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Access to safe water and sanitation is a critical global challenge, posing significant health risks worldwide due to waterborne diseases. This study investigates the efficacy of ultraviolet type C radiation as a disinfection method for improving water quality. The research elucidates UV-C's mechanism of action, highlighting its ability to disrupt DNA and RNA replication, thereby inactivating pathogens. Furthermore, the study analyses the influence of key factors on UV-C disinfection effectiveness, including water turbidity and the presence of dissolved organic matter, which can attenuate UV-C penetration and reduce treatment efficiency. The experimental results demonstrate a substantial reduction in microbial content following UV-C treatment. River water samples exhibited a 57.143% reduction in microbial load, while well water samples showed a 50% reduction. Notably, Escherichia coli (E. coli) concentrations decreased significantly, with an 83.33% reduction in well water and a 62.5% reduction in borehole water. This study makes a novel contribution to the understanding of UV-C disinfection by identifying the presence of resistant organisms, including Adenoviruses, Bacterial spores, and the Protozoan Acanthamoeba, in water samples. This finding expands the scope of UV-C research beyond easily culturable bacteria. To address this challenge, future investigations should explore synergistic disinfection strategies, such as combining UV-C treatment with advanced oxidation processes. Optimising UV-C system designs and developing robust, real-time monitoring systems capable of detecting and quantifying known and emerging UV-resistant pathogens are crucial for ensuring comprehensive water decontamination. [ABSTRACT FROM AUTHOR]

Fresh onions are dehydrated to increase their shelf-life. Primarily, open dehydration techniques like solar dehydration come with the problem of contamination through natural air convection. A solar conduction dryer that uses conduction, convection, and radiation for dehydration of food samples is exploited in this study. The food samples are often contaminated by Bacillus and Aspergillus species spores. As a remedy, pulsed light treatment as a non-thermal technology and infrared treatment as a thermal technology are studied and compared. Bacillus cereus and Aspergillus niger spores are chosen as a representative of bacterial and fungal contamination in onions. Dehydrated onion shreds with varying water activities (0.4, 0.5, 0.6) were treated. The spore inactivation was best described by Weibull model as compared with first-order model. Scanning electron microscopy images of the microbial cells showed surface distortions on the bacterial and fungal spores. The effect of the treatment technologies on the colour, flavour (thiosulphinate and pyruvic acid concentration), total phenolic and flavonoid content, and ascorbic acid concentration are compared. Overall, pulsed light treatment showed promising inactivation with a maximum log reduction of 4.5 log B. cereus spores·g−1 and 3.1 log A. niger spores·g−1 at 2.131 J·cm−2 in samples with water activity 0.6. The inactivation rate increased with an increase in water activity. The colour was better retained in pulsed light treated samples. The thiosulphinate content (9.24 μmol·g−1), total phenolics (0.268 mg GAE·g−1), and flavonoid content (0.344 mg QE·g−1) in the sample were improved upon pulsed light exposure. [ABSTRACT FROM AUTHOR]

Chitin is the second most prevalent polysaccharide found in nature, following cellulose. Amino-oligosaccharides, the byproducts of chitin degradation, exhibit favorable biological properties and potential for various uses. Chitinases play a crucial function in the breakdown of chitin, and their exceptionally effective production has garnered significant interest. Here, in this study, the exochitinase PbChiA, obtained from Paenibacillus barengoltzii, was recombinantly produced and immobilized using the CotG surface protein of Bacillus subtilis WB800N. The resulting strain Bacillus subtilis WB800N pHS-CotG-Chi exhibited exceptional heat stability and efficacy across various pH levels. The chitinolytic activity of the enzyme, which had been isolated and immobilized on the spore surface, was measured to be approximately 16.06 U/mL. Including Ni2+, Zn+2, and K+, and EDTA at various concentration levels in the reaction system, has significantly enhanced the activity of the immobilized enzyme. The immobilized exochitinase demonstrated a notable rate of recycling, as the recombinant spores sustained a relative enzyme activity of more than 70% after three cycles and 62.7% after four cycles. These findings established a basis for additional investigation into the role and practical use of the immobilized bacterial exochitinase in industry. [ABSTRACT FROM AUTHOR]

Pelgipeptins, tridecaptins, and elgicins are among the antimicrobials produced by Paenibacillus elgii. Growth in complex media is commonly applied to obtain lipopeptides from culture's supernatant, but it requires further purification. This study aimed to improve the yield of pelgipeptins and tridecaptins using chemically defined media. The kinetics of antimicrobial lipopeptide yield in chemically defined media were evaluated in P. elgii AC13. Pelgipeptins were detected in the supernatant and the culture pellet, but tridecaptins were mainly associated with cell debris or endospores. We investigated whether removing Ca2+ would impair P. elgii sporogenesis, consequently improving the yield of tridecaptin. The kinetics of both lipopeptides in the presence and absence of Ca2+ were quantitatively and qualitatively evaluated and further correlated with the cell cycle. The impairment of P. elgii AC13 sporogenesis had no effect on tridecaptin production, which remained undetected in the supernatant of the culture. On the other hand, the yield of pelgipeptin in a Ca2+-free medium increased. We showed for the first time that the removal of Ca2+ interrupted the sporogenesis in P. elgii and improved the yield of pelgipeptins. However, Ca2+ absence had no effect on tridecaptin yield, which is possibly degraded or associated with other cell debris components. [ABSTRACT FROM AUTHOR]

The integration of green construction practices within the built environment has been significantly advanced by biotechnological innovations, among which microbially induced biomineralization (MIB), predominantly facilitated by various strains of spore-forming bacilli, emerges as a pivotal mechanism for the self-healing of concrete. However, the practical deployment of this technology faces challenges, notably the compromised viability of bacterial spores due to germination triggered by severe shear stress during concrete mixing. To address this limitation, a water-insoluble polymer (extracellular polymeric substance) produced by Cellulomonas flavigena was utilized to encapsulate and protect the spores. The encapsulation process was rigorously verified through physicochemical methodologies, including X-ray diffraction (XRD) analysis, which revealed alterations in the interlayer spacings of the extracellular polymeric substance (EPS) structure during the encapsulation process, indicating successful EPS coating of the spores. Furthermore, a proof of concept for the enhanced biomineralization capacity of EPS-coated spores was demonstrated. Standard analytical techniques confirmed the precipitation of calcite and vaterite among other minerals, underscoring the effectiveness of this novel approach. This breakthrough paves the way for the development of innovative, sustainable bioconcrete applications, aligning with broader environmental objectives and advancing the field of green construction technology. [ABSTRACT FROM AUTHOR]

Anthrax is a notorious disease of public health importance caused by Bacillus anthracis. The causative agent can also be used as a biological weapon. Spores of these bacteria can sustain extreme environmental conditions and remain viable in soil for decades. Domestic and wild ruminants are highly susceptible to this pathogen, which usually presents as a peracute to acute disease. In humans, cutaneous anthrax is frequent but pulmonary and enteric anthrax are more serious. Humans, animals, and the environment are all involved, making anthrax a perfect target for a One Health approach. The environment plays a key role in disease transmission. At a time when the One Health concept is not mere slogans, collaborative efforts of medical professionals, veterinarians, and environmental scientists will be valuable for the prevention and control of this disease. In this review, we discussed the transmission dynamics of anthrax in the environment, animals, and humans, as well as One Health strategies to control and prevent anthrax. [ABSTRACT FROM AUTHOR]

Clostridioides difficile is a pathogen whose transmission relies on the formation of dormant endospores. Spores are highly resilient forms of bacteria that resist environmental and chemical insults. In recent work, we found that C. difficile SspA and SspB, two small acid-soluble proteins (SASPs), protect spores from UV damage and, interestingly, are necessary for the formation of mature spores. Here, we build upon this finding and show that C. difficile sspA and sspB are required for the formation of the spore cortex layer. Moreover, using an EMS mutagenesis selection strategy, we identified mutations that suppressed the defect in sporulation of C. difficile SASP mutants. Many of these strains contained mutations in CDR20291_0714 (spoIVB2) revealing a connection between the SpoIVB2 protease and the SASPs in the sporulation pathway. This work builds upon the hypothesis that the small acid-soluble proteins can regulate gene expression. Author summary: In prior work, we found that the Clostridioides difficile small acid-soluble proteins, SspA and SspB, are important for the UV resistance that is characteristic of dormant spores (as found in many other spore-forming bacteria). Surprisingly, we also found that the combinatorial deletion of sspA and sspB led to a block in the ability of C. difficile to form dormant spores, a phenotype not observed in other sporulating bacteria. Here, we build upon this work and find that this block can be overcome by mutations in spoIVB2 –σF-regulated protease. Our data suggest that the σG-regulated SspA and SspB directly or indirectly activate spoIVB2 expression during late stages of sporulation and that the identified spoIVB2 alleles overcome the absence of sspA and sspB by increasing spoIVB2 translation efficiency and, thus, abundance during late stages of sporulation. Our data build upon the hypothesis that small acid-soluble proteins can regulate gene expression and indicate that other spore-forming bacteria may have unidentified targets that these proteins may regulate during the sporulation process. [ABSTRACT FROM AUTHOR]

