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Consortia of multicellular magnetotactic bacteria (MMB) are currently the only known example of bacteria without a unicellular stage in their life cycle. Because of their recalcitrance to cultivation, most previous studies of MMB have been limited to microscopic observations. To study the biology of these unique organisms in more detail, we use multiple culture-independent approaches to analyze the genomics and physiology of MMB consortia at single-cell resolution. We separately sequenced the metagenomes of 22 individual MMB consortia, representing 8 new species, and quantified the genetic diversity within each MMB consortium. This revealed that, counter to conventional views, cells within MMB consortia are not clonal. Single consortia metagenomes were then used to reconstruct the species-specific metabolic potential and infer the physiological capabilities of MMB. To validate genomic predictions, we performed stable isotope probing (SIP) experiments and interrogated MMB consortia using fluorescence in situ hybridization (FISH) combined with nanoscale secondary ion mass spectrometry (NanoSIMS). By coupling FISH with bioorthogonal noncanonical amino acid tagging (BONCAT), we explored their in situ activity as well as variation of protein synthesis within cells. We demonstrate that MMB consortia are mixotrophic sulfate reducers and that they exhibit metabolic differentiation between individual cells, suggesting that MMB consortia are more complex than previously thought. These findings expand our understanding of MMB diversity, ecology, genomics, and physiology, as well as offer insights into the mechanisms underpinning the multicellular nature of their unique lifestyle.

Coastal herbivorous fishes consume macroalgae, which is then degraded by microbes along their digestive tract. However, there is scarce genomic information about the microbiota that perform this degradation. This study explores the potential of Kyphosus gastrointestinal microbial symbionts to collaboratively degrade and ferment polysaccharides from red, green, and brown macroalgae through in silico study of carbohydrate-active enzyme and sulfatase sequences. Recovery of metagenome-assembled genomes (MAGs) from previously described Kyphosus gut metagenomes and newly sequenced bioreactor enrichments reveals differences in enzymatic capabilities between the major microbial taxa in Kyphosus guts. The most versatile of the recovered MAGs were from the Bacteroidota phylum, whose MAGs house enzyme collections able to decompose a variety of algal polysaccharides. Unique enzymes and predicted degradative capacities of genomes from the Bacillota (genus Vallitalea) and Verrucomicrobiota (order Kiritimatiellales) highlight the importance of metabolic contributions from multiple phyla to broaden polysaccharide degradation capabilities. Few genomes contain the required enzymes to fully degrade any complex sulfated algal polysaccharide alone. The distribution of suitable enzymes between MAGs originating from different taxa, along with the widespread detection of signal peptides in candidate enzymes, is consistent with cooperative extracellular degradation of these carbohydrates. This study leverages genomic evidence to reveal an untapped diversity at the enzyme and strain level among Kyphosus symbionts and their contributions to macroalgae decomposition. Bioreactor enrichments provide a genomic foundation for degradative and fermentative processes central to translating the knowledge gained from this system to the aquaculture and bioenergy sectors.IMPORTANCESeaweed has long been considered a promising source of sustainable biomass for bioenergy and aquaculture feed, but scalable industrial methods for decomposing terrestrial compounds can struggle to break down seaweed polysaccharides efficiently due to their unique sulfated structures. Fish of the genus Kyphosus feed on seaweed by leveraging gastrointestinal bacteria to degrade algal polysaccharides into simple sugars. This study reconstructs metagenome-assembled genomes for these gastrointestinal bacteria to enhance our understanding of herbivorous fish digestion and fermentation of algal sugars. Investigations at the gene level identify Kyphosus guts as an untapped source of seaweed-degrading enzymes ripe for further characterization. These discoveries set the stage for future work incorporating marine enzymes and microbial communities in the industrial degradation of algal polysaccharides.

The valorization of lignin, a currently underutilized component of lignocellulosic biomass, has attracted attention to promote a stable and circular bioeconomy. Successful approaches including thermochemical, biological, and catalytic lignin depolymerization have been demonstrated, enabling opportunities for lignino-refineries and lignocellulosic biorefineries. Although significant progress in lignin valorization has been made, this review describes unexplored opportunities in chemical and biological routes for lignin depolymerization and thereby contributes to economically and environmentally sustainable lignin-utilizing biorefineries. This review also highlights the integration of chemical and biological lignin depolymerization and identifies research gaps while also recommending future directions for scaling processes to establish a lignino-chemical industry.

UNLABELLED: Growing environmental concerns and the need to adopt a circular economy have highlighted the importance of waste valorization for resource recovery. Microbial consortia-enabled biotechnologies have made significant developments in the biomanufacturing of valuable resources from waste biomass that serve as suitable alternatives to petrochemical-derived products. These microbial consortia-based processes are designed following a top-down or bottom-up engineering approach. The top-down approach is a classical method that uses environmental variables to selectively steer an existing microbial consortium to achieve a target function. While high-throughput sequencing has enabled microbial community characterization, the major challenge is to disentangle complex microbial interactions and manipulate the structure and function accordingly. The bottom-up approach uses prior knowledge of the metabolic pathway and possible interactions among consortium partners to design and engineer synthetic microbial consortia. This strategy offers some control over the composition and function of the consortium for targeted bioprocesses, but challenges remain in optimal assembly methods and long-term stability. In this review, we present the recent advancements, challenges, and opportunities for further improvement using top-down and bottom-up approaches for microbiome engineering. As the bottom-up approach is relatively a new concept for waste valorization, this review explores the assembly and design of synthetic microbial consortia, ecological engineering principles to optimize microbial consortia, and metabolic engineering approaches for efficient conversion. Integration of top-down and bottom-up approaches along with developments in metabolic modeling to predict and optimize consortia function are also highlighted. ONE-SENTENCE SUMMARY: This review highlights the microbial consortia-driven waste valorization for biomanufacturing through top-down and bottom-up design approaches and describes strategies, tools, and unexplored opportunities to optimize the design and stability of such consortia.

The rise of agro-industrial activities over recent decades has exponentially increased lignocellulose biomasses (LCB) production. LCB serves as a cost-effective source for fermentable sugars and other renewable chemicals. This study explores the use of microbial consortia, particularly thermophilic consortia, for LCB deconstruction. Thermophiles produce stable enzymes that retain activity under industrial conditions, presenting a promising approach for LCB conversion. This research focused on two microbial consortia (i.e., microbiomes) that were analyzed for enzyme production using a cheap medium, i.e., a mixture of spent mushroom substrate (SMS) and digestate. The secreted xylanolytic enzymes were characterized in terms of temperature and pH optima, thermal stability, and hydrolysis products from LCB-derived polysaccharides. These enzymes showed optimal activity aligning with common biorefinery conditions and outperformed a formulated enzyme mixture in thermostability tests in the digestate. Phylogenetic and genomic analyses highlighted the genetic diversity and metabolic potential of these microbiomes. Bacillus licheniformis was identified as a key species, with two distinct strains contributing to enzyme production. The presence of specific glycoside hydrolases involved in the cellulose and hemicellulose degradation underscores these consortia's capacity for efficient LCB conversion. These findings highlight the potential of thermophilic microbiomes, isolated from an industrial environment, as a robust source of robust enzymes, paving the way for more sustainable and cost-effective bioconversion processes in biofuel and biochemical production and other biotechnological applications. [ABSTRACT FROM AUTHOR]

