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Ecotoxicology and Environmental Safety Jan 2024The enhanced effects of formaldehyde biodegradation in a biofilm packing tower are investigated in this study. Three experimental groups were established: a blank...
The enhanced effects of formaldehyde biodegradation in a biofilm packing tower are investigated in this study. Three experimental groups were established: a blank control group, a biochar addition group, and a lanthanum addition group. The inlet gas flow rate, the inlet gas concentration, and the structural succession characteristics of the microbial community in the tower were investigated by regular sampling. The intracellular metabolites and key enzymes of the dominant functional bacteria, Pseudomonas P1 and Methylobacterium Q1, in the tower were analyzed. The results indicated that with the biochar addition, the formaldehyde purification efficiency increased significantly from 91.67-94.67 % to 94.12 96.85 %, and the bio-elimination capacity increased with an increase in the inlet gas flow rate from 2.314 to 13.988 mg Lh to 2.697-15.051 mg Lh. With the addition of lanthanum, the purification efficiency increased significantly from 90.80-93.98 % to 94.36-96.78 %, and the bio-elimination capacity increased with an increase in the inlet gas concentration from 1.099-11.284 mg Lh to 1.266-11.961 mg Lh. The microbial community structure in the tower changed with system operation, and the formaldehyde degrading functional bacteria formed the dominant bacteria. It was verified that P1 and Q1 metabolized high concentrations of formaldehyde by the serine cycle and the ribulose monophosphate (RuMP) cycle.
Topics: Lanthanum; Biodegradation, Environmental; Formaldehyde; Bacteria; Charcoal
PubMed: 38150844
DOI: 10.1016/j.ecoenv.2023.115857 -
Environmental Science & Technology Jan 2024Chemical methods for the extraction and refinement of technologically critical rare earth elements (REEs) are energy-intensive, hazardous, and environmentally...
Chemical methods for the extraction and refinement of technologically critical rare earth elements (REEs) are energy-intensive, hazardous, and environmentally destructive. Current biobased extraction systems rely on extremophilic organisms and generate many of the same detrimental effects as chemical methodologies. The mesophilic methylotrophic bacterium AM1 was previously shown to grow using electronic waste by naturally acquiring REEs to power methanol metabolism. Here we show that growth using electronic waste as a sole REE source is scalable up to 10 L with consistent metal yields without the use of harsh acids or high temperatures. The addition of organic acids increases REE leaching in a nonspecific manner. REE-specific bioleaching can be engineered through the overproduction of REE-binding ligands (called lanthanophores) and pyrroloquinoline quinone. REE bioaccumulation increases with the leachate concentration and is highly specific. REEs are stored intracellularly in polyphosphate granules, and genetic engineering to eliminate exopolyphosphatase activity increases metal accumulation, confirming the link between phosphate metabolism and biological REE use. Finally, we report the innate ability of to grow using other complex REE sources, including pulverized smartphones, demonstrating the flexibility and potential for use as a recovery platform for these critical metals.
Topics: Metals, Rare Earth; Metals; Electronic Waste; Ligands
PubMed: 38150661
DOI: 10.1021/acs.est.3c06775 -
Tropical Life Sciences Research Jun 2023A bacterium was isolated from sludge-contaminated soil in a petroleum refinery and tested for its ability to degrade aliphatic hydrocarbon compounds present in petroleum...
