Effects of Trichoderma harzianum and Bacillus subtilis on the root and soil microbiomes of the soybean plant INTACTA RR2 PRO™.

Introduction: Soybean is a significant export product for several countries, including the United States and Brazil. There are numerous varieties of soybean. Among them, a genetically modified type known as INTACTA RR2 PRO™ has been designed to demonstrate resistance to glyphosate and to produce toxins that are lethal to several species of caterpillars. Limited information is available on the use of Trichoderma harzianum and Bacillus subtilis to promote plant growth and their impact on the plant microbiome. Methods: This study aimed to evaluate the effects of these microorganisms on this soybean cultivar by analyzing parameters, such as root and shoot dry matter, nutritional status, and root and soil microbial diversity. Results: The results indicated that treatments with B. subtilis alone or in combination with T. harzianum as seed or seed and soil applications significantly enhanced plant height and biomass compared to the other treatments and the control. No significant differences in phosphorus and nitrogen concentrations were detected across treatments, although some treatments showed close correlations with these nutrients. Microbial inoculations slightly influenced the soil and root microbiomes, with significant beta diversity differences between soil and root environments, but had a limited overall impact on community composition. Discussion: The combined application of B. subtilis and T. harzianum particularly enhanced plant growth and promoted plant-associated microbial groups, such as Rhizobiaceae, optimizing plant-microbe interactions. Furthermore, the treatments resulted in a slight reduction in fungal richness and diversity.

Growth promotion and modulation of the soybean microbiome INTACTA RR PRO with the application of the fungi Trichoderma harzianum and Purpureocillum lilacinum.

Soybean is an economically important crop for animal and human nutrition. Currently, there is a lack of information on the effects of Trichoderma harzianum and Purpureocillum lilacinum on INTACTA RR PRO transgenic soybean plants. The present study evaluated the application of T. harzianum and P. lilacinum under field conditions. The results revealed a significant increase in soybean yield at 423 kg ha-1 in response to the application of P. lilacinum compared with the control treatment. In addition, the application of P. lilacinum promoted a significant increase in phosphorus levels in the plant leaves, and there were significant correlations between the increase in taxon abundance for the genus Erwinia and productivity and the average phosphorus and nitrogen content for the plant leaves, for the taxon Bacillus and nitrogen content and productivity, and for the taxon Sphingomonas and nitrogen content. The Bradyrhizobium taxon was identified in the P. lilacinum treatment as a taxon linking two different networks of taxa and is an important taxon in the microbiota. The results show that the application of the fungus P. lilacinum can increase the productivity of soybean INTACTA RR PRO and that this increase in productivity may be a function of the modulation of the microbiota composition of the plant leaves by the P. lilacinum effect.

Plant Growth-Promoting Rhizobacteria for Sustainable Agricultural Production.

Rhizosheric bacteria with several abilities related to plant growth and health have been denominated Plant Growth-Promoting Rhizobacteria (PGPR). PGPR promote plant growth through several modes of action, be it directly or indirectly. The benefits provided by these bacteria can include increased nutrient availability, phytohormone production, shoot and root development, protection against several phytopathogens, and reduced diseases. Additionally, PGPR can help plants to withstand abiotic stresses such as salinity and drought and produce enzymes that detoxify plants from heavy metals. PGPR have become an important strategy in sustainable agriculture due to the possibility of reducing synthetic fertilizers and pesticides, promoting plant growth and health, and enhancing soil quality. There are many studies related to PGPR in the literature. However, this review highlights the studies that used PGPR for sustainable production in a practical way, making it possible to reduce the use of fertilizers such as phosphorus and nitrogen and fungicides, and to improve nutrient uptake. This review addresses topics such as unconventional fertilizers, seed microbiome for rhizospheric colonization, rhizospheric microorganisms, nitrogen fixation for reducing chemical fertilizers, phosphorus solubilizing and mineralizing, and siderophore and phytohormone production for reducing the use of fungicides and pesticides for sustainable agriculture.

Effect of mycorrhizae on phosphate fertilization efficiency and maize growth under field conditions.