Utilizing vegetable waste to produce bioactive compounds through microbial consortia represents a holistic solution to waste management challenges. Efficient waste collection systems in major cities ensure proper segregation of vegetable waste and lay the groundwork for resource utilization. Segregating waste at its source enhances waste stream quality and facilitates downstream processing. Research and development efforts investigating tailored microbial consortia seek to optimize waste degradation and bioactive compound yields, thereby unlocking the potential of waste. This approach significantly reduces greenhouse gas emissions by diverting vegetable waste from landfills, thereby mitigating climate change effects and improving air quality. Moreover, it conserves natural resources by reducing the need for virgin materials and promoting biodiversity, conservation, and sustainable resource management. Here, the enzymatic activities and phenolic concentrations derived from the biodegradation of vegetable waste were analyzed over 14 days. Protease activity that plays a vital role in breaking down proteins reached a notable level of 300 µg/ml after 14-day incubation. Lipase activity which is essential for lipid breakdown was observed at a concentration of 6.3 µg/ml. Furthermore, phenolic concentration analysis revealed a significant range, with values ranging from 225 µg/ml to 240 µg/ml after 14 days of incubation. Phenolics are phytochemicals possessing antioxidant properties and potential health benefits. These findings provide valuable insight into the efficacy of utilizing vegetable waste as a substrate for enzymatic and phytochemical production. The observed enzymatic activities and phenolic concentrations highlight the potential of vegetable waste as a valuable resource for the sustainable production of industrially relevant compounds. [ABSTRACT FROM AUTHOR]

Population growth has generated an enormous increase in demand for energy and chemicals to supply goods and services and to maintain quality of life. Oil, coal, and natural gas are the primary sources of the chemicals and energy that directly impact the economy. However, the reserves of these resources are continuously reducing. New alternatives have emerged, including biotechnological tools such as microbial consortia (MC) to produce biofuels, chemicals such as organic acids, and processed foods. The diversity of MC as a biotechnological tool allows it to be used in complex substrates, opening the possibility of using other solid waste to implement consolidated bioprocesses (CPs). This review presents an overview of the uses of MC and CP for producing biofuels using different feedstocks. [ABSTRACT FROM AUTHOR]

The effect of mulching and nutrition on the growth and yield of sweet basil was examined by experimenting with four mulch treatments, viz., without mulch, black plastic, silver plastic, and organic mulch combined with four different nutrient compositions, viz., a 100% recommended dose of fertilizer (RDF), a combination of 75% RDF with humic acid, 75% RDF with microbial consortia and 75% RDF, and humic acid and microbial consortia, which served as sixteen treatment combinations with 100% RDF without mulch as a control. Among the different treatments, mulch had a significant effect on growth and yield parameters, with black plastic mulch having the maximum plant height (88.20 cm), number of branches (14.95), plant spread (5415 cm2), stem diameter (12.64 mm), fresh herbage yield (24.55 t/ha) and dry herbage yield (8.72 t/ha). Thus, the study revealed that among the various mulch treatments, black plastic mulch significantly enhanced the growth and yield parameters of sweet basil, demonstrating its efficacy in promoting optimal plant development and productivity. [ABSTRACT FROM AUTHOR]

The positive effects of Trichoderma on the antioxidant responses of nodulated cowpea plants under aluminum (Al) stress are not well documented. This study aims to evaluate the effects of different microbial consortia of Bradyrhizobium yuanmingense (bradyrhizobia) and Trichoderma species (T. asperelloides T02, T. asperellum T77, or T. harzianum T78) on the growth and antioxidant responses of cowpea under Al stress. Coinoculation with Bradyrhizobia and Trichoderma resulted in greater growth (plant height and root length) and biomass (dry weight of shoots and roots) compared to single inoculations. The dual application of bradyrhizobia and T. asperellum T77 to Al-treated plants increased chlorophyll- a (36 %), chlorophyll- b (210 %), and carotenoid (92 %) contents. Under Al stress, plants inoculated with bradyrhizobia exhibited a 53 % increase in anthocyanin content compared to the unstressed control. The highest levels of reduced ascorbate and ascorbate redox state were observed in plants coinoculated with bradyrhizobia and Trichoderma , whereas oxidized ascorbate accumulated more in plants with single inoculations (bradyrhizobia or Trichoderma). Lipid peroxidation and hydrogen peroxide levels were 50 % lower in plants coinoculated with bradyrhizobia and Trichoderma. Additionally, these plants showed increased activities of superoxide dismutase, catalase, ascorbate peroxidase, and peroxidases under Al stress, particularly in those coinoculated with bradyrhizobia and T. asperelloides T02 and T. harzianum T78. Our results confirm that the presence of bradyrhizobia and Trichoderma in the cowpea rhizosphere mitigates oxidative damage caused by reactive oxygen species under Al stress and positively influences cowpea growth and development under stressful conditions. [Display omitted] • Growth and biomass were superior in cowpea coinoculated with bradyrhizobia and Trichoderma. • Dual application of bradyrhizobia and Trichoderma on Al-treated plants improved photosynthetic pigments. • Lipid peroxidation and hydrogen peroxide content were inferior in plants coinoculated with bradyrhizobia and Trichoderma under Al stress. • Antioxidant enzymes were improved in cowpea coinoculated with bradyrhizobia and Trichoderma under Al stress. [ABSTRACT FROM AUTHOR]

Bradyrhizobia are the principal symbiotic partner of the leguminous plant and take active part in biological nitrogen-fixation. The present investigation explores the underlying competition among different strains during colonization in host roots. Six distinct GFP and RFP-tagged Bradyrhizobium strains were engineered to track them inside the peanut roots either independently or in combination. The Bradyrhizobium strains require different time-spans ranging from 4 to 21 days post-infection (dpi) for successful colonization which further varies in presence of another strain. While most of the individual strains enhanced the shoot and root dry weight, number of nodules, and nitrogen fixation capabilities of the host plants, no significant enhancement of plant growth and nodulation efficiency was observed when they were allowed to colonize in combinations. However, if among the combinations one strains is SEMIA 6144, the co-infection results in higher growth and nodulation efficiency of the hosts. From the competition experiments it has been found that Bradyrhizobium japonicum SEMIA 6144 was found to be the most dominant strain for effective nodulation in peanut. The extent of biofilm and exopolysaccharide (EPS) production by these isolates, individually or in combinations, were envisaged to correlate whether these parameters have any impact on the symbiotic association. But the extent of colonization, growth-promotion and nitrogen-fixation ability drastically lowered when a strain present together with other Bradyrhizobium strain. Therefore, it is imperative to understand the interaction between two co-inoculating Bradyrhizobium species for nodulation followed by plant growth promotion to develop suitable consortia for enhancing BNF in peanut and possibly for other legumes. [ABSTRACT FROM AUTHOR]

Utilizing vegetable waste to produce bioactive compounds through microbial consortia represents a holistic solution to waste management challenges. Efficient waste collection systems in major cities ensure proper segregation of vegetable waste and lay the groundwork for resource utilization. Segregating waste at its source enhances waste stream quality and facilitates downstream processing. Research and development efforts investigating tailored microbial consortia seek to optimize waste degradation and bioactive compound yields, thereby unlocking the potential of waste. This approach significantly reduces greenhouse gas emissions by diverting vegetable waste from landfills, thereby mitigating climate change effects and improving air quality. Moreover, it conserves natural resources by reducing the need for virgin materials and promoting biodiversity, conservation, and sustainable resource management. Here, the enzymatic activities and phenolic concentrations derived from the biodegradation of vegetable waste were analyzed over 14 days. Protease activity that plays a vital role in breaking down proteins reached a notable level of 300 µg/ml after 14-day incubation. Lipase activity which is essential for lipid breakdown was observed at a concentration of 6.3 µg/ml. Furthermore, phenolic concentration analysis revealed a significant range, with values ranging from 225 µg/ml to 240 µg/ml after 14 days of incubation. Phenolics are phytochemicals possessing antioxidant properties and potential health benefits. These findings provide valuable insight into the efficacy of utilizing vegetable waste as a substrate for enzymatic and phytochemical production. The observed enzymatic activities and phenolic concentrations highlight the potential of vegetable waste as a valuable resource for the sustainable production of industrially relevant compounds.

