Evaluation of bacterial diversity in a swine manure composting system contaminated with veterinary antibiotics (VAs).

Composting has become an alternative for the treatment of organic effluents, due to its low cost, easy handling, and a great capacity for treating swine manure. As it is a biological process, many microorganisms are involved during the composting process and act in the degradation of organic matter and nutrients and also have the ability to degrade contaminants and accelerate the transformations during composting. The objective of this work was to identify microorganisms present in the swine effluent composting system, under the contamination by most used veterinary drugs in Brazil. The composting took place for 150 days, there was an addition of 200 L of manure (these 25 L initially contaminated with 17 antibiotics) in 25 kg of eucalyptus wood shavings. The microorganisms were measured at times (0 until 150 days) and were identified by the V3-V4 regions of the 16S rRNA for Bacteria, by means of next-generation sequencing (NSG). The results show seven different bacterial phyla (Proteobacteria, Bacteroidetes, Firmicutes, Acidobacteria, Actinobacteria, Spirochaetota and Tenericutes) and 70 bacterial genera (more than 1% significance), of which the most significant ones were Pseudomonas, Sphingobacterium, Devosia, Brucella, Flavisolibacter, Sphingomonas and Nitratireductor. The genus Brucella was found during mesophilic and thermophilic phases, and this genus has not yet been reported an in article involving composting process. With the results obtained, the potential for adaptation of the bacterial community was observed, being under the influence of antibiotics for veterinary use.

Eucalyptus grandis Hill ex Maiden inoculated with Pisolithus microcarpus (UFSC-Pt116) in land subject to the sandy process in Southern Brazil.

Eucalypts is one of the main species used for commercial reforestation in the Rio Grande do Sul State, Brazil. This study aimed to evaluate the survival and early growth of eucalyptus trees in an area subject to sandy process after three years of growth. The Eucalyptus grandis seedlings were grown in a greenhouse, inoculated or not with the isolated ectomycorrhizal Pisolithus microcarpus (UFSC-Pt116), produced in peat or Entisol. After 120 days, the seedlings were transplanted to an area subject to the sandy process, in the São Francisco de Assis city, RS. The plants have been evaluated regarding survival, height, stem diameter, nitrogen, phosphorus and potassium levels and total phosphorus, inorganic phosphorus, organic phosphorus and wood production on different days after planting. The seedlings grown on the Entisol which was inoculated with the isolated UFSC-Pt116 presented higher survival rates, height, stem diameter, nitrogen concentration and wood production then non-inoculated seedlings. Inoculation with ectomycorrhizal fungi enhanced the production of E. grandis seedlings in survival rates, height, stem diameter.