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Summary In this study, a lactic acid bacteria strain isolated from oats was used as a producer to obtain exopolysaccharide (EPS) using MRS agar plates. The findings indicated that the bacterial strain identified as Weissella cibaria (accession number: PP515290) was shown to have good probiotic activity, adapt better to alkaline than acidic conditions, and efficiently produce EPS at concentrations of up to 7.93 g L−1. SEM images showed a smooth surface and compact particle whereas FTIR confirmed the basic functional groups of polysaccharides in the sample. Meanwhile, XRD analysis demonstrated a non‐crystalline amorphous structure and thermal analysis indicated two‐phase thermal decomposition with maximum rate at 210 °C. Subsequently, EPS from W. cibaria was applied as stabiliser in set‐type yogurt (ex situ) in comparison with yogurt using mixed culture with W. cibaria (in situ) and traditional starter culture (control). The results showed that the addition of 2% EPS significantly improved syneresis (14.31%) compared to co‐culture (27.50%) and control (29.80%) as well as increased hardness of yogurt during 2‐week refrigeration. [ABSTRACT FROM AUTHOR]

Biopreservation is a powerful strategy to prolong the shelf life of food products by applying naturally occurring microorganisms and/or their metabolites. Current food trends emphasise the need to develop alternatives for chemical or thermal preservation methods. In this line, different fermentation starters from table olives present the potential to control spoilage or pathogen‐occurring microorganism in table olives storage. One of the most interesting family used as biopreservative culture is Lactobacillaceae and it has also been used in combination with yeasts as olive fermentation starter. Lactic acid bacteria, from Lactobacillaceae family, are characterised by the production of bacteriocins, proteins with the potential for preserving food by changing the organisation of the membrane of spoilage microorganisms. These bacteriocins‐producing bacteria can be directly inoculated, although nanosystem technology is the most promising incorporation strategy. In table olives, the most commonly used starters are Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Saccharomyces cerevisiae, Wickerhamomyces anomalus, among others. These strains with biopreservation characteristics, inoculated alone or in mixed cultures, ensure food safety by conferring the product added value and prolonging product shelf life. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Two distinct bacterial strains were combined in a mixed culture to investigate the degradation of phenol. The mixed cultures consisting of species like Rhodococcus and Bacillus, were isolated from the waste effluent collected from Dankuni coal complex (DCC) in West Bengal. The experimental phenol biodegradation were performed batch wise at an optimized temperature and pH conditions of 37°C and 7.0 for a wide range of phenol concentrations initially, with saline solutions which is not supplemented with nutrients initially. Experimental results concluded a highest possible specific growth rate at 150 mg/L for phenol biodegradation of 2400 mg/L within a span of 72 h. Several significant physicochemical parameters were investigated in order to determine the ideal conditions for phenol breakdown. It was also observed that a spectroscopic study of the intermediate at 260 nm of the phenol biodegradation commenced through the formation of a cis, cis intermediate, indicating ortho‐cleavage pathway. A simulated substrate utilization and growth profiles was obtained by using substrate inhibition model equation using MATLAB R2017a were used to compare for the validation of the obtained experimental growth and substrate characterization data. [ABSTRACT FROM AUTHOR]

17 β‐Estradiol is produced by animals, and humans and excreted through excreta, and has endocrine‐disrupting activity. Bacterial degradation is one of the suitable methods used for the removal of 17 β‐estradiol (E2) from the natural environment. In this study, E2‐degrading bacteria were screened from the enriched sediment sample from the wastewater environment. Two bacterial strains of E2‐degrading bacteria (Stenotrophomonas maltophilia MN08 and Pseudomonas aeruginosa KL10) were determined and >70% of E2‐degradation was achieved. The strain MN08 could rapidly remove approximately 86.5% ± 1.3% of E2 within 7 days of treatment. In addition, the strain KL10 removed 79.5% ± 1% of E2 within the same period. Optimized culture temperature and pH of the medium could improve E2‐degradation. The results demonstrated that the strain MN08 exhibited maximum E2‐degradation activity at 35°C, and pH 8.0. The optimal pH for strain KL10 to degrade E2 ranged from 7.0 to 9.0. The E2‐degradation level for the mixture culture systems can exhibit synergistic E2‐degradation activity. The degradation of the MN08 and KL10 individual strains was 87.3% ± 1.2% and 81.4% ± 1.5%, respectively. The E2‐degradation potential for the mixed culture system was 91.3% ± 2.9% under optimized conditions in which 100 mg/L of E2 served as the sole source of carbon and energy. The present finding demonstrates that the co‐culture of S. maltophilia MN08 and P. aeruginosa KL10 may provide a promising bio‐treatment strategy for the removal of steroids from wastewater. [ABSTRACT FROM AUTHOR]

Phosphorus in wastewater influents is a global issue. Controlling eutrophic water is crucial. Biological phosphorus removal is an economically and environmentally sustainable method for removing phosphorus from wastewater. This study aims to isolate and improve the capacity of aerobic phosphorus-removing bacteria to reduce excessive phosphate concentrations in the environment. Only three out of fourteen bacterial isolates demonstrated the highest phosphate removal efficiency using Toluidine blue-O. Klebsiella pneumoniae 6A, Klebsiella quasipneumoniae 6R, and Enterobacter mori 8R were isolated from activated sludge and identified by 16srRNA. In a single-factor experiment, the effect of incubation periods, phosphate concentrations, carbon sources, sodium acetate concentrations, temperature, pH, and irradiation dosages were studied. Seventy-two hours of incubation, 55 mg/L PO4, sodium acetate as the carbon source, 30°C and pH 7 resulted in maximum phosphorus removal. After optimising the parameters, the removal efficiency of Klebsiella pneumoniae 6A, Klebsiella quasipneumoniae 6R, and Enterobacter mori 8R increased from 73.5% to 85.1%, 79.1% to 98.1%, and 80.6% to 91.9%, respectively. Gamma irradiation showed significant results only in Klebsiella pneumoniae 6A where 100 Gy increased the phosphorous removal efficiency from 85.1% to 100%. Immobilised mixed culture of the three strains adapted better to 100 mg/L Phosphorus than pure cells. Therefore, this technique holds great new promise for phosphorus-contaminated sites bioremediation. [ABSTRACT FROM AUTHOR]

Mitigation of enteric methane (CH4) emissions from ruminant livestock represents an opportunity to improve the sustainability, productivity, and profitability of beef and dairy production. Ruminal methanogenesis can be mitigated via two primary strategies: (1) alternative electron acceptors and (2) enzymatic inhibition of methanogenic pathways. The former utilizes the thermodynamic favorability of certain reactions such as nitrate/nitrite reduction to ammonia (NH3) while the latter targets specific enzymes using structural analogs of CH4 and methanogenic cofactors such as bromochloromethane (BCM). In this study, we investigated the effects of four additives and their combinations on CH4 production by rumen microbes in batch culture. Sodium nitrate (NaNO3), sodium sulfate (Na2SO4), and 3-nitro-1-propionate (3NPA) were included as thermodynamic inhibitors, whereas BCM was included as a enzymatic inhibitor. Individual additives were evaluated at three levels of inclusion in experiments 1 and 2. Highest level of each additive was used to determine the combined effect of NaNO3 + Na2SO4 (NS), NS + 3NPA (NSP), and NSP + BCM (NSPB) in experiments 3 and 4. Experimental diets were high, medium, and low forage diets (HF, MF, and LF, respectively) and consisted of alfalfa hay and a concentrate mix formulated to obtain the following forage to concentrate ratios: 70:30, 50:50, and 30:70, respectively. Diets with additives were placed in fermentation culture bottles and incubated in a water bath (39°C) for 6, 12, or 24h. Microbial DNA was extracted for 16S rRNA and ITS gene amplicon sequencing. In experiments 1 and 2, CH4 concentrations in control cultures decreased in the order of LF, MF, and HF diets, whereas in experiments 3 and 4, CH4 was highest in MF diet followed by HF and LF diets. Culture pH and NH3 in the control decreased in the order of HF, MF, to LF as expected. NaNO3 decreased (p < 0.001) CH4 and butyrate and increased acetate and propionate (p < 0.03 and 0.003, respectively). Cultures receiving NaNO3 had an enrichment of microorganisms capable of nitrate and nitrite reduction. 3NPA also decreased CH4 at 6h with no further decrease at 24 h (p < 0.001). BCM significantly inhibited methanogenesis regardless of inclusion levels as well as in the presence of the thermodynamic inhibitors (p < 0.001) while enriching succinate producers and assimilators as well as propionate producers (p adj < 0.05). However, individual inclusion of BCM decreased total short chain fatty acid (SCFA) concentrations (p < 0.002). Inhibition of methanogenesis with BCM individually and in combination with the other additives increased gaseous H2 concentrations (p < 0.001 individually and 0.028 in combination) while decreasing acetate to propionate ratio (p < 0.001). Only the cultures treated with BCM in combination with other additives significantly (padj < 0.05) decreased the abundance of Methanobrevibacter expressed as log fold change. Overall, the combination of thermodynamic and enzymatic inhibitors presented a promising effect on ruminal fermentation in-vitro, inhibiting methanogenesis while optimizing the other fermentation parameters such as pH, NH3, and SCFAs. Here, we provide a proof of concept that the combination of an electron acceptor and amethane analogmay be exploited to improvemicrobial effciency via methanogenesis inhibition. [ABSTRACT FROM AUTHOR]

