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1.
Microb Cell Fact ; 23(1): 101, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38566056

RESUMEN

BACKGROUND: Short-chain fatty acids (SCFAs) are cost-effective carbon sources for an affordable production of lipids. Hexanoic acid, the acid with the longest carbon chain in the SCFAs pool, is produced in anaerobic fermentation of organic residues and its use is very challenging, even inhibiting oleaginous yeasts growth. RESULTS: In this investigation, an adaptive laboratory evolution (ALE) was performed to improve Yarrowia lipolytica ACA DC 50109 tolerance to high hexanoic acid concentrations. Following ALE, the transcriptomic analysis revealed several genetic adaptations that improved the assimilation of this carbon source in the evolved strain compared to the wild type (WT). Indeed, the evolved strain presented a high expression of the up-regulated gene YALI0 E16016g, which codes for FAT1 and is related to lipid droplets formation and responsible for mobilizing long-chain acids within the cell. Strikingly, acetic acid and other carbohydrate transporters were over-expressed in the WT strain. CONCLUSIONS: A more tolerant yeast strain able to attain higher lipid content under the presence of high concentrations of hexanoic acid has been obtained. Results provided novel information regarding the assimilation of hexanoic acid in yeasts.


Asunto(s)
Yarrowia , Fermentación , Yarrowia/metabolismo , Caproatos/metabolismo , Ácidos Grasos Volátiles/metabolismo , Ácidos Grasos/metabolismo , Ácidos/metabolismo , Perfilación de la Expresión Génica , Carbono/metabolismo
2.
Microbiome ; 12(1): 68, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38570877

RESUMEN

BACKGROUND: The trophic strategy is one key principle to categorize microbial lifestyles, by broadly classifying microorganisms based on the combination of their preferred carbon sources, electron sources, and electron sinks. Recently, a novel trophic strategy, i.e., chemoorganoautotrophy-the utilization of organic carbon as energy source but inorganic carbon as sole carbon source-has been specifically proposed for anaerobic methane oxidizing archaea (ANME-1) and Bathyarchaeota subgroup 8 (Bathy-8). RESULTS: To further explore chemoorganoautotrophy, we employed stable isotope probing (SIP) of nucleic acids (rRNA or DNA) using unlabeled organic carbon and 13C-labeled dissolved inorganic carbon (DIC), i.e., inverse stable isotope labeling, in combination with metagenomics. We found that ANME-1 archaea actively incorporated 13C-DIC into RNA in the presence of methane and lepidocrocite when sulfate was absent, but assimilated organic carbon when cellulose was added to incubations without methane additions. Bathy-8 archaea assimilated 13C-DIC when lignin was amended; however, their DNA was derived from both inorganic and organic carbon sources rather than from inorganic carbon alone. Based on SIP results and supported by metagenomics, carbon transfer between catabolic and anabolic branches of metabolism is possible in these archaeal groups, indicating their anabolic versatility. CONCLUSION: We provide evidence for the incorporation of the mixed organic and inorganic carbon by ANME-1 and Bathy-8 archaea in the environment. Video Abstract.


Asunto(s)
Archaea , Metano , Archaea/genética , Marcaje Isotópico , Oxidación-Reducción , Metano/metabolismo , Carbono/metabolismo , ADN , Anaerobiosis , Sedimentos Geológicos , Filogenia
3.
Sci Rep ; 14(1): 7899, 2024 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-38570566

RESUMEN

Hutchison's niche theory suggests that coexisting competing species occupy non-overlapping hypervolumes, which are theoretical spaces encompassing more than three dimensions, within an n-dimensional space. The analysis of multiple stable isotopes can be used to test these ideas where each isotope can be considered a dimension of niche space. These hypervolumes may change over time in response to variation in behaviour or habitat, within or among species, consequently changing the niche space itself. Here, we use isotopic values of carbon and nitrogen of ten amino acids, as well as sulphur isotopic values, to produce multi-isotope models to examine niche segregation among an assemblage of five coexisting seabird species (ancient murrelet Synthliboramphus antiquus, double-crested cormorant Phalacrocorax auritus, Leach's storm-petrel Oceanodrama leucorhoa, rhinoceros auklet Cerorhinca monocerata, pelagic cormorant Phalacrocorax pelagicus) that inhabit coastal British Columbia. When only one or two isotope dimensions were considered, the five species overlapped considerably, but segregation increased in more dimensions, but often in complex ways. Thus, each of the five species occupied their own isotopic hypervolume (niche), but that became apparent only when factoring the increased information from sulphur and amino acid specific isotope values, rather than just relying on proxies of δ15N and δ13C alone. For cormorants, there was reduction of niche size for both species consistent with a decline in their dominant prey, Pacific herring Clupea pallasii, from 1970 to 2006. Consistent with niche theory, cormorant species showed segregation across time, with the double-crested demonstrating a marked change in diet in response to prey shifts in a higher dimensional space. In brief, incorporating multiple isotopes (sulfur, PC1 of δ15N [baselines], PC2 of δ15N [trophic position], PC1 and PC2 of δ13C) metrics allowed us to infer changes and differences in food web topology that were not apparent from classic carbon-nitrogen biplots.


