Planktonic bacteria and fungi are selectively eliminated by exposure to marine macroalgae in close proximity.

نویسندگان

  • Cindy Lam
  • Andre Stang
  • Tilmann Harder
چکیده

To test whether macroalgae affect microbial colonizers in close proximity in a phylum-specific fashion, the community richness of planktonic bacteria and fungi was analyzed with selective oligonucleotide probes targeting the Cytophaga/Flavobacterium/Bacteroides (CFB), Alphaproteobacteria and Roseobacter group and the ITS1 region of marine fungi. Naturally occuring planktonic microorganisms were incubated in the presence of macroalgae or in seawater previously conditioned with macroalgal metabolites. The red algae Ceramium rubrum and Mastocarpus stellatus as well as seawater conditioned with these algae reduced the community composition of bacteria to a greater extent than the brown alga Laminaria digitata, indicating that metabolites differed among macroalgae or that the susceptibility of planktonic bacteria towards alga-derived antimicrobials correlated with their phylogenetic affiliation. The most affected phylotypes belonged to the CFB and the Roseobacter clade. The planktonic fungal community was only affected in the presence of macroalgae and not in algal-conditioned water, but with a specificity different from that observed for bacteria. The macroalgae L. digitata and M. stellatus exhibited more pronounced antifungal effects than C. rubrum. This study demonstrates macroalgal defenses against epiphytic microorganisms based on natural delivery mechanisms of allelochemicals utilizing a culture-independent approach, thus minimizing the ecological bias inherent to culture-dependent studies based on few microbial isolates.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Evaluation of ecological status of the Persian Gulf inshore waters (Hormozgan rocky bottoms) using macrophytic communities and a macroalgae biological index, EEI

Abstract: Marine macro-algae are very important biological indicators of the ecological status of the marine environment because they are first to react to the pollution entering the sea including nutrients which determine the trophy of the ambient of the environment. The aim of this paper is to evaluate the present trophic level and the health status of the sampling stations according to the E...

متن کامل

Assessment of antibacterial effect of some marine macroalgae against human pathogen

The purpose of this study was to determine antibacterial activity of the marine algae. Different algae were subjected to the three solvents (n-hexan, ethyl acetate, methanol). Antibacterial activity of the extracts was performed using 7 bacterias by disc diffusion method.According to the results of the study, the algae Ulvalinza and Ulvaintestinalis had the highest antibacterial effect against ...

متن کامل

Galls and tumor-like growths on marine macroalgae

Galls and tumor-like growths can be found on numerous marine macroalgae. These growths are characterized by cell hyperplasia and hypertrophy producing an abnormal unorganized cell proliferation. Host tissues involved are typically differentiated and are induced to become meristematic after infection. These growths are associated with bacteria, algae, fungi, various animals, and other agents.

متن کامل

Distribution of seaweeds in Mangrove forests

Many of the mangrove forests are characterized by macroalgae growing epiphytically on pneumatophores, prop roots, stems and other hard substrates. Mangrove macroalgae have an important role as primary producers in the estuarine ecosystem. In the present study, four different mangrove habitats were selected to identify the macroalgae inhabiting the roots of a mangrove species Avicennia marina in...

متن کامل

Evaluation of ecological status of the Persian Gulf inshore waters (Hormozgan rocky bottoms) using macrophytic communities and a macroalgae biological index, EEI

Marine benthic macrophytes (seaweed and seagrasses) are key structural and functional components of some of the most productive ecosystems of the world. They absorb nutrients through their surface directly from the marine environment and thus they are very important biological elements for the estimation of ecological status, representing reliable indicators of coastal waters. The aim of this s...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • FEMS microbiology ecology

دوره 63 3  شماره 

صفحات  -

تاریخ انتشار 2008