Historically, Hawai'i had few massive coral bleaching events, until two consecutive heatwaves in 2014-2015. Consequent mortality and thermal stress were observed in Kāne'ohe Bay (O'ahu). The two most dominant local species exhibited a phenotypic dichotomy of either bleaching resistance or susceptibility (Montipora capitata and Porites compressa), while the third predominant species (Pocillopora acuta) was broadly susceptible to bleaching. In order to survey shifts in coral microbiomes during bleaching and recovery, 50 colonies were tagged and periodically monitored. Metabarcoding of three genetic markers (16S rRNA gene ITS1 and ITS2) followed by compositional approaches for community structure analysis, differential abundance and correlations for longitudinal data were used to temporally compare Bacteria/Archaea, Fungi and Symbiodiniaceae dynamics. P. compressa corals recovered faster than P. acuta and Montipora capitata. Prokaryotic and algal communities were majorly shaped by host species, and had no apparent pattern of temporal acclimatization. Symbiodiniaceae signatures were identified at the colony scale, and were often related to bleaching susceptibility. Bacterial compositions were practically constant between bleaching phenotypes, and more diverse in P. acuta and M. capitata. P. compressa's prokaryotic community was dominated by a single bacterium. Compositional approaches (via microbial balances) allowed the identification of fine-scale differences in the abundance of a consortium of microbes, driving changes by bleaching susceptibility and time across all hosts. The three major coral reef founder-species in Kāne'ohe Bay revealed different phenotypic and microbiome responses after 2014-2015 heatwaves. It is difficult to forecast, a more successful strategy towards future scenarios of global warming. Differentially abundant microbial taxa across time and/or bleaching susceptibility were broadly shared among all hosts, suggesting that locally, the same microbes may modulate stress responses in sympatric coral species. Our study highlights the potential of investigating microbial balances to identify fine-scale microbiome changes, serving as local diagnostic tools of coral reef fitness.

Abstract Background Sponges (phylum Porifera) constantly interact with microbes. They graze on microbes from the water column by filter-feeding and they harbor symbiotic partners within their bodies. In experimental setups, sponges take up symbionts at lower rates compared with seawater microbes. This suggests that sponges have the capacity to differentiate between microbes and preferentially graze in non-symbiotic microbes, although the underlying mechanisms of discrimination are still poorly understood. Genomic studies showed that, compared to other animal groups, sponges present an extended repertoire of immune receptors, in particular NLRs, SRCRs, and GPCRs, and a handful of experiments showed that sponges regulate the expression of these receptors upon encounter with microbial elicitors. We hypothesize that sponges may rely on differential expression of their diverse repertoire of poriferan immune receptors to sense different microbial consortia while filter-feeding. To test this, we characterized the transcriptomic response of two sponge species, Aplysina aerophoba and Dysidea avara, upon incubation with microbial consortia extracted from A. aerophoba in comparison with incubation with seawater microbes. The sponges were sampled after 1 h, 3 h, and 5 h for RNA-Seq differential gene expression analysis. Results D. avara incubated with A. aerophoba-symbionts regulated the expression of genes related to immunity, ubiquitination, and signaling. Within the set of differentially-expressed immune genes we identified different families of Nucleotide Oligomerization Domain (NOD)-Like Receptors (NLRs). These results represent the first experimental evidence that different types of NLRs are involved in microbial discrimination in a sponge. In contrast, the transcriptomic response of A. aerophoba to its own symbionts involved comparatively fewer genes and lacked genes encoding for immune receptors. Conclusion Our work suggests that: (i) the transcriptomic response of sponges upon microbial exposure may imply “fine-tuning” of baseline gene expression as a result of their interaction with microbes, (ii) the differential response of sponges to microbial encounters varied between the species, probably due to species-specific characteristics or related to host’s traits, and (iii) immune receptors belonging to different families of NLR-like genes played a role in the differential response to microbes, whether symbionts or food bacteria. The regulation of these receptors in sponges provides further evidence of the potential role of NLRs in invertebrate host-microbe interactions. The study of sponge responses to microbes exemplifies how investigating different animal groups broadens our knowledge of the evolution of immune specificity and symbiosis.

Introduction The aim of the research was to demonstrate the efficiency of microorganisms and the effectiveness of biodegradation techniques on Low-density polyethylene (LDPE) plastics. The research question was: What is the efficiency of LDPE-degrading microorganisms and the effectiveness of biodegradation techniques? Methods The systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles were obtained from Scopus, Web of Science (WOS), Embase, and Google Scholar. The DeCS/Mesh search terms were: Low-density polyethylene, efficiency, biodegradation, microbial consortia, fungi, bacteria. Inclusion criteria were: scientific articles that included bacteria, fungi, and microbial consortia reported as LDPE degraders that report the percentage of weight loss; articles published from January 2010 to October 2022, and publications in Spanish and English with open access. Exclusion criteria were: studies that do not report gravimetry, the biodegradation time of LDPE, and the genus or species of the polyethylene-degrading microorganism. Results Out of 483 studies found, 50 were included in this Systematic Review (SR). The most frequent study techniques were scanning electron microscopy (SEM), gravimetry, and fourier transform infrared spectroscopy (FTIR), and in the case of microorganisms, the most studied belonged to the genus Pseudomonas, Bacillus, and Aspergillus. Regarding the isolation place, the most frequent mentioned in the reviewed articles were landfill soil and sanitary landfill soil. The efficiency of LDPE-degrading microorganisms was higher in bacteria such as Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp., which obtained a range of DE of 9.00-70.00%, 24.00-64%, 1.15 – 61.00%, 45.00%, and 1.5-40% with DT of 4-150, 120, 4-150, 30, and 30-120 days, respectively; in the case of fungi, the main microorganisms are Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii with efficiencies of 54.34, 48.78, and 46.34%, in 90 days, respectively; and the most efficient microbial consortia were from Enterobacter spp. and Pantoea sp. with 38.00 – 81.00%, in 120 days; and, Pseudomonas protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp. with 55. 00 – 75.00% in 120 days. Conclusions The most efficient microorganisms in LDPE degradation are Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp.; in fungi Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii; and in microbial consortia, those formed by Enterobacter spp. and Pantoea sp., and that of P. protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp.; and the most effective techniques used in LDPE biodegradation are SEM, gravimetry, and FTIR.

Polychlorinated biphenyls (PCBs) are a class of synthetic organic compounds that are widely distributed in the environment and have significant adverse effects on humans as well as the ecosystem. Many microorganisms that can degrade PCBs have been reported, including monocultures of bacteria and fungi, as well as natural and artificial microbial consortia. Generally, anaerobic dechlorination can degrade highly chlorinated PCBs to reduce their toxicity, while aerobic oxidation degrades lowly chlorinated PCBs (four or fewer chlorine atoms) and realizes their complete mineralization into CO2 by disrupting the benzene ring structure. Due to the need for the metabolism of a wide range of PCB congeners in the environment, microbial consortia have become a research hotspot, and their species diversity facilitates metabolic cooperation, enabling them to undertake more complex tasks. In this review, we will discuss the metabolic mechanisms of PCB degradation by monocultures as well as microbial consortia, and focus on the recent progress in the development and optimization of PCB-degrading microbial consortia, the community composition analysis methods, the prevailing optimization strategies such as biostimulation, bioaugmentation, metagenomics, and the combination of other methods for a better remediation effect, which will provide theoretical and practical bases for the rational design, construction and further optimization of efficient microbial consortia for the high-efficiency degradation of PCBs. [ABSTRACT FROM AUTHOR]