Clostridioides difficile detection in community settings is time-intensive, resulting in delays in diagnosing and quarantining infected individuals. However, with the advent of semi-automated devices and improved algorithms in recent decades, the ability to discern CDI infection from asymptomatic carriage has significantly improved. This, in turn, has led to efficiently regulated monitoring systems, further reducing endemic risk, with recent concerns regarding a possible surge in hospital-acquired Clostridioides difficile infections post-COVID failing to materialize. This review highlights established and emerging technologies used to detect community-acquired Clostridioides difficile in research and clinical settings. [ABSTRACT FROM AUTHOR]

The global incidence of invasive fungal infections (IFIs) has increased over the past few decades, mainly in immunocompromised patients, and is associated with high mortality and morbidity. Aspergillus fumigatus is one of the most common and deadliest IFI pathogens. Major hurdles to treating fungal infections remain the lack of rapid and definitive diagnosis, including the frequent need for invasive procedures to provide microbiological confirmation, and the lack of specificity of structural imaging methods. To develop an Aspergillus-specific positron emission tomography (PET) imaging agent, we focused on fungal-specific sugar metabolism. We radiolabeled cellobiose, a disaccharide known to be metabolized by Aspergillus species, and synthesized 2-deoxy-2-[18F]fluorocellobiose ([18F]FCB) by enzymatic conversion of 2-deoxy-2-[18F]fluoroglucose ([18F]FDG) with a radiochemical yield of 60 to 70%, a radiochemical purity of >98%, and 1.5 hours of synthesis time. Two hours after [18F]FCB injection in A. fumigatus pneumonia as well as A. fumigatus, bacterial, and sterile inflammation myositis mouse models, retained radioactivity was only seen in foci with live A. fumigatus infection. In vitro testing confirmed production of β-glucosidase enzyme by A. fumigatus and not by bacteria, resulting in hydrolysis of [18F]FCB into glucose and [18F]FDG, the latter being retained by the live fungus. The parent molecule was otherwise promptly excreted through the kidneys, resulting in low background radioactivity and high target-to-nontarget ratios at A. fumigatus infectious sites. We conclude that [18F]FCB is a promising and clinically translatable Aspergillus-specific PET tracer. Editor's summary: Diagnosis of invasive Aspergillus infections can be difficult, in part because of lack of specificity of imaging methods. Here, Shah and colleagues rapidly synthesized an Aspergillus-specific 2-deoxy 2-[18F]fluorocellobiose ([18F]FCB) positron emission tomography (PET) tracer. Using mouse models of myositis and pulmonary infection, the authors showed that [18F]FCB injection resulted in retained radioactivity only at sites of live Aspergillus infection, but not at sites of heat-killed spore or bacterial injection, and that radioactivity on PET imaging localized to infiltrates and consolidations seen on coregistered CT scans. Longitudinal [18F]FCB PET/CT imaging of mice with Aspergillus myositis also detected infection progression and subclinical residual infection, highlighting the clinical potential of this Aspergillus-specific PET tracer. —Melissa L. Norton [ABSTRACT FROM AUTHOR]

Microbial enhanced oil recovery (MEOR) is a cost effective and efficient method for recovering residual oil. However, the presence of wax (paraffin) in residual oil can substantially reduce the efficiency of MEOR. Therefore, microbial dewaxing is a critical process in MEOR. In this study, a bacterial dewaxing agent of three spore-forming bacteria was developed. Among these bacteria, Bacillus subtilis GZ6 produced the biosurfactant surfactin. Replacing the promoter of the surfactin synthase gene cluster (srfA), increased the titer of surfactin in this strain from 0.33 g/L to 2.32 g/L. The genetically modified strain produced oil spreading rings with diameters increasing from 3.5 ± 0.1 to 4.1 ± 0.2 cm. The LadA F10L/N133R mutant was created by engineering an alkane monooxygenase (LadA) using site-directed mutagenesis in the Escherichia coli host. Compared to the wild-type enzyme, the resulting mutant exhibited an 11.7-fold increase in catalytic efficiency toward the substrate octadecane. When the mutant (pIMPpladA2mu) was expressed in Geobacillus stearothermophilus GZ178 cells, it exhibited a 2.0-fold increase in octadecane-degrading activity. Cultures of the two modified strains (B. subtilis GZ6 (pg3srfA) and G. stearothermophilus GZ178 (pIMPpladA2mu)) were mixed with the culture of Geobacillus thermodenitrificans GZ156 at a ratio of 5:80:15. The resulting composition increased the rate of wax removal by 35% compared to the composition composed of three native strains. This study successfully developed a multi-strain bacterial agent with enhanced oil wax removal capabilities by genetically engineering two bacterial strains. [ABSTRACT FROM AUTHOR]

Background: The exploration of bacterial endospores as potential antitumor agents has garnered increased attention in recent years. This study investigates the impact of Clostridium sporogenes endospores as modifiers of immune regulation on tumor growth, to refine therapeutic protocols for hepatocellular carcinoma. Methods: Hepatocellular carcinoma was induced in adult male albino rats using diethylnitrosamine (DEN) (20mg/kg b.wt/day) orally injected five times a week for 6 consecutive weeks) and subsequently treated with endospores (intravenous injection of endospores once at a dose of 60 million spores/rat), and samples were taken from rats after one month of endospore injection. Multiple parameters, including interferon-gamma (IFN-γ), nuclear factor-κB (NF-κB), tumor necrosis factor-alpha (TNF-α), antioxidant enzymes, malondialdehyde (MDA), and liver function enzymes were assessed. Results: Results demonstrated a remarkable suppression of tumor proliferation and the induction of enduring immunity through IFN-γ stimulation. The levels of inflammatory markers associated with tumor promotion (NF-κB and TNF-α) witnessed significant improvement. This was paralleled by enhancements in antioxidant status and a reduction in lipid peroxidation in liver tissues of the endospore-treated rats compared to the untreated rats. Histopathological examinations, along with elevated liver function enzymes, provided additional support for these observed improvements. Conclusion: this study offers compelling evidence for the potential of safe concentrations of endospores in modulating immune responses and targeting tumor cells, suggesting their plausible roles as adjuvants to augment cancer therapeutic protocols. [ABSTRACT FROM AUTHOR]

Far-ultraviolet C light, with a wavelength of 200–230 nm, has demonstrated broad-spectrum germicidal efficacy. However, due to increased interest in its use as an alternative antimicrobial, further knowledge about its fundamental bactericidal efficacy is required. This study had two objectives. Firstly, it investigated experimentally the Far-UVC dose–response of common bacteria suspended at various cell densities in transparent buffer, ensuring no influence from photosensitive suspending media. Increasing doses of Far-UVC were delivered to Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus in PBS at 101, 102, 103, 105 and 107 CFU·mL−1, with surviving colony-forming units enumerated (n ≥ 3). Secondly, through a systematised literature review, this work sought to explore the impact of genus/species, Gram type, cell form, cell density and irradiance on dose–response. The screening of 483 publications was performed with 25 included in the study. Data for 30 species were collated, analysed and compared with the experimental results. Overall, Gram-positive species showed greater resilience to Far-UVC than Gram-negative; some inter-species and inter-genera differences in resilience were identified; endospores were more resilient than vegetative cells; the results suggested that inactivation efficiency may decrease as cell density increases; and no significant correlation was identified between irradiance and bactericidal dose effect. In conclusion, this study has shown Far-UVC light to be an effective decontamination tool against a vast range of bacterial vegetative cells and endospores. [ABSTRACT FROM AUTHOR]

