hospedeiras. O objetivo deste estudo foi isolar e caracterizar bactérias promotoras do crescimento vegetal (PCV) associadas a plantas de cevada (Hordeum vulgare L.), visando uma futura aplicação como inoculante agrícola. Cento e sessenta linhagens bacterianas foram isoladas a partir de raízes ou solo rizosférico de cevada com base na sua multiplicação em meios seletivos sem nitrogênio. Todos os isolados foram avaliados quanto è sua capacidade de produzir compostos indólicos (CIs), sideróforos e solubilizar fosfato tricálcio, em ensaios in vitro. A maioria dos isolados (74%) foi capaz de sintetizar CIs na presença do precursor L-triptofano, enquanto que 57% produziram sideróforos em meio líquido com deficiência de Fe e 17% foram capazes de solubilizar fosfato tricálcio. Trinta e dois isolados que apresentaram diferentes características PCV foram identificados pelo sequenciamento parcial do gene 16S rRNA. Linhagens pertencentes aos gêneros Cedecea eMicrobacterium promoveram o crescimento de plantas de cevada em condições de fosfato insolúvel, indicando que estas bactérias podem ser utilizadas como inoculantes, contribuindo para a redução da quantidade de fertilizantes aplicados no cultivo da cevada.