Background: Sponges (phylum Porifera) constantly interact with microbes. They graze on microbes from the water column by filter-feeding and they harbor symbiotic partners within their bodies. In experimental setups, sponges take up symbionts at lower rates compared with seawater microbes. This suggests that sponges have the capacity to differentiate between microbes and preferentially graze in non-symbiotic microbes, although the underlying mechanisms of discrimination are still poorly understood. Genomic studies showed that, compared to other animal groups, sponges present an extended repertoire of immune receptors, in particular NLRs, SRCRs, and GPCRs, and a handful of experiments showed that sponges regulate the expression of these receptors upon encounter with microbial elicitors. We hypothesize that sponges may rely on differential expression of their diverse repertoire of poriferan immune receptors to sense different microbial consortia while filter-feeding. To test this, we characterized the transcriptomic response of two sponge species, Aplysina aerophoba and Dysidea avara, upon incubation with microbial consortia extracted from A. aerophoba in comparison with incubation with seawater microbes. The sponges were sampled after 1 h, 3 h, and 5 h for RNA-Seq differential gene expression analysis. Results: D. avara incubated with A. aerophoba-symbionts regulated the expression of genes related to immunity, ubiquitination, and signaling. Within the set of differentially-expressed immune genes we identified different families of Nucleotide Oligomerization Domain (NOD)-Like Receptors (NLRs). These results represent the first experimental evidence that different types of NLRs are involved in microbial discrimination in a sponge. In contrast, the transcriptomic response of A. aerophoba to its own symbionts involved comparatively fewer genes and lacked genes encoding for immune receptors. Conclusion: Our work suggests that: (i) the transcriptomic response of sponges upon microbial exposure may imply "fine-tuning" of baseline gene expression as a result of their interaction with microbes, (ii) the differential response of sponges to microbial encounters varied between the species, probably due to species-specific characteristics or related to host's traits, and (iii) immune receptors belonging to different families of NLR-like genes played a role in the differential response to microbes, whether symbionts or food bacteria. The regulation of these receptors in sponges provides further evidence of the potential role of NLRs in invertebrate host-microbe interactions. The study of sponge responses to microbes exemplifies how investigating different animal groups broadens our knowledge of the evolution of immune specificity and symbiosis. [ABSTRACT FROM AUTHOR]

A reactor with silicone tubes as support medium was used for glycerol fermentation. The experimental set-up consisted of three phases. In P1, the applied glycerol loading rate (gly-LR) was in the range of 6–10 g.L−1.d−1 at an influent pH of 7.9 ± 0.4. In P2, gly-LR was kept constant (18.0 ± 1.8 g.L−1.d−1) with different doses of NaHCO3. Finally in P3, two different gly-LR (9 and 18 g.L−1.d−1) were evaluated, dosing 1 g-NaHCO3 per g-COD of glycerol. Glycerol consumption was close 90%. The main end-product was 1,3-propanediol (1,3-PDO) (0.40 mol.mol-gly−1), but ethanol was also generated, particularly at pH above 8 and low gly-LR (0.20 mol.mol-gly−1). After 1-year operation with glycerol as the only carbon source, a drastic shift in the bacterial community was observed. The 1,3-PDO producers Lacrimispora and Clostridium became dominant, although non-glycerol-degrading fermentative genera, e.g., Actinomyces and Eubacterium, thrived at the expense of cellular breakdown products. [ABSTRACT FROM AUTHOR]

The persistence of PAHs poses a significant challenge for conventional remediation approaches, necessitating the exploration of alternative, sustainable strategies for their mitigation. This review underscores the vital role of specialized microbial species (nitrogen-fixing, phosphate-solubilizing, and biosurfactant-producing bacteria) in tackling the environmental impact of polycyclic aromatic hydrocarbons (PAHs). These resistant compounds demand innovative remediation strategies. The study explores microbial metabolic capabilities for converting complex PAHs into less harmful byproducts, ensuring sustainable mitigation. Synthesizing literature from 2016 to 2023, it covers PAH characteristics, sources, and associated risks. Degradation mechanisms by bacteria and fungi, key species, and enzymatic processes are examined. Nitrogen-fixing and phosphate-solubilizing bacteria contributions in symbiotic relationships with plants are highlighted. Biosurfactant-producing bacteria enhance PAH solubility, expanding microbial accessibility for degradation. Cutting-edge trends in omics technologies, synthetic biology, genetic engineering, and nano-remediation offer promising avenues. Recommendations emphasize genetic regulation, field-scale studies, sustainability assessments, interdisciplinary collaboration, and knowledge dissemination. These insights pave the way for innovative, sustainable PAH-contaminated environment restoration. [ABSTRACT FROM AUTHOR]

Fusarium wilt of banana (FWB) is the most limiting disease in this crop. The phytosanitary emergency caused by FWB since 2019 in Colombia has required the development of ecofriendly control methods. The aim of this study was to test the effectiveness of microbial-based biofungicides against FWB caused by Fusarium oxysporum f. sp. cubense race 1 (Foc R1) and correlate such effect with plant physiological parameters. Five Trichoderma (T1 to T4 and T9) and four Bacillus (T5 to T8)-based biofungicides were evaluated in pot experiments. In vitro, dual confrontation tests were also carried out to test whether the in vitro effects on Foc growth were consistent with the in vivo effects. While Trichoderma-based T3, T4, and T9, and Bacillus-based T8, significantly reduced the growth of Foc R1 in vitro, Trichoderma-based T1, T3, T4, and T9 temporarily reduced the Foc population in the soil. However, the incidence progress of FWB was significantly reduced by Bacterial-based T7 (74% efficacy) and Trichoderma-based T2 (50% efficacy). The molecular analysis showed that T7 prevented the inner tissue colonization by Foc R1 in 80% of inoculated plants. The T2, T4, T7, and T9 treatments mitigated the negative effects caused by Foc R1 on plant physiology and growth. Our data allowed us to identify three promising treatments to control FWB, reducing the progress of the disease, delaying the colonization of inner tissue, and mitigating physiological damages. Further studies should be addressed to determine the modes of action of the biocontrol agents against Foc and validate the utilization in the field. [ABSTRACT FROM AUTHOR]

The exploitation of exciting features of plastics for diverse applications has resulted in significant plastic waste generation, which negatively impacts environmental compartments, metabolic processes, and the well-being of aquatic ecosystems biota. A shotgun metagenomic approach was deployed to investigate the microbial consortia, degradation pathways, and enzyme systems involved in the degradation of plastics in a tropical lentic pond sediment (APS). Functional annotation of the APS proteome (ORFs) using the PlasticDB database revealed annotation of 1015 proteins of enzymes such as depolymerase, esterase, lipase, hydrolase, nitrobenzylesterase, chitinase, carboxylesterase, polyesterase, oxidoreductase, polyamidase, PETase, MHETase, laccase, alkane monooxygenase, among others involved in the depolymerization of the plastic polymers. It also revealed that polyethylene glycol (PEG), polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), polyethylene terephthalate (PET), and nylon have the highest number of annotated enzymes. Further annotation using the KEGG GhostKOALA revealed that except for terephthalate, all the other degradation products of the plastic polymers depolymerization such as glyoxylate, adipate, succinate, 1,4-butanediol, ethylene glycol, lactate, and acetaldehyde were further metabolized to intermediates of the tricarboxylic acid cycle. Taxonomic characterization of the annotated proteins using the AAI Profiler and BLASTP revealed that Pseudomonadota members dominate most plastic types, followed by Actinomycetota and Acidobacteriota. The study reveals novel plastic degraders from diverse phyla hitherto not reported to be involved in plastic degradation. This suggests that plastic pollution in aquatic environments is prevalent with well-adapted degrading communities and could be the silver lining in mitigating the impacts of plastic pollution in aquatic environments. [ABSTRACT FROM AUTHOR]

Nearly all plants and their organs are inhabited by endophytic microbes which play a crucial role in plant fitness and stress resilience. Harnessing endophytic services can provide effective solutions for a sustainable increase in agriculture productivity and can be used as a complement or alternative to agrochemicals. Shifting agriculture practices toward the use of nature-based solutions can contribute directly to the global challenges of food security and environmental sustainability. However, microbial inoculants have been used in agriculture for several decades with inconsistent efficacy. Key reasons of this inconsistent efficacy are linked to competition with indigenous soil microflora and inability to colonize plants. Endophytic microbes provide solutions to both of these issues which potentially make them better candidates for microbial inoculants. This article outlines the current advancements in endophytic research with special focus on endophytic bacilli. A better understanding of diverse mechanisms of disease control by bacilli is essential to achieve maximum biocontrol efficacy against multiple phytopathogens. Furthermore, we argue that integration of emerging technologies with strong theoretical frameworks have the potential to revolutionize biocontrol approaches based on endophytic microbes. [ABSTRACT FROM AUTHOR]

