Microbial metabolic diversity in soils fertigated with residual vinasses

Vinasse is produced in large quantities in the sugar-ethanol industry. We analyzed the utilization of vinasse as culture medium for inoculants of agricultural relevance, and then we evaluated the ecological impact of the residual vinasses. Trichoderma harzianum MT2, a native isolate obtained from tomato rhizosphere, was cultured in sugarcane vinasse in single and in sequential co-cultures with Pseudomonas capeferrum WCS358 and Rhizobium sp. N21.2. After growth, residual vinasses were utilized for fertigation of trays containing soils not fertigated before. Microbial metabolic diversity in fertigated soils was evaluated with Biolog EcoPlates on day 14. The Average Metabolic Response was determined in EcoPlates incubated for 72 h and evaluated through the Principal Component Analysis. Results show that fertigation with residual vinasses from single culture of T. harzianum MT2 and sequential co-culture with P. capeferrum WCS358 has a lower short-term impact on the microbial metabolic diversity, than residual vinasse from sequential co-culture with Rhizobium sp. N21.2.