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Communications Biology May 2024Although a low temperature limit for life has not been established, it is thought that there exists a physical limit imposed by the onset of intracellular vitrification,...
Although a low temperature limit for life has not been established, it is thought that there exists a physical limit imposed by the onset of intracellular vitrification, typically occurring at ~-20 °C for unicellular organisms. Here, we show, through differential scanning calorimetry, that molar concentrations of magnesium perchlorate can depress the intracellular vitrification point of Bacillus subtilis cells to temperatures much lower than those previously reported. At 2.5 M Mg(ClO), the peak vitrification temperature was lowered to -83 °C. Our results show that inorganic eutectic salts can in principle maintain liquid water in cells at much lower temperatures than those previously claimed as a lower limit to life, raising the prospects of active biochemical processes in low temperature natural settings. Our results may have implications for the habitability of Mars, where perchlorate salts are pervasive and potentially other terrestrial and extraterrestrial, cryosphere environments.
Topics: Bacillus subtilis; Perchlorates; Cold Temperature; Vitrification; Calorimetry, Differential Scanning
PubMed: 38755264
DOI: 10.1038/s42003-024-06277-4 -
Microbial Cell Factories May 2024Increasing concerns about climate change and global petroleum supply draw attention to the urgent need for the development of alternative methods to produce fuels....
BACKGROUND
Increasing concerns about climate change and global petroleum supply draw attention to the urgent need for the development of alternative methods to produce fuels. Consequently, the scientific community must devise novel ways to obtain fuels that are both sustainable and eco-friendly. Bacterial alkanes have numerous potential applications in the industry sector. One significant application is biofuel production, where bacterial alkanes can serve as a sustainable eco-friendly alternative to fossil fuels. This study represents the first report on the production of alkanes by endophytic bacteria.
RESULTS
In this study, three Bacillus species, namely Bacillus atrophaeus Camph.1 (OR343176.1), Bacillus spizizenii Camph.2 (OR343177.1), and Bacillus aerophilus Camph.3 (OR343178.1), were isolated from the leaves of C. camphora. The isolates were then screened to determine their ability to produce alkanes in different culture media including nutrient broth (NB), Luria-Bertani (LB) broth, and tryptic soy broth (TSB). Depending on the bacterial isolate and the culture media used, different profiles of alkanes ranging from C to C were detected.
CONCLUSIONS
The endophytic B. atrophaeus Camph.1 (OR343176.1), B. spizizenii Camph.2 (OR343177.1), and B. aerophilus Camph.3 (OR343178.1), associated with C. camphora leaves, represent new eco-friendly approaches for biofuel production, aiming towards a sustainable future. Further research is needed to optimize the fermentation process and scale up alkane production by these bacterial isolates.
Topics: Bacillus; Biofuels; Cinnamomum camphora; Alkanes; Plant Leaves; Endophytes; Culture Media
PubMed: 38750603
DOI: 10.1186/s12934-024-02402-4 -
Frontiers in Cellular and Infection... 2024Exploring the effect of SJQJD on the pulmonary microbiota of chronic obstructive pulmonary disease (COPD) rats through 16S ribosomal RNA (rRNA) sequencing.
OBJECTIVE
Exploring the effect of SJQJD on the pulmonary microbiota of chronic obstructive pulmonary disease (COPD) rats through 16S ribosomal RNA (rRNA) sequencing.
METHODS
A COPD rat model was constructed through smoking and lipopolysaccharide (LPS) stimulation, and the efficacy of SJQJD was evaluated by hematoxylin and eosin (H&E) staining and Enzyme-Linked Immunosorbnent Assay (ELISA). The alveolar lavage fluid of rats was subjected to 16S rRNA sequencing. The diversity of lung microbiota composition and community structure was analyzed and differential microbiota were screened. Additionally, machine learning algorithms were used for screening biomarkers of each group of the microbiota.
RESULTS
SJQJD could improve lung structure and inflammatory response in COPD rats. 16s rRNA sequencing analysis showed that SJQJD could significantly improve the abundance and diversity of bacterial communities in COPD rats. Through differential analysis and machine learning methods, potential microbial biomarkers were identified as , , and .
CONCLUSION
SJQJD could improve tissue morphology and local inflammatory response in COPD rats, and its effect may be related to improve pulmonary microbiota.