Simple Summary: This study examines the use of dairy wastewater to cultivate three types of microalgae: Spirulina platensis, Micractinium, and Chlorella. The research found that these algae can effectively remove nutrients like nitrogen and phosphorus from industrial wastewater. Spirulina sp. and a mixed culture of all three algae performed best, significantly reducing nitrogen levels, while Chlorella sp. also removed a substantial amount of phosphorus. Additionally, microalgae treatment greatly reduced pathogens. These results suggest that microalgae could be a promising method for treating dairy wastewater and improving water quality. This study explores the novel use of mixed cultures of microalgae—Spirulina platensis, Micractinium, and Chlorella—for nutrient removal from dairy wastewater (DW). Microalgae were isolated from a local wastewater treatment plant and cultivated under various light conditions. The results showed significant biomass production, with mixed cultures achieving the highest biomass (2.51 g/L), followed by Spirulina (1.98 g/L) and Chlorella (1.92 g/L). Supplementing DW (75%) with BG medium (25%) significantly enhanced biomass and pH levels, improving pathogenic bacteria removal. Spirulina and mixed cultures exhibited high nitrogen removal efficiencies of 92.56% and 93.34%, respectively, while Chlorella achieved 86.85% nitrogen and 83.45% phosphorus removal. Although growth rates were lower under phosphorus-limited conditions, the microalgae adapted well to real DW, which is essential for effective algal harvesting. Phosphorus removal efficiencies ranged from 69.56% to 86.67%, with mixed cultures achieving the highest removal. Microbial and coliform removal efficiencies reached 97.81%, with elevated pH levels contributing to significant reductions in fecal E. coli and coliform levels. These findings suggest that integrating microalgae cultivation into DW treatment systems can significantly enhance nutrient and pathogen removal, providing a sustainable solution for wastewater management. [ABSTRACT FROM AUTHOR]

The time is right for targeted engineering of electroactive microbes for electrobioproduction. Current mixed culture microbial electrosynthesis (MES) and microbial electromethanogenesis are limited to a few low-value products. The product spectrum of MES will greatly benefit from engineered microbial pure cultures, especially with regard to high-value products. To quickly advance MES, standardized, off-the-shelf electrobioreactors are urgently needed. Microbial electrosynthesis (MES) is an emerging technology that couples renewable electricity to microbial production processes. Although advances in MES performance have been driven largely by microbial mixed cultures, we see a great limitation in the diversity, and hence value, of products that can be achieved in undefined mixed cultures. By contrast, metabolic control of pure cultures and genetic engineering could greatly expand the scope of MES, and even of broader electrobiotechnology, to include targeted high-value products. To leverage this potential, we advocate for more efforts and activities to develop engineered electroactive microbes for synthesis, and we highlight the need for a standardized electrobioreactor infrastructure that allows the establishment and engineering of electrobioprocesses with these novel biocatalysts. [ABSTRACT FROM AUTHOR]

In Alzheimer's disease (AD) pathology, the accumulation of amyloid-beta (Aβ), a main component of senile plaques, activates glial cells and causes neuroinflammation. Excessive neuroinflammation results in neuronal dropouts and finally produces the symptoms of AD. Recent studies suggest that disorder in sphingosine-1-phosphate (S1P) metabolism, especially the decreased expression of sphingosine kinase (SK)1, followed by the reduction in the amount of S1P, can be a promotive factor in AD onset. Thus, we explored the possibility that dysregulated S1P metabolism affects AD through the altered function in glial cells. We evaluated the effect of PF-543, a pharmacological inhibitor of SK1, on the inflammatory responses by lipopolysaccharide (LPS)-activated glial cells, microglia, and astrocytes. The treatment with PF-543 decreased the intracellular S1P content in glial cells. The PF-543 treatment enhanced the nitric oxide (NO) production in the LPS-treated neuron/glia mixed culture. Furthermore, we found that the augmented production of NO and reactive oxygen species (ROS) in the PF-543-treated astrocytes affected the microglial inflammatory responses through humoral factors in the experiment using an astrocyte-conditioned medium. The PF-543 treatment also decreased the microglial Aβ uptake and increased the number of injured neurons in the Aβ-treated neuron/glia mixed culture. These results suggest that a decrease in the glial S1P content can exacerbate neuroinflammation and neurodegeneration through altered glial cell functions. [ABSTRACT FROM AUTHOR]

Introduction: Microbial communities affect several aspects of the earth's ecosystem through their metabolic interaction. The dynamics of this interaction emerge from complex multilevel networks of crosstalk. Elucidation of this interaction could help us to maintain the balance for a sustainable future. Objectives: To investigate the chemical language among highly abundant microbial genera in the rhizospheres of medicinal plants based on the metabolomic analysis at the interaction level. Methods: Coculturing experiments involving three microbial species: Aspergillus (A), Trichoderma (T), and Bacillus (B), representing fungi (A, T) and bacteria (B), respectively. These experiments encompassed various interaction levels, including dual cultures (AB, AT, TB) and triple cultures (ATB). Metabolic profiling by LC-QTOFMS revealed the effect of interaction level on the productivity and diversity of microbial specialized metabolites. Results: The ATB interaction had the richest profile, while the bacterial profile in the monoculture condition had the lowest. Two native compounds of the Aspergillus genus, aspergillic acid and the dipeptide asperopiperazine B, exhibited decreased levels in the presence of the AT interaction and were undetectable in the presence of bacteria during the interaction. Trichodermarin N and Trichodermatide D isolated from Trichoderma species exclusively detected during coexistence with bacteria (TB and ATB). These findings indicate that the presence of Bacillus activates cryptic biosynthetic gene clusters in Trichoderma. The antibacterial activity of mixed culture extracts was stronger than that of the monoculture extracts. The TB extract exhibited strong antifungal activity compared to the monoculture extract and other mixed culture treatments. Conclusion: The elucidation of medicinal plant microbiome interaction chemistry and its effect on the environment will also be of great interest in the context of medicinal plant health Additionally, it sheds light on the content of bioactive constituents, and facilitating the discovery of novel antimicrobials. [ABSTRACT FROM AUTHOR]

Insoluble phosphorous compounds solubilization by soil bacteria is of great relevance since it puts available the phosphorus to be used by plants. The production of organic acids is the main microbiological mechanism by which insoluble inorganic phosphorus compounds are solubilized. In Gram negative bacteria, gluconic acid is synthesized by the activity of the holoenzyme glucose dehydrogenase-pyrroloquinoline quinine named GDH-PQQ. The use of marker genes is a very useful tool to evaluate the persistence of the introduced bacteria and allow to follow-up the effect of biotic and abiotic factors on these beneficial microorganisms in the soil. In previous studies we detected the presence of the pqqE gene in a great percentage of both non-culturable and culturable native soil bacteria. The objective of this study was to analyze the phylogeny of the sequence of pqqE gene and its potential for the study of phosphate solubilizing bacteria from pure and mixed bacterial cultures and rhizospheric soil samples. For this, the presence of the pqqE gene in the genome of phosphate solubilizing bacteria that belong to several bacteria was determined by PCR. Also, this gene was analyzed from mixed bacterial cultures and rhizospheric soil associated to peanut plants inoculated or not with phosphate solubilizing bacteria. For this, degenerate primers designed from several bacterial genera and specific primers for the genus Pseudomonas spp., designed in this study, were used. DNA template used from simple or mixed bacterial cultures and from rhizospheric soil samples was obtained using two different DNA extraction techniques. Results indicated that pqqE gene amplification product was found in the genome of all Gram negative phosphate solubilizing bacteria analyzed. It was possible to detect this gene in the DNA obtained from mixed cultures where these bacteria grew in interaction with other microorganisms and in that obtained from rhizospheric soil samples inoculated or not with these bacteria. The phylogenetic analysis indicated that pqqE gene is a conserved gene within related genera. In conclusion, pqqE gene could be a potential marker for the study of phosphate solubilizing bacterial populations. [ABSTRACT FROM AUTHOR]

