Fungal community determines soil multifunctionality during vegetation restoration in metallic tailing reservoir.

Microorganisms are pivotal in sustaining soil functions, yet the specific contributions of bacterial and fungal succession on the functions during vegetation restoration in metallic tailing reservoirs remains elusive. Here, we explored bacterial and fungal succession and their impacts on soil multifunctionality along a ∼50-year vegetation restoration chronosequence in China's largest vanadium titano-magnetite tailing reservoir. We found a significant increase in soil multifunctionality, an index comprising factors pertinent to soil fertility and microbially mediated nutrient cycling, along the chronosequence. Despite increasing heavy metal levels, both bacterial and fungal communities exhibited significant increase in richness and network complexity over time. However, fungi demonstrated a slower succession rate and more consistent composition than bacteria, indicating their relatively higher resilience to environmental changes. Soil multifunctionality was intimately linked to bacterial and fungal richness or complexity. Nevertheless, when scrutinizing both richness and complexity concurrently, the correlations disappeared for bacteria but remained robust for fungi. This persistence reveals the critical role of the fungal community resilience in sustaining soil multifunctionality, particularly through their stable interactions with powerful core taxa. Our findings highlight the importance of fungal succession in enhancing soil multifunctionality during vegetation restoration in metallic tailing reservoirs, and manipulating fungal community may expedite ecological recovery of areas polluted with heavy metals.

Biological S0 reduction at neutral and acidic conditions: Performance and microbial community shifts in a H2/CO2-fed bioreactor.

Sulfidogenesis is a promising technology for the selective recovery of chalcophile bulk metals (e.g. Cu, Zn, and Co) from metal-contaminated waters such as acid mine drainage (AMD) and metallurgy waste streams. The use of elemental sulfur (S0) instead of sulfate (SO42-) as electron acceptor reduces electron donor requirements four-fold, lowering process costs, and expanding the range of operating conditions to a more acidic pH. We previously reported autotrophic S0 reduction using an industrial mesophilic granular sludge as inoculum under thermoacidophilic conditions. Here, we examined the effect of pH on the S0 reduction performance of the same inoculum, in a gas-lift reactor run at 30°C under neutral (pH 6.9) and acidic (pH 3.8) conditions, continuously fed with mineral media and H2 and CO2. Steady-state volumetric sulfide production rates (VSPR) dropped 2.5-fold upon transition to acidic pH, from 1.79 ± 0.18 g S2-·L-1·d-1 to 0.71 ± 0.07 g S2-·L-1·d-1. Microbial community composition was analyzed using 16S rRNA gene amplicon sequencing. At neutral pH (6.9), the high relative abundance of the S0-reducing genus Sulfurospirillum, previously known only for heterotrophic members, combined with the presence of Acetobacterium and detection of acetate, suggests an important role for heterotrophic S0 reduction facilitated by acetogenesis. Conversely, at acidic pH (3.9), S0 reduction appeared autotrophic, as indicated by the high relative abundance of Desulfurella.

Enhancing mango yield and soil health with organic and slow-release fertilizers: A multifaceted evaluation.

Excessive utilization of chemical fertilizers in mango orchards not only hampers the attainment of sustainable harvests but also poses significant ecological detriments. This investigation proposes a promising solution by advocating the judicious replacement of chemical fertilizers with organic fertilizer (OF) and slow-release fertilizer (SRF), with potential to bolster soil health and augment crop productivity. In light of the promise held by these alternatives, it is imperative to establish detailed fertilization protocols for enhanced sustainable practices in mango farming. This two-year field study employed a comprehensive suite of seven fertilization strategies, unveiling that a 25 % chemical fertilizers substitution with OF and SRF improved mango yields by 12.5 % and 11.3 %, respectively, over standard practices. Additionally, these approaches substantially augmented the nutritional quality of mangoes, evident from Vitamin C enhancements of 53.9 % to 56.9 %, and improvements in sugar-to-acid ratio (19.2 %-30.3 %) and solid-to-acid ratio (12.1 %-25.3 %). Notably, the application of OF and SRF led to increased leaf nitrogen and phosphorus concentrations, while simultaneously reducing soil phosphorus and potassium levels. Furthermore, these fertilizers fostered the growth of beneficial soil microorganisms, namely Actinobacteria and Proteobacteria, and strengthened the synergy within the soil bacterial community, hence optimizing bacterial competition and nutrient cycling. The study proposes that the adoption of OF or SRF can effectively regulate soil nutrient balance, promote resilient and functional soil bacterial ecosystems, and ultimately improve mango yield and fruit quality. It recommends a fertilization scheme incorporating 25 % organic or slow-release nitrogen to align with ecological sustainability goals, promoting a more vigorous and resilient soil and crop system.