This study investigates the microbially induced calcium carbonate precipitation (MICP) in repair mortar, focusing on the impact of calcium precursor dosage and bacterial strain selection. C6H10CaO6·xH2O and (CH3COO)2Ca·xH2O were used as calcium precursors at dosages of 0.1, 0.25, and 0.4 M with Bacillus subtilis VEB4, Priestia megaterium TSB16, and Halobacillus halophilus MCC2188 microbes. Quantitative assessment of precipitate and optimization of precursor dosages were conducted before making mortar cube specimens of size 70.6 × 70.6 × 70.6 mm with bacterial spores and nutrients immobilized in Modified Expanded Perlite. Cracked cube specimens underwent automated wet-dry cycles of 12 h daily for 60 days to induce healing. Comparative analysis of biomortar specimens showed P. megaterium as the most effective in compressive strength recovery (up to 89.33%) and crack healing with a maximum healed crack width of 0.64 mm, followed by B. subtilis with significant CSR improvements. H. halophilus, less efficient in non-saline conditions, healed cracks up to 0.48 mm. Calcium lactate was considered the better calcium source choice for B. subtilis and P. megaterium strains, whereas calcium acetate improved MICP by H. halophilus. Microstructural analysis of healed precipitates collected from cracked cubes identified distinct morphology of MICP and the presence of polymorphs viz, calcite, aragonite, and vaterite. Tailored selection and dosage of calcium precursors for each strain significantly enhanced MICP and improved the quality of healing products in cracks, advancing the understanding of self-healing construction biomaterials. [ABSTRACT FROM AUTHOR]

A dielectric barrier discharge plasma device (DBD) was built, characterized and operated. Ten species of gram-positive and gram-negative bacteria, as well as fungus and spores of Bacillus cereus and its vegetative cells, in addition to eggs and pupae of the potato tuber moth (PTM) were exposed to DBD plasma. A strong detrimental effect on the exposed species was observed in function to the exposure time at helium: air ratio 98:2, electrode gap 1.8 cm, amplitude of discharge voltage 6 kV and an effective power density 208 mW/cm3. The outcome of this work provides valuable data on the use of DBD plasma as an alternative non-heating sterilization method to kill or inhibit microbial growth and protecting potatoes from PTM infestation.

Spores are the main dormant forms of some bacteria under harsh environment conditions, which are widely distributed in nature. Bacterial spores have a rigid structure, which helps resist to environmental stresses such as heat and ultraviolet radiation. At present, it is difficult to inactivate bacterial spores by the conventional sterilization methods used in the food industry. Therefore, bacterial spores are one of the most important factors influencing the food safety. In recent years, the application of non-thermal processing technologies in killing spores has received great deal of attention. Cold plasma is a novel non-thermal physical sterilization technology, which has a broad application prospect in the food industry due to its various advantages such as high bactericidal efficiency, low energy consumption, and secondary pollution-free. In this paper, the application of cold plasma in the inactivation of bacterial spores in foods is reviewed, and the underlying mechanisms are also summarized in detail. Moreover, the effects of diverse factors on cold plasma-induced spores inactivation are analyzed, and the future research direction is also prospected. This article provides important theoretical basis for the practical application of cold plasma in food safety and quality control.

Cumin seeds are frequently utilized in herbal infusions and as flavoring agents in home cuisine. Nevertheless, studies have demonstrated that spices are frequently contaminated with pathogenic bacteria, including bacterial spores. The aim of this study was to assess the effectiveness of a new decontamination method called "Intensification of Vaporization by Decompression to the Vacuum" (IVDV) on intentionally contaminated Cuminum cyminum seeds. The study also examined the impact of this treatment on the color and oil profile of the treated samples. The untreated samples were inoculated with Escherichia coli (ATCC 25922) and Salmonella Typhimurium (ATCC 14028) and then subjected to IVDV treatment. Response surface methodology was employed to obtain safe, high-quality cumin seeds presenting a balance between microbial load, color, and oil profile. The optimal IVDV conditions were achieved at a pressure of 3.5 bar and a time of 133.45 s, resulting in typical 4 log reductions observed with 99.99% of Escherichia coli and Salmonella Typhimurium inactivation. The treated spices presented a mild color modification compared to the untreated ones, manifested by a darker shade (decreased L* value), reduced greenness (increased a* value), and heightened yellowness (increased b* value). The GC-MS analysis detected the existence of seven compounds in the treated cumin, with cuminaldehyde being the primary compound (83.79%). Furthermore, the use of IVDV treatment resulted in an increase in the total content of essential oils in some samples, whereby six monoterpenes were identified in the untreated sample compared to seven monoterpenes in IVDV-treated samples. This innovative technology demonstrated high efficacy in decontaminating C. cyminum seeds, improving the extractability of the essential oils while only slightly affecting the color. [ABSTRACT FROM AUTHOR]

The sous-vide (SV) technique, notable for its precision and ability to preserve food quality, has become a transformative method in culinary arts. This review examines the technical aspects, applications, and limitations of SV, focusing on its impact on food safety, nutritional retention, and quality parameters across various food matrices such as meats, seafood, vegetables, and semi-prepared products. Through an extensive literature review, the study highlights the use of natural inhibitors and essential oils to enhance microbial safety and explores the nutritional benefits of SV in preserving vitamins and minerals. The findings suggest that while SV offers significant benefits in terms of consistent results and extended shelf life, challenges remain in terms of equipment costs and the necessity for specific training, and although sufficient for food preparation/processing, its effectiveness in eliminating microbial pathogens, including viruses, parasites, and vegetative and spore forms of bacteria, is limited. Overall, the research underscores SV's adaptability and potential for culinary innovation, aligning with modern demands for food safety, quality, and nutritional integrity. [ABSTRACT FROM AUTHOR]

This article presents the results of research on the use of a new granular organomineral fertilizer for growing plants of half-highbush cultivars of the lowbush blueberry (Vaccinium angustifolium Ait.). The purpose of the research is studying the effect of a new granular organomineral fertilizer on the agrobiological characteristics of V. angustifolium plants on a peatland in the conditions of the north of the European part of Russia. The developed composition of organomineral fertilizer (NPK 8:8:8, Fe 0.5%, Zn 0.2%, Cu 0.4%) differs from existing fertilizers in a more balanced ratio of micro- and macroelements and the content of vermicompost containing spore forms of bacteria Bacillus subtilis H-13, B. mucilaginosus, and Azotobacter chroococcum. The use of a new organomineral fertilizer on high-moor peat (pH 2.9) contributed to the highest yield of V. angustifolium fruits (190.2 g/bush), which is 1.2 times more than other mineral fertilizers (NPK, etc.). The best morphophysiological indicators of V. angustifolium plants (leaf area, total and working surface of the roots, root weight) when using the developed organomineral fertilizer were noted in September. An increase of 1.2–1.3 times in the collection of dry matter and sugars in fruits was revealed, compared with other fertilizer options, while the vitamin C content practically did not change. New organomineral fertilizer contributes to the optimal supply of the necessary micro- and macroelements throughout the growing season and increases the productivity of V. angustifolium plants when growing depleted peat deposits in the natural and climatic conditions of the European part of Russia. [ABSTRACT FROM AUTHOR]