The properties of kale as a functional food are well established. We sought to determine how fermentation further enhances these properties. We tested different fermentation conditions: (i) spontaneous fermentation with naturally occurring bacteria, (ii) spontaneous fermentation with 2% salt, (iii) Lactococcus lactis, (iv) Lactobacillus acidophilus, (v) mixture of L. lactis and L. acidophilus, (vi) mixture of L. lactis, L. acidophilus, and Clostridium butyricum. We quantified selected bioactive components using high‐performance liquid chromatography (HPLC) and antinutritional factors using a gravimetric method and spectrophotometry. We then determined (i) the antioxidant capacity of the vegetable, (ii) anti‐inflammation capacity, and (iii) the surface microbiota composition by 16S sequencing. All fermentation methods imparted some benefits. However, fermentation with mixed culture of L. lactis and L. acidophilus was most effective in increasing polyphenols and sulforaphane accessibility, increasing antioxidant activity, and reducing antinutritional factors. Specifically, fermentation with L. lactis and L. acidophilus increased total polyphenols from 8.5 to 10.7 mgGAE/g (milligrams of gallium acid equivalent per gram) and sulforaphane from 960.8 to 1777 μg/g (microgram per gram) but decreased the antinutritional factors oxalate and tannin. Total oxalate was reduced by 49%, while tannin was reduced by 55%–65%. The antioxidant capacity was enhanced but not the anti‐inflammation potential. Both unfermented and fermented kale protected equally against lipopolysaccharide (LPS)‐induced inflammation in RAW 264.7 macrophages and prevented increases in inducible nitric oxide synthase (iNOS), tumor necrosis factor‐alpha (TNF‐α), interleukin‐1 beta (IL‐1β), and interleukin‐6 messenger RNA (IL‐6 mRNA) expression by 84.3%, 62%, 68%, and 85.5%, respectively. Unfermented and naturally fermented kale had high proportions of sulfur reducing Desulfubrio and Proteobacteria usually associated with inflammation. Fermenting with L. lactis and/or L. acidophilus changed the bacterial proportions, reducing the Proteobacteria while increasing the genera Lactobacilli and Lactococcus. In summary, fermentation enhances the well‐known beneficial impacts of kale. Fermentation with mixed cultures of L. lactis and L. acidophilus imparts higher benefits compared to the single cultures or fermentation with native bacteria present in the vegetable. [ABSTRACT FROM AUTHOR]

The biodiversity of several beekeeping environments and honey samples was studied. The bacterial and yeast counts ranged from 0.00 to 5.19 Log CFU/g and from 0.00 to 3.33 Log CFU/g, respectively, presenting significant differences between the values. Of the honey samples, two of them exceeded the legislative limit established for total aerobic bacteria (5.19 Log CFU/g and 5.03 Log CFU/g). A total of ninety-eight yeast strains were isolated, with eight different species: Candida albicans, Dekkera anomala, Zygosaccharomyces rouxii, Z. mellis, Kazachstania unispora, Meyerozyma guillermondii, Saccharomyces cerevisiae, and S. unisporus. This implies a low microbial biodiversity and a low genetic variability index (D = 0.116 and 6–19%, respectively) due to the large number of genetically identical individuals found in each species. To select the most adequate strains for mead elaboration (with pure and mixed cultures), the fermentation capacity and organoleptic characteristics were studied. The best yeasts were chosen for the "pure culture fermentation" of honey (Saccharomyces spp. M11A2) and for mixed sequential inoculation (K. unispora M17A2). Both of the yeasts were isolated from honey and selected for their high fermentative capacity and resistance to ethanol. The results of the sensory analysis of the meads that were produced, in addition to one commercial product, were compared and indicated that the one inoculated with the pure culture had the best overall impression. [ABSTRACT FROM AUTHOR]

Candida albicans (C. albicans) and Streptococcus mutans (S. mutans) are frequently detected in the plaque biofilms of children with early childhood caries. This study investigated the effects of sucrose and farnesol on biofilm formation by the oral pathogens S. mutans and C. albicans, including their synergistic interactions. Biofilm formation dynamics were monitored using the Cell Index (CI). The CI for S. mutans increased in the brain–heart infusion medium, peaking at 10 h; however, the addition of sucrose reduced the CI. For C. albicans yeast cells, the CI increased at sucrose concentrations > 0.5%, peaking at 2 h. Mixed cultures of S. mutans and C. albicans yeast cells showed significantly higher CI values in the presence of sucrose, suggesting a synergistic effect on biofilm formation. Farnesol consistently suppressed biofilm formation by C. albicans yeast cells, even in the presence of sucrose, and higher farnesol concentrations resulted in greater inhibition. Regarding C. albicans hyphal cells, sucrose did not enhance biofilm formation, whereas farnesol significantly reduced biofilm formation at all concentrations tested. These findings elucidate the complex roles of sucrose and farnesol in biofilm formation by S. mutans and C. albicans and emphasize the potential of farnesol as an effective oral biofilm inhibitor. [ABSTRACT FROM AUTHOR]

Persistent organic pollutants (POPs), including organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzo-p-furans, pose significant hazards to the environment and living organisms. This concise review aims to consolidate knowledge on the biological processes involved in removing POPs from wastewater, an area less explored compared to conventional physico-chemical methods. The focus is on the potential of various aerobic and anaerobic microorganisms, fungi, and bacteria for efficient bioremediation, mitigating or eradicating the deleterious effects of these chemicals. The review scrutinizes individual bacterial strains and mixed cultures engaged in breaking down persistent organic pollutants in water, highlighting promising results from laboratory investigations that could be scaled for practical applications. The review concludes by underscoring the opportunities for exploring and advancing more sophisticated bioremediation techniques and optimized bioreactors. The ultimate goal is to enhance the efficiency of microbial-based strategies, implicitly reducing the environmental impact of persistent chemicals. [ABSTRACT FROM AUTHOR]

Saccharomyces cerevisiae LBTF 21.3, Pichia manshurica LBTF 21.1, and Leuconostoc lactis LBTF 21.1 were used as single and mixed cultures in coffee fermentations. Fermentations carried out in glass jars with P. manshurica LBTF 21.1/Leuc. lactis LBTF 21.1 showed higher fermentation rates than S. cerevisiae LBTF 21.3/P. manshurica LBTF 21.1 or S. cerevisiae LBTF 21.3/Leuc. lactis LBTF 21.1. The highest cup quality was reached with P. manshurica LBTF 21.1/Leuc. lactis LBTF 21.1 (83.0 points). Full factorial design (22) carried out with P. manshurica LBTF 21.1 revealed that the higher proportion of water added before the fermentation resulted in higher production of acetic acid. A contrary effect of this variable was observed on the production of lactic acid with Leuc. lactis LBTF 21.1. Fermentations conducted in bioreactor evidenced the production of acetaldehyde by P. manshurica LBTF 21.1/Leuc. lactis LBTF 21.1, P. manshurica LBTF 21.1, and Leuc. lactis LBTF 21.1. Additionally, the highest cup quality was reached in fermentations with P. manshurica LBTF 21.1 (82.5 points) followed by Leuc. lactis LBTF 21.1 (81.5 points) and P. manshurica LBTF 21.1/Leuc. lactis LBTF 21.1 (81.0 points). Fermentations of coffee with single and mixed cultures are interesting strategies for the improvement of the sensory quality. [ABSTRACT FROM AUTHOR]

The anaerobic digestion of aqueous condensate from fast pyrolysis is a promising technology for enhancing carbon and energy recovery from waste. Syngas, another pyrolysis product, could be integrated as a co-substrate to improve process efficiency. However, limited knowledge exists on the co-fermentation of pyrolysis syngas and aqueous condensate by anaerobic cultures and the effects of substrate toxicity. This work investigates the ability of mesophilic and thermophilic anaerobic mixed cultures to co-ferment syngas and the aqueous condensate from either sewage sludge or polyethylene plastics pyrolysis in semi-batch bottle fermentations. It identifies inhibitory concentrations for carboxydotrophic and methanogenic reactions, examines specific component removal and assesses energy recovery potential. The results show successful co-fermentation of syngas and aqueous condensate components like phenols and N-heterocycles. However, the characteristics and load of the aqueous condensates affected process performance and product formation. The toxicity, likely resulting from the synergistic effect of multiple toxicants, depended on the PACs' composition. At 37 °C, concentrations of 15.6 gCOD/gVSS and 7.8 gCOD/gVSS of sewage sludge-derived aqueous condensate inhibited by 50% carboxydotrophic and methanogenic activity, respectively. At 55 °C, loads between 3.9 and 6.8 gCOD/gVSS inhibited by 50% both reactions. Polyethylene plastics condensate showed higher toxicity, with 2.8 gCOD/gVSS and 0.3 gCOD/gVSS at 37 °C decreasing carboxydotrophic and methanogenic rates by 50%. At 55 °C, 0.3 gCOD/gVSS inhibited by 50% CO uptake rates and methanogenesis. Increasing PAC loads reduced methane production and promoted short-chain carboxylates formation. The recalcitrant components in sewage sludge condensate hindered e-mol recovery, while plastics condensate showed high e-mol recoveries despite the stronger toxicity. Even with challenges posed by substrate toxicity and composition variations, the successful conversion of syngas and aqueous condensates highlights the potential of this technology in advancing carbon and energy recovery from anthropogenic waste streams. [ABSTRACT FROM AUTHOR]