Asunto(s)
Aminoácidos , Charadriiformes , Animales , Aminoácidos/metabolismo , Isótopos/metabolismo , Aves/metabolismo , Nitrógeno/metabolismo , Carbono/metabolismo , Azufre/metabolismo , Isótopos de Nitrógeno/metabolismo , Isótopos de Carbono/metabolismo
4.
Sci Rep ; 14(1): 7885, 2024 04 03.
Artículo en Inglés | MEDLINE | ID: mdl-38570698

RESUMEN

SbtB is a PII-like protein that regulates the carbon-concentrating mechanism (CCM) in cyanobacteria. SbtB proteins can bind many adenyl nucleotides and possess a characteristic C-terminal redox sensitive loop (R-loop) that forms a disulfide bridge in response to the diurnal state of the cell. SbtBs also possess an ATPase/ADPase activity that is modulated by the redox-state of the R-loop. To investigate the R-loop in the cyanobacterium Synechocystis sp. PCC 6803, site-specific mutants, unable to form the hairpin and permanently in the reduced state, and a R-loop truncation mutant, were characterized under different inorganic carbon (Ci) and light regimes. Growth under diurnal rhythm showed a role of the R-loop as sensor for acclimation to changing light conditions. The redox-state of the R-loop was found to impact the binding of the adenyl-nucleotides to SbtB, its membrane association and thereby the CCM regulation, while these phenotypes disappeared after truncation of the R-loop. Collectively, our data imply that the redox-sensitive R-loop provides an additional regulatory layer to SbtB, linking the CO2-related signaling activity of SbtB with the redox state of cells, mainly reporting the actual light conditions. This regulation not only coordinates CCM activity in the diurnal rhythm but also affects the primary carbon metabolism.


Asunto(s)
Carbono , Synechocystis , Carbono/metabolismo , Estructuras R-Loop , Synechocystis/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Nucleótidos/metabolismo , Oxidación-Reducción , Dióxido de Carbono/metabolismo , Fotosíntesis
5.
Fungal Biol ; 128(2): 1664-1674, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38575239

RESUMEN

Although tyrosol is a quorum-sensing molecule of Candida species, it has antifungal activity at supraphysiological concentrations. Here, we studied the effect of tyrosol on the physiology and genome-wide transcription of Aspergillus nidulans to gain insight into the background of the antifungal activity of this compound. Tyrosol efficiently reduced germination of conidia and the growth on various carbon sources at a concentration of 35 mM. The growth inhibition was fungistatic rather than fungicide on glucose and was accompanied with downregulation of 2199 genes related to e.g. mitotic cell cycle, glycolysis, nitrate and sulphate assimilation, chitin biosynthesis, and upregulation of 2250 genes involved in e.g. lipid catabolism, amino acid degradation and lactose utilization. Tyrosol treatment also upregulated genes encoding glutathione-S-transferases (GSTs), increased specific GST activities and the glutathione (GSH) content of the cells, suggesting that A. nidulans can detoxify tyrosol in a GSH-dependent manner even though this process was weak. Tyrosol did not induce oxidative stress in this species, but upregulated "response to nutrient levels", "regulation of nitrogen utilization", "carbon catabolite activation of transcription" and "autophagy" genes. Tyrosol may have disturbed the regulation and orchestration of cellular metabolism, leading to impaired use of nutrients, which resulted in growth reduction.