Drought affects several plant physiological characteristics such as photosynthesis, carbon metabolism, and chlorophyll content, causing hormonal and nutritional imbalances and reducing nutrient uptake and transport, which inhibit growth and development. The use of bioinoculants based on plant growth-promoting microorganisms such as plant growth-promoting rhizobacteria (PGPR), yeasts, and arbuscular mycorrhizal fungi (AMF) has been proposed as an alternative to help plants tolerate drought. However, most studies have been based on the use of a single type of microorganism, while consortia studies have been scarcely performed. Therefore, the aim of this study was to evaluate different combinations of three PGPR, three AMF, and three yeasts with plant growth-promoting attributes to improve the biochemical, nutritional, and physiological behavior of strawberry plants growing under severe drought. The results showed that the growth and physiological attributes of the non-inoculated plants were significantly reduced by drought. In contrast, plants inoculated with the association of the fungus Claroideoglomus claroideum, the yeast Naganishia albida, and the rhizobacterium Burkholderia caledonica showed a stronger improvement in tolerance to drought. High biomass, relative water content, fruit number, photosynthetic rate, transpiration, stomatal conductance, quantum yield of photosystem II, N concentration, P concentration, K concentration, antioxidant activities, and chlorophyll contents were significantly improved in inoculated plants by up to 16.6%, 12.4%, 81.2%, 80%, 79.4%, 71.0%, 17.8%, 8.3%, 6.6%, 57.3%, 41%, and 22.5%, respectively, compared to stressed non-inoculated plants. Moreover, decreased malondialdehyde levels by up to 32% were registered. Our results demonstrate the feasibility of maximizing the effects of inoculation with beneficial rhizosphere microorganisms based on the prospect of more efficient combinations among different microbial groups, which is of interest to develop bioinoculants oriented to increase the growth of specific plant species in a global scenario of increasing drought stress. [ABSTRACT FROM AUTHOR]

The anthropogenic activities toward meeting the energy requirements have resulted in an alarming rise in environmental pollution levels. Among pollutants, polycyclic aromatic hydrocarbons (PAHs) are the most predominant due to their persistent and toxic nature. Amidst the several pollutants depuration methods, bioremediation utilizing biodegradation is the most viable alternative. This study investigated the biodegradation efficacy using developed microbial consortium PBR-21 for 2–4 ringed PAHs named naphthalene (NAP), anthracene (ANT), fluorene (FLU), and pyrene (PYR). The removal efficiency was observed up to 100 ± 0.0%, 70.26 ± 4.2%, 64.23 ± 2.3%, and 61.50 ± 2.6%, respectively, for initial concentrations of 400 mg L−1 for NAP, ANT, FLU, and PYR respectively. Degradation followed first-order kinetics with rate constants of 0.39 d−1, 0.10 d−1, 0.08 d−1, and 0.07 d−1 and half-life t 1 / 2 of 1.8 h, 7.2 h, 8.5 h, and 10 h, respectively. The microbial consortia were found to be efficient towards the co-contaminants with 1 mM concentration. Toxicity examination indicated that microbial-treated PAHs resulted in lesser toxicity in aquatic crustaceans (Artemia salina) than untreated PAHs. Also, the study suggests that indigenous microbial consortia PBR-21 has the potential to be used in the bioremediation of PAH-contaminated environment. [ABSTRACT FROM AUTHOR]

Petroleum hydrocarbon contamination is a serious concern across the globe. Here, the capability of native bacterial consortium enriched from sediment samples of Map Ta Phut Industrial Estate (MTPIE), Rayong, Thailand was described. The distribution of PAHs was assessed from the sediment samples collected from MTPIE by GC-FID and the toxic unit (TU) was calculated to assess the potential ecological risk to the surrounding biota. This study investigated the degradation potential and determined the PAH-degrading bacterial cultures by enriching collected sediments in PAHs mixtures (naphthalene, phenanthrene, and pyrene). The TPH degradation capacity of each bacterial consortium was validated in a soil microcosm using aged crude oil-contaminated soil. The MTPIE sediments were highly contaminated with PAHs (843.99-3904.39 ng g-1) and posed extremely high ecological risks to benthic biota (TU > 1). The consortium S5-P most significantly removed naphthalene (90.03%) and phenanthrene (88.14%) while the highest removal of pyrene was achieved by the S3-P consortium. Other consortia only partially degraded the PAHs. The dominant microbes in the consortia were determined using PCR-DGGE, it was found that the PAH degrading consortia were known PAH degraders such as Annwoodia, Bacillus, Brevibacillus, Lysinibacillus, Paracoccus, Rhodococcus, Sphingopyxis, Sulfurovum, and Sulfurimonas species and unknown PAH degraders such as Lithuaxuella species. The consortium S5-P showed the highest degradation capacity, removing 74.99% of TPHs in the soil microcosm. Furthermore, the inoculation of PAH-biodegrading bacterial consortia significantly promoted the catechol-2,3-dioxygenase (C23O) and dehydrogenase (DHA) activities which directly correlated with the degradation efficiency of petroleum hydrocarbons (p < 0.05). [ABSTRACT FROM AUTHOR]

Introduction The aim of the research was to demonstrate the efficiency of microorganisms and the effectiveness of biodegradation techniques on Low-density polyethylene (LDPE) plastics. The research question was: What is the efficiency of LDPE-degrading microorganisms and the effectiveness of biodegradation techniques? Methods The systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles were obtained from Scopus, Web of Science (WOS), Embase, and Google Scholar. The DeCS/Mesh search terms were: Low-density polyethylene, efficiency, biodegradation, microbial consortia, fungi, bacteria. Inclusion criteria were: scientific articles that included bacteria, fungi, and microbial consortia reported as LDPE degraders that report the percentage of weight loss; articles published from January 2010 to October 2022, and publications in Spanish and English with open access. Exclusion criteria were: studies that do not report gravimetry, the biodegradation time of LDPE, and the genus or species of the polyethylene-degrading microorganism. Results Out of 483 studies found, 50 were included in this Systematic Review (SR). The most frequent study techniques were scanning electron microscopy (SEM), gravimetry, and fourier transform infrared spectroscopy (FTIR), and in the case of microorganisms, the most studied belonged to the genus Pseudomonas, Bacillus, and Aspergillus. Regarding the isolation place, the most frequent mentioned in the reviewed articles were landfill soil and sanitary landfill soil. The efficiency of LDPE-degrading microorganisms was higher in bacteria such as Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp., which obtained a range of DE of 9.00-70.00%, 24.00-64%, 1.15 – 61.00%, 45.00%, and 1.5-40% with DT of 4-150, 120, 4-150, 30, and 30-120 days, respectively; in the case of fungi, the main microorganisms are Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii with efficiencies of 54.34, 48.78, and 46.34%, in 90 days, respectively; and the most efficient microbial consortia were from Enterobacter spp. and Pantoea sp. with 38.00 – 81.00%, in 120 days; and, Pseudomonas protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp. with 55. 00 – 75.00% in 120 days. Conclusions The most efficient microorganisms in LDPE degradation are Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp.; in fungi Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii; and in microbial consortia, those formed by Enterobacter spp. and Pantoea sp., and that of P. protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp.; and the most effective techniques used in LDPE biodegradation are SEM, gravimetry, and FTIR.