Topics: Pulmonary Disease, Chronic Obstructive; Animals; Microbiota; Lung; Rats; RNA, Ribosomal, 16S; Drugs, Chinese Herbal; Disease Models, Animal; Male; Bacteria; Bronchoalveolar Lavage Fluid; Rats, Sprague-Dawley
PubMed: 38746785
DOI: 10.3389/fcimb.2024.1379831 -
Open Biology May 2024Most successes in computational protein engineering to date have focused on enhancing one biophysical trait, while multi-trait optimization remains a challenge....
Most successes in computational protein engineering to date have focused on enhancing one biophysical trait, while multi-trait optimization remains a challenge. Different biophysical properties are often conflicting, as mutations that improve one tend to worsen the others. In this study, we explored the potential of an automated computational design strategy, called CamSol Combination, to optimize solubility and stability of enzymes without affecting their activity. Specifically, we focus on α-amylase (BLA), a hyper-stable enzyme that finds diverse application in industry and biotechnology. We validate the computational predictions by producing 10 BLA variants, including the wild-type (WT) and three designed models harbouring between 6 and 8 mutations each. Our results show that all three models have substantially improved relative solubility over the WT, unaffected catalytic rate and retained hyper-stability, supporting the algorithm's capacity to optimize enzymes. High stability and solubility embody enzymes with superior resilience to chemical and physical stresses, enhance manufacturability and allow for high-concentration formulations characterized by extended shelf lives. This ability to readily optimize solubility and stability of enzymes will enable the rapid and reliable generation of highly robust and versatile reagents, poised to contribute to advancements in diverse scientific and industrial domains.
Topics: alpha-Amylases; Solubility; Enzyme Stability; Protein Engineering; Bacterial Proteins; Mutation; Bacillus licheniformis; Algorithms; Models, Molecular
PubMed: 38745462
DOI: 10.1098/rsob.240014 -
BMC Microbiology May 2024Globally, drought stress poses a significant threat to crop productivity. Improving the drought tolerance of crops with microbial biostimulants is a sustainable strategy...
Globally, drought stress poses a significant threat to crop productivity. Improving the drought tolerance of crops with microbial biostimulants is a sustainable strategy to meet a growing population's demands. This research aimed to elucidate microbial biostimulants' (Plant Growth Promoting Rhizobacteria) role in alleviating drought stress in oil-seed crops. In total, 15 bacterial isolates were selected for drought tolerance and screened for plant growth-promoting (PGP) attributes like phosphate solubilization and production of indole-3-acetic acid, siderophore, hydrogen cyanide, ammonia, and exopolysaccharide. This research describes two PGPR strains: Acinetobacter calcoaceticus AC06 and Bacillus amyloliquefaciens BA01. The present study demonstrated that these strains (AC06 and BA01) produced abundant osmolytes under osmotic stress, including proline (2.21 and 1.75 µg ml), salicylic acid (18.59 and 14.21 µg ml), trehalose (28.35 and 22.74 µg mg FW) and glycine betaine (11.35 and 7.74 mg g) respectively. AC06 and BA01 strains were further evaluated for their multifunctional performance by inoculating in Arachis hypogaea L. (Groundnut) under mild and severe drought regimes (60 and 40% Field Capacity). Inoculation with microbial biostimulants displayed distinct osmotic-adjustment abilities of the groundnut, such as growth parameters, plant biomass, photosynthetic pigments, relative water content, proline, and soluble sugar in respective to control during drought. On the other hand, plant sensitivity indexes such as electrolyte leakage and malondialdehyde (MDA) contents were decreased as well as cooperatively conferred plant drought tolerance by induced alterations in stress indicators such as catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD). Thus, Acinetobacter sp. AC06 and Bacillus sp. BA01 can be considered as osmolyte producing microbial biostimulants to simultaneously induce osmotic tolerance and metabolic changes in groundnuts under drought stress.
Topics: Arachis; Droughts; Stress, Physiological; Proline; Bacillus amyloliquefaciens; Soil Microbiology; Osmotic Pressure; Betaine; Indoleacetic Acids; Salicylic Acid; Acinetobacter; Hydrogen Cyanide; Trehalose
PubMed: 38745279
DOI: 10.1186/s12866-024-03320-6 -
Environment International May 2024Due to the specific action on bacterial cell wall, β-lactam antibiotics have gained widespread usage as they exhibit a high degree of specificity in targeting bacteria,...
