Nitrogen removal by tubular gel containing Nitrosomonas europaea and Paracoccus denitrificans

Uemoto, Hiroaki; Saiki, Hiroshi

doi:10.1128/aem.62.11.4224-4228.1996

Cited by 36 publications

(3 citation statements)

References 22 publications

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“…The polymeric gel could possibly maintain anaerobic conditions in the inner space of the gel without nitrogen gas because the molecular oxygen in the wastewater probably would be consumed in the outer surface of the gel. In fact, when polymeric beads [10,11] or polymeric tubular gels [12,13], in which nitrifier and denitrifier were co-immobilized, were applied to remove nitrogen, nitrification, namely consumption of molecular oxygen, occurred in the outer layer of the beads or tubular gels and denitrification took place in the core of the beads or tubular gels. The artificial wastewater containing selenate and nitrate will be treated under aerobic conditions using the immobilized mixture of cells of Pseudomonas sp.…”

Section: Discussionmentioning

confidence: 99%

Reduction of Selenium Oxyanions in Wastewater Using Two Bacterial Strains

Murakami

Uemoto

Watanabe

2007

Engineering in Life Sciences

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The biological reduction of selenium oxyanions is capable of reducing both selenate and selenite to insoluble elemental selenium. In this process, however, bacteria inevitably require expensive chemicals such as yeast extract in almost all cases. Therefore, the reduction of selenium oxyanions with inexpensive alcohol would be more practical. A Pseudomonas sp. strain 4C-C isolated from a sludge in a wastewater treatment facility was able to reduce selenate to selenite using ethanol as an electron donor for its anaerobic respiration, but could not reduce selenite to elemental selenium. Paracoccus denitrificans JCM-6892, on the other hand, was observed to be able to reduce selenite to elemental selenium in the presence of ethanol, but not selenate to selenite. Therefore, a mixture containing a suspension of Pseudomonas sp. strain 4C-C and P. denitrificans JCM-6892 cells allowed selenate to be reduced to insoluble elemental selenium via selenite in the presence of ethanol and was also capable of reducing nitrate to nitrogen gas. Aiming at simplicity of the recovery process of insoluble elemental selenium, a polymeric gel immobilized mixture of the two bacterial strains was examined using ethanol as an electron donor. The immobilized mixture could therefore reduce not only selenate to elemental selenium, but also nitrate to nitrogen gas in a single step. The gel that immobilized the microbial mixture changed its color during the process to bright red and no red elemental selenium was left in the wastewater. This indicates that the reduced elemental selenium was completely absorbed in the gel. This simple bacterial combination would therefore be effective in the presence of ethanol to reduce selenium oxyanions in various wastewaters containing selenium and the other oxyanions.

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Section: Discussionmentioning

confidence: 99%

Reduction of Selenium Oxyanions in Wastewater Using Two Bacterial Strains

Murakami

Uemoto

Watanabe

2007

Engineering in Life Sciences

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“…In addition, P. denitrificans is isolated from microbial fuel cell anode biofilm communities and can generate electricity using formic acid as an electron donor (Kiely et al 2010). Furthermore, P. denitrificans can be immobilized in gels with Nitrosomonas europaea for efficient nitrogen removal from wastewater and have great potentials in their applications (Kokufuta et al 1988;Uemoto and Saiki 1996). Hence, understanding biofilm formation in Paracoccus species may optimize the functions of biofilm-based bioreactors.…”

Section: Paracoccus Biofilms In Applicationsmentioning

confidence: 99%

Peculiarities of biofilm formation by Paracoccus denitrificans

Morinaga

Yoshida

Takahashi

et al. 2020

Appl Microbiol Biotechnol

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Most bacteria form biofilms, which are thick multicellular communities covered in extracellular matrix. Biofilms can become thick enough to be even observed by the naked eye, and biofilm formation is a tightly regulated process. Paracoccus denitrificans is a non-motile, Gram-negative bacterium that forms a very thin, unique biofilm. A key factor in the biofilm formed by this bacterium is a large surface protein named biofilm-associated protein A (BapA), which was recently reported to be regulated by cyclic diguanosine monophosphate (cyclic-di-GMP or c-di-GMP). Cyclic-di-GMP is a major second messenger involved in biofilm formation in many bacteria. Though cyclic-di-GMP is generally reported as a positive regulatory factor in biofilm formation, it represses biofilm formation in P. denitrificans. Furthermore, quorum sensing (QS) represses biofilm formation in this bacterium, which is also reported as a positive regulator of biofilm formation in most bacteria. The QS signal used in P. denitrificans is hydrophobic and is delivered through membrane vesicles. Studies on QS show that P. denitrificans can potentially form a thick biofilm but maintains a thin biofilm under normal growth conditions. In this review, we discuss the peculiarities of biofilm formation by P. denitrificans with the aim of deepening the overall understanding of bacterial biofilm formation and functions.

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“…The type strain of this genus, P. denitrificans, lives primarily in soil. The type strain can produce nitric oxide and nitrous oxide, which gives rise to atmospheric damage, and convert nitrate into nitrogen gas single-handedly, which leads to the loss of nitrogen fertiliser in agricultural soil [11].…”

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confidence: 99%

Paracoccus salsus sp. nov., a novel slightly halophilic bacterium isolated from saline lake sediment

Gao

Fang

Liu

et al. 2022

International Journal of Systematic and Evolutionary Microbiology

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A Gram-stain-negative, non-motile, slightly halophilic and non-endospore-forming alphaproteobacterium, designated strain EGI L200073T, was isolated from saline lake sediment sampled in Xinjiang Uygur Autonomous Region, China. The taxonomic position of the isolate was determined using the polyphasic taxonomic analysis and phylogenomic analysis. Phylogenetic analysis based on 16S rRNA gene sequence similarities indicated that strain EGI L200073T formed a distinct clade with Paracoccus seriniphilus DSM 14827T and shared sequence identity of 98.56 %. The novel isolate could be distinguished from other species of the genus Paracoccus by its distinct phenotypic, physiological and genotypic characteristics. Optimal growth of strain EGI L200073T occurred on marine agar 2216 at pH 8.0 and 30 °C. The major respiratory quinone was Q-10, while the major fatty acids (>10%) were summed feature 8 (C17 : 1 ω6c and/or C17 : 1 ω7c) and C18 : 0. The detected polar lipids included diphosphatidylglycerol, phosphatidylcholine and phosphatidylglycerol. Based on the genome sequence of strain EGI L200073T, the G+C content of the novel isolate was 65.7 mol%. The average nucleotide identity, amino acid identity and digital DNA–DNA hybridization values of strain EGI L200073T against related members in the genus Paracoccus were below the cut-off points proposed for delineation of a novel species. According our polyphasic taxonomic data, strain EGI L200073T represents a new species of the genus Paracoccus , for which the name Paracoccus salsus sp. nov. is proposed. The type strain of the proposed novel isolate is EGI L200073T (=KCTC 92045T=CGMCC 1.19242T).

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Nitrogen removal by tubular gel containing Nitrosomonas europaea and Paracoccus denitrificans

Cited by 36 publications

References 22 publications

Reduction of Selenium Oxyanions in Wastewater Using Two Bacterial Strains

Reduction of Selenium Oxyanions in Wastewater Using Two Bacterial Strains

Peculiarities of biofilm formation by Paracoccus denitrificans

Paracoccus salsus sp. nov., a novel slightly halophilic bacterium isolated from saline lake sediment

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