Salinity and drought are the major abiotic stresses that significantly affect growth and productivity, necessitating the development and exploration of technologies to enhance tolerance of the crop plants. This study explored the role of four plant growth-promoting Streptomyces, i.e. Streptomyces chilikensis RC1830 (assigned as A), Streptomyces griseoincarnatus RB7AG (assigned as D), Streptomyces barkulensis RC1831 (assigned as B), and Streptomyces chitinovorans RC1832 (assigned as C) in mitigating stresses and improving rice plant growth (var. Swarna). Rice plants were inoculated with different Streptomyces consortia and exposed to 40 mM NaCl for salinity stress and 55 % FC (Field capacity) for drought stress. The study found that stresses adversely affected physiological parameters and triggered the production of antioxidant enzymes like superoxide dismutase, catalase, and peroxidase. However, inoculation of consortia at a concentration of 108 CFU/mL not only promoted the growth of the plants but also mitigated the negative effects of salinity and drought compared to non-inoculated controls. Among the treatments, ABCD consortia (RC1830, RC1831, RC1832, RB7AG) demonstrated the most significant improvements followed by ABD (RC1830, RC1831, RB7AG), boosting shoot length, root length, total chlorophyll, and proline content. This also enhanced superoxide dismutase, peroxidase, and catalase activities under stress conditions. Overall, Streptomyces inoculation improved stress tolerance in rice plants by enhancing photosynthetic capacity, antioxidant defense mechanisms, and proline content. These PGPS inoculants present a promising ecological approach to mitigate the impacts of abiotic stress on crops.

The dynamic structures of microbial communities emerge from the complex network of interactions between their constituent microorganisms. Quantitative measurements of these interactions are important for understanding and engineering ecosystem structure. Here, we present the development and application of the BioMe plate, a redesigned microplate device in which pairs of wells are separated by porous membranes. BioMe facilitates the measurement of dynamic microbial interactions and integrates easily with standard laboratory equipment. We first applied BioMe to recapitulate recently characterized, natural symbiotic interactions between bacteria isolated from the Drosophila melanogaster gut microbiome. Specifically, the BioMe plate allowed us to observe the benefit provided by two Lactobacillus strains to an Acetobacter strain. We next explored the use of BioMe to gain quantitative insight into the engineered obligate syntrophic interaction between a pair of Escherichia coli amino acid auxotrophs. We integrated experimental observations with a mechanistic computational model to quantify key parameters associated with this syntrophic interaction, including metabolite secretion and diffusion rates. This model also allowed us to explain the slow growth observed for auxotrophs growing in adjacent wells by demonstrating that, under the relevant range of parameters, local exchange between auxotrophs is essential for efficient growth. The BioMe plate provides a scalable and flexible approach for the study of dynamic microbial interactions. IMPORTANCE Microbial communities participate in many essential processes from biogeochemical cycles to the maintenance of human health. The structure and functions of these communities are dynamic properties that depend on poorly understood interactions among different species. Unraveling these interactions is therefore a crucial step toward understanding natural microbiota and engineering artificial ones. Microbial interactions have been difficult to measure directly, largely due to limitations of existing methods to disentangle the contribution of different organisms in mixed cocultures. To overcome these limitations, we developed the BioMe plate, a custom microplate-based device that enables direct measurement of microbial interactions, by detecting the abundance of segregated populations of microbes that can exchange small molecules through a membrane. We demonstrated the possible application of the BioMe plate for studying both natural and artificial consortia. BioMe is a scalable and accessible platform that can be used to broadly characterize microbial interactions mediated by diffusible molecules.

Introduction The aim of the research was to demonstrate the efficiency of microorganisms and the effectiveness of biodegradation techniques on Low-density polyethylene (LDPE) plastics. The research question was: What is the efficiency of LDPE-degrading microorganisms and the effectiveness of biodegradation techniques? Methods The systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles were obtained from Scopus, Web of Science (WOS), Embase, and Google Scholar. The DeCS/Mesh search terms were: Low-density polyethylene, efficiency, biodegradation, microbial consortia, fungi, bacteria. Inclusion criteria were: scientific articles that included bacteria, fungi, and microbial consortia reported as LDPE degraders that report the percentage of weight loss; articles published from January 2010 to October 2022, and publications in Spanish and English with open access. Exclusion criteria were: studies that do not report gravimetry, the biodegradation time of LDPE, and the genus or species of the polyethylene-degrading microorganism. Results Out of 483 studies found, 50 were included in this Systematic Review (SR). The most frequent study techniques were scanning electron microscopy (SEM), gravimetry, and fourier transform infrared spectroscopy (FTIR), and in the case of microorganisms, the most studied belonged to the genus Pseudomonas, Bacillus, and Aspergillus. Regarding the isolation place, the most frequent mentioned in the reviewed articles were landfill soil and sanitary landfill soil. The efficiency of LDPE-degrading microorganisms was higher in bacteria such as Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp., which obtained a range of DE of 9.00-70.00%, 24.00-64%, 1.15 – 61.00%, 45.00%, and 1.5-40% with DT of 4-150, 120, 4-150, 30, and 30-120 days, respectively; in the case of fungi, the main microorganisms are Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii with efficiencies of 54.34, 48.78, and 46.34%, in 90 days, respectively; and the most efficient microbial consortia were from Enterobacter spp. and Pantoea sp. with 38.00 – 81.00%, in 120 days; and, Pseudomonas protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp. with 55. 00 – 75.00% in 120 days. Conclusions The most efficient microorganisms in LDPE degradation are Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp.; in fungi Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii; and in microbial consortia, those formed by Enterobacter spp. and Pantoea sp., and that of P. protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp.; and the most effective techniques used in LDPE biodegradation are SEM, gravimetry, and FTIR.

Anaerobic digestion of municipal mixed sludge produces methane that can be converted into renewable natural gas. To improve economics of this microbial mediated process, metabolic interactions catalyzing biomass conversion to energy need to be identified. Here, we present a two-year time series associating microbial metabolism and physicochemistry in a full-scale wastewater treatment plant. By creating a co-occurrence network with thousands of time-resolved microbial populations from over 100 samples spanning four operating configurations, known and novel microbial consortia with potential to drive methane production were identified. Interactions between these populations were further resolved in relation to specific process configurations by mapping metagenome assembled genomes and cognate gene expression data onto the network. Prominent interactions included transcriptionally active Methanolinea methanogens and syntrophic benzoate oxidizing Syntrophorhabdus, as well as a Methanoregulaceae population and putative syntrophic acetate oxidizing bacteria affiliated with Bateroidetes (Tenuifilaceae) expressing the glycine cleavage bypass of the Wood-Ljungdahl pathway.

Microorganisms play a pivotal role in the growth and development of plants, making their interaction a promising avenue for managing plant diseases, including those affecting oil palm cultivation. In this study, endophytic microbes such as actinomycetes, bacteria, and fungi were isolated from healthy oil palm tissue in susceptible areas to serve as stock isolates. These isolates underwent in vitro evaluation to determine their efficacy in controlling Ganoderma boninense and to identify bioactive metabolites. Additionally, in planta tests were conducted using bioformulations. A dual culture assay was utilized to assess the inhibitory effects of three different stock isolates on G. boninense. To detect bioactive metabolites responsible for the inhibition, particularly phenazine and syringic acid, a series of procedures involving fermentation, extraction, and LC-MS analysis were employed. Furthermore, the efficacy of bioformulations employing various carriers and consisting of either microbial consortia was meticulously evaluated in a nursery setting. The main focus of this evaluation was to determine their capacity to effectively curb disease onset and maintain the vegetative growth of oil palm during the progression of G. boninense. Several strains of indigenous bacteria (Pseudomonas aeruginosa strain JQ-41, Serratia marcescens strain S16, Stenotrophomonas rhizophila strain CASMBAUDAL2), an actinobacterium (Streptomyces sp.), and a fungus (Trichoderma sp.) exhibited significant growth inhibition against G. boninense. Based on the results obtained from the LC-MS analysis of the ethyl acetate extract, it was revealed that the extract contains 2 compounds known as antifungal agents, namely phenazine and syringic acid. The most effective approach to mitigate infection involved the preventive application of bioformulations containing mixed bacterial isolates or microbial consortia. After 12 months of observation, these bioformulations demonstrated efficacy comparable to that of Marfu-P, a commercially available biofungicide for oil palm seedlings. The study establishes the effectiveness of endophytic bioformulations as a viable strategy to manage the onset of G. boninense disease, highlighting the potential of microorganisms as an alternative solution for controlling basal stem rot in the nursery. [ABSTRACT FROM AUTHOR]

