Microbiology in LSS Abstracts
Diagnostic Approach to
Biofilms in Biofilters Gerald Johnson DVM, DACVP, Viodiaq Consulting Ltd, LLC Watch Video (Login required) Full Abstract
Biofilms are complex microbial communities that adhere to wet surfaces and process aquatic borne nutrients cooperatively. Biofilms in the recirculating water systems for fishes provide an example in which the bacteria have been identified and studied by normal bacteriological methods. Designed for ammonia and nitrite reduction, the nitrification process in biofilters adds a living community to the aquarium that requires similar provision of oxygen, nutrition, and waste transport to that of the animals in that water. The biofilms in biofilters require appropriate diagnostic evaluation when they become incapacitated. |
The Role of the Aquarium Microbiome: Implications for Simulated Environments and Animal Health
Courtney Warren, Yale University Watch Video (Login required) Full Abstract
The microbial constituents of aquaria demonstrate tremendous variability, are strongly influenced by simple alterations to the tank environment, and have profound impacts on tank chemistry and the well-being of larger fauna. To date there remains little data on the role and distribution of many species of microbes within aquaria, and no systematic assessment of archaea has been attempted. In this study, samples from water, filter material, or substrates were collected from over 750 tank systems at aquariums around the United States of America. Parallel sampling of rRNA sequences via Illumina MiSeq next-generation sequencing, and laboratory extraction and analysis of glycerol dialkyl glycerol tetraethers (archaeal membrane lipids), were compared with concomitant aquarist records of tank environmental and water quality variables (including tank features such as lighting, ammonia concentration, organic density, etc.). Statistical correlations between taxonomic groups, lipids, and environmental conditions were assessed. Additional experiments addressing the role of additives (large animal food sources, etc.) were also conducted. This dataset has been used to evaluate the role of non-temperature influences on archaeal lipids, and has the potential to address important questions about what governs the distribution and constituents of the microbiome, and how they can be adjusted to optimize water quality. ACKNOWLEDGEMENTS Our thanks to the Yale Climate and Energy Institute and the Connecticut Space Grant Consortium for their financial support, and to America’s aquariums for their time and labor. |
Monitoring Bacteria Counts in Fish
Exhibits for Diver Safety Jill Arnold, National Aquarium Watch Video (Login required) Full Abstract
In the absence of aquarium-specific guidelines for water bacteria limits, most zoo/aquarium staff rely on state and local limits for recreational water use. The specific indicator organisms vary; some states monitor E. coli and/or Enterococcus species. Total/Fecal coliforms (Gram negative bacteria) and Streptococcus/Enterococcus (Gram positive) are measured by the standard multi-tube fermentation technique, reporting results as most probable number (MPN/100mL) or the membrane filtration method, reported as colony forming units (CFU/100 mL). EPA guidelines are based upon frequency of reported illness associated to recreational water exposure. Further studies are needed to determine if these guidelines are applicable to divers in public aquarium systems. |