A bacterium was isolated from sludge-contaminated soil in a petroleum refinery and tested for its ability to degrade aliphatic hydrocarbon compounds present in petroleum sludge. The isolate was grown on minimal salt media agar supplemented with 1% (w/v) petroleum sludge. The isolate was tentatively identified as s p. s t rain ZASH based on the partial 16s rDNA molecular phylogeny. The bacterium grew optimally between the temperatures of 30°C and 35°C, pH 7 and 7.5, 0.5% and 1.5% (v/v) Tween 80 as the surfactant, and between 1% and 2% (w/v) peptone as the nitrogen source. The constants derived from the Haldane equation were μmax = 0.039 hr, = 0.385% (w/v) total petroleum hydrocarbons (TPH) or 3,850 mg/L TPH, and =1.12% (w/v) TPH or 11,200 mg/L. The maximum biodegradation rate exhibited by this strain was 19 mg/L/hr at an initial TPH concentration of 10,000 mg/L. Gas chromatography analysis revealed that after 15 days the strain was able to degrade all aliphatic n-alkanes investigated with different efficiencies. Shorter n-alkanes were generally degraded more rapidly than longer n-alkanes with 90% removal for C-12 compared to only 30% removal for C-36. The addition of sawdust did not improve bacterial degradation of petroleum hydrocarbons, but it assisted in the removal of remaining undegraded hydrocarbons through adsorption.
PubMed: 38144383
DOI: 10.21315/tlsr2023.34.2.10 -
Journal of Environmental Sciences... May 2024Dichloromethane (DCM) has been listed as a toxic and harmful water pollutant, and its removal needs attention. Microbial electrolysis cells (MECs) are viewed as a...
Dichloromethane (DCM) has been listed as a toxic and harmful water pollutant, and its removal needs attention. Microbial electrolysis cells (MECs) are viewed as a promising alternative for pollutant removal, which can be strengthened from two aspects: microbial inoculation and acclimation. In this study, the MEC for DCM degradation was inoculated with the active sludge enhanced by Methylobacterium rhodesianum H13 (strain H13) and then acclimated in the form of a microbial fuel cell (MFC). Both the introduction of strain H13 and the initiation in MFC form significantly promoted DCM degradation. The degradation kinetics were fitted by the Haldane model, with V, K, K and v values of 103.2 mg/L/hr, 97.8 mg/L, 268.3 mg/L and 44.7 mg/L/hr/cm, respectively. The cyclic voltammogram implies that DCM redox reactions became easier with the setup of MEC, and the electrochemical impedance spectrogram shows that the acclimated and enriched microbes reduced the charge transfer resistance from the electrode to the electrolyte. In the biofilm, the dominant genera shifted from Geobacter to Hyphomicrobium in acclimation stages. Moreover, Methylobacterium played an increasingly important role. DCM metabolism mainly occurred through the hydrolytic glutathione S-transferase pathway, given that the gene dcmA was identified rather than the dhlA and P450/MO. The exogenous electrons facilitated the reduction of GSSG, directly or indirectly accelerating the GSH-catalyzed dehalogenation. This study provides support for the construction of an efficient and stable MEC for DCM removal in water environment.
Topics: Methylene Chloride; Electrolysis; Kinetics; Bioelectric Energy Sources; Microbiota; Electrodes
PubMed: 38105043
DOI: 10.1016/j.jes.2023.05.029 -
MBio Jan 2024Bacteria known as pink-pigmented facultative methylotrophs colonize many diverse environments on earth, play an important role in the carbon cycle, and in some cases...
Bacteria known as pink-pigmented facultative methylotrophs colonize many diverse environments on earth, play an important role in the carbon cycle, and in some cases promote plant growth. However, little is known about how these organisms interact with each other and their environment. In this work, we identify one of the chemical signals commonly used by these bacteria and discover that this signal controls swarming motility in the pink-pigmented facultative methylotroph DSM5686. This work provides new molecular details about interactions between these important bacteria and will help scientists predict these interactions and the group behaviors they regulate from genomic sequencing information.
Topics: Quorum Sensing; Acyl-Butyrolactones; Methylobacterium
PubMed: 38085021
DOI: 10.1128/mbio.01999-23 -
BioRxiv : the Preprint Server For... Nov 2023The influence of lanthanide biochemistry during methylotrophy demands a reassessment of how the composition and metabolic potential of methylotrophic phyllosphere...