Enterobacter ludwigii b3 in the rhizosphere of wild rice assists cultivated rice in mitigating drought stress by direct and indirect methods.

Drought is the primary factor limiting rice production in ecosystems. Wild rice rhizosphere bacteria possess the potential to assist in the stress resistance of cultivated rice. This study examines the impact of wild rice rhizosphere bacteria on cultivated rice under drought conditions. From the rhizosphere soil of wild rice, 20 potential drought-resistant strains were isolated. Subsequent to the screening, the most effective strain b3, was identified as Enterobacter ludwigii. Pot experiments were conducted on the cultivated Changbai 9 rice. It was found that inoculation with the E. ludwigii b3 strain improved the drought resistance of the rice, promotion of rice growth (shoot height increased by 13.47 %), increased chlorophyll content (chlorophyll a, chlorophyll b and carotenoid increased by 168.74 %, 130.68 % and 87.89 %), improved antioxidant system (content of glutathione was increased by 60.35 %), and accumulation of osmotic regulation substances (soluble sugar and soluble protein increased by 70.36 % and 142.03 %). Furthermore, E. ludwigii b3 had a transformative effect on the rhizosphere bacterial community of cultivated rice, increasing its abundance and diversity while simultaneously recruiting beneficial rhizosphere bacteria, resulting in a more complex community. Additionally, E. ludwigii b3 acted directly and indirectly on cultivated rice through its metabolites (organic acids, amino acids, flavonoids and other substances), which helped alleviate drought stress. In conclusion, the E. ludwigii b3 shows promise as a drought-resistant strain and has the potential to improve the growth and productivity of cultivated rice in arid agricultural ecosystems. This study represents the first investigation of E. ludwigii in the rhizosphere of wild rice under drought conditions on cultivated rice.

Plants Restoration Drives the Gobi Soil Microbial Diversity for Improving Soil Quality.

Desertification and salt stress are major causes of terrestrial ecosystem loss worldwide, and the Gobi, representing a salt-stressed area in inland China, has a major impact on the ecosystems and biodiversity of its surrounding environment. The restoration of the Gobi Desert is an important way to control its expansion, but there are few studies on the evaluation of restoration. In this study, soils under different restoration scenarios, namely, soils in restored areas (R1, R2), semi-restored areas (SR1, SR2), and unrestored control areas (C1, C2), were used to investigate differences in microbial diversity and physicochemical properties. The results showed that the soil was mainly dominated by particles of 4-63 µm (26.45-37.94%) and >63 µm (57.95-72.87%). Across the different restoration levels, the soil pH (7.96-8.43) remained basically unchanged, salinity decreased from 9.23-2.26 to 0.24-0.25, and water content remained constant (10.98-12.27%) except for one restored sample in which it was higher (22.32%). The effective Al, Cu, and Zn in the soil increased, but only slightly. Total organic matter (TOM) decreased from 3.86-5.20% to 1.31-1.47%, and total organic nitrogen (TON) decreased from 0.03-0.06% to 0.01-0.02%, but the difference in total organic carbon (TOC) was not significant. High-throughput testing revealed that the bacterial population of the restored area was dominated by A4b (6.33-9.18%), MND1 (4.94-7.39%), and Vicinamibacteraceae (7.04-7.39%). Regarding archaea, samples from the restored areas were dominated by Marine Group II (76.17-81.49%) and Candidatus Nitrososphaera (6.07-9.75%). PCoA showed that the different restoration levels were the main cause of the differences between the samples. Additionally, salinity was the dominant factor that induced this difference, but it was inhibited by the restoration and targeted enrichment of some of these functional genera. Desert restoration should therefore focus on conserving water rather than adding nutrients. Planting salt- and drought-tolerant vegetation will contribute to the initial restoration of the desert and the restoration of the microbiological content of the soil as it migrates over time, creating a cycle of elements. Restoration stimulates and enhances the microbial diversity of the soil via beneficial microorganisms.

