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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 -
The Science of the Total Environment Aug 2023Many studies have demonstrated that climate change affects the biogeochemical cycle of pollutants, but the mechanisms of arsenic (As) biogeochemical processes under high...
Many studies have demonstrated that climate change affects the biogeochemical cycle of pollutants, but the mechanisms of arsenic (As) biogeochemical processes under high CO levels are unknown. Here, rice pot experiments were carried out to explore the underlying mechanisms of the impacts of elevated CO on the reduction and methylation processes of As in paddy soils. The results revealed that elevated CO might increase As bioavailability and promote As(V)-to-As(III) transformation in the soil as well as higher As(III) and dimethyl arsenate (DMA) accumulation in rice grains, thus increasing health risk. In As-contaminated paddy soil, two key genes involved in the biotransformation of As (arsC and arsM) and associated host microbes were identified as being significantly promoted by increasing CO levels. Elevated CO enriched the soil microbes harboring arsC (Bradyrhizobiaceae and Gallionellaceae), which aided in the reduction of As(V) to As(III). Simultaneously, elevated CO enriched soil microbes harboring arsM (Methylobacteriaceae and Geobacteraceae), allowing As(V) to be reduced to As(III) and then methylated to DMA. The findings of the Incremental Lifetime Cancer Risk (ILTR) assessment suggested that elevated CO exacerbated the individual adult ILTR from rice food As(III) consumption by 9.0 % (p < 0.05). These findings show that elevated CO aggravates the exposure risk of As(III) and DMA in rice grains by changing microbial populations involved in As biotransformation in paddy soils.
Topics: Arsenic; Methylation; Soil; Carbon Dioxide; Oryza; Soil Pollutants
PubMed: 37201836
DOI: 10.1016/j.scitotenv.2023.164240 -
Archives of Microbiology Feb 2024Hydrocarbons are considered as one of the most common and harmful environmental pollutants affecting human health and the environment. Bioremediation as an...
Hydrocarbons are considered as one of the most common and harmful environmental pollutants affecting human health and the environment. Bioremediation as an environmentally friendly, highly efficient, and cost-effective method in remediating oil-contaminated environments has been interesting in recent decades. In this study, hydrocarbon degrader bacterial strains were isolated from the highly petroleum-contaminated soils in the Dehloran oil field in the west of Iran. Out of 37 isolates, 15 can grow on M9 agar medium that contains 1.5 g L of crude oil as the sole carbon source. The morphological, biochemical, and 16SrRNA sequencing analyses were performed for the isolates. The choosing of the isolates as the hydrocarbon degrader was examined by evaluating the efficacy of their crude oil removal at a concentration of 10 g L in an aqueous medium. The results showed that five isolates belonging to Pseudomonas sp., Pseudomonas oryzihabitans, Roseomonas aestuarii, Pantoea agglomerans, and Arthrobacter sp. had a hyper hydrocarbon-degrading activity and they could remove more than 85% of the total petroleum hydrocarbon (TPH) after 96 h. The highest TPH removal of about 95.75% and biodegradation rate of 0.0997 g L h was observed for P. agglomerans. The gas chromatography-mass spectroscopy (GC-MS) analysis was performed during the biodegradation process by P. agglomerans to detect the degradation intermediates and final products. The results confirmed the presence of intermediates such as alcohols and fatty acids in the terminal oxidation pathway of alkanes in this biodegradation process. A promising P. agglomerans NB391 strain can remove aliphatic and aromatic hydrocarbons simultaneously.
Topics: Humans; Pantoea; Petroleum; Iran; Soil Pollutants; Hydrocarbons; Hydrocarbons, Aromatic; Biodegradation, Environmental; Soil; Soil Microbiology
PubMed: 38351169
DOI: 10.1007/s00203-023-03819-y -
Journal of Hazardous Materials Jun 2024Microcystis typically forms colonies under natural conditions, which contributes to occurrence and prevalence of algal blooms. The colonies consist of Microcystis and...
Dissolved organic matter, calcium ion and extracellular polymeric substances on living associated bacteria of Microcystis colony are crucial for unicellular Microcystis to efficiently form colonies.
