Evaluation of oil and gas platforms on the Louisiana continental shelf for organisms with biotechnology potential

Abstract

From Project Overview: “The first concern of this study, therefore, was, to identify the organisms that make up the biofouling or epifaunal communities on platforms. The second objective of this study was to preliminarily determine the potential of any of these organisms to be source of pharmaceuticals or any other commercially important products. Finally, the concentration and distribution of potentially important species on the structures and the variability of that distribution with platform location, and the density of organisms at various depths on the platform and seasonal variation of occurrence was considered.

Some of the groups of organisms common to the Gulf of Mexico platforms that show potential for biotechnology applications were included in this study. These include bacteria, particularly members of the Class Actinobacteria, that have yielded numerous bioactive compounds valued as a source of pharmaceuticals and enzymes; marine algae that provide a range of natural products from agar to pharmaceuticals; benthic foraminiferans, especially agglutinated wall species; byssate molluscs that have potential in the production of bioadhesives for many uses from transdermal drug delivery systems to surgical adhesives; and bryozoans, particularly Bugula neritina, the only source of bryostatin, a drug used in cancer treatment.

Two collecting trips were made from Port Fourchon, Louisiana, on the M/V Spree. On the first cruise, June 9, 2001, Tropical Storm Allison prevented sampling except at one of the five chosen platforms, ST 23. On the second cruise, May 4-5, 2002, four platforms were sampled and one platform could not be sampled due to dangerous diving conditions.

At each sampling site, divers outlined a 25 cm x 25 cm area, using a metal template. A diver suctioned loose surface material from this area with a 60 cc syringe. All encrusting organisms were then scraped and preserved by methods appropriate to the taxa studied. The following is a summary of the findings from each group of organisms.

BACTERIA: The study demonstrated that the biomatrix associated with gas and oil platforms contains large numbers of bacterial species many of which are novel and belong to taxonomic groups known to be of biotechnological importance. The construction of total genome libraries from the biomatrix of oil and gas platforms and their expression will no doubt provide novel bioactivities from both the micro and macro components of these complex systems. This study established that the biomatrix encrusted on oil and gas platforms represents a potential starting material for such studies.

ALGAE: The total number of algal taxa collected during this study was 24. The best represented group was Rhodophyta (approximately 50% of the taxa collected). Seven new taxa were added to the list of macroalgae identified from the platforms and one new report of Antithamnionella breviramosa from the Gulf of Mexico. Approximately 50% of the taxa collected are known to have biotechnological potential.

FORAMINIFERA: A rich assemblage of benthic Foraminifera was recognized in the scrapings and the syringe samples. The species included both grazers and attached forms. The assemblage density was highly variable. The most conspicuous aspect of the foraminiferal distribution was the abundance of attached taxa; some sessile species that are rare or absent in soft substrates live in relative profusion on the platforms. In addition, the foraminiferal community includes many vagrant foraminiferal species. Agglutinated foraminiferal species hold promise as a source of bioadhesives for biotechnological and biomedical applications, because they can secrete and then harden adhesive organic compounds in an aqueous medium although no species with known biotechnical potential were found.

BRYOZOA: To date the only marine compound to enter phase II clinical trials is bryostatin 1. Bryostatin 1 combats the growth of cultured cancer cells and has shown some promise aiding patients suffering from non-Hodgkin's lymphoma and lymphocytic leukemia. Bryostatin 1 was initially isolated from the bryozoan Bugula neritina, but in California that named species turned out to be composed of several cryptic species, only one of which produces bryostatin I. The compound occurs in an endosymbiotic bacteria present within B. neritina. B. neritina as currently recognized in US waters comprises three cryptic species: the deep water Pacific form, a Shallow/Southern form present both in shallower Pacific waters and along the Atlantic coast south of Cape Hatteras, and a third form present in the Atlantic north of the Cape Hatteras region. This study found that neither the species collected from the Gulf ofMexico platforms nor those found in the Atlantic produce the commercially important bryostatin I.

MOLLUSCS: The platforms sampled hosted a low diversity molluscan assemblage dominated by byssate bivalves. Twenty-seven bivalve and gastropod species were identified, with Isognomon bicolor and Barbatia candida making up about 90% of the total assemblage. Changes in relative abundance of taxa among platforms were in part caused by mollusks collected in this study with the greatest biotechnology potential include the byssate bivalves Isognomon and Barbatia that produce bioadhesives. The byssus is a bundle of proteinaceous threads secreted by some bivalves that attaches to a substrate by an adhesive plaque. These adhesives are of biotechnological interest because they provide strong, durable adhesion to wet surfaces. Taxonomic and genetic heterogeneity of marine organisms must be anticipated prior to surveys for biotechnologically useful molecules and studies of ecological processes. This study examined the genetic variability of the bivalve community associated with northern GOM oil platforms in order to (1) determine if there were cryptic species and (2) examine the genetic variation within and among platforms. Data collected indicated that all of the individuals were Barbatia candida.”