The Wide Area Demonstration (WAD) was a field exercise conducted under the U.S. EPA's Analysis of Coastal Operational Resiliency program, in conjunction with the U.S. Department of Homeland Security and the U.S. Coast Guard. The purpose of the WAD was to operationalize at field scale aspects of remediation activities that would occur following an outdoor release of Bacillus anthracis spores, including sampling and analysis, decontamination, data management, and waste management. The WAD was conducted in May 2022 at Fort Walker (formerly known as Fort A.P. Hill) and utilized Bacillus atrophaeus as a benign simulant for B. anthracis. B. atrophaeus spores were inoculated onto the study area at the beginning of the study, and air samples were collected daily during each of the different phases of the WAD using Dry Filter Units (DFUs). Ten DFU air samplers were placed at the perimeter of the study area to collect bioaerosols onto two parallel 47-mm diameter polyester felt filters, which were then subsequently analyzed in a microbiological laboratory for the quantification of B. atrophaeus. The study demonstrated the use of DFUs as a rugged and robust bioaerosol collection device. The results indicated that the highest B. atrophaeus spore air concentrations (up to ~ 5 colony forming units/m3) occurred at the beginning of the demonstration (e.g. during inoculation and characterization sampling phases) and generally downwind from the test site, suggesting transport of the spores was occurring from the study area. Very few B. atrophaeus spores were detected in the air after several weeks and following decontamination of exterior surfaces, thus providing an indication of the site decontamination procedures' effectiveness. No B. atrophaeus spores were detected in any of the blank or background samples. Implications: Following an incident involving a release of Bacillus anthracis spores or other biological threat agent into the outdoor environment, understanding the factors that may affect the bioagent's fate and transport can help predict viable contaminant spread via the ambient air. This paper provides scientific data for the first time on ambient air concentrations of bacterial spores over time and location during different phases of a field test in which Bacillus atrophaeus (surrogate for B. anthracis) spores were released outdoors as part of a full-scale study on sampling and decontamination in an urban environment. This study advances the knowledge related to the fate and transport of bacterial spores (such as those causing anthrax disease) as an aerosol in the outdoor environment over the course of three weeks in a mock urban environment and has exposure and health risk implications. The highest spore air concentrations occurred at the beginning of the study (e.g. during inoculation of surfaces and characterization sampling), and in the downwind direction, but diminished over time; few B. atrophaeus spores were detected in the air after several weeks and following decontamination. Therefore, in an actual incident, potential reaerosolization of the microorganism and subsequent transport in the air during surface sampling and remediation efforts should be considered for determining exclusion zone locations and estimating potential risk to neighboring communities. The data also provide evidence suggesting that the large-scale decontamination of outdoor surfaces may reduce air concentrations of the bioagent, which is important since exposure of B. anthracis via inhalation is a primary concern. [ABSTRACT FROM AUTHOR]

Aim Ohmic heating (OH) (i.e. heating by electric field) more effectively kills bacterial spores than traditional wet heating, yet its mechanism remains poorly understood. This study investigates the accelerated spore inactivation mechanism using genetically modified spores. Methods and results We investigated the effects of OH and conventional heating (CH) on various genetically modified strains of Bacillus subtilis : isogenic PS533 (wild type_1), PS578 [lacking spores' α/β-type small acid-soluble proteins (SASP)], PS2318 (lacking recA , encoding a DNA repair protein), isogenic PS4461 (wild type_2), and PS4462 (having the 2Duf protein in spores, which increases spore wet heat resistance and decreases spore inner membrane fluidity). Removal of SASP brought the inactivation profiles of OH and CH closer, suggesting the interaction of these proteins with the field. However, the reemergence of a difference between CH and OH killing for SASP-deficient spores at the highest tested field strength suggested there is also interaction of the field with another spore core component. Additionally, RecA-deficient spores yielded results like those with the wild-type spores for CH, while the OH resistance of this mutant increased at the lower tested temperatures, implying that RecA or DNA are a possible additional target for the electric field. Addition of the 2Duf protein markedly increased spore resistance both to CH and OH, although some acceleration of killing was observed with OH at 50 V/cm. Conclusions In summary, both membrane fluidity and interaction of the spore core proteins with electric field are key factors in enhanced spore killing with electric field-heat combinations. [ABSTRACT FROM AUTHOR]

In recent years, bacteria have gained considerable attention as a promising drug carrier that is critical in improving the effectiveness and reducing the side effects of anti‐tumor drugs. Drug carriers can be utilised in various forms, including magnetotactic bacteria, bacterial biohybrids, minicells, bacterial ghosts and bacterial spores. Additionally, functionalised and engineered bacteria obtained through gene engineering and surface modification could provide enhanced capabilities for drug delivery. This review summarises the current studies on bacteria‐based drug delivery systems for anti‐tumor therapy and discusses the prospects and challenges of bacteria as drug carriers. Furthermore, our findings aim to provide new directions and guidance for the research on bacteria‐based drug systems. [ABSTRACT FROM AUTHOR]

Biotechnological processes are essential for producing climate-friendly high-value chemicals or pharmaceutical compounds, which can include steps catalyzed by enzymes. Therefore, establishing new, robust, and cheap enzyme production processes is desirable. One possible way to enhance processes is through the use of the spore display method. Spore display can present heterologous proteins on the surface of bacterial spores, offering numerous advantages in a range of biotechnological applications. This study demonstrates the implementation of the spore display method in Paenibacillus polymyxa, achieved by modifying the spore surface, incorporating an anchoring protein, and attaching green fluorescent protein to it, allowing the visualization of fluorescent spores. Following the initial experiment, a native lipase (Lip3), a heterologous lipase (LipA) from Bacillus subtilis, a native esterase (PnbA) from P. polymyxa, and a lipoyl synthase were expressed during sporulation and displayed on the spore surface. The activity profiles were determined in the temperature range from 4 °C to 70 °C. The PnbA reached its optimum at 4 °C, whereas the LipA from B. subtilis showed 4.4-fold higher activity at 42 °C compared to the control. Furthermore, we explored a possible new technique for the purification of enzymes with the TEV cleavage site between the anchor and the protein of interest. Finally, we showed a not-yet-described side activity of the lipoyl synthase over a wide temperature range. [ABSTRACT FROM AUTHOR]

Caldanaerobacter subterraneus subsp. keratinolyticus subsp. nov. strain KAk was isolated from a geothermal hot spring located in Kazakhstan. Growth occurred at temperatures ranging from 50 to 80 °C, with approximately 70 °C as optimum. It also thrived in pH conditions ranging from 4.0 to 9.0, with the best growth occurring at 6.8. Under optimal conditions in a glucose-containing medium, the cells were predominantly observed singly, in pairs, or less frequently in chains, and did not form endospores. However, under conditions involving growth with merino wool or feathers, or under suboptimal conditions, the cells of strain KAk exhibited a notably elongated and thinner morphology, with lengths ranging from 5 to 8 µm, and spores were observed. The KAk strain exhibited efficient degradation of feather keratin and merino wool at temperatures ranging from 65 to 70 °C. Analysis of the 16S rRNA gene sequence placed KAk within the genus Caldanaerobacter, family Thermoanaerobacteraceae, with the highest similarity to C. subterraneus subsp. tengcongensis MB4T (98.84% sequence identity). Furthermore, our analysis of the draft genome sequence indicated a genome size of 2.4 Mbp, accompanied by a G+C value of 37.6 mol%. This study elucidated the physiological and genomic characteristics of strain KAk, highlighting its keratinolytic capabilities and distinctiveness compared to other members of the genus Caldanaerobacter. [ABSTRACT FROM AUTHOR]

Azotobacter chroococcum and Bacillus subtilis were selected as fermentation strains, and biogas residue after anaerobic digestion of kitchen waste and residual sludge was used as fermentation substrate. A single factor optimization test was used to optimize the solid-state fermentation parameters of biogas residue with the number of viable bacteria and the number of spores as indexes. The results showed that the optimum inoculation conditions involved the following: 55% initial moisture content, 15% initial inoculation amount, 30 ℃, and 1:1 initial inoculation ratio for 13 days. Pot experiment showed that the prepared three kinds of bacterial fertilizers could not only effectively promote the growth of white clover, improve the composition of soil nutrients, but also change the structure of soil bacterial community, which is of great significance to the health of soil ecosystem in white clover. [ABSTRACT FROM AUTHOR]

Arthrobotrys flagrans, a nematode‐eating fungus, is an effective component of animal parasitic nematode biocontrol agents. In the dried formulation, the majority of spores are in an endogenous dormant state. This study focuses on dormant chlamydospore and nondormant chlamydospore of A. flagrans to investigate the differences in cyclic adenosine monophosphate (cAMP) and protein content between the two types of spores. cAMP and soluble proteins were extracted from the nondormant chlamydospore and dormant chlamydospore of two isolates of A. flagrans. The cAMP Direct Immunoassay Kit and Bradford protein concentration assay kit (Coomassie brilliant blue method) were used to detect the cAMP and protein content in two types of spores. Results showed that the content of cAMP in dormant spores of both isolates was significantly higher than that in nondormant spores (p < 0.05). The protein content of dormant spores in DH055 bacteria was significantly higher than that of nondormant spores (p < 0.05). In addition, the protein content of dormant spores of the SDH035 strain was slightly higher than that of nondormant spores, but the difference was not significant (p > 0.05). The results obtained in this study provide evidence for the biochemical mechanism of chlamydospore dormancy or the germination of the nematophagous fungus A. flagrans. [ABSTRACT FROM AUTHOR]

