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Adaptation of intertidal biofilm communities is driven by metal ion and oxidative stresses.

Zhang W, Wang Y, Lee OO, Tian R, Cao H, Gao Z, Li Y, Yu L, Xu Y, Qian PY - Sci Rep (2013)

Bottom Line: To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared.The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism.We hypothesize that a complex signaling network is used for stress tolerance and propose a model illustrating the relationships between these functions and environmental metal ion concentrations and oxidative stresses.

View Article: PubMed Central - PubMed

Affiliation: 1] KAUST Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China [2].

ABSTRACT
Marine organisms in intertidal zones are subjected to periodical fluctuations and wave activities. To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared. The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism. In addition, these genes were more enriched in 12-day than 6-day intertidal biofilms. We hypothesize that a complex signaling network is used for stress tolerance and propose a model illustrating the relationships between these functions and environmental metal ion concentrations and oxidative stresses. These findings show that bacteria use diverse mechanisms to adapt to intertidal zones and indicate that the community structures of intertidal biofilms are modulated by metal ion and oxidative stresses.

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CAZy families with significant differences between the 12-I and 12-S biofilms (Fisher's G-test, P < 0.01).**P < 0.01 and ***P < 0.001.
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f4: CAZy families with significant differences between the 12-I and 12-S biofilms (Fisher's G-test, P < 0.01).**P < 0.01 and ***P < 0.001.

Mentions: Biofilm's EPS, which contains several components including monosaccharides and polysaccharides, plays an important role in environmental stress responses, including the protective response against oxidative stress2526 and ion chelation527. We hypothesized that enhancement of EPS synthesis might be a strategy employed by intertidal biofilms to cope with environmental stresses. Because the results obtained for the COG categories revealed a lack of congruency among intertidal and subtidal biofilms, metagenomic sequences were assigned to the KEGG database, which is particularly useful for comparison of metabolic pathways, with the goal of identifying EPS components associated with metabolic pathways. Figure 3 illustrates the pathways involved in carbohydrate metabolism and glycan biosynthesis and metabolism that were significantly changed between intertidal and subtidal biofilms. Compared with the 12-S biofilm, all of the sugar biosynthesis pathways were enriched in the 12-I biofilm e.g., metabolism of amino sugars, starch and sucrose, fructose and mannose and biosynthesis of N-glycan (Fig. 3A), which are common in bacterial EPS28. Similarly, compared to the 6-S biofilm, biosynthesis pathways associated with fructose and mannose metabolism as well as O-glycan biosynthesis were enriched in the 6-I biofilm (Fig. 3B). In addition, a BLAST search against the Carbohydrate-Active Enzymes (CAZy) specialist database confirmed the results and revealed detailed activities of carbon metabolism proteins. Comparison of the 12-I and 12-S biofilm metagenomes using STAMP (Fisher's G-test, P < 0.01) showed that a significant difference in all of the CAZy protein families (Fig. 4). In particular, the 12-I biofilm was enriched for polysaccharide biosynthesis gene families, including cellulose synthase, chitin synthase, xylanases and glucanase. These results suggested that enhancement of EPS might be a strategy utilized by microbes in intertidal biofilms to cope with environmental stresses.


Adaptation of intertidal biofilm communities is driven by metal ion and oxidative stresses.

Zhang W, Wang Y, Lee OO, Tian R, Cao H, Gao Z, Li Y, Yu L, Xu Y, Qian PY - Sci Rep (2013)

CAZy families with significant differences between the 12-I and 12-S biofilms (Fisher's G-test, P < 0.01).**P < 0.01 and ***P < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3822395&req=5

f4: CAZy families with significant differences between the 12-I and 12-S biofilms (Fisher's G-test, P < 0.01).**P < 0.01 and ***P < 0.001.
Mentions: Biofilm's EPS, which contains several components including monosaccharides and polysaccharides, plays an important role in environmental stress responses, including the protective response against oxidative stress2526 and ion chelation527. We hypothesized that enhancement of EPS synthesis might be a strategy employed by intertidal biofilms to cope with environmental stresses. Because the results obtained for the COG categories revealed a lack of congruency among intertidal and subtidal biofilms, metagenomic sequences were assigned to the KEGG database, which is particularly useful for comparison of metabolic pathways, with the goal of identifying EPS components associated with metabolic pathways. Figure 3 illustrates the pathways involved in carbohydrate metabolism and glycan biosynthesis and metabolism that were significantly changed between intertidal and subtidal biofilms. Compared with the 12-S biofilm, all of the sugar biosynthesis pathways were enriched in the 12-I biofilm e.g., metabolism of amino sugars, starch and sucrose, fructose and mannose and biosynthesis of N-glycan (Fig. 3A), which are common in bacterial EPS28. Similarly, compared to the 6-S biofilm, biosynthesis pathways associated with fructose and mannose metabolism as well as O-glycan biosynthesis were enriched in the 6-I biofilm (Fig. 3B). In addition, a BLAST search against the Carbohydrate-Active Enzymes (CAZy) specialist database confirmed the results and revealed detailed activities of carbon metabolism proteins. Comparison of the 12-I and 12-S biofilm metagenomes using STAMP (Fisher's G-test, P < 0.01) showed that a significant difference in all of the CAZy protein families (Fig. 4). In particular, the 12-I biofilm was enriched for polysaccharide biosynthesis gene families, including cellulose synthase, chitin synthase, xylanases and glucanase. These results suggested that enhancement of EPS might be a strategy utilized by microbes in intertidal biofilms to cope with environmental stresses.

Bottom Line: To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared.The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism.We hypothesize that a complex signaling network is used for stress tolerance and propose a model illustrating the relationships between these functions and environmental metal ion concentrations and oxidative stresses.

View Article: PubMed Central - PubMed

Affiliation: 1] KAUST Collaborative Research Program, Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong SAR, China [2].

ABSTRACT
Marine organisms in intertidal zones are subjected to periodical fluctuations and wave activities. To understand how microbes in intertidal biofilms adapt to the stresses, the microbial metagenomes of biofilms from intertidal and subtidal zones were compared. The genes responsible for resistance to metal ion and oxidative stresses were enriched in both 6-day and 12-day intertidal biofilms, including genes associated with secondary metabolism, inorganic ion transport and metabolism, signal transduction and extracellular polymeric substance metabolism. In addition, these genes were more enriched in 12-day than 6-day intertidal biofilms. We hypothesize that a complex signaling network is used for stress tolerance and propose a model illustrating the relationships between these functions and environmental metal ion concentrations and oxidative stresses. These findings show that bacteria use diverse mechanisms to adapt to intertidal zones and indicate that the community structures of intertidal biofilms are modulated by metal ion and oxidative stresses.

Show MeSH
Related in: MedlinePlus