Phosphorus (P) is a plant macronutrient that is indispensable for maize (Zea mays L.) production. However, P is difficult to manage in weathered soils, and its fertilization practice has low efficiency because it becomes unavailable for absorption by plant roots. Symbiosis of plants with arbuscular mycorrhizal fungi increases plant growth and enhances P uptake from the soil that is not directly available to the roots. Thus, the objective of this study was to determine how inoculation with Rhizophagus intraradices and phosphate fertilization interacts and influences the development and productivity of second-crop maize. The experiment was conducted in Selvíria, Mato Grosso do Sul, Brazil, in 2019 and 2020, both in a Typic Haplorthox. A randomized block design in subdivided plots was used for the phosphate application during crop sowing (0, 25, 50, 75, and 100% concentrations of the recommended level), and the secondary treatments were the doses of mycorrhizal inoculant (0, 60, 120 and 180 g ha-1) applied to the seed using a dry powder inoculant containing 20,800 infectious propagules per gram of the arbuscular mycorrhizal fungus R. intraradices. Only in the first year of the experiment, inoculation and phosphate fertilization promoted benefits to the maize crop, indicating potential to increase yield.

Growth-promoting microorganisms in the development of orchid seedlings of Phalaenopsis, Cymbidium, and Dendrobium genera

The demand for sustainable agricultural production systems is increasing, and using growth-promoting microorganisms in plants has stood out because it decreases or even replaces chemical fertilizer use, reducing production costs. This study aimed to evaluate the response of some microorganisms applied to the seedlings of primary orchids cultivated in Brazil (Phalaenopsis sp. 'Taisuco Swan', Cymbidium atropurpureum, and Dendrobium secundum). The experimental design was completely randomized. There were seven treatments (absence of microorganisms ­ control, Trichoderma sp. in sodium alginate, Trichoderma sp. in clay, Trichoderma sp. in sodium alginate and clay, Trichoderma sp. in a liquid medium, Azospirillum brasilense + Bacillus subtilis in a liquid medium, and Bacillus pumilus in a liquid medium), four replications, and three plants per plot. The seedlings were grown in a greenhouse and evaluated 190 days after microorganism inoculation. The evaluation of morpho-physiological characteristics differed according to the particularities of each genus. The Bacillus pumilus and Azospirillum brasilense + Bacillus subtilis rhizobacteria in a liquid medium for Phalaenopsis sp. 'Taisuco Swan' and the Trichoderma sp. fungus in a liquid medium for Cymbidium atropurpureum increased seedling growth and development. Azospirillum brasilense + Bacillus subtilis in a liquid medium for the Dendrobium secundum orchid promoted more root biomass. Using beneficial microorganisms in orchid cultivation is promising, and seedling growth and development depend on their inoculation and the morpho-physiological characteristics of each plant.

Effect of the application of vermicompost and millicompost humic acids about the soybean microbiome under water restriction conditions.

Humic substances (HSs) are constituent fractions of organic matter and are highly complex and biologically active. These substances include humic acids (HA), fulvic acids (FA), and humin. HS are known to stimulate the root system and plant growth and to mitigate stress damage, including hydric stress. Humic acids have already been reported to increase microbial growth, affecting their beneficial effect on plants. However, there is scarce information on whether HA from vermicompost and millicompost, along with Bradyrhizobium, improves the tolerance of soybean to water restriction. This study aimed to evaluate the responses of soybean plants to the application of vermicompost HA (HA-V) and millicompost (HA-M) along with Bradyrhizobium sp. under water restriction. The experiment was carried out in a greenhouse, and the treatments received Bradyrhizobium sp. inoculation with or without the application of HA from vermicompost and millicompost with or without water restriction. The results showed that HA provided greater soybean growth and nodulation than the control. The application of HA-M stimulated an increase in the richness of bacterial species in roots compared to the other treatments. After the application of water stress, the difference between the treatments disappeared. Microbial taxa were differentially abundant in plants, with the fungal fraction most affected by HA application in stressed roots. HA-V appears to be more prominent in inducing taxa under stress conditions. Although the results showed slight differences between HA from vermicompost and millicompost regarding plant growth, both humic acids promoted an increase in plant development compared to the control.

Effect of Indole-3-Acetic Acid on Tomato Plant Growth.