Oxygen regulation of microbial communities and chemical compounds in cigar tobacco curing.

Introduction: Curing is a critical process that determines the sensory quality of cigars. The impact of oxygen on cigar curing and the mechanisms by which it regulates microbial changes affecting cigar quality are not well understood. Methods: In this study, we selected handmade cigars from the same batch and conducted curing experiments in environments with varying oxygen concentrations (equivalent to 0.1%, 6-12, and 15% of atmospheric oxygen concentration). We collected samples over 60 days and analyzed the distribution of microbial communities using high-throughput sequencing. Combined with the analysis of total sugars, proteins, flavor substances, and other chemical compounds, we elucidated how different oxygen concentrations affect the cigar curing process, influence microbial community succession, and ultimately impact cigar quality. Results: Our results revealed significant differences in bacterial community composition under different oxygen conditions. Under aerobic conditions, Cyanobacteria were the dominant bacteria, while under oxygen-limited conditions, Staphylococcus and Corynebacterium predominated. As oxygen concentration decreased, so did the richness and diversity of the bacterial community. Conversely, oxygen concentration had a lesser impact on fungi; Aspergillus was the dominant genus in all samples. We also found that Enterococcus showed a positive correlation with aspartic acid, alanine, and 4-aminobutyric acid and a negative correlation with cysteine. Cigars cured at 15% oxygen concentration for 60 days exhibited optimal quality, particularly in terms of flavor richness and sweetness. Discussion: These findings suggest that oxygen concentration can alter cigar quality by regulating aerobic and anaerobic microbial community succession. The relationship between specific microbial communities and flavor compounds also provides a theoretical reference for developing artificial control technologies in the cigar curing process.

No signs of microbial-influenced corrosion of cast iron and copper in bentonite microcosms after 400 days.

High-level radioactive waste needs to be safely stored for a long time in a deep geological repository by using a multi-barrier system. In this system, suitable barrier materials are selected that ideally show long-term stability to prevent early radionuclide release into the biosphere. In this study, different container matals (copper and cast iron) and pore water compositions (Opalinus Clay pore water and saline cap rock solution) were combined with Bavarian bentonite in static batch experiments to investigate microbial-influenced corrosion. The increasing concentration of iron and copper in the solution as well as detected corrosion products on the metal surface are indicative of anaerobic corrosion of the respective metals during an incubation of 400 days at 37 °C. However, although the intrinsic microbial bentonite community was stimulated with either lactate or H2, an acceleration of cast iron- and copper corrosion did not occur. Furthermore, neither corrosive bacteria nor conventional bacterial corrosion products, such as metal sulfides, were detected in any of the analyzed samples. The analyses of geochemical parameters (e.g. ferrous iron-, iron-, copper- and potassium concentrations as well as redox potentials) showed significant changes in some cast iron- and copper-containing setups, but these changes did not correlate with the microbial community structure in the respective microcosms, as confirmed by statistical analyses. Hence, the analyzed Bavarian bentonite (type B25) showed no significant contribution to cast iron and copper corrosion under the applied conditions after 400 days of incubation. From this perspective, bentonite B25 could be a suitable candidate as a geotechnical barrier in future repositories.

Globally distributed marine Gemmatimonadota have unique genomic potentials.