Microbial communities are vital to our lives, yet their ecological functioning and dynamics remain poorly understood. This understanding is crucial for assessing threats to these systems and leveraging their biotechnological applications. Given that temporal dynamics are linked to community functioning, this study investigated the drivers of community succession in the wine yeast community. We experimentally generated population dynamics data and used it to create an interpretable model with a gradient boosted regression tree approach. The model was trained on temporal data of viable species populations in various combinations, including pairs, triplets, and quadruplets, and was evaluated for predictive accuracy and input feature importance. Key findings revealed that the inoculation dosage of non- Saccharomyces species significantly influences their performance in mixed cultures, while Saccharomyces cerevisiae consistently dominates regardless of initial abundance. Additionally, we observed multispecies interactions where the dynamics of Wickerhamomyces anomalus were influenced by Torulaspora delbrueckii in pairwise cultures, but this interaction was altered by the inclusion of S. cerevisiae. This study provides insights into yeast community succession and offers valuable machine learning-based analysis techniques applicable to other microbial communities, opening new avenues for harnessing microbial communities. [ABSTRACT FROM AUTHOR]

Most bacterial species synthesize extracellular polymeric substances (EPS) with diverse compositional, structural, and functional characteristics. When under sustained hydrodynamic flow, bacteria form streamers, which are filamentous matrix structures porous in nature. So far, investigations on streamers have been limited to pure culture bacterial species, overlooking the aggregate nature of bacterial flocs and biofilms. The aim of this work is to analyze the effects of the cultivation conditions (controlling the EPS synthesis), the hydrodynamics, and the bacterial species type on streamer formation by pure and mixed culture using microfluidic separators. Enterobacter A47 (EPS-producing bacterium) and Cupriavidus necator (non-EPS producing bacterium) are used for the experimental work. It has been found that the EPS secreted by the bacteria and flow conditions play a very significant role in streamer formation dynamics. Strong flow conditions (i.e., high flow rates and small constrictions with tortuous architecture) favor the fast development of streamers, whereas intermediate flow rates result in sustained growth for longer filtration times, leading to dense streamers. Our analysis confirms that the presence of EPS in the bacterial suspension critically controls streamer formation by forming bacterial aggregates, or flocs, and bridging between different aggregates. We also found that streamer formation is significantly enhanced with mixed bacterial culture, which may be attributed to the symbiotic relationships influencing the concentration and characteristics of EPS and the material behavior in general. [ABSTRACT FROM AUTHOR]

Sour beers play an important role in the brewing market, and their production has been growing exponentially. In light of this, six microorganisms directly related to this class of beer were studied, and the fermentation behavior of six strains used in the past for traditional commercial Berliner Weisse beer production was monitored. The microorganisms used were Lactobacillus brevis, Lactobacillus parabrevis, Brettanomyces bruxellensis, and Brettanomyces anomalus and two strains of Saccharomyces cerevisiae. The six microorganisms were selected in a previous work, and a comparison between single and mixed fermentations was carried out via daily measurements of the fermentation parameters like pH, extract, and cell count during 22 days. The ability to isolate a specific microorganism from a mixed culture was investigated using three commonly used nutrient media and aerobic/anaerobic growth conditions. Both Lactobacillus and Brettanomyces could be isolated; however, the conditions imposed were not sufficient in order to isolate Saccharomyces. Fermentations carried out with LAB and Brettanomyces showed a decrease in Lactobacillus growth if compared to pure fermentations, but no influence on the growth of Brettanomyces could be perceived. In general, fermentations carried out in the presence of Saccharomyces were dominated by this yeast. Its quick growth seems to be responsible for the high end pH values observed as well as the decrease in cell growth for both LAB and Brettanomyces. A decrease in the cell viability of Saccharomyces was followed by an increased growth of the other microorganisms involved, possibly meaning that the molecules released through apoptosis are used by both LAB and Brettanomyces as a valuable nutrient source. The volatile compound concentrations of the first group were higher in fermentations with Saccharomyces, whereas esters' concentration was higher in fermentations carried out only with Brettanomyces and Lactobacillus. Furthermore, understanding how these microorganisms interact during the fermentation process can help brewers better control production and ensure the consistency in the quality of the final product. The end pH values and acidity reached levels acceptable for Berliner Weisse beer. This innovative approach certainly contributes to the evolution and refinement of the art of brewing. [ABSTRACT FROM AUTHOR]

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The present study investigates the sustainable biosynthesis of selenium nanoparticles utilizing different probiotic strains namely Lactobacillus delbrueckii sub. sp. bulgaricus, Lactobacillus rhamnosus, Streptococcus thermophiles and mixed culture. The synthesis and analysis were concentrated on using multiple analytical techniques, including thermogravimetric analysis-differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, dynamic light scattering, and energy-dispersive X-ray spectroscopy. Major functional groups were identified by FTIR analysis that include conjugated ketones (C=O stretching) at 1648.82 cm−1 to 1688.54 cm−1, halo compounds (C–Br stretching) at 448.85 cm−1 to 879.54 cm−1, and fluoro compounds (C–F stretching) at 668.10 cm−1 to 1065.89 cm−1. Based on strain-specific measurements using SEM and TEM, the size of the nanoparticles ranged from 16 nm to 68.96 nm in diameter. Both extracellular and intracellular synthesis of the particles were identified. Significant amount of selenium were found using EDX analysis, with Lactobacillus rhamnosus and mix culture having the highest and the lowest concentrations at 97.50% and 90.58% by weight, respectively. Zeta potential measurements, indicating high colloidal stability, ranged from − 27.9 mV to − 23.1 mV and demonstrated that the nanoparticles synthesized by Lactobacillus rhamnosus was most stable among all. The synthesized nanoparticles were purely amorphous, according to XRD patterns. The TGA–DSC measurement showed that the nanoparticles exhibit varied levels of weight loss at different phases while being thermally stable. Lactobacillus rhamnosus showed maximum viability that is 8.67 log CFU/g and the least was seen in mix culture that is 7.22 log CFU/g. With applications in food fortification and biomedicine, this study highlights the potential of using probiotic strains for the synthesis of selenium nanoparticles. It also highlights an innovative approach that combines the fields of nanotechnology as well as biotechnology for sustainable and biocompatible solutions in the field of Food Science and Technology. [ABSTRACT FROM AUTHOR]

Different culture media have various materials that impact root system architecture (RSA) and root system quality in plants. Finding the most compatible RSA of cucumber seedlings among the eight mixed culture media is critical to plant productivity. In this experiment, cucumber seeds were sown in eight mixed culture media, including a volume ratio of 30:10:60 of 1- perlite-vermicompost-coco peat as the control group, 2 - peat moss-vermicompost-palm peat, 3- cocopeat-vermicompost-palm peat, 4- perlite-vermicompost-palm peat, and 30:70 ratios of 5- peat moss- palm peat, 6- cocopeat -palm peat, 7- perlite -palm peat and 8- vermicompost-palm peat under greenhouse conditions. RSA of the seedlings was evaluated by GiA-Roots software via imaging at the fourleaf stage. The results showed that the minimum network length, network area, and network perimeter (821.6 cm, 7598.3 cm2, and 2102.3 cm, respectively) in the seedlings occurred on perlite-vermicompost-c oco peat (control) which lacked palm peat. The minimum network volume, number of connected components, and network depth were observed in the control. However, the maximum network length, network volume, number of connected components, network width, network area, and network perimeter (88862.8 cm, 2076390.9 cm3, 23. 2, 4567.4 cm, 332356.1 cm2, and 132068.9 cm, respectively) occurred in seedlings on peat moss-vermicompost-palm peat (30:10:60). Thus, a culture medium containing 30% peat moss, 60% palm peat, and 10% vermicompost improved RSA in cucumber seedlings. Palm peat was recommended as a sustainable resource to comprise culture media for cucumber seedlings. [ABSTRACT FROM AUTHOR]