Plant growth-promoting bacteria have several abilities to promote plant growth and development. One of these skills is the synthesis of indole-3-acetic acid (IAA), which mainly promotes root and shoot development. The bacteria Bacillus subtilis and Azospirillum brasilense have been widely used in agriculture with this function. However, little is known about whether the joint inoculation of these bacteria can reduce plant development by the excess of IAA produced as a result of the joint inoculation. The objective of the present study was to verify the effect of IAA on the inoculation of B. subtilis and A. brasilense in three tomato genotypes. The Micro-Tom genotype without mutation for IAA synthesis, Entire, has high sensitivity to IAA, and the diageotropic genotype (dgt) has low sensitivity to IAA. The results show that the plant parameter most sensitive to microbial inoculation is the number of roots. No treatment increased the shoot dry mass parameters for the Micro-Tom genotype and dgt, root dry mass for the Micro-Tom genotype, plant height for the Micro-Tom and Entire genotypes, root area and root volume for the genotype dgt. The Azm treatment reduced plant height compared to the control in the dgt, the BS + Azw and BS + Azm treatments in the Micro-Tom genotype and the Azw + Azm treatment in the dgt genotype reduced the plant diameter compared to the control. BS and BS + Azw reduced the number of roots in the Micro-Tom. The results strongly support that the mixture of B. subtilis and A. brasilense can reduce some parameters of plant development; however, this effect is possibly an interference in the mode of action of growth promotion of each isolate and is not related to an excess of IAA produced by the bacteria.

Effects of Chemical Fertilization and Microbial Inoculum on Bacillus subtilis Colonization in Soybean and Maize Plants.

Plant growth-promoting endophytic microorganisms in agriculture have been expanding in Brazil and are an excellent strategy to face the challenges of current agriculture, such as reducing production costs with fewer environmental impacts, without detriment to productivity. However, little is known about the factors that can affect the colonization of endophytic such as inoculant concentration and mineral fertilization. The present study aimed to evaluate the influence of these factors on soybean and maize crops and found that for soybean crops, the highest Bacillus subtilis concentration of 1 × 104 and 1 × 1010 CFU ml-1 promoted the highest number of recovered bacteria, when there was no mineral fertilization. However, mineral fertilization limited the number of recovered bacteria, suggesting that mineral fertilization interferes with endophytic colonization. For maize crops, the highest number of recovered bacteria occurred from the concentration of 1 × 106 CFU ml-1, not differing from the highest concentrations. A mineral fertilization dose of 25% promoted the greatest B. subtilis recovery compared to the other treatments. Regarding plant development, the highest microbial inoculum concentrations did not necessarily promote greater positive growth promotion effects compared to the concentration of 1 × 104 CFU ml-1 for both crops. The results also suggest that the higher number of endophytic bacteria recovered in the plant does not necessarily affect plant growth in the same proportion. For soybean plants, there is a strong tendency that with the increase in the B. subtilis inoculant concentration, the need for mineral fertilization doses to achieve the same plant development is consequently increased, and inoculations with 1 × 105 and 1 × 106 CFU ml-1 with fertilization doses between 44% and 62% are the ideal combinations for greater plant development. In maize plants, the best growth promotion response (height) was obtained using inoculation concentration of 1 × 102 and 1 × 1010 CFU ml-1, increasing according to the increase in fertilization doses. The findings suggest, for soybean crop, that these high inoculum concentrations required more photosynthetic metabolites from the plants and more nutrients from the soil. Thus, the need for mineral fertilization for plant growth must be increased.

Inoculum Concentration and Mineral Fertilization: Effects on the Endophytic Microbiome of Soybean.

Soybean crops are of great economic importance worldwide and in Brazil. This crop is a commodity that provides large amounts of financial resources to the country. Soybean productivity is influenced by several biotic and abiotic factors, and most of these factors cannot be controlled by agricultural practices. Due to the soybean cultivars used and their required yields, the soybean crop, similar to other agriculturally important crops, requires large amounts of mineral fertilizers. There are several microorganisms that colonize soybean plant roots without causing symptoms or damage. These microorganisms that colonize plant tissues are called endophytes and can often promote plant growth and development. Little is known about the factors that influence endophyticism. The aim of the present study was to evaluate whether Bacillus subtilis inoculant concentrations and levels of mineral fertilization recommended for the crop have any influence on the endophytic microbiome of soybean plant roots. The results show that B. subtilis inoculations did not affect the endophytic community of the roots; however, the evaluation of the microbial community structure according to the alpha diversity metrics observed richness, Chao1 index, Shannon index and Simpson index showed that microbial diversity of endophytes was higher at fertilization levels of 50 and 100%, with a significant difference (p < 0.05) between 0 and 50% and 0 and 100% fertilization.