Laboratory pasteurization count (LPC) enumerates thermoduric bacteria and is one parameter used to assess raw milk quality. No regulatory limit has presently been set for LPC, but LPC data are used by some dairy processors and cooperatives to designate raw milk quality premiums paid to farmers and may also be used for troubleshooting bacterial contamination issues. Although it is occasionally used as a proxy for levels of bacterial spores in raw milk, limited knowledge is available on the types of organisms that are enumerated by LPC in contemporary raw milk supplies. Although historical studies have reported that thermoduric bacteria quantified by LPC may predominantly represent gram-positive cocci, updated knowledge on microbial populations enumerated by LPC in contemporary organic raw milk supplies is needed. To address this gap, organic raw milk samples from across the United States (n = 94) were assessed using LPC, and bacterial isolates were characterized. LPC ranged from below detection (<0.70 log cfu/mL) to 4.07 log cfu/mL, with a geometric mean of 1.48 log cfu/mL. Among 380 isolates characterized by 16S rDNA sequencing, 52.6%, 44.5%, and 2.4% were identified as gram-positive sporeformers, gram-positive nonsporeformers, and gram-negatives, respectively; 0.5% could not be categorized into those groups because they could only be assigned a higher level of taxonomy. Isolates identified as gram-positive sporeformers were predominantly Bacillus (168/200), and gram-positive nonsporeformers were predominantly Brachybacterium (56/169) and Kocuria (47/169). To elucidate if the LPC level can be an indicator of the type of thermoduric (e.g., sporeforming bacteria) present in raw milk, we evaluated the proportion of sporeformers in raw milk samples with LPC of ≤100 cfu/mL, 100 to 200 cfu/mL, and ≥200 cfu/mL (51%, 67%, and 35%), showing a trend for sporeformers to represent a smaller proportion of the total thermoduric population when LPC increases, although overall linear regression showed no significant association between the proportion of sporeformers and the LPC concentration. Hence, LPC level alone provides no insight into the makeup of the thermoduric population in raw milk, and further characterization is needed to elucidate the bacterial drivers of elevated LPC in raw milk. We therefore further characterized the isolates from this study using MALDI-TOF mass spectrometry (MALDI-TOF MS), a rapid microbial identification tool that is more readily available to dairy producers than 16S rDNA PCR and sequencing. Although our data indicated agreement between 16S rDNA sequencing and MALDI-TOF MS for 66.6% of isolates at the genus level, 24.2% and 9.2% could not be reliably identified or were mischaracterized using MALDI-TOF MS, respectively. This suggests that further optimization of this method is needed to allow for accurate characterization of thermoduric organisms commonly found in raw milk. Ultimately, our study provides a contemporary perspective on thermoduric bacteria selected by the LPC method and establishes that the LPC alone is not sufficient for identifying the bacterial drivers of LPC levels. Further development of rapid characterization methods that are accessible to producers, cooperatives, and processors will support milk quality troubleshooting efforts and ultimately improve outcomes for dairy industry community members. [ABSTRACT FROM AUTHOR]

The rapid detection of the spore form of Clostridioides difficile has remained a challenge for clinicians. To address this, we have developed a novel, precise, microwave-enhanced approach for near-spontaneous release of DNA from C. difficile spores via a bespoke microwave lysis platform. C. difficile spores were microwave-irradiated for 5 s in a pulsed microwave electric field at 2.45 GHz to lyse the spore and bacteria in each sample, which was then added to a screen-printed electrode and electrochemical DNA biosensor assay system to identify presence of the pathogen's two toxin genes. The microwave lysis method released both single-stranded and double-stranded genome DNA from the bacterium at quantifiable concentrations between 0.02 μg/mL to 250 μg/mL allowing for subsequent downstream detection in the biosensor. The electrochemical bench-top system comprises of oligonucleotide probes specific to conserved regions within tcdA and tcdB toxin genes of C. difficile and was able to detect 800 spores of C. difficile within 300 µL of unprocessed human stool samples in under 10 min. These results demonstrate the feasibility of using a solid-state power generated, pulsed microwave electric field to lyse and release DNA from human stool infected with C. difficile spores. This rapid microwave lysis method enhanced the rapidity of subsequent electrochemical detection in the development of a rapid point-of-care biosensor platform for C. difficile. [ABSTRACT FROM AUTHOR]

Traditional culture-based methods, though a "gold standard" for bacterial detection in various industrial sectors, do often not fulfill today's high requirements regarding rapidity, on-site applicability, and cost-efficiency both during operation and evaluation. Here, the feasibility of using an adenosine triphosphate (ATP)-based assay for determining microbial contaminations in paints and cosmetics was investigated and compared with standard plate count techniques and dipslides. Therefore, we initially determined the level of sensitivity and assessed the accuracy and concordance among the different methods via spiking tests using a mix of frequently abundant bacterial species to simulate microbial contamination. Bioluminescence intensity was linearly proportional to log colony counts over five orders of magnitude (R2 = 0.99), indicating a high level of sensitivity. Overall, the accuracy varied depending on the test specimen, most probably due to matrix-related quenching effects. Although the degree of conformity was consistently higher at target concentrations ≥ 105 CFU·mL−1, microbial contaminations were detectable down to 103 CFU·mL−1, thus meeting the high requirements of various industries. ATP-based results tended to be within an order of magnitude lower than the reference. However, bearing that in mind, the developed assay serves as a rapid, real-time alternative for routine quality control and hygiene monitoring. [ABSTRACT FROM AUTHOR]

The concepts of "D-value," "thermal death time" and "commercial sterility," innovative and useful at their inception, are based on untenable assumptions, notably that the log-linear isothermal inactivation model has universal applicability, that extrapolation over several orders of magnitude below the detection level is permissible, and that total microbial inactivation is theoretically impossible. Almost all commonly observed inactivation patterns, the log-linear is just a special case, can be described by both deterministic and fully stochastic models, examples of which are given. Unlike the deterministic, the stochastic models predict either complete elimination of the targeted cells or spores in realistic finite time, or residual survival. In most cases, the published survival data do not contain enough information to establish which actually happens. The microbial safety of thermally processed foods can be compromised not only by under-processing but also by a variety of mishaps whose occurrence probabilities are unrelated to the inactivation kinetics. Moreover, the available sampling plans to detect microbial contamination in sterilized containers through incubation alone are insensitive to levels of potential safety concerns. In principle, many of these issues could be resolved by developing new dramatically improved detection methods and/or verifiable methods to predict very low levels of microbial survival. [ABSTRACT FROM AUTHOR]

Spores are the main dormant forms of some bacteria under harsh environment conditions, which are widely distributed in nature. Bacterial spores have a rigid structure, which helps resist to environmental stresses such as heat and ultraviolet radiation. At present, it is difficult to inactivate bacterial spores by the conventional sterilization methods used in the food industry. Therefore, bacterial spores are one of the most important factors influencing the food safety. In recent years, the application of non-thermal processing technologies in killing spores has received great deal of attention. Cold plasma is a novel non-thermal physical sterilization technology, which has a broad application prospect in the food industry due to its various advantages such as high bactericidal efficiency, low energy consumption, and secondary pollution-free. In this paper, the application of cold plasma in the inactivation of bacterial spores in foods is reviewed, and the underlying mechanisms are also summarized in detail. Moreover, the effects of diverse factors on cold plasma-induced spores inactivation are analyzed, and the future research direction is also prospected. This article provides important theoretical basis for the practical application of cold plasma in food safety and quality control. [ABSTRACT FROM AUTHOR]

Tumors of the central nervous system (CNS) are severe and refractory diseases with poor prognosis, especially for patients with malignant glioblastoma and brain metastases. Currently, numerous studies have explored the potential role of bacteria and intestinal flora in tumor development and treatment. Bacteria can penetrate the blood–brain barrier (BBB), targeting the hypoxic microenvironment at the core of tumors, thereby eliminating tumors and activating both the innate and adaptive immune responses, rendering them promising therapeutic agents for CNS tumors. In addition, engineered bacteria and derivatives, such as bacterial membrane proteins and bacterial spores, can also be used as good candidate carriers for targeted drug delivery. Moreover, the intestinal flora can regulate CNS tumor metabolism and influence the immune microenvironment through the "gut–brain axis". Therefore, bacterial anti-tumor therapy, engineered bacterial targeted drug delivery, and intervention of the intestinal flora provide therapeutic modalities for the treatment of CNS tumors. In this paper, we performed a comprehensive review of the mechanisms and therapeutic practices of bacterial therapy for CNS tumors and discussed potential future research directions in this field. [ABSTRACT FROM AUTHOR]