BACKGROUND: Gemmatimonadota bacteria are widely distributed in nature, but their metabolic potential and ecological roles in marine environments are poorly understood. RESULTS: Here, we obtained 495 metagenome-assembled genomes (MAGs), and associated viruses, from coastal to deep-sea sediments around the world. We used this expanded genomic catalog to compare the protein composition and update the phylogeny of these bacteria. The marine Gemmatimonadota are phylogenetically different from those previously reported from terrestrial environments. Functional analyses of these genomes revealed these marine genotypes are capable of degradation of complex organic carbon, denitrification, sulfate reduction, and oxidizing sulfide and sulfite. Interestingly, there is widespread genetic potential for secondary metabolite biosynthesis across Gemmatimonadota, which may represent an unexplored source of novel natural products. Furthermore, viruses associated with Gemmatimonadota have the potential to "hijack" and manipulate host metabolism, including the assembly of the lipopolysaccharide in their hosts. CONCLUSIONS: This expanded genomic diversity advances our understanding of these globally distributed bacteria across a variety of ecosystems and reveals genetic distinctions between those in terrestrial and marine communities. Video Abstract.

Diversity analyses of bacterial symbionts in four Sclerodermus (Hymenoptera: Bethylidae) parasitic wasps, the dominant biological control agents of wood-boring beetles in China.

Objective: Sclerodermus wasps are important biocontrol agents of a class of wood borers. Bacterial symbionts influence the ecology and biology of their hosts in a variety of ways, including the formation of life-long beneficial or detrimental parasitic infections. However, only a few studies have explored the species and content of the symbionts in the Sclerodermus species. Methods: Here, a high-throughput sequencing study of the V3-V4 region of the 16S ribosomal RNA gene revealed a high level of microbial variety in four Sclerodermus waps, and their diversities and functions were also predicted. Results: The three most prevalent phyla of microorganisms in the sample were Firmicutes, Bacteroides, and Proteus. The KEEG pathways prediction results indicated that the three pathways with the highest relative abundances in the S. sichuanensis species were translation, membrane transport, and nucleotide metabolism. These pathways differed from those observed in S. guani, S. pupariae, and S. alternatusi, which exhibited carbohydrate metabolism, membrane transport, and amino acid metabolism, respectively. Bacteroides were found to be abundant in several species, whereas Wolbachia was the most abundant among S. sichuanensis, with a significant negative correlation between temperature and carriage rate. Conclusions: These results offer insights into the microbial communities associated with the bethylid wasps, which is crucial for understanding how to increase the reproductive capacity of wasps, enhance their parasitic effects, and lower cost in biocontrol.

Spatial distribution of PAHs and microbial communities in intertidal sediments of the Pearl River Estuary, South China.

The exploration of sediment pollution caused by PAHs and its impact on microbial communities can provide valuable insights for the remediation of sediments. The spatial distribution of PAHs and their impact on the microbial community within the Pearl River Estuary were investigated in this study. The findings revealed that the total concentration ranges of 16 PAHs were between 24.26 and 3075.93 ng/g, with naphthalene, fluorene, and phenanthrene potentially exerting adverse biological effects. More PAHs were found to accumulate in subsurface sediments, and their average accumulation rates gradually decreased as the number of rings in PAHs increased, ranging from 180 % for 2-ring to 36 % for 6-ring. The phyla Proteobacteria, Bacteroidetes, Actinobacteria, and Chloroflexi were found to dominate both surface and subsurface sediments The correlation between microbial genera and PAHs contents was weak in sediments with low levels of PAHs contamination, while a more significant positive relationship was observed in sediments with high levels of PAHs contamination. The physicochemical properties of sediments, such as pH, soil structure and Cu significantly influence bacterial community composition in highly contaminated sediments. Additionally, the network analysis revealed that certain bacterial genera, including Novosphingobium, Robiginitalea and Synechococcus_CC9902, played a pivotal role in the degradation of PAHs. These findings are significant in comprehending the correlation between bacterial communities and environmental factors in intertidal ecosystems, and establish a scientific foundation for bioremediation of intertidal zones.

