Ecological Role of Exopolysaccharides of Bacillariophyta: A Review

2017 ◽  
Vol 19 (1) ◽  
pp. 5-24 ◽  
Author(s):  
E. I. Shnyukova ◽  
E. K. Zolotareva
Keyword(s):  
Ecological Role

An inter-dependence of flood and drought: disentangling amphibian beta diversity in seasonal floodplains

2017 ◽  
Vol 68 (11) ◽  
pp. 2115 ◽  
Author(s):  
Leonardo F. B. Moreira ◽  
Tainá F. Dorado-Rodrigues ◽  
Vanda L. Ferreira ◽  
Christine Strüssmann
Keyword(s):  
Community Structure ◽  
Environmental Factors ◽  
Quantitative Data ◽  
Explanatory Variable ◽  
Biotic Interactions ◽  
Ecological Role ◽  
Β Diversity ◽  
Amphibian Community ◽  
Dry Seasons

Species composition in floodplains is often affected by different structuring factors. Although floods play a key ecological role, habitat selection in the dry periods may blur patterns of biodiversity distribution. Here, we employed a partitioning framework to investigate the contribution of turnover and nestedness to β-diversity patterns in non-arboreal amphibians from southern Pantanal ecoregion. We investigated whether components of β-diversity change by spatial and environmental factors. We sampled grasslands and dense arboreal savannas distributed in 12 sampling sites across rainy and dry seasons, and analysed species dissimilarities using quantitative data. In the savannas, both turnover and nestedness contributed similarly to β diversity. However, we found that β diversity is driven essentially by turnover, in the grasslands. In the rainy season, balanced variation in abundance was more related to altitude and factors that induce spatial patterns, whereas dissimilarities were not related to any explanatory variable during dry season. In the Pantanal ecoregion, amphibian assemblages are influenced by a variety of seasonal constraints on terrestrial movements and biotic interactions. Our findings highlighted the role of guild-specific patterns and indicated that mass effects are important mechanisms creating amphibian community structure in the Pantanal.

Erratum: FeAs2 biomineralization on encrusted bacteria in hot springs: an ecological role of symbiotic bacteria

2004 ◽  
Vol 41 (4) ◽  
pp. 481
Author(s):  
Kazue Tazaki ◽  
Islam ABM Rafiqul ◽  
Kaori Nagai ◽  
Takayuki Kurihara
Keyword(s):  
Hot Springs ◽  
Symbiotic Bacteria ◽  
Ecological Role

Ecological Role of 6OH-BDE47: Is It a Chemical Offense Molecule Mediated by Enoyl-ACP Reductases?

2021 ◽  
Author(s):  
Jianxian Sun ◽  
Holly Barrett ◽  
David Ross Hall ◽  
Steven Kutarna ◽  
Xiaoqin Wu ◽  
...  
Keyword(s):  
Ecological Role

scholarly journals Biodegradation of the Allelopathic Chemical Pterostilbene by a Sphingobium sp. Strain from the Peanut Rhizosphere

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Ri-Qing Yu ◽  
Zohre Kurt ◽  
Fei He ◽  
Jim C. Spain
Keyword(s):  
Pathogenic Fungi ◽  
Bacterial Degradation ◽  
Ecological Role ◽  
Microbial Infection ◽  
Catabolic Pathway ◽  
Content Type ◽  
Dead End ◽  
Initial Cleavage ◽  
Bacterial Interference

ABSTRACT Many plants produce allelopathic chemicals, such as stilbenes, to inhibit pathogenic fungi. The degradation of allelopathic compounds by bacteria associated with the plants would limit their effectiveness, but little is known about the extent of biodegradation or the bacteria involved. Screening of tissues and rhizosphere of peanut (Arachis hypogaea) plants revealed substantial enrichment of bacteria able to grow on resveratrol and pterostilbene, the most common stilbenes produced by the plants. Investigation of the catabolic pathway in Sphingobium sp. strain JS1018, isolated from the rhizosphere, indicated that the initial cleavage of pterostilbene was catalyzed by a carotenoid cleavage oxygenase (CCO), which led to the transient accumulation of 4-hydroxybenzaldehyde and 3,5-dimethoxybenzaldehyde. 4-Hydroxybenzaldehyde was subsequently used for the growth of the isolate, while 3,5-dimethoxybenzaldehyde was further converted to a dead-end metabolite with a molecular weight of 414 (C24H31O6). The gene that encodes the initial oxygenase was identified in the genome of strain JS1018, and its function was confirmed by heterologous expression in Escherichia coli. This study reveals the biodegradation pathway of pterostilbene by plant-associated bacteria. The prevalence of such bacteria in the rhizosphere and plant tissues suggests a potential role of bacterial interference in plant allelopathy. IMPORTANCE Pterostilbene, an analog of resveratrol, is a stilbene allelochemical produced by plants to inhibit microbial infection. As a potent antioxidant, pterostilbene acts more effectively than resveratrol as an antifungal agent. Bacterial degradation of this plant natural product would affect the allelopathic efficacy and fate of pterostilbene and thus its ecological role. This study explores the isolation and abundance of bacteria that degrade resveratrol and pterostilbene in peanut tissues and rhizosphere, the catabolic pathway for pterostilbene, and the molecular basis for the initial cleavage of pterostilbene. If plant allelopathy is an important process in agriculture and management of invasive plants, the ecological role of bacteria that degrade the allelopathic chemicals must be equally important.

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