Spore formation is required for environmental survival and transmission of the human enteropathogenic Clostridioides difficile. In all bacterial spore formers, sporulation is regulated through activation of the master response regulator, Spo0A. However, the factors and mechanisms that directly regulate C. difficile Spo0A activity are not defined. In the well-studied Bacillus species, Spo0A is directly inactivated by Spo0E, a small phosphatase. To understand Spo0E function in C. difficile, we created a null mutation of the spo0E ortholog and assessed sporulation and physiology. The spo0E mutant produced significantly more spores, demonstrating Spo0E represses C. difficile sporulation. Unexpectedly, the spo0E mutant also exhibited increased motility and toxin production, and enhanced virulence in animal infections. We uncovered that Spo0E interacts with both Spo0A and the toxin and motility regulator, RstA. Direct interactions between Spo0A, Spo0E, and RstA constitute a previously unknown molecular switch that coordinates sporulation with motility and toxin production. Reinvestigation of Spo0E function in B. subtilis revealed that Spo0E induced motility, demonstrating Spo0E regulation of motility and sporulation among divergent species. Further, 3D structural analyses of Spo0E revealed specific and exclusive interactions between Spo0E and binding partners in C. difficile and B. subtilis that provide insight into the conservation of this regulatory mechanism among different species. Author summary: Clostridioides difficile causes severe diarrheal disease and death in humans and livestock animals, and is a major public health concern. As an anaerobe, C. difficile transmission relies on the formation of hardy spores, while its pathogenesis requires the productions of toxins. Herein, we describe a previously unknown regulatory mechanism involving the sporulation factor Spo0E that controls spore and toxin production, as well as motility. We demonstrate that this multi-functional regulatory mechanism is also operational in the distant relative, Bacillus subtilis. The identification of specific interactions between Spo0E and the regulators RstA and Spo0A show how these factors work together to control toxin, motility, and spore formation. Moreover, the conservation of this system in other bacteria suggests that similar regulatory mechanisms exist in a wide range of species. [ABSTRACT FROM AUTHOR]

Engineered living materials (ELMs) incorporate living material to provide a gain of function over existing materials, such as self-repair. The use of bacteria in ELMs has been studied extensively in concrete, where repair can be facilitated by bacterial ureolytic calcium carbonate (CaCO3) precipitation; however, the study of bacteria in other construction materials is limited. We examined the ability of bacterial species to survive in common latex binder chemistries, a model paint formulation, and through the film-forming process. The longest survival was by bacterial spores of Bacillus simplex str. GGC-P6A, which survive in latex emulsions, a liquid coating composition, and in a dried film for >28 days. Surprisingly, our data show that non-spore-forming Escherichia coli survive at least 15 days in liquid composition, which appear to be influenced by the composition of the outer membrane, nutrient scavenging, and the ability to metabolize toxic acrylate. Spores of GGC-P6A were shown to grow in solid paint films from sites of damage, resulting in crack filling through carbonate precipitation, demonstrating the potential for self-repair through microbially mediated CaCO3 precipitation without directed pH modification. These data suggest that a range of bacterial species, in particular members of Bacilli, may facilitate new applications of bio-augmented, self-healing coating systems. [ABSTRACT FROM AUTHOR]

Adherence of Bacillus cereus spores to dairy industry equipment is a serious problem, causing food spoilage and, occasionally, outbreaks of foodborne diseases. Antimicrobial essential oils (EOs) have been proposed as an alternative to synthetic disinfectants due to their environmentally friendly properties. The aim of this study was to assess the effect of Cymbopogon winterianus and Juniperus phoenicea EOs on planktonic and adherent B. cereus spores to stainless steel surfaces. Eleven strains of B. cereus were used in this study. The chemical composition of the C. winterianus and J. phoenicea oils was analyzed by gas chromatography (GC)/mass spectrometry (MS). Ninety components were identified for C. winterianus, being geranial (37 %), neral (29 %), beta-myrcene (16 %) and geraniol (4 %) the most abundant constituents. Twelve components were identified for J. phoenicea, being alpha-pinene (65 %) the most abundant constituent. The results of the minimal inhibitory concentration and minimal bactericidal concentration revealed that C. winterianus was the most effective EO (p

Enumeration of endospores of butyric acid-forming clostridia in cheese milk is an essential part of milk quality monitoring for cheese producers to avoid late blowing, severe spoilage caused by clostridia during ripening. However, due to the lack of an internationally standardized method, different methods are used and it is important to consider how the choice of method affects the results. This is particularly relevant when clostridial spore counts in milk are considered for quality payments. The aim of this study was to evaluate the specificity of the AMP-6000 method for the enumeration of endospores of cheese spoiling clostridia in milk. First, to assess the prevalence of Clostridium diversity and to determine potential non-target species, we identified isolates from positive reactions of the AMP-6000 method used to quantify clostridial endospores in raw milk and teat skin samples by MALDI-TOF MS. Based on these results, a strain library was designed to evaluate method inclusivity and exclusivity using pure cultures of target and non-target strains according to ISO 16140-2:2016. Most target Clostridium tyrobutyricum strains, as well as all tested C. butyricum and C. sporogenes strains were inclusive. However, C. beijerinckii may be underestimated as only some strains gave positive results. All non-target strains of bacilli and lysinibacilli, but not all paenibacilli, were confirmed to be exclusive. This study provides performance data to better understand the results of microbiological enumeration of butyric acid-forming clostridia in milk and serves as a basis for future methodological considerations and improvements. [ABSTRACT FROM AUTHOR]

Background: Application of biofertilizers is an appropriate replacement of harmful chemical fertilizers to fulfil the rising demands of herbal medicine. The main objective of this study was to establish a potent biofertilizer with the help of microbial consortia and observe their effects on the primary growth of Aloe barbadensis Mill. Methods: Rhizospheric soil of the plant Aloe barbadensis Mill. was taken and isolation, characterization and identification of the vesicular arbuscular mycorrhiza (VAM) fungi, rhizospheric bacteria and the VAM fungal spore associated bacteria was done. To check the microbial effects on morphological parameters of the plant, a total number of eight experimental sets were prepared by using different microbial strains. Result: In our experiment, VAM+ABM1 treated plant set showed the significant responses in plant primary growth which can be used as a potent biofertilizer in more sustainable way. [ABSTRACT FROM AUTHOR]

The industrial rearing of the yellow mealworm (Tenebrio molitor) for feed and food purposes on agricultural by-products may expose larvae and adults to entomopathogens used as biocontrol agents in crop production. Bacterial spores/toxins or fungal conidia from species such as Bacillus thuringiensis or Metarhizium brunneum could affect the survival and growth of insects. Therefore, the aim of this study was to investigate the potential benefits of a wheat bran diet supplemented with probiotic bacteria and dried egg white on larval development and survival and its effects on the gut microbiome composition. Two probiotic bacterial species, Pediococcus pentosaceus KVL B19-01 and Lactiplantibacillus plantarum WJB, were added to wheat bran feed with and without dried egg white, as an additional protein source, directly from neonate larval hatching until reaching a body mass of 20 mg. Subsequently, larvae from the various diets were exposed for 72 h to B. thuringiensis, M. brunneum, or their combination. Larval survival and growth were recorded for 14 days, and the bacterial microbiota composition was analyzed using 16S rDNA sequencing prior to pathogen exposure and on days 3 and 11 after inoculation with the pathogens. The results showed increased survival for T. molitor larvae reared on feed supplemented with P. pentosaceus in the case of co-infection. Larval growth was also impacted in the co-infection treatment. No significant impact of egg white or of P. pentosaceus on larval growth was recorded, while the addition of Lb. plantarum resulted in a minor increase in individual mass gain compared with infected larvae without the latter probiotic. On day 14, B. thuringiensis was no longer detected and the overall bacterial community composition of the larvae was similar in all treatments. On the other hand, the relative operational taxonomic unit (OTU) abundance was dependent on day, diet, and probiotic. Interestingly, P. pentosaceus was present throughout the experiments, while Lb. plantarum was not found at a detectable level, although its transient presence slightly improved larval performance. Overall, this study confirms the potential benefits of some probiotics during the development of T. molitor while underlining the complexity of the relationship between the host and its microbiome. [ABSTRACT FROM AUTHOR]

