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Archives of Microbiology Dec 2023Duckweed has been highlighted as an invaluable resource because of its abilities to remove nitrogen and phosphorus from wastewater coupling with the production of high...
Duckweed has been highlighted as an invaluable resource because of its abilities to remove nitrogen and phosphorus from wastewater coupling with the production of high starch/protein-containing plant biomass. Duckweed recruits microbes and particularly forms a stable "core" bacterial microbiota, which greatly reduces the colonization efficiency of plant growth-promoting bacteria (PGPB). In this study, natural duckweeds were enriched in a sterilized-partially treated wastewater effluent from a poultry farm. After 24 days of cultivation, the duckweed-associated bacteria (DAB) were isolated and evaluated for their plant growth-promoting (PGP) potentials by co-cultivation with axenic Spirodela polyrhiza. Ten species were found in more than one location and could be considered candidates for the stable "core" DAB. Among them, all isolates of Acinetobacter soli, Acidovorax kalamii, Brevundimonas vesicularis, Pseudomonas toyotomiensis, and Shinella curvata increased duckweed growth in Hoagland medium. The highest PGP ability was observed in Sh. curvata W12-8 (with EPG value of 208.72%), followed by Paracoccus marcusii W7-16 (171.31%), Novosphingobium subterraneum W5-13 (156.96%), and Ac. kalamii W7-18 (156.96%). However, the highest growth promotion in the wastewater was observed when co-cultured with W7-16, which was able to increase biomass dry weight and root length of duckweed by 3.17 and 2.26 folds, respectively.
Topics: Animals; Araceae; Farms; Poultry; Wastewater
PubMed: 38148332
DOI: 10.1007/s00203-023-03778-4 -
Fish & Shellfish Immunology Feb 2024In recent years, a substantial number of studies have been dedicated to exploring the potential benefits of probiotics in aquaculture. Rhodobacter sphaeroides can be...
In recent years, a substantial number of studies have been dedicated to exploring the potential benefits of probiotics in aquaculture. Rhodobacter sphaeroides can be used in aquaculture-related environmental bioremediation, and its protein is also used as a feed additive in Penaeus vannamei culture. To investigate the effects of releasing R. sphaeroides as environmental probiotics on P. vannamei, we employed 16S rRNA gene and mRNA transcriptome sequencing. Our study focused on assessing alterations in intestinal bacteria and intestinal gene expression in P. vannamei, establishing correlations between them. Our findings revealed a significant increase in the relative abundances of Rhodobacter, Paracoccus, Sulfitobacter, and other bacterial OTUs within the intestinal bacterial community. Additionally, we observed enhanced complexity and stability in the intestinal bacterial correlation network, indicating improved synergy among bacteria and reduced competition. Moreover, the introduction of R. sphaeroides resulted in the down-regulation of certain immune genes and the up-regulation of genes linked to growth and metabolism in the intestinal tissues of P. vannamei. Importantly, we identified a noteworthy correlation between the changes in intestinal bacteria and these alterations in intestinal tissue gene expressions. By conducting analyses of the intestinal bacterial community and intestinal tissue transcriptome, this study revealed the effects of releasing R. sphaeroides as sediment probiotics in P. vannamei culture water. These results serve as vital scientific references for the application of R. sphaeroides in P. vannamei aquaculture.
Topics: Animals; Transcriptome; Rhodobacter sphaeroides; RNA, Ribosomal, 16S; Aquaculture; Probiotics; Penaeidae
PubMed: 38142021
DOI: 10.1016/j.fsi.2023.109316 -
Journal of Environmental Management Nov 2023Soil salinization can affect the ecological environment of soil and alter greenhouse gas (GHG) emissions. Chitooligosaccharides and Arbuscular mycorrhizal fungi (AMF)...
Soil salinization can affect the ecological environment of soil and alter greenhouse gas (GHG) emissions. Chitooligosaccharides and Arbuscular mycorrhizal fungi (AMF) reduced the GHG fluxes of salinized soil, and this reduction was attributed to an alteration in the rhizosphere microecology, including changes in the activities of β-glucosidase, acid phosphatase, N-acetyl-β-D-glucosidase, and Leucine aminopeptidase. Additionally, certain bacteria species such as paracoccus, ensifer, microvirga, and paracyclodium were highly correlated with GHG emissions. Another interesting finding is that foliar spraying of chitooligosaccharides could transport to the soybean root system, and improve soybean tolerance to salt stress. This is achieved by enhancing the activities of antioxidant enzymes, and the changes in amino acid metabolism, lipid metabolism, and membrane transport. Importantly, the Co-application of chitooligosaccharides and Arbuscular mycorrhiza fungi was found to have a greater effect compared to their application alone.
