No abstract

In recent years, development of sustainable and ecological food production is of worldwide interest. It seems clear that this phenomenon is causing a changes in the aquaculture focused research, with the development of new integration systems. However, it is still necessary to understand different aspects involved in new integrated systems, including co-culture systems such as shrimp and seaweed. This study evaluated the effect of green seaweed as food source on white shrimp Penaeus vannamei intestinal bacterial communities. Survival, growth performance and feed utilization were evaluated after a 4-week experimental trial with shrimp P. vannamei fed with only pellet (P), only U. clathrata (UC), clathrata+pellet (UCP), Ulva only U. lactuca (UL) and Ulva lactuca+pellet (ULP). No significant differences observed between U. lactuca+pellet (ULP) and Ulva clathrata+pellet (UCP) compared to the control (P). Analysis of intestinal bacterial communities revealed significant differences on community variation in ULP, UL and UC in respect to the control (P) (p<0.05). We found that Proteobacteria is the major phylum in all treatments, followed by Bacteroidetes for UC, UCP and UL and Actinobacteria for P and ULP treatments. Relative abundance of Vibrio was higher in the control (P), showing a significant decrease in UC treatment. The results of this study provide information about changes in the intestinal bacterial community of shrimp by incorporatin the green seaweeds U. clatratha and U. lactuca as natural feed. Our findings provide a better understanding of integrated aquaculture systems, specifically those utilizing seaweed as a natural feed source.

No abstract

Poultry litter is a valuable nutrient resource for agricultural production but is also a potential source for introducing antibiotic resistance genes (ARGs) and litter‐associated bacteria (LAB) to the environment. Prairie strips have been demonstrated as an effective conservation practice to improve environmental quality in agroecosystems. This research aims to assess prairie strips’ potential for reducing the transport of LAB and ARGs in runoff after litter application. Plot‐scale rainfall simulations were performed using a replicated block design, with soil and surface runoff samples taken during the rainfall event. Microbial taxa and ARGs were characterized in the litter, soil, and water samples. In plots with litter application, LAB and ARGs were mainly detected in runoff, with very low detection in soils. Detection of ARGs in runoff, irrespective of strip installations, is consistent with previous observations of litter as a source of antimicrobial resistance (AMR) risks. The effectiveness of prairie strips to remove LAB and ARGs varied. In two of the three prairie strip plots, fewer AMR indicators were detected relative to control plots, suggesting that the prairie strips can potentially reduce these risks. In one plot, which was also associated with increased flow rate, we observed increased AMR indicators despite the installation of a prairie strip. Our observations highlight the need to prioritize understanding of soil properties even within the same site. Although we show that prairie strips can potentially reduce AMR risks, further research is needed to better understand the influence of rainfall timing, soil, and litter characteristics.