The changes in the cell physiology (growth rate, cell size, and cell DNA content), photosynthetic efficiency, toxicity, and sexuality under variable light and nutrient (phosphates) conditions were evaluated in cultures of the dinoflagellate Alexandrium minutum obtained from a red tide in the Ría de Vigo (NW Spain). The cells were grown at low (40 and 150 µE m−2 s−1), moderate (400 µE m−2 s−1), and high (800 µE m−2 s−1) light intensities in a medium with phosphate (P+) and without (P−). Cultures were acclimated to the irradiance conditions for one week, and the experiment was run for ~1 month. The cell size and DNA content were monitored via flow cytometry. Two different clonal strains were employed as a monoculture (in a P− or P+ medium) or, to foster sexuality and resting cyst formation, as a mixed culture (only in a P− medium). A. minutum growth was favored by increasing light intensities until 400 µE m−2 s−1. The DNA content analyses indicated the accumulation of S-phase cells at the highest light intensities (400 and 800 µE m−2 s−1) and therefore the negative effects on cell cycle progression. Only when the cells were grown in a P− medium did higher light intensities trigger dose-dependent, significantly higher toxicities in all the A. minutum cultures. This result suggests that the toxicity level is responsive to the combined effects of (high) light and (low) P stress. The cell size was not significantly affected by the light intensity or P conditions. The optimal light intensity for resting cyst formation was 150 µE m−2 s−1, with higher irradiances reducing the total encystment yield. Encystment was not observed at the lowest light intensity tested, indicative of the key role of low-level irradiance in gamete and/or zygote formation, in contrast to the stressor effect of excessive irradiance on planozygote formation and/or encystment. [ABSTRACT FROM AUTHOR]

Mammalian α-defensins are a family of abundant effector peptides of the mucosal innate immune system. Although primarily considered to be antimicrobial, α-defensins can increase rather than block infection by certain prominent bacterial and viral pathogens in cell culture and in vivo. We have shown previously that exposure of mouse and human adenoviruses (HAdVs) to α-defensins is able to overcome competitive inhibitors that block cell binding, leading us to hypothesize a defensin-mediated binding mechanism that is independent of known viral receptors. To test this hypothesis, we used genetic approaches to demonstrate that none of several primary receptors nor integrin co-receptors are needed for human α-defensin-mediated binding of HAdV to cells; however, infection remains integrin dependent. Thus, our studies have revealed a novel pathway for HAdV binding to cells that bypasses viral primary receptors. We speculate that this pathway functions in parallel with receptor-mediated entry and contributes to α-defensin-enhanced infection of susceptible cells. Remarkably, we also found that in the presence of α-defensins, HAdV tropism is expanded to non-susceptible cells, even when viruses are exposed to a mixture of both susceptible and non-susceptible cells. Therefore, we propose that in the presence of sufficient concentrations of α-defensins, such as in the lung or gut, integrin expression rather than primary receptor expression will dictate HAdV tropism in vivo. In summary, α-defensins may contribute to tissue tropism not only through the neutralization of susceptible viruses but also by allowing certain defensin-resistant viruses to bind to cells independently of previously described mechanisms. Author summary: In this study, we demonstrate a novel mechanism for binding of human adenoviruses (HAdVs) to cells that is dependent upon interactions with α-defensin host defense peptides but is independent of known viral receptors and co-receptors. To block normal receptor-mediated HAdV infection, we made genetic changes to both host cells and HAdVs. Under these conditions, α-defensins restored cell binding; however, infection still required the function of HAdV integrin co-receptors. This was true for multiple types of HAdVs that use different primary receptors and for cells that are either naturally devoid of HAdV receptors or were engineered to be receptor deficient. These observations suggest that in the presence of concentrations of α-defensins that would be found naturally in the lung or intestine, there are two parallel pathways for HAdV binding to cells that converge on integrins for productive infection. Moreover, these binding pathways function independently, and both operate in mixed culture. Thus, we have found that viruses can co-opt host defense molecules to expand their tropism. [ABSTRACT FROM AUTHOR]

Hybrid thermochemical–biological processes have the potential to enhance the carbon and energy recovery from organic waste. This work aimed to assess the carbon and energy recovery potential of multifunctional processes to simultaneously sequestrate syngas and detoxify pyrolysis aqueous condensate (PAC) for short-chain carboxylates production. To evaluate relevant process parameters for mixed culture co-fermentation of syngas and PAC, two identical reactors were run under mesophilic (37 °C) and thermophilic (55 °C) conditions at increasing PAC loading rates. Both the mesophilic and the thermophilic process recovered at least 50% of the energy in syngas and PAC into short-chain carboxylates. During the mesophilic syngas and PAC co-fermentation, methanogenesis was completely inhibited while acetate, ethanol and butyrate were the primary metabolites. Over 90% of the amplicon sequencing variants based on 16S rRNA were assigned to Clostridium sensu stricto 12. During the thermophilic process, on the other hand, Symbiobacteriales, Syntrophaceticus, Thermoanaerobacterium, Methanothermobacter and Methanosarcina likely played crucial roles in aromatics degradation and methanogenesis, respectively, while Moorella thermoacetica and Methanothermobacter marburgensis were the predominant carboxydotrophs in the thermophilic process. High biomass concentrations were necessary to maintain stable process operations at high PAC loads. In a second-stage reactor, Aspergillus oryzae converted acetate, propionate and butyrate from the first stage into L-malate, confirming the successful detoxification of PAC below inhibitory levels. The highest L-malate yield was 0.26 ± 2.2 molL-malate/molcarboxylates recorded for effluent from the mesophilic process at a PAC load of 4% v/v. The results highlight the potential of multifunctional reactors where anaerobic mixed cultures perform simultaneously diverse process roles, such as carbon fixation, wastewater detoxification and carboxylates intermediate production. The recovered energy in the form of intermediate carboxylates allows for their use as substrates in subsequent fermentative stages. [ABSTRACT FROM AUTHOR]

This study reports a successful continuous biohydrogen production from rice straw hydrolysate in both 3-L and 20-L dynamic membrane bioreactor (DMBR). In the 3-L DMBR (DMBR I), the maximum average bio-H 2 production performance was 32.13 ± 0.71 L H 2 /L-d, 1.27 ± 0.03 mol H 2 /mol hexose-equiv consumed , and 96.39 ± 2.12 L H 2 /d, respectively. The H 2 production performance of 20-L DMBR (DMBR II) was comparable to DMBR I, which were 33.15 ± 0.42 L H 2 /L-d, 1.46 ± 0.03 mol H 2 /mol hexose-equiv consumed , and 663 ± 8 L H 2 /d, respectively. Rapid decline of hydraulic retention time (HRT) in the early stages of operation led to the metabolic flux of the mixed culture from the lactic acid pathway to the H 2 -producing pathway. Genus Clostridium was the dominant microbial population in DMBR I and DMBR II. This study provides operational criteria and insights in the scale-up design and operation of biohydrogen production from lignocellulosic biomass. • Rice straw was converted to H 2 in 3-L and 20-L dynamic membrane bioreactor. • 663 ± 8 L H 2 /d was recovered continuously from a 20-L bioreactor. • Maximum H 2 production was 33.8 L H 2 /L-d and 1.3 mol H 2 /mol hexose in 20-L bioreactor. • Rapid decrease of HRT in early-stage shifted HLa pathway to H 2 -producing pathway. • Feeding of rice straw hydrolysate shifted H 2 -producing pathway from HBu to HAc. [ABSTRACT FROM AUTHOR]

In recent years, the production of volatile fatty acids (VFA) through mixed culture fermentation (MCF) has been gaining attention. Most authors have focused on the fermentation of carbohydrates, while other possible substrates, such as proteins, have not been considered. Moreover, there is little information about how operational parameters affect the microbial communities involved in these processes, even though they are strongly related to reactor performance and VFA selectivity. Hence, this study aims to evaluate how microbial composition changes according to three different parameters (pH, type of protein and micronutrient addition) during anaerobic fermentation of protein‐rich side streams. For this, two continuous stirred tank reactors (CSTR) were fed with two different proteins (casein and gelatine) and operated at different conditions: three pH values (5.0, 7.0 and 9.0) with only macronutrients supplementation and two pH values (5.0 and 7.0) with micronutrients' supplementation as well. Firmicutes, Proteobacteria and Bacteroidetes were the dominant phyla in the two reactors at all operational conditions, but their relative abundance varied with the parameters studied. At pH 7.0 and 9.0, the microbial composition was mainly affected by protein type, while at acidic conditions the driving force was the pH. The influence of micronutrients was dependent on the pH and the protein type, with a special effect on Clostridiales and Bacteroidales populations. Overall, this study shows that the acidogenic microbial community is affected by the three parameters studied and the changes in the microbial community can partially explain the macroscopic results, especially the process selectivity. [ABSTRACT FROM AUTHOR]