Topography- and depth-dependent rhizosphere microbial community characteristics drive ecosystem multifunctionality in Juglans mandshurica forest.

Rhizosphere microbial community characteristics and ecosystem multifunctionality (EMF), both affected by topographic factors, are closely correlated. However, more targeted exploration is yet required to fully understand the variations of rhizosphere microbial communities along topographic gradients in different soil layers, as well as whether and how they regulate EMF under specific site conditions. Here, we conducted relevant research on Juglans mandshurica forests at six elevation gradients and two slope positions ranging from 310 to 750 m in Tianjin Baxian Mountain. Results demonstrated that rhizosphere soil physicochemical properties and enzyme activities of both layers (0-20 cm and 20-40 cm) varied significantly with elevation, while only at top layer did slope position have significant impacts on most indicators. Bacterial richness and diversity were higher in the top layer at slope bottom and middle-high elevation, the difference in fungi was not as noticeable. Both topographic factors and soil depth significantly impacted microbial community structure, with Candidatus_Udaeobacter of bacteria, Mortierella, Sebacina, and Hygrocybe of fungi mainly contributing to the dissimilarity between communities. EMF rose with increasing elevation, bacteria were more critical drivers of this process than fungi, and topographic factors could affect EMF by altering bacterial diversity and dominant taxa abundance. For evaluating EMF, the aggregate structure of sub layer and the carbon cycle-related indicators of top layer were of higher importance. Our results revealed the depth-dependent characteristics of the rhizosphere microbial community along topographic gradients in studied stands, as well as the pivotal regulatory role of bacteria on EMF, while also highlighting depth as an important variable for analyzing soil properties and EMF. This work helps us better understand the response of individuals and communities of J. mandshurica to changing environmental conditions, further providing a scientific reference for the management and protection of secondary forests locally and in North China.

Deciphering Indigenous Bacterial Diversity of Co-Polluted Sites to Unravel Its Bioremediation Potential: A Metagenomic Approach.

Polluted drains across the globe are affected due to reckless disposal of untreated industrial effluents resulting in significant water pollution affecting microbial community structure/dynamics. To elucidate this, polluted samples were collected from Budha Nala (BN) drain, Tung Dhab (TD) drain, and wastewater treatment plant (WWTP) receiving an inflow of organic pollutants as well as heavy metals due to anthropogenic activities. The sample of unpolluted pristine soil (PS) was used as control, as there is no history of usage of organic chemicals at this site. The bacterial diversity of these samples was sequenced using the Illumina MiSeq platform by amplifying the V3/V4 region of 16S rRNA. The majority of operational taxonomic unit (OTUs) at polluted sites belonged to phyla Proteobacteria specifically Gammaproteobacteria class, followed by Actinobacteria, Bacteriodetes, Chloroflexi, Firmicutes, Planctomycetes, WS6, and TM7, whereas unpolluted site revealed the prevalence of Proteobacteria followed by Actinobacteria, Planctomycetes, Firmicutes, Acidobacteria, Chloroflexi, Bacteroidetes, Verrucomicrobia, and Nitrospirae. The data sets decode unclassified species of the phyla Proteobacteria, Bacteriodetes, Chloroflexi, Firmicutes, and WS6, along with some unclassified bacterial species. The study provided a comparative study of changed microbial community structure, their possible functions across diverse geographical locations, and identifying specific bacterial genera as pollution bio-indicators of aged polluted drains.

Dysbiosis and interactions of the mycobiome and bacteriome in mucosal lesions of erosive and non-erosive oral lichen planus patients.