Due to the specific action on bacterial cell wall, β-lactam antibiotics have gained widespread usage as they exhibit a high degree of specificity in targeting bacteria, but causing minimal toxicity to host cells. Under antibiotic pressure, bacteria may opt to shed their cell walls and transform into L-form state as a means to evade the antibiotic effects. In this study, we explored and identified diverse optimal conditions for both Gram-negative bacteria (E. coli DH5α (CTX)) and Gram-positive bacteria (B. subtilis ATCC6633), which were induced to L-form bacteria using lysozyme (0.5 ppm) and meropenem (64 ppm). Notably, when bacteria transformed into L-form state, both bacterial strains showed varying degrees of increased resistance to antibiotics polymyxin E, meropenem, rifampicin, and tetracycline. E. coli DH5α (CTX) exhibited the most significant enhancement in resistance to tetracycline, with a 128-fold increase, while B. subtilis ATCC6633 showed a 32-fold increase in resistance to tetracycline and polymyxin E. Furthermore, L-form bacteria maintained their normal metabolic activity, combined with enhanced oxidative stress, served as an adaptive strategy promoting the sustained survival of L-form bacteria. This study provided a theoretical basis for comprehending antibiotic resistance mechanisms, developing innovative treatment strategies, and confronting global antibiotic resistance challenges.
Topics: Anti-Bacterial Agents; Oxidative Stress; Escherichia coli; Bacillus subtilis; Drug Resistance, Bacterial; Microbial Sensitivity Tests; Tetracycline; Meropenem
PubMed: 38735077
DOI: 10.1016/j.envint.2024.108729 -
Nutrients Apr 2024Beneficial health effects of omega-3 polyunsaturated fatty acids (-3 PUFA) are partly attributed to specialized pro-resolving mediators (SPMs), which promote... (Randomized Controlled Trial)
Randomized Controlled Trial
Beneficial health effects of omega-3 polyunsaturated fatty acids (-3 PUFA) are partly attributed to specialized pro-resolving mediators (SPMs), which promote inflammation resolution. Strategies to improve -3 PUFA conversion to SPMs may, therefore, be useful to treat or prevent chronic inflammatory disorders. Here, we explored a synbiotic strategy to increase circulating SPM precursor levels. Healthy participants (n = 72) received either SynΩ3 (250 mg eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) lysine salts; two billion CFU Bacillus megaterium; n = 23), placebo (n = 24), or fish oil (300 mg EPA plus DHA; N = 25) capsules daily for 28 days in a randomized, double-blind placebo-controlled parallel 3-group design. Biomarkers were assessed at baseline and after 2 and 28 days of intervention. The primary analysis involved the comparison between SynΩ3 and placebo. In addition, SynΩ3 was compared to fish oil. The synbiotic SynΩ3 comprising Bacillus megaterium DSM 32963 and -3 PUFA salts significantly increased circulating SPM precursor levels, including 18-hydroxy-eicosapentaenoic acid (18-HEPE) plus 5-HEPE, which was not achieved to this extent by fish oil with a similar -3 PUFA content. Omega-3 indices were increased slightly by both SynΩ3 and fish oil. These findings suggest reconsidering conventional -3 PUFA supplementation and testing the effectiveness of SynΩ3 particularly in conditions related to inflammation.
Topics: Humans; Male; Female; Bacillus megaterium; Adult; Double-Blind Method; Fatty Acids, Omega-3; Synbiotics; Eicosapentaenoic Acid; Young Adult; Docosahexaenoic Acids; Middle Aged; Biomarkers; Healthy Volunteers; Fish Oils
PubMed: 38732601
DOI: 10.3390/nu16091354 -
Plants (Basel, Switzerland) Apr 2024Biochar and beneficial microorganisms have been widely used in ecological agriculture. However, the impact of biochar loaded with microbes (BM) on plant growth remains...