A significant variation in the relative representation of copies of bacterial genes of dye-decolorizing DyP peroxidases typical for the genus Shewanella and a number of other microorganisms was found in the bottom sediments of freshwater reservoirs. It was found that the specific rate of decolorization of crystal violet in a laboratory bioelectrochemical system by a mixed culture of bottom sediments, which showed the highest representation of DyP genes, depended on the method of electrical stimulation of the external circuit and the concentration of the dye. After an increase in the concentration of more than 20 microns, the maximum speed was achieved in the presence of an ionistor polarly connected to the external electrical circuit of the bioelectrochemical system and amounted to 3.23 ± 0.11 μM/h, while with the opposite polarity connection, a minimum value of 2.07 ± 0.08 μM/h was observed. In the case of an open circuit and a resistor, similar indicators occurred with 2.88 ± 0.09 and 2.67 ± 0.12 μM/h, respectively. When analyzing the decolorization products, a consistent decrease in the maxima of the absorption bands of the dye was noted, indicating its more complete degradation by the mixed culture. The results may be of interest for the development of methods to improve the efficiency of bioelectrochemical methods of environmental biotechnology by electrostimulation of the external circuit. [ABSTRACT FROM AUTHOR]

Phenotypic susceptibility testing of the Mycobacterium tuberculosis complex (MTBC) isolate requires culture growth, which can delay rapid detection of resistant cases. Whole genome sequencing (WGS) and data analysis pipelines can assist in predicting resistance to antimicrobials used in the treatment of tuberculosis (TB). This study compared phenotypic susceptibility testing results and WGS-based predictions of antimicrobial resistance (AMR) to four first-line antimicrobials—isoniazid, rifampin, ethambutol, and pyrazinamide—for MTBC isolates tested between the years 2018–2022. For this 5-year retrospective analysis, the WGS sensitivity for predicting resistance for isoniazid, rifampin, ethambutol, and pyrazinamide using Mykrobe was 86.7%, 100.0%, 100.0%, and 47.8%, respectively, and the specificity was 99.4%, 99.5%, 98.7%, and 99.9%, respectively. The predictive values improved slightly using Mykrobe corrections applied using TB Profiler, i.e., the WGS sensitivity for isoniazid, rifampin, ethambutol, and pyrazinamide was 92.31%, 100%, 100%, and 57.78%, respectively, and the specificity was 99.63%. 99.45%, 98.93%, and 99.93%, respectively. The utilization of WGS-based testing addresses concerns regarding test turnaround time and enables analysis for MTBC member identification, antimicrobial resistance prediction, detection of mixed cultures, and strain genotyping, all through a single laboratory test. WGS enables rapid resistance detection compared to traditional phenotypic susceptibility testing methods using the WHO TB mutation catalog, providing an insight into lesser-known mutations, which should be added to prediction databases as high-confidence mutations are recognized. The WGS-based methods can support TB elimination efforts in Canada and globally by ensuring the early start of appropriate treatment, rapidly limiting the spread of TB outbreaks. [ABSTRACT FROM AUTHOR]

Onychomycoses are nail infections that require prolonged therapy and have high recurrence rates. Dermatophytes are the main etiological agents of these infections, followed by yeasts and non-dermatophyte filamentous fungi. The limited antifungal arsenal used to treat onychomycosis and the change in the susceptibility profile of these agents contribute to the chronicity and recalcitrant profile of infections. The present study aimed to determine the antifungal activity of extracts obtained from pure and mixed cultures of Candida parapsilosis, Trichophyton mentagrophytes, and Trichophyton rubrum. Additionally, in vivo toxicity tests with Galleria mellonella and time-kill assays were carried out. The susceptibility profiles of dermatophytes were determined using a microdilution technique with minimum inhibitory concentrations (MICs) between 250 and 8000 µg/mL. The time-kill assay, compared to growth control, resulted in the death of dermatophytes within 48 h. No toxicity of the extracts was detected in experiments with Galleria mellonella larvae under the test conditions. The extracts of pure and mixed cultures of Candida parapsilosis and dermatophytes present antifungal activity against T. mentagrophytes and T. rubrum. Isolating and identifying compounds in the extracts may allow the development of new therapeutic approaches to control fungal infections. [ABSTRACT FROM AUTHOR]

Water samples taken from the Çubuk Stream (Ankara, Turkey) were inoculated into nutrient broth media containing Setazol Navy Blue SBG (SNB), an organic pollutant, and heavy metal Cr(VI), an inorganic pollutant, to obtain a pollutant-resistant mixed microbial culture. Experiments were conducted with this culture to remove SNB and heavy metal. The optimum conditions, where the mixed bacterial culture removed the pollutants most effectively, were determined, showing that the highest capacity for removal took place at pH 8 with removal percentages 96.3% for Cr(VI) and 78.5% for SNB. In media with 50.4 mg/L SNB and 9.7 mg/L Cr(VI), the SNB removal was 87.3%, and the Cr(VI) removal was 96.6% at the end of the 7-day incubation period. The highest removal was observed with a biomass concentration of 8% (v/v) of mixed culture [50 mg/L SNB dye+25 mg/L Cr(VI)]. The removal was 100% for both Cr(VI) and the SNB dye. The bacteria with the highest removal were isolated and identified using 16S rDNA gene sequence analysis as Microbacterium oxydans and Leucobacter aridicollis. The role of various functional groups and the structures of the microorganisms that might be involved in the removal mechanisms were discussed using their FTIR spectra. This report is the first study that investigates a mixed bacterial culture and pure cultures (M. oxydans and L. aridicollis) isolated from that mixed culture, removing both SNB and Cr(VI) simultaneously. [ABSTRACT FROM AUTHOR]

The present work studied the effects of alkali pretreatment on the cellulosic biomass of rice straw. The improvement in the cellulose content and reduction in the lignin and hemicellulose percentage was observed with alkali pretreatment. Fourier transformation infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) analysis confirm the modification in the surface structure of alkali rice straw. Further, the study investigated the potential of different types of seed sludge as inoculum sources for dark fermentative biohydrogen production. In comparison to other sludge samples (beverage industry, food industry, and sewage treatment plant sludge), the mixed culture of sewage treatment plant sludge had the highest cumulative volume of biohydrogen (90.52 mL), as well as the highest hydrogen production yield (0.75 moleH2/mole) with the substrate utilization of 86.72%. The results provide information on the best sludge source for enhancing biohydrogen production in the dark fermentation method. [ABSTRACT FROM AUTHOR]

The goal of the present work was to study the recovery of copper, nickel, and platinum group metals (PGMs) (Pt and Pd) from low-grade copper–nickel ore containing pyrrhotite, pentlandite, and chalcopyrite by column bioleaching followed by cyanidation. The ore sample contained the following: Ni—0.74%, Cu—0.23%, Fe—14.8%, Stotal—8.1%, and Ssulfide—7.8%. The Pt and Pd contents in the ore sample were 0.2535 and 0.515 g/t, respectively. Biological leaching in columns was carried out at 25, 35, and 45 °C for 140 days. A mixed culture of acidophilic microorganisms was used as an inoculum. Cu and Ni extraction depended on temperature, and at 45 °C, copper and nickel recovery was the highest, being 2.1 and 1.8 times higher than that at 25 °C, respectively. As a result, up to 35% of nickel and up to 10% of copper were recovered by bioleaching within 140 days. Bioleaching resulted in an increase in Pt and Pd recovery by cyanidation, but the effect on Pd recovery was insignificant. Pt recovery varied in the range of 3–40% depending on process conditions; Pd recovery was 44–55%. [ABSTRACT FROM AUTHOR]

Mercury (Hg) is a prevalent and harmful contaminant that persists in the environment. For phytoremediation, it is important to discover which plants can bioaccumulate meaningful amounts of Hg while also tolerating its toxicity. Additionally, increasing biodiversity could create a more resilient and self-sustaining system for remediation. This study explores whether mixed populations of Lemna minor and Spirodela polyrhiza can better bioaccumulate and tolerate Hg than monocultures. Mono- and mixed cultures of L. minor and S. polyrhiza were grown in mesocosms of 0.5 µg/L or 100 µg/L Hg (HgCl2) spiked water for 96 h. Change in weight of duckweed was used to assess Hg tolerance. Diffusive gradients in thin-films (DGTs) were used as surrogate monitoring devices for bioavailable levels of Hg. For biomass growth, the mixed culture of the L. minor was greater than the monoculture at the high dose. The L. minor accumulated more Hg in the mixed culture at the low dose while the S. polyrhiza was higher in the mixed at the high dose. Hg speciation in water was modeled using Windermere Humic Aqueous Model 7 (WHAM7) to compare the bioavailable species indicated by the DGTs. Potentially due to the controlled conditions, the WHAM7 output of bioavailable Hg was almost 1:1 to that estimated by the DGTs, indicating good predictive capability of geochemical modeling and passive sampler DGT on metal bioavailability. Overall, the mixed cultures statistically performed as well as or better than the monocultures when tolerating and bioaccumulating Hg. However, there needs to be further work to see if the significant differences translate into practical differences worth the extra resources to maintain multiple species. [ABSTRACT FROM AUTHOR]