Chemical seed treatment and mycorrhizal inoculation provide better development and nutrition of common bean plants.

BACKGROUND: Chemical seed treatment is an established practice in agriculture to protect crops from soil-borne pathogens and pests. Arbuscular mycorrhizal fungi (AMF) benefit plants by extending soil exploration as well as water and nutrient uptake. The objective of this work was to analyze the effects of combinations of seed treatments with doses of inoculant containing Rhizoglomus intraradices on vegetative development, root colonization and nutrition of Phaseolus vulgaris plants and soil microbiota. RESULTS: Seed treatment benefited the vegetative development and nutrition of beans, with the treatments metalaxyl + fludioxonil + tiabendazole and pyraclostrobin + thiophanate methyl + fipronil standing out regarding the contents of nitrogen (N), phosphorus (P), iron (Fe) and zinc (Zn) of the aerial parts. Mycorrhizal inoculation linearly increased dehydrogenase activity, root biomass and total plant biomass, with increments reaching 27%. There was an interaction between seed treatment and inoculation dose for aboveground biomass and the contents of potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), manganese (Mn) and root colonization, with expressive results for the combination of the two highest doses of inoculant with metalaxyl + fludioxonil + tiabendazole or pyraclostrobin + methylthiophanate + fipronil in the seeds. CONCLUSION: Chemical seed treatment and mycorrhizal inoculation benefited bean plants and their nutritional status. The best combinations for the bean crop were metalaxyl + fludioxonil + tiabendazole with 41.4 mg of the inoculant per 100 seeds and pyraclostrobin + thiophanate methyl + fipronil with 62.1 mg of the inoculant per 100 seeds. © 2022 Society of Chemical Industry.

Endophytic fungi: a tool for plant growth promotion and sustainable agriculture.

Endophytic fungi are found in most, if not all, plant species on the planet. They colonise inner plant tissues without causing symptoms of disease, thus providing benefits to the host plant while also benefiting from this interaction. The global concern for the development of more sustainable agriculture has increased in recent years, and research has been performed to decipher ecology and explore the potential of endophytic interactions in plant growth. To date, many studies point to the positive aspects of endophytic colonisation, and in this review, such research is summarised based on the direct (acquisition of nutrients and phytohormone production) and indirect (induced resistance, production of antibiotics and secondary metabolites, production of siderophores and protection for abiotic and biotic stresses) benefits of endophytic colonisation. An in-depth discussion of the mechanisms is also presented.

Effect of Aspergillus and Bacillus Concentration on Cotton Growth Promotion.

There are no studies in literature on the effect of inoculant concentrations on plant growth promotion. Therefore, in the present study, two experiments were carried out, one under pot conditions and the other in the field with cotton crop, in order to verify the effect of Aspergillus and Bacillus concentrations on the biometric and nutritional parameters of plant and soil, in addition to yield. The pot experiment evaluated the effect of different concentrations, ranging from 1 × 104 to 1 × 1010 colony-forming units per milliliter (CFU mL-1) of microorganisms Bacillus velezensis (Bv188), Bacillus subtilis (Bs248), B. subtilis (Bs290), Aspergillus brasiliensis (F111), Aspergillus sydowii (F112), and Aspergillus sp. versicolor section (F113) on parameters plant growth promotion and physicochemical and microbiological of characteristics soil. Results indicated that the different parameters analyzed are influenced by the isolate and microbial concentrations in a different way and allowed the selection of four microorganisms (Bs248, Bv188, F112, and F113) and two concentrations (1 × 104 and 1 × 1010 CFU mL-1), which were evaluated in the field to determine their effect on yield. The results show that, regardless of isolate, inoculant concentrations promoted the same fiber and seed cotton yield. These results suggest that lower inoculant concentrations may be able to increase cotton yield, eliminating the need to use concentrated inoculants with high production cost.