Genetically modified microorganisms (GMMs) possess significant potential for a wide range of applications; however, their execution in real‐world scenarios, particularly in environments characterized by scarce nutrients and unpredictable conditions, proves daunting. Drawing inspiration from the adaptability of natural seeds, living seed materials that combine a core–shell structure ZIF‐8 and genetically engineered spores are introduced. By genetically modifying the Bacillus subtilis strain to express distinct fluorescent proteins, the visualization of spores within the hollow sphere is facilitated, allowing for differentiation between spore and bacteria states. Importantly, the ZIF‐8 shell exhibits responsiveness to diverse nutrient levels, providing enhanced environmental resistance in comparison to bare spores upon exposure to hypochlorous acid, UV‐C radiation, and even vacuum conditions. Moreover, the potential of living seed materials for living sensors of small molecules is showcased by elucidating that spores can be resuscitated into functional bacteria after release from ZIF‐8 material. This research establishes a novel approach for the general fabrication of Metal‐Organic Frameworks (MOF)‐based living spore hybrid materials, offering environmentally controlled release of living materials across a multitude of applications. [ABSTRACT FROM AUTHOR]

Aims This study investigated the antimicrobial efficacy of ultrasound technology (US) in combination with two different disinfectants (Disinfectant A and Disinfectant B), containing peracetic acid (PAA) and quaternary ammonium compounds (QACs), respectively, against two sporigenic pathogens, Aspergillus brasiliensis and Bacillus subtilis. Methods and results The microbicidal activity of the coupled treatment was compared with the use of the disinfectants alone, and the efficacy of the disinfection strategies was evaluated by the log reduction of the population of the microorganism inoculated onto stainless-steel surface. The combination treatment resulted in a log reduction of 5.40 and 3.88 (Disinfectant A + US) against A. brasiliensis and B. subtilis , at 850 and 500 ppm PAA, compared to 265 and 122 (Disinfectant A only). For Disinfectant B, in combination with US, showed a logarithmic reduction of 5.04 and 4.79 against A. brasiliensis and B. subtilis at 078% v v−1 and 392% v v−1 QACs, respectively, vs. 1.58 and 1.64 (Disinfectant B only). Moreover, no colonies or not statistically significant growth was observed within the US bath containing the disinfectant. Conclusions The antimicrobial efficacy of the two disinfectants was greatly enhanced when used in combination with US, and this also makes it possible to avoid the overuse of chemicals for disinfection. [ABSTRACT FROM AUTHOR]

Bacterial spores owe their incredible resistance capacities to molecular structures that protect the cell content from external aggressions. Among the determinants of resistance are the quaternary structure of the chromosome and an extracellular shell made of proteinaceous layers (the coat), the assembly of which remains poorly understood. Here, in situ cryo-electron tomography on lamellae generated by cryo-focused ion beam micromachining provides insights into the ultrastructural organization of Bacillus subtilis sporangia. The reconstructed tomograms reveal that early during sporulation, the chromosome in the forespore adopts a toroidal structure harboring 5.5-nm thick fibers. At the same stage, coat proteins at the surface of the forespore form a stack of amorphous or structured layers with distinct electron density, dimensions and organization. By analyzing mutant strains using cryo-electron tomography and transmission electron microscopy on resin sections, we distinguish seven nascent coat regions with different molecular properties, and propose a model for the contribution of coat morphogenetic proteins. Bacterial endospores are among the most resilient forms of life. Here, authors reveal ultrastructural details of the spore chromosome and the multiprotein, multilayered extracellular coat, shedding light on mechanisms contributing to spore resistance. [ABSTRACT FROM AUTHOR]

Abstract—Spore-forming bacteria have a unique resistance to negative environmental conditions, including aggressive space factors, and are an excellent model for studying adaptation mechanisms and survival strategies at the molecular level. The study analyzed the genome of Bacillus velezensis, which remained viable after a 2-year exposure in outer space on the outer surface of the ISS as part of the Test space experiment. A comparative analysis of the draft genomes of the exhibit strain and the ground control did not reveal significant changes; the average nucleotide identity was 99.98%, which indicates the ability of microorganisms to maintain genome stability in space conditions, due to both increased stress resistance of bacterial spores and efficient operation of the system of repair of accumulated changes. The study of a single nucleotide polymorphism in the genome of B. velezensis revealed nine point substitutions, three of which are in intergenic regions, six in protein-coding genes, three of them are missense mutations, two nucleotide deletions leading to a shift in the reading frame, and one synonymous substitution. The profiles of the housekeeping genes were determined during MLST typing and it was found that the allelic profiles obtained for B. velezensis T15.2 and 924 strains do not correspond to any of the previously described sequence types.The presented results indicate the ability of B. velezensis bacteria to maintain the viability of spores and the integrity of the genome for a long time under extreme conditions of outer space, which is important for the problem of planetary protection, as well as the potential possibility of performing biotechnological processes based on B. velezensis during space exploration. [ABSTRACT FROM AUTHOR]

Some bacteria (notably the genera Bacillus and Clostridium) have the capacity to form endospores that can survive for millions of years in isolated habitats. The genomes of such ancient bacteria provide unique opportunities to understand bacterial evolution and metabolic capabilities over longer time scales. Herein, we sequenced the genome of a 2000-year-old bacterial strain (Mal05) isolated from intact apple seeds recovered during archaeological excavations of a Roman villa in Italy. Phylogenomic analyses revealed that this strain belongs to the species Bacillus stercoris and that it is placed in an early-branching position compared to most other strains of this species. Similar to other Bacillus species, B. stercoris Mal05 had been previously shown to possess antifungal activity. Its genome encodes all the genes necessary for the biosynthesis of fengycin and surfactin, two cyclic lipopeptides known to play a role in the competition of Bacilli with other microorganisms due to their antimicrobial activity. Comparative genomics and analyses of selective pressure demonstrate that these genes are present in all sequenced B. stercoris strains, despite the fact that they are not under strong purifying selection. Hence, these genes may not be essential for the fitness of these bacteria, but they can still provide a competitive advantage against other microorganisms present in the same environment. [ABSTRACT FROM AUTHOR]

Clostridioides difficile infection (CDI) remains a significant contributor to healthcare costs and morbidity due to high rates of recurrence. Currently, available antibiotic treatment strategies further disrupt the fecal microbiome and do not address the alterations in commensal flora (dysbiosis) that set the stage for CDI. Advances in microbiome-based research have resulted in the development of new agents, classified as live biotherapeutic products (LBPs), for preventing recurrent CDI (rCDI) by restoring eubiosis. Prior to the LBPs, fecal microbiota transplantation (FMT) was available for this purpose; however, lack of large-scale availability and safety concerns have remained barriers to its widespread use. The LBPs are an exciting development, but questions remain. Some are derived directly from human stool while other developmental products contain a defined microbial consortium manufactured ex vivo, and they may be composed of either living bacteria or their spores, making it difficult to compare members of this heterogenous drug class to one another. None have been studied head-to head or against FMT in preventing rCDI. As a class, they have considerable variability in their biologic composition, biopharmaceutic science, route of administration, stages of development, and clinical trial data. This review will start by explaining the role of dysbiosis in CDI, then give the details of the biopharmaceutical components for the LBPs which are approved or in development including how they differ from FMT and from one another. We then discuss the clinical trials of the LBPs currently approved for rCDI and end with the future clinical directions of LBPs beyond C. difficile. [ABSTRACT FROM AUTHOR]

Bacterial endospores are extremely resilient cells, capable of withstanding the most dramatic environmental challenges. New work identifies a trade-off between resistance to UV radiation and germination efficiency, a trade-off mediated by an unexpected sporulation 'contingency locus'. [ABSTRACT FROM AUTHOR]