The design and study of active microbial consortia able to degrade plastics represent an exciting area of research toward the development of bio-based alternatives to efficiently transform plastic waste. This forum article discusses concepts and mechanisms to inform emerging strategies for engineering microbiomes to transform plastics under controlled settings. [ABSTRACT FROM AUTHOR]

Nitrogen-rich wastewater is a major environmental issue that requires proper treatment before disposal. This comprehensive overview covers biological, physical, and chemical nitrogen removal methods. Simultaneous nitrification–denitrification (SND) is most effective in saline water when utilizing both aerobic and anoxic conditions with diverse microbial populations for nitrogen removal. Coupling anammox with denitrification could increase removal rates and reduce energy demand. Suspended growth bioreactors effectively treated diverse COD/N ratios and demonstrated resilience to low C/N ratios. Moving biofilm bioreactors exhibit reduced mortality rates, enhanced sludge–liquid separation, increased treatment efficiency, and stronger biological structures. SND studies show ≥90% total nitrogen removal efficiency (%RETN) in diverse setups, with Defluviicoccus, Nitrosomonas, and Nitrospira as the main microbial communities, while anammox–denitrification achieved a %RETN of 77%. Systems using polyvinyl alcohol/sodium alginate as a growth medium showed a %RETN ≥ 75%. Air-lift reflux configurations exhibited high %RETN and %RENH4, reducing costs and minimizing sludge formation. Microwave pretreatment and high-frequency electric fields could be used to improve the %RENH4. Adsorption/ion exchange, membrane distillation, ultrafiltration, and nanofiltration exhibit promise in industrial wastewater treatment. AOPs and sulfate-based oxidants effectively eliminate nitrogen compounds from industrial wastewater. Tailoring proposed treatments for cost-effective nitrogen removal, optimizing microbial interactions, and analyzing the techno-economics of emerging technologies are crucial. [ABSTRACT FROM AUTHOR]

Microorganisms play a central role in biotechnology and it is key that we develop strategies to engineer and optimize their functionality. To this end, most efforts have focused on introducing genetic manipulations in microorganisms which are then grown either in monoculture or in mixed‐species consortia. An alternative strategy to optimize microbial processes is to rationally engineer the environment in which microbes grow. The microbial environment is multidimensional, including factors such as temperature, pH, salinity, nutrient composition, etc. These environmental factors all influence the growth and phenotypes of microorganisms and they generally “interact” with one another, combining their effects in complex, non‐additive ways. In this piece, we overview the origins and consequences of these “interactions” between environmental factors and discuss how they have been built into statistical, bottom‐up predictive models of microbial function to identify optimal environmental conditions for monocultures and microbial consortia. We also overview alternative “top‐down” approaches, such as genetic algorithms, to finding optimal combinations of environmental factors. By providing a brief summary of the state of this field, we hope to stimulate further work on the rational manipulation and optimization of the microbial environment. [ABSTRACT FROM AUTHOR]

Various studies have addressed the impact of microbial inoculants on the composition of the resident microbiome. How microbial inoculants impact plant metabolism and interact with the resident rhizobiota under herbivory stress remains elusive. Here, we investigated the impact of two bacterial and two fungal inoculants, inoculated as single species and as a synthetic community, on the rhizosphere microbiome and volatilome of tomato plants (Solanum lycopersicum) comparing nonstress conditions to exposed to leaf herbivory by Spodoptera exigua. Based on amplicon sequencing analysis, rhizobacterial community composition was significantly affected by all four inoculants and the magnitude of this effect was dependent on herbivory stress. Fungal community composition was altered by the microbial inoculants but independent of herbivory stress. The rhizosphere volatilome was impacted by the microbial inoculation and differences between treatments were evened under herbivory stress. Each microbial inoculant caused unique changes in the volatilome of stressed plants but also shared similar responses, in particular the enhanced production of dimethyl disulfide and benzothiazole. In conclusion, the introduction of microbial inoculants in the tomato rhizosphere caused unique as well as common changes in the rhizosphere microbiome and volatilome, but these changes were minor compared to the microbiome changes induced by herbivory stress. [ABSTRACT FROM AUTHOR]

The present study evaluates the association of the blue–green microalga Arthrospira maxima (Spirulina), which is known for its CO2 fixation, biomass, and high-value metabolite production, with the microalga growth-promoting bacterium Azospirillum brasilense under the stressful composition of biogas. The results demonstrated that A. maxima co-cultured with A. brasilense under the high CO2 (25%) and methane (CH4; 75%) concentrations of biogas recorded a CO2 fixation rate of 0.24 ± 0.03 g L–1 days–1, thereby attaining a biomass production of 1.8 ± 0.03 g L–1. Similarly, the biochemical composition quality of this microalga enhanced the attainment of higher contents of carbohydrates, proteins, and phycocyanin than cultured alone. However, metabolites other than tryptophan (Trp) and indole-3-acetic acid could have supported this beneficial interaction. Overall, the results demonstrate that this prokaryotic consortium of A. maxima–A. brasilense established a synergic association under biogas, which represents a sustainable strategy to improve the bio-refinery capacity of this microalga and increase the usefulness of A. brasilense in multiple economic sectors. [ABSTRACT FROM AUTHOR]

As methane fermentation is inhibited by ammonia derived from organic waste, anaerobic microbial communities tolerant to enriched wastewater with high concentrations of ammonia and salt must be obtained for methane fermentation. Therefore, acclimation cultures were prepared in bottles for 60–80 weeks with artificial wastewater medium added every 2 weeks, using three types of sludge from wastewater treatment plants in food factories. These cultures were maintained without substantially decreasing methanogenesis and gradually increasing NH4-N and salt concentrations to 5 and 34 g/L, respectively, via the accumulation of ammonia and salt through anaerobic digestion and direct addition. The culture did not show the severe inhibition of methanogenesis or the accumulation of volatile fatty acids (VFAs) such as acetic and propionic acids. The analysis of bacterial consortia in the acclimated sludge based on the 16S rRNA sequence showed that hydrogenotrophic methanogenic bacteria of the genus Methanoculleus were dominant among archaea, whereas bacteria from the orders Clostridiales and Bacteroidales were dominant among eubacteria. Further, VFA-assimilating bacteria, including synthetic acetate-oxidizing bacteria coupled with hydrogenotrophic Methanoculleus to convert methane from acetate, were present to prevent the excessive accumulation of VFAs in the acclimation culture. The proposed acclimation process can enhance the anaerobic digestion of wastewater for methane production. [ABSTRACT FROM AUTHOR]

Deoxynivalenol (DON), one of the most widespread mycotoxins in food and feed, poses a persistent health threat to humans and farm animals, and is difficult to eliminate. The utilization of the biotransformation mechanism by microorganisms to detoxify DON is a promising strategy. Although individual strains are capable of DON degradation, their isolation and purification are challenging and time-consuming. Recently, the microbial consortia concept has been proposed, owing to their ability to perform more complex tasks and are more tolerant to environmental changes than individual strains or species. In this study, the novel microbial consortia C1 that could efficiently convert DON to de-epoxy DON (DOM-1) was screened from the cecum contents of ducks. After 24 h anaerobic incubation, 100 μg/ml DON was completely degraded by C1. In vitro, C1 can effectively degrade DON in corn steep liquor (CSL) with an efficiency of 49.44% within 14 days. Furthermore, C1 effectively alleviated the DON poisoning in mice. After C1 treatment, the serum DON level decreased by 40.39%, and the reduction in serum total protein and albumin levels were mitigated. Additionally, C1 is effective in protecting the mouse liver against 5 mg/kg DON. These findings suggest that C1 could be a promising DON biological detoxifier and provide novel microbial resources for preventing DON contamination. [ABSTRACT FROM AUTHOR]