Humic Substances in Combination With Plant Growth-Promoting Bacteria as an Alternative for Sustainable Agriculture.

Plant growth-promoting bacteria (PGPB) and humic substances (HSs) are promising options for reducing the use of pesticides and mineral fertilizers. Although many studies have shown the effects of PGPB and HSs separately, little information is available on plant responses to the combined application of these biostimulants despite the great potential for the simultaneous action of these biological inputs. Thus, the objective of this review is to present an overview of scientific studies that addressed the application of PGPB and HSs to different crops. First, we discuss the effect of these biostimulants on biological nitrogen fixation, the various effects of the inoculation of beneficial bacteria combined with the application of HSs on promoting the growth of nonleguminous plants and how this combination can increase bacterial colonization of plant hosts. We also address the effect of PGPB and HSs on plant responses to abiotic stresses, in addition to discussing the role of HSs in protecting plants against pathogens. There is a lack of studies that address the role of PGPB + HSs in biocontrol. Understanding the factors involved in the promotion of plant growth through the application of PGPB and HSs can assist in the development of efficient biostimulants for agricultural management. This approach has the potential to accelerate the transition from conventional cultivation to sustainable agrosystems.

Effect of Chemical Fertilization on the Impacts of Plant Growth-Promoting Rhizobacteria in Maize Crops.

The use of chemical fertilizers strongly promotes productivity in agricultural crops; therefore, large amounts of chemical fertilizers have been used. The use of plant growth-promoting bacteria may be a strategy to reduce the use of chemical fertilizers; however, little is known about the effect of chemical fertilization on the performance of these bacteria through plant-microbe interactions. The present study aimed to verify the performance of Bacillus subtilis, Azospirillum brasilense, B. pumilus, B. amyloliquefaciens, Herbaspirillum seropedicae, Gluconacetobacter diazotrophicus, and the mixtures A. brasilense + B. subtilis, B. pumilus + B. amyloliquefaciens, and H. seropedicae + G. diazotrophicus on parameters such as nitrogen and phosphorus extraction from soil, the concentrations of these nutrients in maize plants, and plant growth in both fertilized and unfertilized soil. The results showed that H. seropedica increased the nitrogen content by 6.6 g kg-1 in leaves and 2.2 g kg-1 in the root when comparing the unfertilized with the fertilized condition. G. diazotrophicus increased the nitrogen content by 3.7 g kg-1 in leaves and 2.4 g kg-1 in the root. B. pumilus increased the phosphorous content by 1.7 g kg-1 in leaves, and B. amyloliquefaciens increased the phosphorous content by 0.61 g kg-1. The present study showed that even though the bacteria presented good performance related to plant growth under fertilized conditions, H. seropedicae, G. diazotrophicus, B. pumilus, and B. amyloliquefaciens could be used in the maize crop with a reduced chemical fertilization dose.

Purpureocillium lilacinum and Metarhizium marquandii as plant growth-promoting fungi.

BACKGROUND: Especially on commodities crops like soybean, maize, cotton, coffee and others, high yields are reached mainly by the intensive use of pesticides and fertilizers. The biological management of crops is a relatively recent concept, and its application has increased expectations about a more sustainable agriculture. The use of fungi as plant bioinoculants has proven to be a useful alternative in this process, and research is deepening on genera and species with some already known potential. In this context, the present study focused on the analysis of the plant growth promotion potential of Purpureocillium lilacinum, Purpureocillium lavendulum and Metarhizium marquandii aiming its use as bioinoculants in maize, bean and soybean. METHODS: Purpureocillium spp. and M. marquandii strains were isolated from soil samples. They were screened for their ability to solubilize phosphorus (P) and produce indoleacetic acid (IAA) and the most promising strains were tested at greenhouse in maize, bean and soybean plants. Growth promotion parameters including plant height, dry mass and contents of P and nitrogen (N) in the plants and in the rhizospheric soil were assessed. RESULTS: Thirty strains were recovered and characterized as Purpureocillium lilacinum (25), Purpureocillium lavendulum (4) and Metarhizium marquandii (1). From the trial for P solubilization and IAA production, seven strains were selected and inoculated in maize, bean and soybean plants. These strains were able to modify in a different way the evaluated parameters involving plant growth in each crop, and some strains distinctly increased the availability of P and N, for the last, an uncommon occurrence involving these fungi. Moreover, the expected changes identified at the in vitro analysis were not necessarily found in planta. In addition, this study is the first to evaluate the effect of the isolated inoculation of these fungi on the growth promotion of maize, bean and soybean plants.