Topics: Mycorrhizae; Glycine max; Greenhouse Gases; Rhizosphere; Soil; Plant Roots; Fungi; Soil Microbiology
PubMed: 37634403
DOI: 10.1016/j.jenvman.2023.118836 -
Journal of Environmental Management Feb 2024It is well accepted that tidal wetland vegetation performs a significant amount of water filtration for wetlands. However, there is currently little information on how...
It is well accepted that tidal wetland vegetation performs a significant amount of water filtration for wetlands. However, there is currently little information on how various wetland plants remove nitrogen (N) and phosphorus (P) and how they differ in their denitrification processes. This study compared and investigated the denitrification and phosphorus removal effects of three typical wetland plants in the Yangtze River estuary wetland (Phragmites australis, Spartina alterniflora, and Scirpus mariqueter), as well as their relevant mechanisms, using an experimental laboratory-scale horizontal subsurface flow constructed wetland (CW). The results showed that all treatment groups with plants significantly reduced N pollutants as compared to the control group without plants. In comparison to S. mariqueter (77.2-83.2%), S. alterniflora and P. australis had a similar total nitrogen (TN)removal effectiveness of nearly 95%. With a removal effectiveness of over 99% for ammonium nitrogen (NH-N), P. australis outperformed S. alterniflora (95.6-96.8%) and S. mariqueter (94.6-96.5%). The removal of nitrite nitrogen (NO-N)and nitrate nitrogen (NO-N)from wastewater was significantly enhanced by S. alterniflora compared to the other treatment groups. Across all treatment groups, the removal rate of PO-P was greater than 95%. P. australis and S. alterniflora considerably enriched more N than S. mariqueter, according to the results of the N isotope labeling experiment. While the rhizosphere and bulk sediments of S. alterniflora were enriched with more simultaneous desulfurization-denitrification bacterial genera (such as Paracoccus, Sulfurovum, and Sulfurimonas), which have denitrification functions, the rhizosphere and bulk sediments of P. australis were enriched with more ammonia-oxidizing archaea and ammonia-oxidizing bacteria. As a result, compared to the other plants, P. australis and S. alterniflora demonstrate substantially more significant ability to remove NH-N and NO-N/NO-N from simulated domestic wastewater.
Topics: Wetlands; Nitrogen; Phosphorus; Ammonia; Nitrogen Dioxide; Wastewater; Plants; Poaceae; China
PubMed: 38109823
DOI: 10.1016/j.jenvman.2023.119864 -
Heliyon Jan 2024The cotton mealybug, Tinsley and papaya mealybug, Williams and Granara de Willink (Hemiptera: Pseudococcidae) are becoming major threats to the production of R. Br....
The cotton mealybug, Tinsley and papaya mealybug, Williams and Granara de Willink (Hemiptera: Pseudococcidae) are becoming major threats to the production of R. Br. (Asclepiadaceae) in India. Management mainly depends on chemical insecticides which cause a serious problem of pesticide residue and insecticide resistance. The use of biorational insecticides such as biopesticides, botanicals, insect growth regulators, and microbial insecticides is important components of an Integrated Pest Management (IPM) program for successful management. We evaluated the bio-efficacy of twelve biorational insecticides, including entomopathogenic fungi (EPF), using the leaf spray method in laboratory conditions at 25 ± 1 °C, 70 % ± 5 % RH. The results revealed that the highest percent mortality was recorded by acetamiprid 20 % SP (100.00 %), followed by azadirachtin (98.27 %), (2 × 10 spores/mL) (85.70 %) and leaf extract (76.87 %) at 120 h after treatment (HAT) in . In , 100.00 %, 96.39 % and 85.67 % and 74.90 % mortalities were achieved by acetamiprid 20 % SP, azadirachtin, (2 × 10 spores/mL) and leaf extract, respectively, at 120 HAT during the first spray. Various biorational insecticides showed a more or less similar trend of percent mortality in both species during the second spray. In both species, the lowest percent mortality was recorded by leaf extract (46.29, 44.54) and (41.03, 46.39) at 120 Hours after treatment in the first and second spray, respectively. It was concluded that all the prescribed treatments are more effective than the control. Overall, azadirachtin recorded the highest percent mortality after acetamiprid and had the shortest LT (12.52 h) and (13.87 h) values in and , respectively. Our study emphasizes that biopesticides like Azadirachtin 1 % EC (10000 ppm), (2 × 10 spores/mL) (5 mL/L) and leaf extract (5 %) may be recommended as alternatives to synthetic insecticides. Botanicals and EPF would be the most effective approach for sustainable integrated management of and in the ecosystem.