Pre-eclampsia (PE) is a hypertensive disorder of pregnancy which is associated with increased risk of neurodevelopmental disorders in exposed offspring. The pathophysiological mechanisms mediating this relationship are currently unknown, and one potential candidate is the anti-angiogenic factor soluble Fms-like tyrosine kinase 1 (sFlt-1), which is highly elevated in PE. While sFlt-1 can impair angiogenesis via inhibition of VEGFA signalling, it is unclear whether it can directly affect neuronal development independently of its effects on the vasculature. To test this hypothesis, the current study differentiated the human neural progenitor cell (NPC) line ReNcell® VM into a mixed culture of mature neurons and glia, and exposed them to sFlt-1 during development. Outcomes measured were neurite growth, cytotoxicity, mRNA expression of nestin, MBP, GFAP, and ßIII-tubulin, and neurosphere differentiation. sFlt-1 induced a significant reduction in neurite growth and this effect was timingand dose-dependent up to 100 ng/ml, with no effect on cytotoxicity. sFlt-1 (100 ng/ml) also reduced ßIII-tubulin mRNA and neuronal differentiation of neurospheres. Undifferentiated NPCs and mature neurons/glia expressed VEGFA and VEGFR-2, required for endogenous autocrine and paracrine VEGFA signalling, while sFlt-1 treatment prevented the neurogenic effects of exogenous VEGFA. Overall, these data provide the first experimental evidence for a direct effect of sFlt-1 on neurite growth and neuronal differentiation in human neurons through inhibition of VEGFA signalling, clarifying our understanding of the potential role of sFlt-1 as a mechanism by which PE can affect neuronal development. [ABSTRACT FROM AUTHOR]

To enhance comprehension of the impact of mixed fermentation using Torulaspora delbrueckii Bio-119667 (TD) on the aroma composition of Munage grape base-wine (MGBW), we analysed the aroma composition of MGBW using HS-SPME-GC-MS widely targeted metabolomics. The levels of volatile aroma components, including terpenes, higher alcohols, aldehydes, heterocyclic compounds, and esters, were significantly higher in MGBW produced by mixed fermentation compared to the pure Saccharomyces yeast control fermentation. The study found that the content of esters increased by 26.3% after mixed fermentation, indicating the contribution of TD to the formation of ester flavour components during the fermentation of MGBW. After analysing aroma activity values, we discovered that 49 out of 115 esters (25.5% of the total) significantly contributed to the aroma profile of MGBW (rOAV > 1). Of these esters, 16 were identified as key aroma compounds (rOAV > 1, VIP > 1) produced by mixed fermentation with the participation of TD. This finding further supports the contribution of TD to the improvement of MGBW's aroma composition. This study reveals the role of non-Saccharomyces yeast strain Torulaspora delbrueckii Bio-119667 in improving the aroma composition of MGBW produced by mixed culture fermentation and the biosynthetic pathways of key aroma components therein. [ABSTRACT FROM AUTHOR]

The objective of this work was to evaluate the use of pond bacteria paired with acetate and sawdust as viable inoculums for facilitating heterotrophic denitrification in household slow sand filters. This was achieved through culturing pond sediment bacteria and pairing it with both carbon sources in nitrate contaminated batch and filter column experiments. The inoculum culture tested positive for denitrifying bacteria including those of the Bacillus, Paraclostridium and Clostridium genera. Batch experiments conducted over 17 h with the acetate carbon source achieved complete denitrification for the C/N ratios of 2 and 5 at concentrations of 200 and 400 mg/L of nitrate. Incomplete denitrification was attained at C/N ratio of 0.5. Sawdust batches loaded with 1 g sawdust under similar concentration, volume, and time loading achieved incomplete denitrification with nitrite accumulation of up to 100 mg/L. In inoculated filter column experiments fed with 2 L of contaminated feed daily, the acetate carbon source fed filters achieved complete denitrification at feed concentrations of 200 and 400 mg/L nitrate, while sand/sawdust mixed columns only achieved complete denitrification for the 200 mg/L nitrate feed. 400 mg/L nitrate feed was reduced to 237 mg/L. No significant nitrite accumulation was observed in the filters. TOC readings in the control, sawdust and acetate filters were 7.072, 13.702 and 11.764 mg/L carbon at the 200 mg/L nitrate feed and 5.984, 6.630, and 7.142 mg/L carbon at the 400 mg/L nitrate feed. [ABSTRACT FROM AUTHOR]

Porang (Amorphophallus oncophylus) tubers are one of the export commodities due to their glucomannan content. This study aimed to investigate the characteristics of water fermentation and the quality of porang fermented flour with the addition of Lactobacillus plantarum (LP), Bacillus subtilis (BS), and Saccharomyces cerevisiae (SC). Fermentation was conducted using four treatments, namely LP+BS, LP+SC, BS+SC which consisted of 10%v/v of inoculum, respectively, and LP+BS+SC which consisted of 7%v/v LP, 7% BSv/v, and 6%SCv/v. During fermentation, pH, total acidity, and total microorganisms were observed. Proximate, glucomannan content, starch content, fiber content, and antibacterial and prebiotics characteristics were observed for fermented porang flour. The results showed that pH decreased while total acidity increased during fermentation. Total aerobic bacteria had the highest population at 24 hours of fermentation while lactic acid bacteria had the highest population at 24- and 48-hour fermentation. Yeast reached the highest population at 72 hours of fermentation. Porang fermented flour with the addition of BS+SC contained the highest glucomannan content, carbohydrate, and fiber content. Moreover, the flour with BS+SC had an antibacterial effect against Escherichia coli and Staphylococcus aureus and supported the growth of Lactobacillus acidophilus. Porang fermented flour which is processed with the addition of a mixed culture of BS and SC can be developed to improve the nutrititional and functional properties of porang flour. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the performance of a bioreactor at an upflow packed bed with synthetic wastewater containing phenol under continuous operation. The used microorganism was formed by a mixed culture isolated from a wastewater treatment plant. The mean residence time (tm = 3.92 h) in the bioreactor was obtained experimentally by following the tracer NaCl 0.5 M concentration in a continuous effluent stream. For the first time, we calculated the superficial velocities of liquid (uL) and gas (uG) in a three-phase medium (air-water-sand) in the absence of biomass; these velocities vary from 5.40 × 10–3 to 5.84 × 10–3 and from 0.36 × 10–3 to 3.67 × 10–3 m/s, respectively. Afterwards, the effects of airflow (AF = 10, 20, and 30 L/h), liquid flow rates (LF = 3, 5, and 9 mL/min), and initial phenol concentration (C0 = 100, 200, 300, 500, and 700 mg/L) on the biodegradation rate of phenol were studied. The results indicate that the rate of continuous biodegradation increases with the initial phenol concentration and decreases both with the AF and LF rates. The biofilm concentration uniformly increases with increasing the height of the sand bed. The process in the continuous model also contributed to a high elimination efficiency of 100%. [ABSTRACT FROM AUTHOR]

A laboratory scale study was designed and conducted to assess the biodegradation of Bonny light crude oil by plasmid and nonplasmid borne soil bacterial strains using biostimulation and bioaugmentation techniques. The enrichment technique, turbidometric test, plasmid curing test, molecular identification method, biostimulation test, bioaugmentation test and gas chromatographic technique were carried out using standard analytical techniques. The physicochemical analysis result showed that the pH was slightly neutral, the organic carbon content was higher (2.32 to 4.34%), the conductivity was higher (0.41 to 0.44 µS/cm), and the water holding capacity was lower (0.27 percent and 10.11 kg, respectively). Based on their capacity to use crude oil, the results showed that 22 of the 60 isolated bacterial strains had higher pollutant degrading potentials (A600nm > 0.3). The identified potent hydrocarbon degraders includes: Bacillus spp., Pseudomonas aeruginosa KAVK01 and Ochrobacterium E85b strains. The highest degradation efficiency of 91% was found in soil that had been contaminated with 3 % (v/w) crude oil, amended with inorganic salts, and inoculated with plasmid-borne mixed cultures. The result further indicated that the consortium of plasmid borne isolates enhanced the reduction of the crude oil from the initial concentration of 10,318 ppm to 501 ppm (95 %) whereas 64 % decontamination was facilitated by the consortium of plasmid cured isolates. The information gathered from this investigation may be useful in choosing bacterial species, particularly plasmid-borne ones that can be employed to biodegrade soil contaminated by crude oil in Nigeria's Niger Delta region as well as the sample collection locations. [ABSTRACT FROM AUTHOR]