Introduction The aim of the research was to demonstrate the efficiency of microorganisms and the effectiveness of biodegradation techniques on Low-density polyethylene (LDPE) plastics. The research question was: What is the efficiency of LDPE-degrading microorganisms and the effectiveness of biodegradation techniques? Methods The systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Articles were obtained from Scopus, Web of Science (WOS), Embase, and Google Scholar. The DeCS/Mesh search terms were: Low-density polyethylene, efficiency, biodegradation, microbial consortia, fungi, bacteria. Inclusion criteria were: scientific articles that included bacteria, fungi, and microbial consortia reported as LDPE degraders that report the percentage of weight loss; articles published from January 2010 to October 2022, and publications in Spanish and English with open access. Exclusion criteria were: studies that do not report gravimetry, the biodegradation time of LDPE, and the genus or species of the polyethylene-degrading microorganism. Results Out of 483 studies found, 50 were included in this Systematic Review (SR). The most frequent study techniques were scanning electron microscopy (SEM), gravimetry, and fourier transform infrared spectroscopy (FTIR), and in the case of microorganisms, the most studied belonged to the genus Pseudomonas, Bacillus, and Aspergillus. Regarding the isolation place, the most frequent mentioned in the reviewed articles were landfill soil and sanitary landfill soil. The efficiency of LDPE-degrading microorganisms was higher in bacteria such as Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp., which obtained a range of DE of 9.00-70.00%, 24.00-64%, 1.15 – 61.00%, 45.00%, and 1.5-40% with DT of 4-150, 120, 4-150, 30, and 30-120 days, respectively; in the case of fungi, the main microorganisms are Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii with efficiencies of 54.34, 48.78, and 46.34%, in 90 days, respectively; and the most efficient microbial consortia were from Enterobacter spp. and Pantoea sp. with 38.00 – 81.00%, in 120 days; and, Pseudomonas protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp. with 55. 00 – 75.00% in 120 days. Conclusions The most efficient microorganisms in LDPE degradation are Enterobacter spp., Pantoea spp., Pseudomonas spp., Escherichia coli, and Bacillus spp.; in fungi Neopestalotiopsis phangngaensis, Colletotrichum fructicola, and Thyrostroma jaczewskii; and in microbial consortia, those formed by Enterobacter spp. and Pantoea sp., and that of P. protegens, Stenotrophomonas sp., B. vallismortis and Paenibacillus sp.; and the most effective techniques used in LDPE biodegradation are SEM, gravimetry, and FTIR.

Microbial degradation of petroleum hydrocarbons plays a vital role in mitigating petroleum contamination and heavy oil extraction. In this study, a Saccharomyces cerevisiae capable of degrading hexadecane has been successfully engineered, achieving a maximum degradation rate of up to 20.42%. However, the degradation ability of this strain decreased under various pressure conditions such as high temperature, high osmotic pressure, and acidity conditions. Therefore, a S. cerevisiae with high tolerance to these conditions has been constructed. And then, we constructed an “anti-stress hydrocarbon-degrading” consortium comprising engineered yeast strain SAH03, which degrades hexadecane, and glutathione synthetic yeast YGSH10, which provides stress resistance. This consortium was able to restore the degradation ability of SAH03 under various pressure conditions, particularly exhibiting a significant increase in degradation rate from 5.04% to 17.04% under high osmotic pressure. This study offers a novel approach for improving microbial degradation of petroleum hydrocarbons.

The rise of agro-industrial activities over recent decades has exponentially increased lignocellulose biomasses (LCB) production. LCB serves as a cost-effective source for fermentable sugars and other renewable chemicals. This study explores the use of microbial consortia, particularly thermophilic consortia, for LCB deconstruction. Thermophiles produce stable enzymes that retain activity under industrial conditions, presenting a promising approach for LCB conversion. This research focused on two microbial consortia (i.e., microbiomes) that were analyzed for enzyme production using a cheap medium, i.e., a mixture of spent mushroom substrate (SMS) and digestate. The secreted xylanolytic enzymes were characterized in terms of temperature and pH optima, thermal stability, and hydrolysis products from LCB-derived polysaccharides. These enzymes showed optimal activity aligning with common biorefinery conditions and outperformed a formulated enzyme mixture in thermostability tests in the digestate. Phylogenetic and genomic analyses highlighted the genetic diversity and metabolic potential of these microbiomes. Bacillus licheniformis was identified as a key species, with two distinct strains contributing to enzyme production. The presence of specific glycoside hydrolases involved in the cellulose and hemicellulose degradation underscores these consortia’s capacity for efficient LCB conversion. These findings highlight the potential of thermophilic microbiomes, isolated from an industrial environment, as a robust source of robust enzymes, paving the way for more sustainable and cost-effective bioconversion processes in biofuel and biochemical production and other biotechnological applications.

The objective of this research was to determine the potential use of eco-friendly technologies to reduce the clubroot disease caused by Plasmodiophora brassicae, the main constraint of cruciferous crops worldwide. Two commercial bioproducts were evaluated in susceptible broccoli, one based on the PGPR consortium (Bacillus amyloliquefaciens, Bacillus pumilus, and Agrobacterium radiobacter K84) and the other one based on Trichoderma koningiopsis Th003 (Tricotec® WG). Additionally, the resistant broccoli cv. Monclano® was tested under two concentrations of resting spores (RS) of P. brassicae, 1 x 10³ and 1 x 105 RS g-1 of soil. The first phase of evaluations with broccoli was carried out under a greenhouse, while susceptible broccoli, cauliflower, and red cabbage were included in a subsequent field phase. Tebuconazole + Trifloxystrobin mixture and Fluazinam were included as positive controls. The effectiveness of the bioproducts depended on the nature of the biocontrol agent, the concentration of P. brassicae, and the dose of treatment. Tricotec® showed consistent plant growth promotion but no biocontrol effect against clubroot, and the rhizobacteria-based bioproduct significantly reduced the disease in both greenhouse and field experiments. Higher disease severity was observed with the higher dose of Tricotec®. Under field conditions, the rhizobacteria reduced the incidence progress by 26%, 39%, and 57% under high, medium, and low pressure of the pathogen, respectively. However, no reduction of clubroot severity under high pressure of the pathogen was observed. Complete inhibition of club formation in roots was achieved via the fungicide, but a phytotoxic effect was observed under greenhouse conditions. Fungicides reduced the incidence progress of clubroot, but not the severity under high inoculum pressure in the field. The fungicides, the bacterial treatment, and the combination of bioproducts tended to delay the progress of the disease compared with the negative control and Tricotec alone. The resistant broccoli showed a low level of disease under high concentrations of P. brassicae (less than 10% incidence and up to 2% severity). These results suggested the overall potential of commercial tools based on the PGPR consortium and plant resistance to control P. brassicae. The integration of control measures, the role of Trichoderma spp. in P. brassicae--cruciferous pathosystems, and the need to recover highly infested soils will be discussed. [ABSTRACT FROM AUTHOR]

There has been an exceptional rise in the number of industries in recent times, resulting in a leap in pollution caused, in addition to a large amount of waste being generated. Industrial pollution affects the entire ecosystem, predominantly the air, water, and soil. Remediation of air, water, and soil from industrial pollutants thus becomes a matter of concern due to detrimental effects. Remediation of the wastes generated by the industries has been carried out by several substances. The present research paper discusses with the use of soil microbial consortia for industrial waste bioremediation. Over the past decades studies have being emphasised on the use of microbial consortia rather than the use of individual strains, with increasing consideration given to environmental sustainability, with the aid of interdisciplinary approaches. An in-depth study has been carried out on the different microbes, used for remediation with special focus on soil microbial consortia. The manuscript also describes at length the benefits of the use of these microbes, different contaminants and wastes for which these have been tested, different kinds of microbial consortia explored, and the limitations and advantages associated with the use of these. The present work helps in understanding the use of microbial consortia as an efficient and promising biomaterial with an edge over other materials for industrial waste remediation. A brief study of the patents in the area of the use of soil microbial consortia has also been carried out in the present work. An analysis of the distribution of patents country-wise, technology main areas, patent publication trend, and top patent applicants and inventors has also been carried to give an idea of the patents pertaining to the application of soil microbial consortia. [ABSTRACT FROM AUTHOR]