PubMed: 38187271
DOI: 10.1016/j.heliyon.2023.e23648 -
Journal of Oleo Science 2024The effects of microwave drying conditions of a Paracoccus carotinifaciens culture solution on astaxanthin Z-isomerization and degradation were investigated. The...
The effects of microwave drying conditions of a Paracoccus carotinifaciens culture solution on astaxanthin Z-isomerization and degradation were investigated. The microwave drying significantly increase the ratio of astaxanthin Z-isomers, and the higher the microwave power and the longer the drying time, the higher the total Z-isomer ratio of astaxanthin, but such conditions also accelerated astaxanthin degradation. We found that the addition of powdered oils enhanced the Z-isomerization reaction. For example, when the P. carotinifaciens culture solution was dried at 1000 W power for 5 min without and with powdered rapeseed oil, total Z-isomer ratios of astaxanthin in resulting dried powder were 14.9 and 47.4%, respectively. Furthermore, the storage test of the dried P. carotinifaciens powder showed that astaxanthin Z- isomers were stable at 4℃ in a low-oxygen atmosphere. As astaxanthin Z-isomers have greater bioavailability and potentially exhibit superior biological activities than the all-E-isomer, the dried P. carotinifaciens powder obtained by the method of this study is expected to be used as a value-added astaxanthin source.
Topics: Isomerism; Microwaves; Powders; Paracoccus; Xanthophylls
PubMed: 38311406
DOI: 10.5650/jos.ess23093 -
Environmental Research Jun 2024The key to the resource recycling of saline wastes in form of polyhydroxyalkanoates (PHA) is to enrich mixed cultures with salt tolerance and PHA synthesis ability....
The key to the resource recycling of saline wastes in form of polyhydroxyalkanoates (PHA) is to enrich mixed cultures with salt tolerance and PHA synthesis ability. However, the comparison of saline sludge from different sources and the salt tolerance mechanisms of salt-tolerant PHA producers need to be clarified. In this study, three kinds of activated sludge from different salinity environments were selected as the inoculum to enrich salt-tolerant PHA producers under aerobic dynamic feeding (ADF) mode with butyric acid dominated mixed volatile fatty acid as the substrate. The maximum PHA content (PHAm) reached 0.62 ± 0.01, 0.62 ± 0.02, and 0.55 ± 0.03 g PHA/g VSS at salinity of 0.5%, 0.8%, and 1.8%, respectively. Microbial community analysis indicated that Thauera, Paracoccus, and Prosthecobacter were dominant salt-tolerant PHA producers at low salinity, Thauera, NS9_marine, and SM1A02 were dominant salt-tolerant PHA producers at high salinity. High salinity and ADF mode had synergistic effects on selection and enrichment of salt-tolerant PHA producers. Combined correlation network with redundancy analysis indicated that trehalose synthesis genes and betaine related genes had positive correlation with PHAm, while extracellular polymeric substances (EPS) content had negative correlation with PHAm. The compatible solutes accumulation and EPS secretion were the main salt tolerance mechanisms of the PHA producers. Therefore, adding compatible solutes is an effective strategy to improve PHA synthesis in saline environment.
Topics: Polyhydroxyalkanoates; Salinity; Salt Tolerance; Sewage; Bacteria
PubMed: 38499223
DOI: 10.1016/j.envres.2024.118722 -
Microbiology Spectrum Jun 2024In the nitrogen biogeochemical cycle, the reduction of nitrous oxide (NO) to N by NO reductase, which is encoded by gene, is the only biological pathway for NO...
UNLABELLED
In the nitrogen biogeochemical cycle, the reduction of nitrous oxide (NO) to N by NO reductase, which is encoded by gene, is the only biological pathway for NO consumption. In this study, we successfully isolated a strain of denitrifying R-1 from sewage treatment plant sludge. This strain has strong NO reduction capability, and the average NO reduction rate was 5.10 ± 0.11 × 10 µmol·h·cell under anaerobic condition in a defined medium. This reduction was accompanied by the stoichiometric consumption of acetate over time when NO served as the sole electron acceptor and the reduction can yield energy to support microbial growth, suggesting that microbial NO reduction is related to the energy generation process. Genomic analysis showed that the gene cluster encoding NO reductase of R-1 was composed of R, Z, D, F, Y, L, and Z, which was identified as that in other strains in clade I. Respiratory inhibitors test indicated that the pathway of electron transport for NO reduction was different from that of the traditional electron transport chain for aerobic respiration. Cu, silver nanoparticles, O, and acidic conditions can strongly inhibit the reduction, whereas NO or NH can promote it. These findings suggest that modular NO reduction of R-1 is linked to the electron transport and energy conservation, and dissimilatory NO reduction is a form of microbial anaerobic respiration.