Plant-parasitic nematodes are important economic pests of a range of tropical crops. Strategies for managing these pests have relied on a range of approaches, including crop rotation, the utilization of genetic resistance, cultural techniques, and since the 1950’s the use of nematicides. Although nematicides have been hugely successful in controlling nematodes, their toxicity to humans, domestic animals, beneficial organisms, and the environment has raised concerns regarding their use. Alternatives are therefore being sought. The Pasteuria group of bacteria that form endospores has generated much interest among companies wanting to develop microbial biocontrol products. A major challenge in developing these bacteria as biocontrol agents is their host-specificity; one population of the bacterium can attach to and infect one population of plantparasitic nematode but not another of the same species. Here we will review the mechanism by which infection is initiated with the adhesion of endospores to the nematode cuticle. To understand the genetics of the molecular processes between Pasteuria endospores and the nematode cuticle, the review focuses on the nature of the bacterial adhesins and how they interact with the nematode cuticle receptors by exploiting new insights gained from studies of bacterial infections of Carnorhabditis elegans. A new Velcro-like multiple adhesin model is proposed in which the cuticle surface coat, which has an important role in endospore adhesion, is a complex extracellular matrix containing glycans originating in seam cells. The genes associated with these seam cells appear to have a dual role by retaining some characteristics of stem cells. [ABSTRACT FROM AUTHOR]

Concrete cracks and local damage can affect the bond performance between concrete and steel bars, thereby reducing the durability of reinforced concrete structures. Compared with general concrete crack repair methods, biomineralization repair not only has effective bonding capabilities but is also particularly environmentally friendly. Therefore, this study aimed to apply biomineralization technology to repair damaged fiber-reinforced lightweight aggregate concrete (LWAC). Two groups of LWAC specimens were prepared. The experimental group used lightweight aggregates (LWAs) containing bacterial spores and nutrient sources, while the control group used LWAs without bacterial spores and nutrient sources. These specimens were first subjected to compression tests and pull-out tests, respectively, and thus were damaged. After the damaged specimen healed itself in different ways for 28 days, secondary compression and pull-out tests were conducted. The self-healing method of the control group involved placing the specimens in an incubator. The experimental group was divided into experimental group I and experimental group II according to the self-healing method. The self-healing method of experimental group I was the same as that of the control group. The self-healing method of experimental group II involved soaking the specimen in a mixed solution of urea and calcium acetate for two days, and then taking it out and placing it in an incubator for two days, with a cycle of four days. The test results show that in terms of the relative bond strength ratio, the experimental group II increased by 17.9% compared with the control group. Moreover, the precipitate formed at the cracks in the sample was confirmed to be calcium carbonate with the EDS and XRD analysis results, which improved the compressive strength and bond strength after self-healing. This indicates that the biomineralization self-healing method used in experimental group II is more effective. [ABSTRACT FROM AUTHOR]

The development of microcracks in recycled aggregate concrete (RAC) directly impacts its durability; hence, these cracks need to be treated. The authors propose bacterial self-healing by introducing Bacillus megaterium strains into 50% and 100% RAC mixes to heal cracks in RAC on their own. A protective bacterial carrier is needed to protect the bacteria in the high-pH environment of concrete and in a dense microstructure so that the CaCO3 production capacity of the bacteria is not affected. For this purpose, diatomaceous earth (DE) and reused concrete aggregate (RCA) were investigated in this study as potential carriers for the immobilization of bacterial spores that heal cracks in RAC on their own. Filling of surface cracks, the self-healing ratio within concrete, recovery of compressive strength, and water impermeability were examined to test self-healing, and were compared with those of samples containing directly inserted bacteria. Cracks with a maximum width of 0.47, 0.50, and 0.55 mm were completely filled in the specimens containing directly inserted bacteria, immobilized bacteria in RCA, and immobilized bacteria in DE, respectively. Specimens containing bacteria immobilized in DE and RCA had better self-healing performance in terms of recovery of concrete properties and self-healing ratio within concrete than did specimens containing bacteria directly added. Additionally, specimens containing bacteria immobilized in DE exhibited better self-healing results in precracked specimens up to 56 days of age, whereas self-healing by bacteria immobilized in RCA was found to be more effective in precracked specimens at 120 days of age. Overall, it was concluded that DE and RCA can be used as carriers for bacterial immobilization in self-healing RAC, which would not only maintain the durability of RAC but also increase its service life. Biobased self-healing in recycled aggregate concrete offers practical applications in the construction industry. This innovative technology incorporates biobased materials such as bacteria and encapsulated healing agents into the concrete mix, allowing for autonomous healing of cracks and damage. The use of recycled aggregates further enhances the sustainability of the concrete, reducing the environmental impact. The self-healing mechanism operates by activating the bacteria and releasing the healing agents upon crack formation, which then react with the surrounding environment to seal the cracks. This self-healing capability extends the lifespan of concrete structures, reducing the need for costly repairs and maintenance. Additionally, the biobased nature of this approach aligns with sustainable development goals, promoting the use of renewable resources and reducing reliance on traditional repair methods that involve energy-intensive processes and nonrenewable materials. The practical application of biobased self-healing in recycled aggregate concrete demonstrates the potential for more-durable and eco-friendly construction practices. [ABSTRACT FROM AUTHOR]

Solubilizing extracellular matrix (ECM) materials and transforming them into hydrogels has expanded their potential applications both in vitro and in vivo. In this study, hydrogels are prepared by decellularization of human placental tissue using detergent and enzymes and by the subsequent creation of a homogenized acellular placental tissue powder (P‐ECM). A perfusion‐based decellularization approach is employed using detergent and enzymes. The P‐ECM with and without gamma irradiation is then utilized to prepare P‐ECM hydrogels. Physical and biological evaluations are conducted to assess the suitability of the P‐ECM hydrogels for biocompatibility. The decellularized tissue has significantly reduced cellular content and retains the major ECM proteins. Increasing the concentration of P‐ECM leads to improved mechanical properties of the P‐ECM hydrogels. The biocompatibility of the P‐ECM hydrogel is demonstrated through cell proliferation and viability assays. Notably, gamma‐sterilized P‐ECM does not support the formation of a stable hydrogel. Nonetheless, the use of HCl during the digestion process effectively decreases spore growth and bacterial bioburden. The study demonstrates that P‐ECM hydrogels exhibit physical and biological attributes conducive to soft tissue reconstruction. These hydrogels establish a favorable microenvironment for cell growth and the need for investigating innovative sterilization methods. [ABSTRACT FROM AUTHOR]

Fecal microbiota transplantation (FMT) has emerged as a promising therapeutic approach for dysbiosis‐related diseases. However, the clinical practice of crude fecal transplants presents limitations in terms of acceptability and reproductivity. Consequently, two alternative solutions to FMT are developed: transplanting bacteria communities or virome. Advanced methods for transplanting bacteria mainly include washed microbiota transplantation and bacteria spores treatment. Transplanting the virome is also explored, with the development of fecal virome transplantation, which involves filtering the virome from feces. These approaches provide more palatable options for patients and healthcare providers while minimizing research heterogeneity. In general, the evolution of the next generation of FMT in global trends is fecal microbiota components transplantation which mainly focuses on transplanting bacteria or virome. [ABSTRACT FROM AUTHOR]

Bacillus anthracis, a formidable Gram-positive bacterium, stands as one of the most notorious and enigmatic pathogens known to mankind. Its distinct characteristics have captured the attention of scientists and the collective human imagination for centuries. This bacterium is responsible for causing Anthrax, one of the world's most feared infectious diseases. Substantial endeavors have been undertaken since the 2001 anthrax attacks in the United States to develop effective methods for anthrax spore detection. These initiatives aim to swiftly and accurately identify the presence of anthrax spores to prevent the spread of the disease. The detection of Bacillus anthracis spores plays a critical role in maintaining biosecurity and preventing disease outbreaks. These spores contain a unique component called dipicolinic acid (DPA), which accounts for approximately 5–15% of the spore's dry mass. DPA is exclusively found in bacterial spores and serves as an ideal biomarker for the detection of Bacillus anthracis spores. Therefore, accurate detection of DPA plays a crucial role in understanding spore formation and bacterial identification. This review article summarized various types of nanomaterials, including metallic nanoparticles, carbon dots, quantum dots, metal–organic frameworks and other materials, that have been used for colorimetric and fluorescent sensing of DPA. Furthermore, this review article also provides information about the sensing mechanism, detection limit, selectivity, pH and practical applications of the sensors reported in the literature. We hope that this article will inspire interest in the promising research area of nanomaterials-based sensors for the recognition of DPA. [ABSTRACT FROM AUTHOR]