Understanding the effects of planted forests on soil properties is of great importance to meet increasing demands for wood production and contributing to forest ecosystem services and soil carbon sequestration. However, the influence of mono- and mixed tree plantations on soil chemical properties remains incompletely explained, particularly in tropical semi-evergreen forests. In this study, a monoplantation of Michelia champaca and Tectona grandis, as well as their mixed plantation, were studied on soil variables (pH, SOC, N, P, K) at different depths (0-10, 10-20, and 20-30 cm) in tropical semi-evergreen forest of the Khadimnagar National Park, Bangladesh. All examined pedovariables showed no significant differences among plantation types, notably in the surface soil layer (up to 10 cm). However, significant oscillations were found in the deepest soil layer (20- 30 cm), where M. champaca and mixed-species plantations obtained the lowest SOC (0.55-0.66%) and N (0.05-0.06%) concentrations. In the intermediate soil layer (10-20 cm) K concentrations were the lowest in M. champaca (19.6 mg/kg) and mixed-species plantation (17.6 mg/kg), while T. grandis recorded the highest K concentration (27.4 mg/kg). Additionally, the results indicated an increase in pH with soil depth (from 5.30 in the topsoil to 7.00 in the deepest layer), with T. grandis showing the lowest values across examined soil layers (5.76-5.95) and significantly differing from M. champaca, which exhibited the highest pH over the soil profile (6.29-6.51). Such results suggest the leaching of basic cations (Ca2+, Mg2+, K+ ) over the soil profile due to pronounced monsoon rainfalls. Further research is necessary to fully elucidate underlying mechanisms behind the observed impact of examined plantations on chemical soil variables. Considering other variables such as litter chemical composition and various physical and microbiological soil properties can offer valuable guidelines for enhancing more sustainable management of a tropical semi-evergreen forest, prone to soil acidity and water erosion. [ABSTRACT FROM AUTHOR]

Shewanella putrefaciens is an opportunistic pathogen rarely responsible for human infection. However, it has been reported that it causes skin and soft tissue infections and bacteremia in immune-compromised patients, such as cellulitis, abscesses, bacteremia, and wound infection. It is an oxidase and catalase-positive non-fermenter gram-negative rod that produces hydrogen sulfide. We report the case of a 90-year-old woman, who presented an invasive infectious burn wound associated with Shewanella putrefaciens bacteremia. She was admitted into the burn center of the military hospital M.S Nekkache of Algiers, suffering from 40% TBSA with a history of diabetes. After one week of admission, the patient complained of a high fever. Microbiological culture of the catheter tip was positive and showed pale colonies on the MacConkey agar, non-lactose fermenting plate. Nutritive agar medium culture showed red pale tan colonies with a concentration >10° CFU. Identification and antibiotic susceptibility were obtained by the Phoenix system (Becton-Dickinson, USA) as Shewanella putrefaciens. This was confirmed by standards and semi-automated microbiological techniques. Gram stain showed Gram-negative bacilli with positive oxidase and catalase reactions. Production of hydrogen sulfide was confirmed by the semi-automated API 20NE method (biomerieux, France). The isolate was resistant to gentamicin, amikacin, ceftazidime, aztreonam, amoxicillin-clavulanic acid, cefepime, trimethoprim/sulfamethoxazole, and nitrofurantoin. In our case, S. putrefaciens was found in a mixed culture with Klebsiella pneumoniae. No earlier exposure of the patient to marine water had been noticed. Blood culture indicated colonies growth of Acinetobacter baumannii. No further isolation of this bacteria was noticed after treatment. The patient was given imipenem, vancomycin and colistin. Despite our best efforts, the patient could not be saved because of sepsis and renal function failure. [ABSTRACT FROM AUTHOR]

Campylobacter spp. are the main cause of foodborne gastroenteritis worldwide, and the biofilm growth mode seems to play a key role in their prevalence. In this work, the effect of lactic acid (LA) on planktonic growth and biofilm production by eight Campylobacter spp. raw chicken meat isolates was investigated using polystyrene and stainless steel as the abiotic substrata. Results revealed that the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum biofilm inhibitory concentration (MBIC) values of LA against the Campylobacter isolates ranged from 1024 to 4096 μg/mL depending on the isolate, mode of growth (planktonic vs. biofilm; single vs. mixed culture), and the growth medium. Overall, the results of this work offer insights into the biofilm control of a pathogen of public health importance. [ABSTRACT FROM AUTHOR]

Although textile industries lead the economic sector in several countries, the pollution that they cause, particularly to water bodies, is a serious environmental concern. Dyes and their metabolites are harmful to human and aquatic life due to their toxic, mutagenic, and carcinogenic potential. In this study, we have made an effort to treat the complex Congo red (CR) dye-containing wastewater in an anaerobic-aerobic sequential bioreactor. The impact of CR dye concentration (20-100 mg/L) on the performance of sequential bioreactor was examined. The CR dye removal efficiencies (REs) of 97, 88.1, 75.9, 68.7, and 42.56% were obtained at 20, 40, 60, 80 and 100 mg/L of CR dye, respectively. Similarly, the overall Chemical oxygen demand (COD) RE of 90% was also obtained. It was found that the CR dye and COD REs were high at low concentrations of CR dye. The obtained experimental data was fitted with growth and substrate inhibition models. A phytotoxic study indicated that the Chickpea (Cicer arietinum L.) grown in treated wastewater showed better germination (93%) than untreated wastewater (66%). [ABSTRACT FROM AUTHOR]

Cellulose-rich agricultural residues are promising renewable sources for producing various value-added products such as 2nd generation biofuels. However, the efficiency of the bioconversion process is not always satisfactory due to the slow and incomplete degradation of lignocellulosic biomass. An interesting approach would be using microbial communities with high lignocellulose-degrading ability for environmentally friendly pretreatment. This study focused on characterizing the degradation performance of bacteria, fungal, and yeast strains and designing and constructing different microbial consortia for solid-state treatment of wheat bran and wheat straw. The microbial consortia, namely BFY4 and BFY5, contained different bacteria, fungal, and yeast led to high ratios of sugar accumulation ranging from 3.21 to 3.5 with degradation rates over 33%, owing to more favorable hydrolytic enzyme activities and improved reducing sugar yield during the process. After 72 h, the highest FPase (0.213 IU/gds) and xylanase (7.588 IU/gds) activities were also detected in the wheat straw pretreated by BFY4 and BFY5, respectively, while CMCase activity peaked (0.928 IU/gds) when wheat bran was used as substrate. The amount of released glucose increased during the treatment process when the two substrates were used in the same ratio. Our results indicated that substrate composition also plays an important role in the degradation capacity of mixed cultures. These findings can be instrumental in advancing the primary knowledge required to apply such bioprocesses at the pilot scale. [ABSTRACT FROM AUTHOR]

Cellulolytic enzymes are used in different industries; many of them are obtained from fungi and bacteria that use agro-industrial waste with a high cellulose content as a substrate. Some fungi of the genera Trichoderma and Aspergillus synthesize cellulases with different mechanisms of action and mixed cultures of these fungi have been proposed as a strategy to improve the hydrolysis of cellulosic materials associated with the production of these enzymes. The objective of this study was to verify the production of cellulases from mixed and pure cultures of native isolates of T. reesei and A. fumigatus with cellulolytic activity using rice husks as a substrate. Both fungi produce enzymes that catalyze the release of reducing sugars from carboxymethylcellulose. Solid state fermentation was carried out following a factorial design and the effect of the type of inoculum and incubation time on the cellulolytic activity of the extracts obtained was analyzed. Cellulases production after 15 days of incubation was higher than that obtained with 8 days of culture and it was confirmed through an analysis of variance that the cellulases production for the mixed and pure cultures of T. reesei on day 15 (34.5 and 31.9 U/g, respectively) did not present significant differences. It was shown in this work that rice husks have the potential to be used to obtain fungal enzymes, although the activity of enzymes obtained using this byproduct is lower than that produced with other cellulosic materials. [ABSTRACT FROM AUTHOR]

The sensory quality of an ice cream with prebiotic microcapsules composed of three natural polymeric materials was evaluated, which was capable of maintaining the viability of a mixed culture of probiotic strains during storage (-18 °C). The free and microencapsulated strains were added to the ice cream base before ripening. Viability in MRS broth, at 36 ± 1 °C/24 h, pH, acidity, texture and sensory quality of the ice cream were evaluated using the triangular test between ice cream with and without microcapsules and the hedonic test. The viability remained above 7 log CFU/g, without significant differences in the texture of the ice cream, with the sample with microcapsules being the most widely accepted. It is concluded that the prebiotic microcapsules managed to maintain the therapeutic viability of three probiotic strains during storage (≥ 107 CFU/mL) with a greater degree of acceptance by consumers. [ABSTRACT FROM AUTHOR]