Assessing the Temporal Succession of Microfouling Communities on Copper-Nickel and Titanium Metals Deployed in Marine Environments
Abstract
Marine biofouling is a complex multistep process involving initial surface conditioning and microfouling (e.g., microbial biofilms) on submerged surfaces, followed by macrofouling (e.g., barnacles attachment), and is a major concern for maritime industries globally. Microbial biofilm formation was reported to cause microbiologically influenced corrosion (MIC) in metals like Copper-Nickel (CuNi). Despite extensive research efforts on MIC, its principle and mechanism that leads to increased corrosion are not completely understood. For instance, although microbial biofilm formation on submerged surfaces potentially involves microflora related to bacteria, archaea, and eukaryota, most of the studies are primarily focused on exploring the bacterial-mediated biofilm formation. Studies focusing on the three forms of microflora forming biofilms on submerged surfaces and understanding their complex interactions are very rare, particularly none with regards to current naval relevant material of interest such as CuNi. Furthermore, these microbial biofilms are comprised of both live and dead. Therefore, a comprehensive understanding of the microflora composition that is active/livein biofilms is necessary to fully know about their MIC capabilities. Additionally, in order to form primary succession (early colonization) on antimicrobial metals like CuNi, the initial biofilm-forming microflora should possess either copper (Cu) resistance/tolerance mechanism or both MIC and Cu resistance capabilities. Thus, identifying initial active microflora involved in the expression of functional genes responsible for Cu tolerance/resistance and biofilm formation (such as diguanylate cyclases genes) at the early succession stages could provide novel insights regarding fundamental principles and mechanisms of MIC. In this regard, the current study aims to characterize the temporal succession of the total and active microfouling communities on CuNi and Titanium (control) metal coupons deployed in field and different microcosm environments such as flow and stagnant conditions over long durations and explore their inter-taxa association and species co-occurrence patterns. Additionally, the functional genes responsible for Cu resistance and biofilm formation by active microflora in the biofilms of metal coupons will be investigated. The specific research objectives of the proposed research are i) Assess the impact of abiotic conditions (physicochemical properties) of seawater collected from two different locations (Key West and Melbourne, FL) to drive corrosion on CuNi and Ti metals under laboratory conditions, ii) Evaluate the impact of flow and stagnation conditions of seawater (collected from Key West and Melbourne, FL) on the temporal succession and microbial diversity of total and active microflora, together with functional genes involved in biofilm formation and Cu resistance, and its effects on oxide composition and corrosion under laboratory conditions, and iii) Explore the real-time impact of dynamic environmental conditions (field studies at FIT, FL) on the temporal succession and microbial diversity of total and active microflora, together with functional genes for Cu resistance and biofilm formation, and oxide composition and corrosion to recognize any discrepancies with laboratory experiments. The collective results will provide critically needed insights into the MIC mechanisms such as initial members (early colonizers as biomarkers) and important functional genes involved in early succession and throughout biofilm maintenance as well as the similarities and dissimilarities of laboratory microcosm studies with the dynamic field environment studies.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 12, 2023
- Source ID
- N000142312325
Entities
People
- Vikram Kapoor
Organizations
- Office of Naval Research
- United States Navy
- University of Texas at San Antonio