Microcystis typically forms colonies under natural conditions, which contributes to occurrence and prevalence of algal blooms. The colonies consist of Microcystis and associated bacteria (AB), embedded in extracellular polymeric substances (EPS). Previous studies indicate that AB can induce Microcystis to form colonies, however the efficiency is generally low and results in a uniform morphotype. In this study, by using filtrated natural water, several AB strains induced unicellular M. aeruginosa to form colonies resembling several Microcystis morphotypes. The mechanisms were investigated with Methylobacterium sp. Z5. Ca was necessary for Z5 to induce Microcystis to form colonies, while dissolved organic matters (DOM) facilitated AB to agglomerate Microcystis to form large colonies. EPS of living Z5, mainly the aromatic protein components, played a key role in colony induction. Z5 initially aggregated Microcystis via the bridging effects of Ca and DOM, followed by the induction of EPS synthesis and secretion in Microcystis. In this process, the colony forming mode shifted from cell adhesion to a combination of cell adhesion and cell division. Intriguingly, Z5 drove the genomic rearrangement of Microcystis by upregulating some transposase genes. This study unveiled a novel mechanism about Microcystis colony formation and identified a new driver of Microcystis genomic evolution.
Topics: Microcystis; Calcium; Extracellular Polymeric Substance Matrix; Methylobacterium
PubMed: 38677120
DOI: 10.1016/j.jhazmat.2024.134352 -
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 -
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 -
Chemosphere Mar 2024The increasing concern for environmental remediation has led to a search for effective methods to remove eutrophic nutrients. In this study, Methylobacterium gregans...
The increasing concern for environmental remediation has led to a search for effective methods to remove eutrophic nutrients. In this study, Methylobacterium gregans DC-1 was utilized to improve nitrogen removal in a sequencing batch biofilm reactor (SBBR) via aerobic denitrification. This bacterium has the extraordinary characteristics of strong auto-aggregation and a high ability to remove nitrogen efficiently, making it an ideal candidate for enhanced treatment of nitrogen-rich wastewater. This strain was used for the bioassessment of a test reactor (SBBRbio), which showed a shorter biofilm formation time compared to a control reactor (SBBRcon) without this strain inoculation. Moreover, the enhanced biofilm was enriched in TB-EPS and had a wider variety of protein secondary structures than SBBRcon. During the stabilization phase of SBBRbio, the EPS molecules showed the highest proportion of intermolecular hydrogen bonding. It is possible that bioaugmentation with this strain positively affects the structural stability of biofilm. At influent ammonia loadings of 100 and 150 mg. L, the average reduction of ammonia and nitrate-nitrogen was higher in the experimental system compared to the control system. Additionally, nitrite-N accumulation was lower and NO production decreased compared to the control. Analysis of the microbial community structure demonstrated successful colonization in the bioreactor by a highly nitrogen-tolerant strain that efficiently removed inorganic nitrogen. These results illustrate the great potential of this type of denitrifying bacteria in the application of bioaugmentation systems.
Topics: Denitrification; Ammonia; Nitrogen; Biofilms; Methylobacterium; Bioreactors; Water Purification; Nitrification
PubMed: 38387667
DOI: 10.1016/j.chemosphere.2024.141467 -
Animals : An Open Access Journal From... Apr 2024The gut microbiome significantly influences the health and productivity of silkworms (), the cornerstone of sericulture. With the increasing use of cost-effective...
The gut microbiome significantly influences the health and productivity of silkworms (), the cornerstone of sericulture. With the increasing use of cost-effective artificial diets in sericulture, it is crucial to understand how these diets impact the silkworm gut microbiomes. Here we employed 16S rRNA sequencing to delineate the impact of three distinct dietary regimens on the silkworm gut microbiomes: exclusive mulberry leaf diet (SY), exclusive artificial feed diet (SL), and a sequential transition from artificial feed to mulberry leaves (ZS). Our results unveiled stark differences in microbial diversity across the groups, with the ZS group displaying an intermediary complexity. LefSe and random forest analyses identified Methylobacteriaceae, , and as significantly enriched in the ZS group, suggesting their potential to facilitate silkworms' adaptation to dietary transitions. Functional profiling revealed differential pathway regulation, indicating a metabolic reconfiguration in response to dietary modulations. Notably, the enrichment of and in both the SL and ZS groups highlights their potential as probiotics in artificial diets. Our findings provide insights into the diet adaptation mechanisms of silkworm gut microbiota, paving the way for harnessing the intestinal bacteria to enhance silkworm health and silk production through targeted microbial interventions in sericulture practices.