IMPORTANCE
Nitrous oxide (NO) is a potent greenhouse gas and contributor to ozone layer destruction, and atmospheric NO has increased steadily over the past century due to human activities. The release of NO from fixed N is almost entirely controlled by microbial NO reductase activities. Here, we investigated the ability to obtain energy for the growth of R-1 by coupling the oxidation of various electron donors to NO reduction. The modular NO reduction process of denitrifying microorganism not only can consume NO produced by itself but also can consume the external NO generated from biological or abiotic pathways under suitable condition, which should be critical for controlling the release of NO from ecosystems into the atmosphere.
Topics: Paracoccus denitrificans; Nitrous Oxide; Electron Transport; Denitrification; Oxidoreductases; Oxidation-Reduction; Sewage; Bacterial Proteins; Electrons
PubMed: 38647341
DOI: 10.1128/spectrum.03811-23 -
Angewandte Chemie (International Ed. in... Nov 2023Extensive study on renewable energy storage has been sparked by the growing worries regarding global warming. In this study, incorporating the latest advancements in...
Extensive study on renewable energy storage has been sparked by the growing worries regarding global warming. In this study, incorporating the latest advancements in microbial electrochemistry and electrochemical CO reduction, a super-fast charging biohybrid battery was introduced by using pure formic acid as an energy carrier. CO electrolyser with a slim-catholyte layer and a solid electrolyte layer was built, which made it possible to use affordable anion exchange membranes and electrocatalysts that are readily accessible. The biohybrid battery only required a 3-minute charging to accomplish an astounding 25-hour discharging phase. In the power-to-formate-to-bioelectricity process, bioconversion played a vital role in restricting both the overall Faradaic efficiency and Energy efficiency. The CO electrolyser was able to operate continuously for an impressive total duration of 164 hours under Gas Stand-By model, by storing N gas in the extraction chamber during stand-by periods. Additionally, the electric signal generated during the discharging phase was utilized for monitoring water biotoxicity. Functional genes related to formate metabolism were identified in the bioanode and electrochemically active bacteria were discovered. On the other hand, Paracoccus was predominantly found in the used air cathode. These results advance our current knowledge of exploiting biohybrid technology.
Topics: Electrochemistry; Carbon Dioxide; Formates; Electrolysis
PubMed: 37801326
DOI: 10.1002/anie.202312147 -
Environmental Research Jul 2024With the continuous development of intensive mariculture, the application of the integrated bioremediation system of aquaculture wastewater (IBSAW) is increasingly...
With the continuous development of intensive mariculture, the application of the integrated bioremediation system of aquaculture wastewater (IBSAW) is increasingly promoted. However, the process and nutrients removal performance of the IBSAW need to be further optimized due to its immature technologies. In this study, exogenous compound bacteria (ECB) were added to IBSAW to investigate its pollutants removal efficiency and the relevant mechanisms. High-throughput sequencing and Geochip gene array were used to analyze the correlation between nutrients and bacteria, and the abundance of N and P cycling genes were quantified. Multivariable statistics, dimensionality reduction analysis, and network analysis were applied to explore the mechanisms of IBSAW operation. The results showed that the nutrients decreased significantly after adding ECB, with the brush treatment group significantly outperforming the ceramsite in removing NO and PO. Ceramsite has an advantage in removing NO-N. The addition of ECB and different substrates significantly affected the composition of bacterial communities. The contents of nosZ and nirKS related to denitrification in the treatment groups were significantly higher than those in the control group, and the contents in the brush treatment group were significantly higher than that of ceramsite. The biomarkers Psychroserpens and Ruegeria on the biofilm of the brush treatment group were positively correlated with nirKS, while Mycobacterium, Erythrobacter and Paracoccus, Pseudohaliea in the ceramsite group were positively correlated with nirS and nirK, respectively. Therefore, it is speculated that the ECB significantly promoted the increase of denitrification bacteria by affecting the composition of bacterial communities, and the ECB combined with functional genera improved the efficiency of nutrients removal in the system. This study provided a reference for understanding the process and mechanism of nutrients removal, optimizing the wastewater purification technology of the IBSAW and improving the performance of the system.
Topics: Biodegradation, Environmental; Bacteria; Wastewater; Phosphorus; Aquaculture; Nitrogen; Waste Disposal, Fluid; Water Pollutants, Chemical
PubMed: 38574987
DOI: 10.1016/j.envres.2024.118864