Efficacy of alginate- and clay-encapsulated microorganisms on the growth of Araçá-Boi seedlings (Eugenia stipitata)

The present work aimed to evaluate the effects of encapsulated microorganisms on seedlings of Eugenia stipitata, popularly known as araçá-boi, to evaluate the interaction between the inoculum and encapsulating agents such as clay and alginate. The experiment was carried out in a completely randomized design using a 3×2 factorial scheme. The treatments were control, inoculum, clay without microbial inoculum, clay with microbial inoculum, alginate without microbial inoculum, and alginate with microbial inoculum. The seedlings were grown under nursery conditions over a period of 3 months. No treatment increased the height, stem diameter, shoot dry matter or root dry matter of the araçá-boi seedlings. The use of alginate increased the ammonium content compared to the clay and control treatments. Alginate and clay increased the nitrate content in relation to the control. Alginate increased the total number of bacteria in relation to the clay and control treatments. The application of inoculum combined with alginate increased the nitrate content only in relation to the clay and control treatments. Although the application of inoculum promoted an increase in the nitrate content compared to the uninoculated treatments, there was no effect for the other parameters analyzed. The results suggest that clay and alginate encapsulating agents with the presence or absence of microorganisms may improve some soil parameters.

Multivariate analysis and modeling of soil quality indicators in long-term management systems.

Soil management systems, as well as the long-term application of nitrogen fertilization, might promote changes in soil quality (SQ). The knowledge of how agronomic practices influence SQ is the main factor in the development of most sustainable management systems. Thus, the aim of this study was to evaluate the influence of long-term management systems on SQ through the analysis of 10 soil quality indicators (SQIs), to select the most sensitive SQIs through principal components analysis (PCA) and to propose a mathematical model that could estimate the activities of enzymes based on SQI values with simple and low-cost procedures in relation to enzyme measurement. Soil samples were collected from three experiments in which soils were used for this purpose over more than two decades. The first experiment consisted of winter fallow and maize seeding as a summer crop in a conventional tillage system (CT) that received nitrogen fertilization at doses of 0, 90 and 180 kg ha-1. The second and third experiments consisted of no-tillage (NT) using maize/maize (NT M/M) and legume/maize (NT L/M) crop rotation, respectively, both using nitrogen fertilization at the same doses as in the first experiment. The no-tillage system with legume/maize crop rotation favored the development of microorganisms and improved the soil quality. The effects of nitrogen fertilization on SQIs varied according to the management system. The microbial respiration (MR), the metabolic quotient (q CO2), total organic carbon (TOC), nitrogen microbial biomass (NMC), urease enzyme activity (UEA), dehydrogenase activity (DA) and amylase activity (AA) were the most efficient SQIs. The adjusted mathematical models presented a good predictive capacity to estimate the urease activity in CT and NT M/M and the amylase activity in the CT system.

Sugarcane growth and nutrition levels are differentially affected by the application of PGPR and cane waste.

Mineral and organic fertilization can be optimized by using rhizobacteria which increases dry matter, yield, and nutrients in the soil and plant, among the other biological inputs. However, the discovery of single microbes or a consortium that can benefit plants has been a challenge. In this context, this study aimed to evaluate the effects of Bacillus subtilis and Bacillus pumilus combined with mineral fertilization and sugar and alcohol industry by-products in presprouted and the initial growth phase of sugar cane seedlings. The study was carried out in two phases. Phase 1 included presprouted seedlings with T1 =  untreated control, T2 =  B. subtilis, T3 =  B. pumilus, and T4 =  B. subtilis + B. pumilus treatments. Phase 2 included the same treatments with four types of fertilization: F1 =  mineral fertilization, F2 =  mineral fertilization + vinasse, F3 =  mineral fertilization + filter cake, and F4 =  mineral fertilization + filter cake compost. Of the phase 1 treatments, T2 (B. subtilis) was the best promoter of root growth and the total dry matter compared to the control with an increase of 23.0% compared to the control. In phase 2, B. pumilus application, increased the total dry matter by 13%, the number of tillers by 37%, and the diameter of the tillers by 48% when combined with mineral fertilization. The combined application of B. subtilis and B. pumilus increased the phosphorus content by 13% in soil treated with mineral fertilization and filter cake compost. The results of the this study strongly suggest that the use of B. subtilis and B. pumilus together with these by-products can improve soil fertility parameters and decrease adverse effects associated with vinasse fertilization, in addition to providing shoot and root growth and providing collective synergy for a high yield of sugarcane production with environmental benefits.