Biochar and beneficial microorganisms have been widely used in ecological agriculture. However, the impact of biochar loaded with microbes (BM) on plant growth remains to be understood. In this study, BM was produced by incubating pecan biochar with the bacterial strain N33, and the effects of BM on pecan growth and the microbial community in the rhizosphere were explored. BM application significantly enhanced the biomass and height of pecan plants. Meanwhile, BM treatment improved nutrient uptake in plants and significantly increased the chlorophyll, soluble sugars, and soluble proteins of plants. Furthermore, BM treatment improved the soil texture and environment. Finally, BM application substantially enhanced the diversity of soil fungi and bacteria as well as the relative abundances of the phyla and , and families and , as shown by high-throughput sequencing. Together, this study clarified the growth-promotive effects of BM on pecan plants and suggested an alternative to synthetic fertilizers in their production.
PubMed: 38732441
DOI: 10.3390/plants13091226 -
Molecules (Basel, Switzerland) Apr 2024A novel second-generation blue fluorescent polyamidoamine dendrimer peripherally modified with sixteen 4--dimethylaninoethyloxy-1,8-naphthalimide units was synthesized....
A novel second-generation blue fluorescent polyamidoamine dendrimer peripherally modified with sixteen 4--dimethylaninoethyloxy-1,8-naphthalimide units was synthesized. Its basic photophysical characteristics were investigated in organic solvents of different polarity. It was found that in these solvents, the dendrimer is colorless and emitted blue fluorescence with different intensities depending on their polarity. The effect of the pH of the medium on the fluorescence intensity was investigated and it was found that in the acidic medium, the fluorescence is intense and is quenched in the alkaline medium. The ability of the dendrimer to detect metal ions (Pb, Zn, Mg, Sn, Ba, Ni, Sn, Mn, Co, Fe, and Al) was also investigated, and it was found that in the presence of Fe, the fluorescent intensity was amplified more than 66 times. The antimicrobial activity of the new compound has been tested in vitro against Gram-positive and Gram-negative . The tests were performed in the dark and after irradiation with visible light. The antimicrobial activity of the compound enhanced after light irradiation and was found slightly more sensitive than . The increase in antimicrobial activity after light irradiation is due to the generation of singlet oxygen particles, which attack bacterial cell membranes.
Topics: Naphthalimides; Dendrimers; Polyamines; Microbial Sensitivity Tests; Anti-Bacterial Agents; Fluorescence; Pseudomonas aeruginosa; Hydrogen-Ion Concentration; Bacillus cereus; Light; Fluorescent Dyes; Spectrometry, Fluorescence
PubMed: 38731451
DOI: 10.3390/molecules29091960 -
Molecules (Basel, Switzerland) Apr 2024The root of L. has been widely used in traditional medicine for its antimicrobial properties. In this study, the fractionation of methanol extract from the root was...
The root of L. has been widely used in traditional medicine for its antimicrobial properties. In this study, the fractionation of methanol extract from the root was conducted. Four fractions (A, B, C, and D) were obtained and tested against a range of bacteria and fungi. The results showed promising antibacterial activity, especially against , where the minimal inhibitory concentration (MIC) was determined to be equal to 0.08 mg/mL and 0.16 mg/mL for heptane (fraction B) and ethyl acetate (fraction C), respectively. In the case of the methicillin-resistant (MRSA) ATCC 43300 strain, the same fractions yielded higher MIC values (2.5 and 5.0 mg/mL, respectively). This was accompanied by a lack of apparent cytotoxicity to normal human BJ foreskin fibroblasts, enterocytes derived from CaCo2 cells, and zebrafish embryos. Further analyses revealed the presence of bioactive chlorogenic acids in the fractionated extract, especially in the ethyl acetate fraction (C). These findings support the traditional use of the root from and pave the way for the development of new formulations for treating bacterial infections. This was further evaluated in a proof-of-concept experiment where fraction C was used in the ointment formulation, which maintained high antimicrobial activity against MRSA and displayed low toxicity towards cultured fibroblasts.
Topics: Methicillin-Resistant Staphylococcus aureus; Bacillus cereus; Plant Extracts; Humans; Microbial Sensitivity Tests; Anti-Bacterial Agents; Plant Roots; Animals; Caco-2 Cells; Methanol; Chemical Fractionation; Zebrafish
PubMed: 38731430
DOI: 10.3390/molecules29091939