Effects of the antimicrobial tylosin on the microbial community structure of an anaerobic sequencing batch reactor

Abstract

Morgenroth, Eberhard; and Raskin, Lutgarde, "Effects of the antimicrobial tylosin on the microbial community structure of an anaerobic sequencing batch reactor" (2010). Civil Engineering Faculty Publications. 37. http://digitalcommons.unl.edu/civilengfacpub/37 AbstractThe effects of the antimicrobial tylosin on a methanogenic microbial community were studied in a glucosefed laboratory-scale anaerobic sequencing batch reactor (ASBR) exposed to stepwise increases of tylosin (0, 1.67, and 167 mg/L). The microbial community structure was determined using quantitative fluorescence in situ hybridization (FISH) and phylogenetic analyses of bacterial 16S ribosomal RNA (rRNA) gene clone libraries of biomass samples. During the periods without tylosin addition and with an influent tylosin concentration of 1.67 mg/L, 16S rRNA gene sequences related to Syntrophobacter were detected and the relative abundance of Methanosaeta species was high. During the highest tylosin dose of 167 mg/L, 16S rRNA gene sequences related to Syntrophobacter species were not detected and the relative abundance of Methanosaeta decreased considerably. Throughout the experimental period, Propionibacteriaceae and high GC Gram-positive bacteria were present, based on 16S rRNA gene sequences and FISH analyses, respectively. The accumulation of propionate and subsequent reactor failure after long-term exposure to tylosin are attributed to the direct inhibition of propionate-oxidizing syntrophic bacteria closely related to Syntrophobacter and the indirect inhibition of Methanosaeta by high propionate concentrations and low pH.

Fate of tylosin a and its effect on anaerobic digestion using two tylosin inclusion methods

“…Our result is in agreement with that of Shimada et al [11], who reported that tylosin significantly decreased the relative abundance of Methanosaeta. However, Chelliapan et al [18] found that methanogens were well adapted to tylosin at levels of 100 and 800 mg=L in an up-flow anaerobic stage reactor (UASR).…”

“…Shimada et al [10] reported that addition of TYL to anaerobic sequential batch reactor reduced the utilization of acetate, propionate, and butyrate and in addition, inhibiting saturated fatty acid, beta-oxidizing syntrophic and gram-positive homoacetogenic bacteria. More recently, Shimada et al [11] studied the effects of TYL on methanogenic V C 2013 American Institute of Chemical Engineers community in a glucose-fed laboratory-scale anaerobic sequential batch reactor reported that at high dose of 167 mg TYL=L, syntrophobacter species were not detected but the relative abundance of methanosaeta decreased considerably.…”

Electro-Fenton pretreatment for the improvement of tylosin biodegradability

“…In batch tests, the specific biogas production was also completely inhibited in the presence of tylosin. According to these authors [10], this failure was the consequence of the direct inhibition of propionate-oxidizing syntrophic bacteria, closely related to Syntrophobacter and the indirect inhibition of Methanosaeta by high propionate concentration and low pH. This inhibition was also noticed by Stasinakis [11].…”

Towards Predictive Models of the Human Gut Microbiome

“…The microbial community can be very diverse both at the phylogenetic and functional levels 5 . While it is essential to maintain a proper microbial composition to assure efficient wastewater treatment 6,7 , the bioengineer has only a limited number of operational handles on the system. The operational variables include aeration, mixing and flow rate, which if not optimally chosen can lead to bioreactor failure 8 .…”