The influence of lanthanide biochemistry during methylotrophy demands a reassessment of how the composition and metabolic potential of methylotrophic phyllosphere communities are affected by the presence of these metals. To investigate this, methylotrophs were isolated from soybean leaves by selecting for bacteria capable of methanol oxidation with lanthanide cofactors. Of the 344 pink-pigmented facultative methylotroph isolates, none were obligately lanthanide-dependent. Phylogenetic analyses revealed that all strains were nearly identical to each other and to model strains from the clade of , with providing higher resolution than 16s RNA for strain-specific identification. Despite the low species diversity, the metabolic capabilities of the community diverged greatly. Strains encoding identical PQQ-dependent alcohol dehydrogenases displayed significantly different growth from each other on alcohols in the presence and absence of lanthanides. Several strains also lacked well-characterized lanthanide-associated genes thought to be important for phyllosphere colonization. Additionally, 3% of our isolates were capable of growth on sugars and 23% were capable of growth on aromatic acids, substantially expanding the range of multicarbon substrates utilized by members of the clade in the phyllosphere. Whole genome sequences of eleven novel strains are reported. Our findings suggest that the expansion of metabolic capabilities, as well as differential usage of lanthanides and their influence on metabolism among closely related strains, point to evolution of niche partitioning strategies to promote colonization of the phyllosphere.
PubMed: 38077020
DOI: 10.1101/2023.06.28.546956 -
Environmental Pollution (Barking, Essex... Feb 2024While traditional culture-dependent methods can effectively detect certain microorganisms, the comprehensive composition of the municipal drinking water (DW) microbiome,...
While traditional culture-dependent methods can effectively detect certain microorganisms, the comprehensive composition of the municipal drinking water (DW) microbiome, including bacteria, archaea, and viruses, remains unknown. Metagenomic sequencing has opened the door to accurately determine and analyze the entire microbial community of DW, providing a comprehensive understanding of DW species diversity, especially in the context of public health concerns during the COVID-19 era. In this study, we found that most of the culturable bacteria and some fecal indicator bacteria, such as Escherichia coli and Pseudomonas aeruginosa, were non-culturable using culture-dependent methods in all samples. However, metagenomic analysis showed that the predominant bacterial species in the DW samples belonged to the phyla Proteobacteria and Planctomycetes. Notably, the genus Methylobacterium was the most abundant in all water samples, followed by Sphingomonas, Gemmata, and Azospirilum. While low levels of virulence-associated factors, such as the Esx-5 type VII secretion system (T7SS) and DevR/S, were detected, only the erythromycin resistance gene erm(X), an rRNA methyltransferase, was identified at low abundance in one sample. Hosts corresponding to virulence and resistance genes were identified in some samples, including Mycobacterium spp. Archaeal DNA (Euryarchaeota, Crenarchaeota) was found in trace amounts in some DW samples. Viruses such as rotavirus, coxsackievirus, human enterovirus, and SARS-CoV-2 were negative in all DW samples using colloidal gold and real-time reverse transcription polymerase chain reaction (RT‒PCR) methods. However, DNA encoding a new order of reverse-transcribing viruses (Ortervirales) and Herpesvirales was found in some DW samples. The metabolic pathways of the entire microbial community involve cell‒cell communication and signal secretion, contributing to cooperation between different microbial populations in the water. This study provides insight into the microbial community and metabolic process of DW in Hangzhou, China, utilizing both culture-dependent methods and metagenomic sequencing combined with bioinformatics tools during the COVID-19 pandemic era.
Topics: Humans; Drinking Water; Pandemics; Bacteria; Archaea; Microbiota; RNA, Ribosomal, 16S
PubMed: 38048871
DOI: 10.1016/j.envpol.2023.123066 -
The Science of the Total Environment Feb 2024Airborne microorganisms are important parts of the Moutai-flavor Baijiu brewing microbial community, which directly affects the quality of Baijiu. However, environmental...
