Role of bacterivorous organisms on fungal-based systems for natural tannin degradation

Heliyon

Gualtiero Mori¹  Alexey Potekhin²  Franco Verni³  Letizia Modeo⁴  Giulio Petroni⁴  Alessandra Bardi⁵  Giulio Munz⁶  Cristiana Sigona⁷ 

[1] CIME, Centro Interdipartimentale di Microscopia Elettronica, Univerisità di Pisa, via A. Volta 4, 56126, Pisa, Italy;CISUP, Centro per l'Integrazione della Strumentazione dell'Università di Pisa, Lungarno Pacinotti 43, Pisa, Italy;CER2CO (Centro Ricerca Reflui Conciari), Via Arginale Ovest 81, 56028, San Romano-San Miniato, Pisa, Italy;Department of Biology, University of Pisa, Via Alessandro Volta 4, 56126, Pisa, Italy;Department of Civil and Environmental Engineering, University of Florence, Via Santa Marta 3, 50139, Florence, Italy;Department of Microbiology, Faculty of Biology, Saint-Petersburg State University, 7/9 University Embankment, 199034, Saint Petersburg, Russia;Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain;

关键词: Biotechnology;    Microbiology;    Microorganism;    Mycology;    Protozoa;    Bacterivorous organisms;   

DOI  :  

来源: DOAJ

【 摘 要 】

Tannery wastewater presents high concentrations of organic load and pollutant recalcitrant molecules (e.g. tannins), which reduce the efficiency of biological treatment processes. Recent studies showed that several fungal species and strains are effective in the degradation of tannins. However, high bacterial load can negatively affect fungal growth, reducing system stability and degradation performances.The aim of the present study was to evaluate the effects of the introduction of bacterivorous grazers (ciliates and/or rotifers) in batch scale experiments using fungi to remove Tara tannin, i.e. to check the potential synergistic effect between fungi and bacterivorous grazers in the degradation of recalcitrant compounds. In this context, the ciliated grazers Paramecium calkinsi, Tetrahymena sp., Pseudovorticella sp., and the rotifer Lecane inermis, preliminary selected according to their ability to grow in a solution prepared with Tara tannin, were separately tested. Activated sludge, including a complex mixture of native grazers, was used as experimental control. The following parameters were monitored: bacterial load, number of grazers/mL and Soluble Chemical Oxygen Demand (SCOD). Colony Forming Unit (CFU)/grazers ratio was also calculated. Particular attention was paid to: i) bacterial load reduction and ii) enhancement of recalcitrant compounds degradation, and we observed that in all experimental conditions where grazers occurred bacterial load was significantly reduced and the system achieved a higher SCOD removal in a shorter time. Our findings provide useful insights for the stabilization of fungal-based systems in non-sterile conditions.

【 授权许可】

Unknown