Asunto(s)
Antifúngicos , Aspergillus nidulans , Alcohol Feniletílico/análogos & derivados , Antifúngicos/farmacología , Antifúngicos/metabolismo , Transcriptoma , Glutatión/genética , Glutatión/metabolismo , Glutatión/farmacología , Carbono/metabolismo , Regulación Fúngica de la Expresión Génica , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
6.
Funct Plant Biol ; 512024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38588720

RESUMEN

Reproductive development of fruiting trees, including mango (Mangifera indica L.), is limited by non-structural carbohydrates. Competition for sugars increases with cropping, and consequently, vegetative growth and replenishment of starch reserves may reduce with high yields, resulting in interannual production variability. While the effect of crop load on photosynthesis and the distribution of starch within the mango tree has been studied, the contribution of starch and sugars to different phases of reproductive development requires attention. This review focuses on mango and examines the roles of non-structural carbohydrates in fruiting trees to clarify the repercussions of crop load on reproductive development. Starch buffers the plant's carbon availability to regulate supply with demand, while sugars provide a direct resource for carbon translocation. Sugar signalling and interactions with phytohormones play a crucial role in flowering, fruit set, growth, ripening and retention, as well as regulating starch, sugar and secondary metabolites in fruit. The balance between the leaf and fruit biomass affects the availability and contributions of starch and sugars to fruiting. Crop load impacts photosynthesis and interactions between sources and sinks. As a result, the onset and rate of reproductive processes are affected, with repercussions for fruit size, composition, and the inter-annual bearing pattern.


Asunto(s)
Frutas , Mangifera , Animales , Almidón/metabolismo , Aves , Árboles , Carbono/metabolismo , Azúcares/metabolismo
7.
J Agric Food Chem ; 72(14): 7765-7773, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38556742

RESUMEN

Climate change affects the content and composition of soil organic carbon (SOC). However, warming-induced changes in the SOC compounds remain unknown. Using nuclear magnetic resonance spectroscopy, molecular mixing models, and Fourier transform ion cyclotron resonance mass spectrometry, we analyzed the variations and relationships in molecular compounds in Mollisol with 10-56 g C kg-1 soil-1 by translocating soils under six climate regimes. We found that increased temperature and precipitation were negatively correlated with carbohydrate versus lipid and lignin versus protein. The former was consistent across soils with varying SOC contents, but the latter decreased as the SOC content increased. The carbohydrate-lipid correlations were related to dithionite-citrate-extractable Fe, while the lignin-protein correlations were linked to changes in moisture and pyrophosphate-extractable Fe/Al. Our findings indicate that the reduction in the mineral protection of SOC is associated with molecular alterations in SOC under warming conditions.


Asunto(s)
Carbono , Suelo , Suelo/química , Carbono/metabolismo , Lignina , Lípidos , Carbohidratos
8.
Mycorrhiza ; 34(1-2): 33-44, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38520554

RESUMEN

Although the absence of normal leaves is often considered a sign of full heterotrophy, some plants remain at least partially autotrophic despite their leafless habit. Leafless orchids with green stems and capsules probably represent a late evolutionary stage toward full mycoheterotrophy and serve as valuable models for understanding the pathways leading to this nutritional strategy. In this study, based on molecular barcoding and isotopic analysis, we explored the physiological ecology of the leafless orchid Eulophia zollingeri, which displays green coloration, particularly during its fruiting phase. Although previous studies had shown that E. zollingeri, in its adult stage, is associated with Psathyrellaceae fungi and exhibits high 13C isotope signatures similar to fully mycoheterotrophic orchids, it remained uncertain whether this symbiotic relationship is consistent throughout the orchid's entire life cycle and whether the orchid relies exclusively on mycoheterotrophy for its nutrition during the fruiting season. Our study has demonstrated that E. zollingeri maintains a specialized symbiotic relationship with Psathyrellaceae fungi throughout all life stages. However, isotopic analysis and chlorophyll data have shown that the orchid also engages in photosynthesis to meet its carbon needs, particularly during the fruiting stage. This research constitutes the first discovery of partial mycoheterotrophy in leafless orchids associated with saprotrophic non-rhizoctonia fungi.


