## 4 Conclusions  
The research allowed to draw the following conclusions:  
* In an intermittently aerated reactor fed with high-TSS wastewater from meat industry higher N and P removal and a higher concentration of biomass was observed, but also a higher concentration of suspended solids in treated wastewater, smaller diameters of granules and deteriorated settling properties of biomass mainly as a result of the reduction of EPS content in biomass was noted;
* CCA analysis showed that microbial structure significantly changed in time; an increase in abundances of _Arenimonas_ sp., _Thuera_ sp., and _Dokdonella_ sp. characterized mature granules in period of stable treatment of meat-processing wastewater;
* Constant aeration in the cycle increases the number of nitrifying and denitfying genes in biomass (_amoA_ and _nosZ_ analysis) while intermittent aeration increases microbial diversity of granules;  
Figure 8: CCA of community of bacteria in the reactors. Environmental variables are represented by grey arrows (Cycle—Number of the reactor cycles, AEROBIC—Constant aeration in the reactor cycle, INT—intermittent aeration in the reactor cycle). The taxa are named by letters and numbers: _Aicobacterium_ sp. (S1), _Tetrasphara_ sp. (S2), _Pseudonocardi bubensis_ (S3), _Flexibacter_ sp. (S4), _Flexobacterium_ sp. (S5), _Terrimonas arctica_ (S6), _Caldilinea_ sp. (S7), _Roseiflexus_ sp. (S8), _Trichococcus_ sp. (S9), _Ignavibacterium_ sp. (S10), _Nitrospira_ sp. (S11), _Brevundimonas_ sp. (S12), _Hyphomicrobium_ sp. (S13), _Mesorhizobium_ sp. (S14), _Amaricoccus macauensis_ (S15), _Amaricoccus tumworthensis_ (S16), _Genmobacter_ sp. (S17), _Paracooccus_ _lutimaris_ (S18), _Paracooccus_ sp. (S19), _Paracooccus_ _yeyei_ (S20), _Rhodobacter_ sp. (S21), _Tetraoccus__ecchi_ (S22), _Maciwibrio_ sp. (S23), _Burkholderia_ sp. (S24), _Hydrogenophaga_ sp. (S25), _Ottowia_ sp. (S26), _Rhodoferax_ sp. (S27), _Dechloromonas_ sp. (S28), _Thuera_ sp. (S29), _Nannocystis_ sp. (S30), _Tolumonas_ sp. (S31), _Steroidobacter_ sp. (S32), _Pseudomonas_ sp. (S33), _Candidatus Competicbacter_ (S34), _Aquimonas_ sp. (S35), _Dokdonella ginsengiol_ (S36), _Arenimonas_ sp. (S37), _Lysobacter daejonenensis_ (S38).  
Constant aeration favored growth of microorganisms from the _Rhodanobacteraceae_, _Rhodobacteraceae_ and _Xanthomonadaceae_ families while in intermittently aerated reactors _Competibacteraceae_ family was more abundant (7.8%) and appeared.  
Conceptualization, P.J., and A.C.-K.; methodology, P.J. and A.C.-K.; software, P.J.; validation, P.J.; formal analysis, P.J., and A.C.-K.; investigation, P.J., and P.S.; resources, P.J.; data curation, P.J., and A.C.-K.; writing--Original draft preparation, P.J.; writing--Review and editing, A.C.-K. and P.S.; visualization, P.J.; supervision, A.C.-K.; project administration, P.J.; funding acquisition, A.C.-K. All authors have read and agreed to be published version of the manuscript.  
This research was funded by Minister of Science and Higher Education grant number 010/RID/2018/19 and Development Program at the University of Warmia and Mazury in Olsztyn grant number POWR.03.05. 00-00-Z310/17.  
Project financially supported by Minister of Science and Higher Education in the range of the program entitled \"Regional Initiative of Excellence\" for the years 2019-2022, Project No. 010/RID/2018/19, amount of funding 12,000,000 PLN and was written as a result of the author's internship in Aalborg University, Denmark, co-financed by the European Union under the European Social Fund (Operational Program Knowledge Education Development), carried out in the project Development Program at the University of Warmia and Mazury in Olsztyn (POWR.03.05. 00-00-Z310/17).  
The authors declare no conflict of interest.