Anais do Congresso Paranaense de Microbiologia
Anais do III Congresso Paranaense de Microbiologia

Biofertilizers, when poorly managed, alter the physical, chemical and mainly biological characteristics of the soil. This residue has been considered one capable of insert bacteria that will be incorporated into the natural biota of soil and can directly affect the microorganisms of agricultural interest. The genus Azospirillum is a very important one because they are bacteria that promote plant growth (BPCPs). They are organisms of free life, of wide distribution in the soil and of great interest for the maize crop. The objective of this work was to evaluate the effect of biofertilizer with or without probiotic on the density and diversity of native Azospirillum sp. isolated from a latosol in the forage turnip (Raphanus sativus L.). The experiment was conducted in the city of Palotina – PR during the autumn and winter of 2016. The experimental design was carried out in randomized blocks with three treatments and four replications, being, T1, application of the biofertilizer with probiotic; T2 biofertilizer without probiotic and T3 as negative control, without biofertilizer or probiotic. The density evaluation was done by counting colony-forming units (CFUs), from two samples collected (C1 e C2) during the cycle of forage turnip, used as plant-model. The diversity was carried by the morphological classification of the colonies formed, the culture was made in a selective medium for the known group, the NFB medium. The results were analyzed by the Tukey test at 5% probability and the clusters were formed through the UPGMA algorithm using the Program R. Bacteria diversity differences wasn’t statistically significant between the CFUs obtained from the selective medium for the different treatments. This result indicates that the application of the organic compound didn’t alter and/or impair the density of the community of Azospirillum sp. in soil (T1: 137,50; T2: 69,94; T3: 65,88). For morphological classification, it was also possible to identify only two distinct morphological groups throughout the experiment. Revealing the common ancestry between the individuals and the conservation of the group even under the influence of the biofertilizer. It is concluded that the biofertilizers don’t modify the Azospirillum sp. community and can be applied to the soil without causing a deficit to the producer, but more studies are necessary to define the effect of the product in the long term.