Article
Microbiology
Qin Li, Yashi Li, Xiaomeng Liu, Sanfeng Chen
Summary: Two strains HN-1(T) and 39 isolated from different plant rhizospheres in China were found to have high nitrogenase activities and nearly identical 16S rRNA gene sequences, indicating they belong to the same species. They were identified as a novel species of the genus Paenibacillus, named Paenibacillus sinensis, based on distinct phenotypic and genomic characteristics, despite their close relationship to Paenibacillus stellifer.
ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY
(2022)
Article
Plant Sciences
Thomas A. Bytnerowicz, Jennifer L. Funk, Duncan N. L. Menge, Steven S. Perakis, Amelia A. Wolf
Summary: Nitrogen (N)-fixing trees challenge the basic rule of leaf economics by showing that higher leaf nitrogen concentrations do not necessarily result in higher rates of photosynthesis. Understanding how leaf nitrogen affects photosynthesis and water use efficiency is crucial for this ecologically important group.
JOURNAL OF ECOLOGY
(2023)
Article
Microbiology
Qin Li, Yin-zhao Zuo, Miao Gao, San-feng Chen
Summary: A nitrogen-fixing, endospore-forming, motile, rod-shaped bacterium, designated Paenibacillus caui, was isolated from rhizosphere soil of a peach tree collected from Handan, Hebei, PR China. The strain has a genome size of 4.4 Mb and is most closely related to Paenibacillus phoenicis and Paenibacillus faecis.
INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY
(2022)
Article
Ecology
Sian Kou-Giesbrecht, Jennifer L. Funk, Steven S. Perakis, Amelia A. Wolf, Duncan N. L. Menge
Summary: The study showed that nitrogen-fixing trees initially mitigated climate change more effectively than non-fixing trees, but under higher nitrogen supply, nitrogen-fixing trees ultimately mitigated climate change less effectively than non-fixing trees.
Article
Engineering, Environmental
Quanlong Wang, Xueying Feng, Yingying Liu, Wenguang Li, Wenzhi Cui, Yuhuan Sun, Shuwu Zhang, Fayuan Wang, Baoshan Xing
Summary: Microplastics (MPs) are widely distributed in agroecosystems and pose a potential threat to soil-plant systems. The effects of high-density polyethylene (HDPE), polystyrene (PS), and polylactic acid (PLA) on peanuts and soil N-fixing bacterial communities were explored. MPs did not have phytotoxic effects on plant biomass, and PS and PLA even increased plant height. All MPs changed soil nitrogen contents and the activities of urease and FDAse. PLA especially had pronounced effects on plant nitrogen content and soil N-fixing bacterial community structure. The findings suggest that biodegradable MPs may have more profound consequences for nitrogen biogeochemical cycling than traditional MPs.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Review
Biochemistry & Molecular Biology
David A. Day, Penelope M. C. Smith
Summary: This review focuses on how iron is transported across the symbiosome membrane and accessed by the bacteroids within root nodules of legumes.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Ecology
Sian Kou-Giesbrecht, Duncan N. L. Menge
Summary: Nitrogen-fixing trees have the potential to double soil nitrous oxide emissions compared to non-fixing trees and soils, potentially increasing global emissions by up to 4.1% and offsetting climate change mitigation efforts through reforestation by up to 4.4%.
Article
Ecology
Riin Tamme, Meelis Partel, Urmas Koljalg, Lauri Laanisto, Jaan Liira, Ulo Mander, Mari Moora, Ulo Niinemets, Maarja Opik, Ivika Ostonen, Leho Tedersoo, Martin Zobel
Summary: The distribution of nitrogen-fixing plant species worldwide shows regional hotspots and coldspots related to environmental conditions and biogeographical history. The diversity and relative richness of nitrogen-fixing plants are highest in warm and wet climates, dry biomes, Australasia, warm and dry climates, tropical and temperate grasslands, and Eurasia.
GLOBAL ECOLOGY AND BIOGEOGRAPHY
(2021)
Article
Biotechnology & Applied Microbiology
Rafael Ambrosio, Leonardo Curatti
Summary: The study focused on the dynamic algal cross-feeding properties of a genetically-modified Azotobacter vinelandii strain with varied levels of glutamine synthetase accumulation. By manipulating the overaccumulation of GS and transitioning cells into a noninducing medium, the researchers observed effects on bacterial growth, ammonium-excretion, and cross-feeding with algae. The behavior of the bacterial population could be finely tuned for multiple bacterial cell generations, but eventually faster-growing cells with no ammonium excretion arose, highlighting the need for further genetic engineering improvements for safe and effective N-biofertilizer use in an open environment.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2021)
Article
Microbiology
Beatriz do Carmo Dias, Fabio Faria da Mota, Diogo Jurelevicius, Lucy Seldin
Summary: This study investigated the nitrogen fixation genes of Paenibacillus brasilensis PB24, identifying the nif operon and regulatory genes involved in biological nitrogen fixation. Gene expression analysis revealed that the presence of NH4 affected the expression of structural and regulatory genes in PB24. Furthermore, the regulatory mechanism of GlnR in PB24 differed from other Paenibacillus species, indicating different binding site distributions.
MICROBIOLOGICAL RESEARCH
(2021)
Article
Forestry
L. Nehring, J. M. Kranabetter, G. J. Harper, B. J. Hawkins
Summary: This study investigates the relationship between tree-ring delta N-15 and soil N dynamics in N-2-fixing red alder trees, and explores the influence of alder-fixed N on neighboring conifers. The findings suggest that the delta N-15 values in tree-rings can reflect N accretion rates in red alder and provide insights into the nitrogen dynamics under different tree species combinations.
Review
Biotechnology & Applied Microbiology
Fanuel Kawaka
Summary: This review discusses the preferred taxonomic methods for characterizing symbiotic bacteria in the rhizosphere, highlighting the continued use of phenotypic and cultural techniques despite challenges. The development of new taxonomic techniques has greatly improved the identification of symbiotic bacteria and led to the discovery of novel species effective in biological nitrogen fixation.
Review
Biotechnology & Applied Microbiology
Jillian M. Petersen, Benedict Yuen
Summary: Nitrogen fixation is a widespread metabolic trait in certain types of microorganisms called diazotrophs. Various organisms have evolved symbioses with diverse diazotrophic bacteria, with enormous economic and ecological benefits. Chemosynthetic nitrogen-fixing symbionts, recently discovered in marine clams, play a crucial role in providing nitrogen in symbiotic relationships.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Environmental Sciences
Meiyang Zhao, Yue Zhao, Wenfang Gao, Lina Xie, Guogang Zhang, Caihong Song, Zimin Wei
Summary: Chicken manure, a high-nitrogen organic waste, produces large amounts of ammonia during composting, leading to environmental pollution and reduced compost quality. Adding calcium superphosphate to compost can enhance the nitrogen-fixing ability of bacterial communities, resulting in increased nitrogen accumulation and altered participation strategy of bacterial communities within the nitrogen cycle.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Review
Biochemistry & Molecular Biology
Nicholas J. Booth, Penelope M. C. Smith, Sunita A. Ramesh, David A. Day
Summary: Legumes form a symbiosis with rhizobia to access atmospheric nitrogen for plant growth. The process is energetically demanding, with a high demand for carbon supplied as sucrose. Transport pathways for malate and other organic acids to support nitrogen-fixing bacteroids have been identified, but further research is needed.
