Article
Ecology
Ivan J. Moreno, Bianca Brahamsha, Mohamed S. Donia, Brian Palenik
Summary: The microbial mat communities in the hot springs of the Black Canyon of the Colorado River were studied using both culture-independent and -dependent methods. The results showed that these communities are mainly composed of cyanobacterial taxa, along with a diverse community of protists and other eukaryotes. The use of full-length rRNA gene sequencing allowed for a higher resolution of the community, and correlation analysis supported the co-occurrence of cyanobacteria, chloroflexi, and bacteroidetes.
Article
Soil Science
Li Wu, Maria E. Farias, Rosa M. Torres, Ling Xia, Shaoxian Song, Abdullah A. Saber, Shubin Lan
Summary: This study investigates the effects of salt on the biocrust community by adding salt to induced biocrusts collected from the field. The results show that certain cyanobacteria-inoculated biocrusts can survive under certain salinity levels, although both salt and drought stresses have significant impacts on microbial biomass and metabolism. Salt stress also leads to a shift in microbial community structure.
SOIL BIOLOGY & BIOCHEMISTRY
(2022)
Article
Marine & Freshwater Biology
Georgia Thomson-Laing, Niamh Dyer, Ruby Whyte-Wilding, Susanna A. Wood
Summary: The increase in benthic mats dominated by anatoxin-producing Microcoleus autumnalis poses a growing health risk to humans and animals worldwide. In in situ experiments, it was found that the area and expansion of M. autumnalis mats tended to increase downstream, with a complex mix of drivers affecting proliferation and varying hierarchy of importance among different sites. Further research is needed to understand the non-linear drivers of M. autumnalis proliferation and the factors influencing their growth in different environments.
Article
Biochemistry & Molecular Biology
Meng-Yun Chen, Wen-Kai Teng, Liang Zhao, Bo-Ping Han, Li-Rong Song, Wen-Sheng Shu
Summary: In this study, the evolutionary trajectory and driving forces of biological nitrogen fixation (BNF) by cyanobacteria were explored through genome analysis. The distribution of diazotrophic cyanobacteria carrying nitrogen fixation gene clusters (NFGCs) was found to be uneven and shaped by multiple independent losses. Two types of NFGCs were identified, with one type being ancestral and abundant, and the other type resembling anaerobic bacteria and sparse, possibly acquired through horizontal gene transfer. The origin of BNF in cyanobacteria coincided with major evolutionary events such as the origin of multicellularity and simultaneous genetic innovations.
MOLECULAR BIOLOGY AND EVOLUTION
(2022)
Article
Environmental Sciences
Yinliu Wang, Signe Lett, Kathrin Rousk
Summary: This study found that moss-associated nitrogen fixation is less sensitive to organic nitrogen inputs than inorganic nitrogen inputs, and highlights the importance of considering different nitrogen forms and species-specific responses when estimating the impact of nitrogen inputs on ecosystem functions.
Article
Environmental Sciences
Ting Hu, Anwei Chen, Yuexi Jiang, Chenmin Sun, Si Luo, Jihai Shao
Summary: A newly recorded diazotrophic cyanobacterium was found to promote rice growth and reduce heavy metal accumulation in acidified and heavy metal contaminated paddy soil.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Microbiology
Brenda S. Pratte, Teresa Thiel
Summary: This study identified unique and overlapping functions of two homologous transcriptional activators, CnfR1 and CnfR2, in regulating two distinct nitrogenase systems in Anabaena variabilis. CnfR1 was found to be promiscuous in activating both nitrogenase systems, while CnfR2 relied on additional cellular factors to activate only one nitrogenase system.
MICROBIOLOGY SPECTRUM
(2021)
Article
Environmental Sciences
Xiaochun Wang, Hongnuo Ge, Yunying Fang, Chunlong Liu, Kamel M. Eltohamy, Zekai Wang, Xinqiang Liang
Summary: This study investigated the effect of biochar addition on colloidal phosphorus (P-coll) content and its associated microbial communities and phosphatase activities during drying and rewetting cycles. The results showed that biochar significantly reduced P-coll content and increased phosphatase-producing microbial communities and phosphatase activities. This research provides a novel understanding of how biochar reduces P-coll loss by regulating microbial communities during drying and rewetting events.
Article
Microbiology
Mercedes Nieves-Morion, Enrique Flores, Martin J. Whitehouse, Aurelien Thomen, Rachel A. Foster
Summary: The study investigated single-cell C and N-2 fixation and metabolic dynamics along filaments in the model heterocyst-forming cyanobacterium Anabaena sp. strain PCC 7120 using stable isotopes and imaging techniques. The results revealed a substantial variability of metabolic states in wild-type filaments in culture, demonstrating the unpredicted heterogeneity of cellular metabolic activity.
Article
Environmental Sciences
Tyler J. Kohler, Joel G. Singley, Adam N. Wlostowski, Diane M. McKnight
Summary: The study investigates the role of nitrogen-fixing bacteria in regulating the composition of microbial mats in Antarctic streams, and confirms the importance of nitrogen fixation in stream nutrient budgets.
Article
Environmental Sciences
Gema L. Batanero, Andy J. Green, Juan A. Amat, Marion Vittecoq, Curtis A. Suttle, Isabel Reche
Summary: Coastal wetlands are valuable aquatic ecosystems with high productivity that provide important services, but are at risk of salinization due to predicted rise of sea level and freshwater extractions. Salinization may shift microbial activity from heterotrophic bacterial-dominated processes towards archaeal-dominated processes, influenced by factors like nitrogen concentration, salinity, and virus abundance. More research is needed to accurately predict future scenarios in coastal wetlands.
Article
Biology
Tomoaki Watanabe, Tokumasa Horiike
Summary: The study aimed to identify the origin of nitrogen fixation development in Cyanobacterium by focusing on molybdenum dependent nitrogenase. It was found that nitrogen fixing genes were acquired in the common ancestor of Cyanobacteria and subsequently lost in some lineages. The mosaic distribution of diazotrophic bacteria in the cyanobacterial lineage was due to the independent loss of nif genes inherited from common cyanobacterial ancestors in each lineage.
Article
Microbiology
Eric D. Kees, Senthil K. Murugapiran, Annastacia C. Bennett, Trinity L. Hamilton
Summary: This study used a metagenomic approach to examine thermophilic cyanobacteria in Yellowstone National Park. The results showed that temperature is the primary determinant of taxonomic makeup of the recovered cyanobacterial MAGs, while total Fe, community morphology, and biogeography also play a role in the distribution and abundance of upper-temperature-limit-adapted cyanobacteria.
Article
Microbiology
Sophie Rabouille, Benjamin Randall, Amelie Talec, Patrick Raimbault, Thierry Blasco, Amel Latifi, Andreas Oschlies
Summary: Experimental findings show that the marine diazotroph Crocosphaera watsonii WH8501 has minimal NO3- uptake and is not affected by the presence of NO3- in terms of nitrogen fixation rate and cell metabolism. This suggests that assumptions and models regarding N-2 fixation should be reconsidered, as diazotrophy appears to be insensitive to NO3-.
Article
Environmental Sciences
Toke Due Sjogren, Yinliu Wang, Kathrin Rousk
Summary: Nitrogen fixation by moss-associated cyanobacteria is a crucial N source in pristine ecosystems, but its vulnerability to heavy metal pollution varies depending on the dominant moss species.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)