Airborne microorganisms are important parts of the Moutai-flavor Baijiu brewing microbial community, which directly affects the quality of Baijiu. However, environmental factors usually shape airborne microbiomes in different distilleries, even in the different production areas of the same distillery. Unfortunately, current understanding of environmental factors shaping airborne microbiomes in distilleries is very limited. To bridge this gap, we compared airborne microbiomes in the Moutai-flavor Baijiu core production areas of different distilleries in the Chishui River Basin and systematically investigated the key environmental factors that shape the airborne microbiomes. The top abundant bacterial communities are mainly affiliated to the phyla Actinobacteriota, Firmicutes, and Proteobacteri, whereas Ascomycota and Basidiomycota are the predominant fungal communities. The Random Forest analysis indicated that the biomarkers in three distilleries are Saccharomonospora and Bacillus, Thermoactinomyces, Oceanobacillus, and Methylobacterium, which are the core functional flora contributing to the production of Daqu. The correlation and network analyses showed that the distillery age and environmental temperature have a strong regulatory effect on airborne microbiomes, suggesting that the fermentation environment has a domesticating effect on air microbiomes. Our findings will greatly help us understand the relationship between airborne microbiomes and environmental factors in distilleries and support the production of the high-quality Moutai-flavor Baijiu.
Topics: Bacillaceae; Bacillus; Fermentation; Firmicutes; Methylobacterium
PubMed: 38040348
DOI: 10.1016/j.scitotenv.2023.169010 -
Bioresource Technology Feb 2024This study explored the potential of methanol as a sustainable feedstock for biomanufacturing, focusing on Methylobacterium extorquens, a well-established representative...
This study explored the potential of methanol as a sustainable feedstock for biomanufacturing, focusing on Methylobacterium extorquens, a well-established representative of methylotrophic cell factories. Despite this bacterium's long history, its untapped photosynthetic capabilities for production enhancement have remained unreported. Using genome-scale flux balance analysis, it was hypothesized that introducing photon fluxes could boost the yield of 3-hydroxypropionic acid (3-HP), an energy- and reducing equivalent-consuming chemicals. To realize this, M. extorquens was genetically modified by eliminating the negative regulator of photosynthesis, leading to improved ATP levels and metabolic activity in non-growth cells during a two-stage fermentation process. This modification resulted in a remarkable 3.0-fold increase in 3-HP titer and a 2.1-fold increase in its yield during stage (II). Transcriptomics revealed that enhanced light-driven methanol oxidation, NADH transhydrogenation, ATP generation, and fatty acid degradation were key factors. This development of photo-methylotrophy as a platform technology introduced novel opportunities for future production enhancements.
Topics: Methylobacterium; Fermentation; Methanol; Adenosine Triphosphate; Metabolic Engineering; Lactic Acid
PubMed: 38008225
DOI: 10.1016/j.biortech.2023.130104 -
Microorganisms Nov 2023is the causal agent of several plant diseases affecting fruit and nut crops. strain SR1.6/6 was isolated from and shown to promote plant growth by producing...
is the causal agent of several plant diseases affecting fruit and nut crops. strain SR1.6/6 was isolated from and shown to promote plant growth by producing phytohormones, providing nutrients, inhibiting , and preventing Citrus Variegated Chlorosis. However, the molecular mechanisms involved in the interaction among these microbes are still unclear. The present work aimed to analyze physiological and molecular aspects of SR1.6/6 and 9a5c in co-culture. The transcriptome and secretome analyses indicated that down-regulates cell division and transport genes and up-regulates stress via induction of chaperones and pathogenicity-related genes including, the lipase-esterase LesA, a protease, as well as an oligopeptidase in response to competition. On the other hand, also down-regulated transport genes, except for iron uptake, which was up-regulated. Secretome analysis identified four proteins in exclusively produced in co-culture with , among these, three are related to phosphorous uptake. These results suggest that inhibits growth mainly due to nutrient competition for iron and phosphorous, thus promoting starvation, besides producing enzymes that degrade cell wall, mainly hydrolases. The understanding of these interactions provides a direction for control and management of the phytopathogen , and consequently, helps to improve citrus growth and productivity.
PubMed: 38004766
DOI: 10.3390/microorganisms11112755