Asunto(s)
Agaricales , Micorrizas , Orchidaceae , Micorrizas/fisiología , Isótopos de Carbono/análisis , Madera/química , Madera/metabolismo , Simbiosis , Carbono/metabolismo , Orchidaceae/microbiología
9.
J Environ Manage ; 356: 120750, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38520849

RESUMEN

The nitrate denitrifying anaerobic methane oxidation-anaerobic ammonia oxidation (DAMO-anammox) can accomplish nitrogen removal and methane (CH4) reduction. This process greatly contributes to carbon emission mitigation and carbon neutrality. In this study, we investigated the electron transfer process of functional microorganisms in the iron-mediated DAMO-anammox system. Fe3+ could be bound to several functional groups (-CH3, COO-, -CH) in extracellular polymeric substance (EPS), and the functional groups bound were different at different iron concentration. Fe3+ underwent reduction reactions to produce Fe2+. Most Fe3+ and Fe2+ react with microorganisms and formed chelates with EPS. Three-dimensional fluorescence spectra showed that Fe3+ affected the secretion of tyrosine and tryptophan, which were essential for cytochrome synthesis. The presence of Fe3+ accelerated c-type cytochrome-mediated extracellular electron transfer (EET), and when more Fe3+ existed, the more cytochrome C expressed. DAMO archaea (M. nitroreducens) in the system exhibited a high positive correlation with the functional genes (resa and ccda) for cytochrome c synthesis. Some denitrifying microorganisms showed positive correlations with the abundance of riboflavin. This finding showed that riboflavin secreted by functional microorganisms acted as an electron shuttle. In addition, DAMO archaea were positively correlated with the hair synthesis gene pily1, which indicated that direct interspecies electron transfer (DIET) may exist in the iron-mediated DAMO-anammox system.


Asunto(s)
Compuestos de Amonio , Hierro , Oxidación Anaeróbica del Amoníaco , Matriz Extracelular de Sustancias Poliméricas/metabolismo , Citocromos c/metabolismo , Electrones , Desnitrificación , Anaerobiosis , Archaea , Oxidación-Reducción , Metano , Carbono/metabolismo , Riboflavina/metabolismo , Reactores Biológicos , Compuestos de Amonio/metabolismo , Nitrógeno/metabolismo , Nitritos/metabolismo
10.
J Hazard Mater ; 469: 134095, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38521035

RESUMEN

Biogenic manganese oxides (BioMnOx) produced by Mn(II)-oxidizing bacteria (MnOB) have garnered considerable attention for their exceptional adsorption and oxidation capabilities. However, previous studies have predominantly focused on the role of BioMnOx, neglecting substantial investigation into MnOB themselves. Meanwhile, whether the xenobiotics could support the growth of MnOB as the sole carbon source remains uncertain. In this study, we isolated a strain termed Pseudomonas sp. AN-1, capable of utilizing phenol as the sole carbon source. The degradation of phenol took precedence over the accumulation of BioMnOx. In the presence of 100 mg L-1 phenol and 100 µM Mn(II), phenol was entirely degraded within 20 h, while Mn(II) was completely oxidized within 30 h. However, at the higher phenol concentration (500 mg L-1), phenol degradation reduced to 32% and Mn(II) oxidation did not appear to occur. TOC determination confirmed the ability of strain AN-1 to mineralize phenol. Based on the genomic and proteomics studies, the Mn(II) oxidation and phenol mineralization mechanism of strain AN-1 was further confirmed. Proteome analysis revealed down-regulation of proteins associated with Mn(II) oxidation, including MnxG and McoA, with increasing phenol concentration. Notably, this study observed for the first time that the expression of Mn(II) oxidation proteins is modulated by the concentration of carbon sources. This work provides new insight into the interaction between xenobiotics and MnOB, thus revealing the complexity of biogeochemical cycles of Mn and C.


Asunto(s)
Fenol , Pseudomonas , Fenol/metabolismo , Pseudomonas/metabolismo , Xenobióticos/metabolismo , Óxidos/metabolismo , Oxidación-Reducción , Compuestos de Manganeso/metabolismo , Fenoles/metabolismo , Bacterias/metabolismo , Carbono/metabolismo
11.
Ecol Appl ; 34(3): e2967, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38469663

