Title : Na walewale kahakai: Community diversity of marine biofilms grown in orthogonal orientations across an urbanized gradient
Abstract:
Biofilms are complex colonies of bacteria and other microorganisms that have colonized a surface, and are abundant in marine environments. These communities are generally defined by the extracellular substances they produce on the surface they have colonized (Shikuma et al). Just as the surface biofilm adhere to can vary greatly from inanimate object to living surfaces, the community of microbes that make up the biofilms can also vary. Biofilms develop rather easily in aqueous environments but can also grow outside aquatic environments in humid areas. Microbes play critical roles in marine ecosystems and are major contributors to intertidal community health (Decho). Because biofilms form extracellular polymeric secretions (EPS) allowing stabilization to surfaces and buffer their cells to resist otherwise common physical stressors, like changes in salinity and temperature that can be detrimental to other microbes. Recent studies have shown that pathogenic bacteria can thrive in biofilms across various water systems (Hu et al. 2003 and Shikuma et al). Closer examination of EPS has shown to enhance the survival and propagation of pathogens entering from freshwater sources (Decho). This unique property makes biofilms a new and emerging area of interest in understanding the health of nearshore communities and assessing water quality. Biofilm can develop under different spatial conditions and can adhere to most natural and artificial surfaces in both the Horizontal and Vertical orientation. Most studies focus on surface types rather than orientation when collecting wild marine biofilms; this could potentially and inadvertently exclude certain communities. This paper aims to investigate microbial diversity of multi-species biofilms grown under natural conditions along a nutrient gradient. We used statistical analysis to gain insight into 1) whether there is a significant variation in the community diversity amongst communities grown in varying orthogonal orientations and 2) Is there significant community variation amongst biofilm grown horizontally vs. vertically across a human use gradient.