PubMed: 38731265
DOI: 10.3390/ani14091261 -
PloS One 2024Assessing the microbes present on tree fruit carpospheres as the fruit enters postharvest processing could have useful applications, as these microbes could have a major...
Assessing the microbes present on tree fruit carpospheres as the fruit enters postharvest processing could have useful applications, as these microbes could have a major influence on spoilage, food safety, verification of packing process controls, or other aspects of processing. The goal of this study was to establish a baseline profile of bacterial communities associated with apple (pome fruit), peach (stone fruit), and Navel orange (citrus fruit) at harvest. We found that commercial peaches had the greatest bacterial richness followed by oranges then apples. Time of harvest significantly changed bacterial diversity in oranges and peaches, but not apples. Shifts in diversity varied by fruit type, where 70% of the variability in beta diversity on the apple carposphere was driven by the gain and loss of species (i.e., nestedness). The peach and orange carposphere bacterial community shifts were driven by nearly an even split between turnover (species replacement) and nestedness. We identified a small core microbiome for apples across and between growing seasons that included only Methylobacteriaceae and Sphingomonadaceae among the samples, while peaches had a larger core microbiome composed of five bacterial families: Bacillaceae, Geodermtophilaceae, Nocardioidaceae, Micrococcaeceae, and Trueperaceae. There was a relatively diverse core microbiome for oranges that shared all the families present on apples and peaches, except for Trueperaceae, but also included an additional nine bacterial families not shared including Oxalobacteraceae, Cytophagaceae, and Comamonadaceae. Overall, our findings illustrate the important temporal dynamics of bacterial communities found on major commercial tree fruit, but also the core bacterial families that constantly remain with both implications being important entering postharvest packing and processing.
Topics: Humans; Prunus persica; Seasons; Bacteria; Citrus sinensis; Fruit
PubMed: 38625898
DOI: 10.1371/journal.pone.0297453 -
Archives of Microbiology Jun 2024Ten strains of psychrotolerant methylotrophic bacteria were isolated from the samples collected in Larsemann and Bunger Hills (Antarctica). Most of the isolates are...
Ten strains of psychrotolerant methylotrophic bacteria were isolated from the samples collected in Larsemann and Bunger Hills (Antarctica). Most of the isolates are assigned to the genus Pseudomonas, representatives of the genera Janthinobacterium, Massilia, Methylotenera and Flavobacterium were also found. Majority of isolates were able to grow on a wide range of sugars, methylamines and other substrates. Optimal growth temperatures for the isolated strains varied from 6 °C to 28 °C. The optimal concentration of NaCl was 0.5-2.0%. The optimal pH values of the medium were 6-7. It was found that three strains synthesized indole-3-acetic acid on a medium with L-tryptophan reaching 11-12 μg/ml. The values of intracellular carbohydrates in several strains exceeded 50 μg/ml. Presence of calcium-dependent and lanthanum-dependent methanol dehydrogenase have been shown for some isolates. Strains xBan7, xBan20, xBan37, xBan49, xPrg27, xPrg48, xPrg51 showed the presence of free amino acids. Bioprospection of Earth cryosphere for such microorganisms has a potential in biotechnology.
Topics: Antarctic Regions; Biotechnology; Phylogeny; Indoleacetic Acids; Methylobacteriaceae; Hydrogen-Ion Concentration; RNA, Ribosomal, 16S; Cold Temperature; Sodium Chloride; Culture Media; Tryptophan
PubMed: 38907777
DOI: 10.1007/s00203-024-04056-7