RESUMEN

The future ecosystem carbon cycle has important implications for biosphere-climate feedback. The magnitude of future plant growth and carbon accumulation depends on plant strategies for nutrient uptake under the stresses of nitrogen (N) versus phosphorus (P) limitations. Two archetypal theories have been widely acknowledged in the literature to represent N and P limitations on ecosystem processes: Liebig's Law of the Minimum (LLM) and the Multiple Element Limitation (MEL) approach. LLM states that the more limiting nutrient controls plant growth, and commonly leads to predictions of dramatically dampened ecosystem carbon accumulation over the 21st century. Conversely, the MEL approach recognizes that plants possess multiple pathways to coordinate N and P availability and invest resources to alleviate N or P limitation. We implemented these two contrasting approaches in the E3SM model, and compiled 98 in situ forest N or P fertilization experiments to evaluate how terrestrial ecosystems will respond to N and P limitations. We find that MEL better captured the observed plant responses to nutrient perturbations globally, compared with LLM. Furthermore, LLM and MEL diverged dramatically in responses to elevated CO2 concentrations, leading to a two-fold difference in CO2 fertilization effects on Net Primary Productivity by the end of the 21st century. The larger CO2 fertilization effects indicated by MEL mainly resulted from plant mediation on N and P resource supplies through N2 fixation and phosphatase activities. This analysis provides quantitative evidence of how different N and P limitation strategies can diversely affect future carbon and nutrient dynamics.


Asunto(s)
Dióxido de Carbono , Ecosistema , Dióxido de Carbono/metabolismo , Nitrógeno/metabolismo , Fósforo/análisis , Plantas , Carbono/metabolismo , Suelo
12.
Plant Physiol Biochem ; 208: 108502, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38492486

RESUMEN

Gamma-aminobutyric acid (GABA) is an amino acid with a four-carbon structure, widely distributed in various organisms. It exists as a zwitterion, possessing both positive and negative charges, enabling it to interact with other molecules and participate in numerous physiological processes. GABA is widely distributed in various plant cell compartments such as cytoplasm mitochondria, vacuoles, peroxisomes, and plastids. GABA is primarily synthesized from glutamate using glutamate decarboxylase and participates in the GABA shunt within mitochondria, regulating carbon and nitrogen metabolism in plants The transport of GABA is regulated by several intracellular and intercellular transporters such as aluminium-activated malate transporters (ALMTs), GABA transporters (GATs), bidirectional amino acid transporters (BATs), and cationic amino acid transporters (CATs). GABA plays a vital role in cellular transformations, gene expression, cell wall modifications, and signal transduction in plants. Recent research has unveiled the role of GABA as a signaling molecule in plants, regulating stomatal movement and pollen tube growth. This review provides insights into multifaceted impact of GABA on physiological and biochemical traits in plants, including cellular communication, pH regulation, Krebs cycle circumvention, and carbon and nitrogen equilibrium. The review highlights involvement of GABA in improving the antioxidant defense system of plants, mitigating levels of reactive oxygen species under normal and stressed conditions. Moreover, the interplay of GABA with other plant growth regulators (PGRs) have also been explored.


Asunto(s)
Plantas , Ácido gamma-Aminobutírico , Ácido gamma-Aminobutírico/metabolismo , Plantas/metabolismo , Carbono/metabolismo , Estrés Fisiológico/genética , Transducción de Señal , Nitrógeno/metabolismo
13.
J Plant Physiol ; 295: 154203, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38428153

RESUMEN

Root growth and development need proper carbon partitioning between sources and sinks. Photosynthesis products are unloaded from the phloem and enter the root meristem cell by cell. While sugar transporters play a major role in phloem loading, phloem unloading occurs via the plasmodesmata in growing root tips. The aperture and permeability of plasmodesmata strongly influence symplastic unloading. Recent research has dissected the symplastic path for phloem unloading and identified several genes that regulate phloem unloading in the root. Callose turnover and membrane lipid composition alter the shape of plasmodesmata, allowing fine-tuning to adapt phloem unloading to the environmental and developmental conditions. Unloaded sugars act both as an energy supply and as signals to coordinate root growth and development. Increased knowledge of how phloem unloading is regulated enhances our understanding of carbon allocation in plants. In the future, it may be possible to modulate carbon allocation between sources and sinks in a manner that would contribute to increased plant biomass and carbon fixation.