Sorologia e suscetibilidade antimicrobiana em isolados de Escherichia coli de pesque-pagues / Serology and patterns of antimicrobial susceptibility in Escherichia coli isolates from pay-to-fish ponds

Pesquisou-se a ocorrência de Escherichia coli (EPEC, EIEC, O157) em água e peixe (pele, trato digestivo e músculo) de pesque-pagues da microbacia do Córrego Rico, Jaboticabal (SP). Foram isoladas 115 cepas de E. coli, entre as quais 49 (43%) foram sorogrupadas como EPEC. Os sorogrupos mais frequentes foram O125, O126 e O158. Dentre as amostras testadas, 60 (52%) apresentaram resistência simultânea a dois antimicrobianos. A análise de correspondência foi realizada com o intuito de verificar as possíveis correspondências envolvendo o local de isolamento, sorogrupos e multirresistência e, com isso, pôde-se observar que o músculo apresentou menor correspondência com os demais fatores analisados. Porém, o isolamento de sorogrupos EPEC neste estudo representa risco à saúde dos consumidores.(AU)

The occurrence of Escherichia coli (EPEC, EIEC and O157) in water and fish (skin, gut and muscle) in pay-to-fish ponds of the micro bay of Córrego Rico, in Jaboticabal (SP), was assessed. One hundred and fifteen strains of E. coli were isolated, and 49 (43%) were serogrouped as EPEC. The most common serogroups were O125, O126 and O158. Among the tested samples, 60 (52%) showed simultaneous resistance to two antimicrobials. A correspondence analysis was performed to assess possible correlations involving the site of isolation, serogroups and multi-resistance. The results of this analysis showed that the muscle was less correlated with the the other factors. However, the isolation of EPEC serogroups in this study demonstrates a risk to public health.(AU)

Detection of Shiga toxigenic (STEC) and enteropathogenic (EPEC) Escherichia coli in dairy buffalo.

Enteropathogenic (EPEC) and Shiga toxigenic (STEC) Escherichia coli are among the bacteria most associated with enteric diseases in man. The aims of this study were to determine the prevalence of STEC and EPEC in dairy buffalo and then characterize these isolates genetically. To determine the prevalence of these bacteria, samples were collected from the feces and milk of buffaloes. In total, 256 samples were collected in 3 samplings, of which 76 samples tested positive for either the stx1, stx2 or eae genes or a combination thereof. From the positive samples, 22 STEC and 11 atypical EPEC (aEPEC) isolates were obtained. The isolates showed 23 different genetic profiles. No profile was very frequent in STEC isolates. On the other hand, the profile eae+, ehxA+, iha+, efa1+, toxB+, paa+, lpfAO113+ was found in 45% of the aEPEC isolates. In addition to stx1, stx2 and eae, the genes ehxA, efa1, saa, lpfAO113, lpfAO157/OI-141, lpfAO157/OI-154, toxB and iha were present in the isolates. Serogroup O26 was found in 26% of the aEPEC. Other serogroups detected include O87, O145, O176 and O179. The isolates were sensitive to almost all drugs tested and some isolates shared the same fingerprint patterns by enterobacterial repetitive intergenic consensus sequence-PCR (ERIC-PCR). The results suggest that, besides major reservoirs of STEC, buffaloes are also aEPEC reservoirs. The detection of a serogroup (O26), and putative virulence genes (efa1 ehxA, paa and lpfAO113), previously associated with aEPEC isolated from humans with diarrhea in aEPEC from buffaloes should be studied further.