Asunto(s)
Floema , Plantas , Floema/metabolismo , Plantas/metabolismo , Transporte Biológico , Meristema , Carbono/metabolismo
14.
Appl Microbiol Biotechnol ; 108(1): 273, 2024 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-38520566

RESUMEN

An ever-growing body of literature evidences the protective role of polyhydroxyalkanoates (PHAs) against a plethora of mostly physical stressors in prokaryotic cells. To date, most of the research done involved bacterial strains isolated from habitats not considered to be life-challenging or extremely impacted by abiotic environmental factors. Polar region microorganisms experience a multitude of damaging factors in combinations rarely seen in other of Earth's environments. Therefore, the main objective of this investigation was to examine the role of PHAs in the adaptation of psychrophilic, Arctic-derived bacteria to stress conditions. Arctic PHA producers: Acidovorax sp. A1169 and Collimonas sp. A2191, were chosen and their genes involved in PHB metabolism were deactivated making them unable to accumulate PHAs (ΔphaC) or to utilize them (Δi-phaZ) as a carbon source. Varying stressors were applied to the wild-type and the prepared mutant strains and their survival rates were assessed based on CFU count. Wild-type strains with a functional PHA metabolism were best suited to survive the freeze-thaw cycle - a common feature of polar region habitats. However, the majority of stresses were best survived by the ΔphaC mutants, suggesting that the biochemical imbalance caused by the lack of PHAs induced a permanent cell-wide stress response thus causing them to better withstand the stressor application. Δi-phaZ mutants were superior in surviving UV irradiation, hinting that PHA granule presence in bacterial cells is beneficial despite it being biologically inaccessible. Obtained data suggests that the ability to metabolize PHA although important for survival, probably is not the most crucial mechanism in the stress-resistance strategies arsenal of cold-loving bacteria. KEY POINTS: • PHA metabolism helps psychrophiles survive freezing • PHA-lacking psychrophile mutants cope better with oxidative and heat stresses • PHA granule presence enhances the UV resistance of psychrophiles.


Asunto(s)
Polihidroxialcanoatos , Polihidroxialcanoatos/metabolismo , Bacterias/metabolismo , Carbono/metabolismo
15.
Int J Biol Macromol ; 264(Pt 1): 130378, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38428774

RESUMEN

Polyethylene is the most commonly used plastic product, and its biodegradation is a worldwide problem. Latex clearing protein derived from Streptomyces sp. strain K30 (LcpK30) has been reported to be able to break the carbon-carbon double bond inside oxidized polyethylene and is an effective biodegradation enzyme for polyethylene. However, the binding of the substrate to the enzyme was difficult due to the hydrophobic nature of polyethylene. Therefore, to further improve the efficiency of LcpK30, the effect of different anchor peptides on the binding capacity of LcpK30 to the substrate was screened in this study. The results of fluorescence confocal microscopy showed that the anchoring peptide LCI had the most significant improvement in effect and was finally selected for further application in a UV-irradiated PE degradation system. The degradation results showed that LCI was able to improve the degradation efficiency of LcpK30 by approximately 1.15 times in the presence of equimolar amounts of protein compared with wild-type. This study further improves the application of LcpK30 in the field of polyethylene degradation by modification.


Asunto(s)
Látex , Streptomyces , Látex/química , Polietileno , Proteínas Bacterianas/química , Péptidos/metabolismo , Carbono/metabolismo , Biodegradación Ambiental
17.
Bioresour Technol ; 397: 130508, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38431057

RESUMEN

C. pyrenoidosa, a species of microalgae, has been recognized as a viable protein source for human consumption. The primary challenges in this context are the development of an efficient extraction process and the valorization of the resultant waste streams. This study, situated within the paradigm of circular economy, presents an innovative extraction approach that achieved a protein extraction efficiency of 62 %. The extracted protein exhibited remarkable oil-water emulsifying performances, such as uniform morphology with high creaming stability, suggesting a sustainable alternative to conventional emulsifiers. Additionally, hydrothermal liquefaction technique was employed for converting the residual biomass and waste solution from the extraction process into biocrude. A biocrude yield exceeding 40 wt%, characterized by a carbon content of 73 % and a higher heating value of 36 MJ/kg, were obtained. These findings demonstrate the promising potential of microalgae biorefinery, which is significant for paving toward circular economy and zero-waste society.


Asunto(s)
Chlorella , Microalgas , Humanos , Microalgas/metabolismo , Biocombustibles , Carbono/metabolismo , Proteínas/metabolismo , Biomasa
18.
J Agric Food Chem ; 72(11): 5867-5877, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38446418

RESUMEN

De novo biosynthesis of high-value added food additive p-coumaric acid (p-CA) direct from cellulose/hemicellulose is a more sustainable route compared to the chemical route, considering the abundant cellulose/hemicellulose resources. In this study, a novel factory was constructed for the production of p-CA in Yarrowia lipolytica using cellulose/hemicellulose as the sole carbon source. Based on multicopy integration of the TAL gene and reprogramming the shikimic acid pathway, the engineered strain produced 1035.5 ± 67.8 mg/L p-CA using glucose as a carbon source. The strains with overexpression of cellulases and hemicellulases produced 84.3 ± 2.4 and 65.3 ± 4.6 mg/L p-CA, using cellulose (carboxymethyl-cellulose) or hemicellulose (xylan from bagasse) as the carbon source, respectively. This research demonstrated the feasibility of conversion of cost-effective cellulose/hemicellulose into a value-added product and provided a sustainable cellulolytic cell factory for the utilization of cellulose/hemicellulose.


Asunto(s)
Ácidos Cumáricos , Polisacáridos , Yarrowia , Yarrowia/genética , Yarrowia/metabolismo , Ingeniería Metabólica , Celulosa/metabolismo , Carbono/metabolismo
19.
Bioresour Technol ; 398: 130512, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38437960

RESUMEN

The reuse of wastewater after seawater cultivation is critically important. In this study, a phosphorus-supplemented seawater-wastewater cyclic system (PSSWCS) based on Chlorella pyrenoidosa SDEC-35 was developed. With the addition of phosphorus, the algal biomass and the ability to assimilate nitrogen and carbon were improved. At the nitrogen to phosphorus ratio of 20:1, the biomass productivity per mass of nitrogen reached 3.6 g g-1 (N) day-1 in the second cycle. After the third cycle the protein content reached 35.7% of dry mass, and the major metabolic substances in PSSWCS reached the highest content level of 89.5% (35.7% protein, 38.3% lipid, and 15.5% carbohydrate). After the fourth cycle the lipid content maintained at 40.1%. Furthermore, 100.0% recovery of wastewater in PSSWCS increased the nitrogen and carbon absorption to 15.0 and 396.8 g per tonne of seawater. This study achieved seawater-wastewater recycle and produced high-lipid and high-protein algae by phosphorus addition.


Asunto(s)
Chlorella , Microalgas , Aguas Residuales , Chlorella/metabolismo , Microalgas/metabolismo , Biomasa , Nitrógeno/metabolismo , Agua de Mar , Fósforo/metabolismo , Lípidos , Carbono/metabolismo
20.
Sci Total Environ ; 925: 171763, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38494030

RESUMEN

Microbial biofilms are behind microbiologically influenced corrosion (MIC). Sessile cells in biofilms are many times more concentrated volumetrically than planktonic cells in the bulk fluids, thus providing locally high concentrations of chemicals. More importantly, "electroactive" sessile cells in biofilms are capable of utilizing extracellularly supplied electrons (e.g., from elemental Fe) for intracellular reduction of an oxidant such as sulfate in energy metabolism. MIC directly caused by anaerobic biofilms is classified into two main types based on their mechanisms: extracellular electron transfer MIC (EET-MIC) and metabolite MIC (M-MIC). Sulfate-reducing bacteria (SRB) are notorious for their corrosivity. They can cause EET-MIC in carbon steel, but they can also secrete biogenic H2S to corrode other metals such as Cu directly via M-MIC. This study investigated the use of conductive magnetic nanowires as electron mediators to accelerate and thus identify EET-MIC of C1020 by Desulfovibrio vulgaris. The presence of 40 ppm (w/w) nanowires in ATCC 1249 culture medium at 37 °C resulted in 45 % higher weight loss and 57 % deeper corrosion pits after 7-day incubation. Electrochemical tests using linear polarization resistance and potentiodynamic polarization supported the weight loss data trend. These findings suggest that conductive magnetic nanowires can be employed to identify EET-MIC. The use of insoluble 2 µm long nanowires proved that the extracellular section of the electron transfer process is a bottleneck in SRB MIC of carbon steel.


Asunto(s)
Desulfovibrio vulgaris , Desulfovibrio , Nanocables , Humanos , Acero , Electrones , Carbono/metabolismo , Biopelículas , Desulfovibrio/metabolismo , Corrosión , Sulfatos/metabolismo , Pérdida de Peso
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