Background: Oral lichen planus (OLP) is a common oral mucosal disease, clinically categorized into erosive OLP (EOLP) and non-erosive OLP (NEOLP) based on symptoms, but its pathogenic mechanism remains unclear. This study aims to explore the relationship between OLP and the oral microbiome. Methods: We collected oral mucosal samples from 49 patients and 10 healthy individuals and conducted 16S rRNA and ITS gene sequencing to explore the oral fungal and bacterial communities. Results: We observed significantly lower α diversity of fungi in the EOLP group, with Candida being significantly enriched as the main dominant genus. In the NEOLP group, Aspergillaceae were significantly enriched. The EOLP group showed significant enrichment of Aggregatibacter and Lactobacillus, but the relative abundance of Streptococcus was notably lower than in the other two groups. In the NEOLP group, two species including Prevotella intermedia were significantly enriched. The microbial co-occurrence and co-exclusion networks display distinct characteristics across the three groups, with Lactobacillus assuming a significant bridging role in the ELOP group. Conclusions: Our study indicates that EOLP and NEOLP experience varying degrees of dysbiosis at both the fungal and bacterial levels. Therefore, the pathogenic mechanisms and interactive relationships of these microbiota associated with OLP merit further in-depth investigation.

The microbial community in the oral lesions of EOLP patients exhibits highly distinctive features, both in terms of bacteria and fungi.In NEOLP patients, the overall bacterial composition does not exhibit significant differences compared to the healthy population, but P. intermedia and Aspergillaceae are notably enriched.

Exploration of gut microbial diversity of pheasants through pyrosequencing of 16S rRNA gene.

Despite the diversity of microbiota in birds is similar to that of other animals, there is a lack of research on the gut microbial diversity of nondomesticated bird species. This study aims to address this gap in knowledge by analyzing the bacterial communities present in the gut of two important game bird species, the Ring-necked pheasant (Phasianus colchicus) and the Green pheasant (Phasianus versicolor) to understand the gut microbial diversity of these species. The gut microbiome of 10 individual pheasants from two different species was studied using pooled fecal samples. We used 16S rRNA gene sequencing on the Ion S5 XL System next-generation sequencing with Mothur and SILVA Database for taxonomic division. An average of 141 different operational taxonomic units were detected in the gut microbiome. Analysis of microbial classification revealed the presence of 191 genera belonging to 12 different phyla in both pheasants. Alpha diversity indices revealed that P. colchicus exhibited most prevalence firmicutes with bacillus species microbial community than P. versicolor. Alpha diversity indices indicated that P. colchicus had a more diverse community and P. versicolor had a greater diversity of evolutionary lineages, while both species had similar levels of species richness and sample inclusiveness. These findings may have implications for the health and well-being of pheasants, serving as a reference for their bacterial diversity. Additionally, they provide a baseline for future research and conservation efforts aimed at improving the health and well-being of these and possibly other avian species.

Differential responses of soil bacteria, fungi and protists to root exudates and temperature.

The impact of climate warming on soil microbes has been well documented, with studies revealing its effects on diversity, community structure and network dynamics. However, the consistency of soil microbial community assembly, particularly in response to diverse plant root exudates under varying temperature conditions, remains an unresolved issue. To address this issue, we employed a growth chamber to integrate temperature and root exudates in a controlled experiment to examine the response of soil bacteria, fungi, and protists. Our findings revealed that temperature independently regulated microbial diversity, with distinct patterns observed among bacteria, fungi, and protists. Both root exudates and temperature significantly influenced microbial community composition, yet interpretations of these factors varied among prokaryotes and eukaryotes. In addition to phototrophic bacteria and protists, as well as protistan consumers, root exudates determined to varying degrees the enrichment of other microbial functional guilds at specific temperatures. The effects of temperature and root exudates on microbial co-occurrence patterns were interdependent; root exudates primarily simplified the network at low and high temperatures, while responses to temperature varied between single and mixed exudate treatments. Moreover, temperature altered the composition of keystone species within the microbial network, while root exudates led to a decrease in their number. These results emphasize the substantial impact of plant root exudates on soil microbial community responses to temperature, underscoring the necessity for future climate change research to incorporate additional environmental variables.

Challenges in water kefir production and limitations in human consumption: A comprehensive review of current knowledge.

Water kefir is a convenient dairy-free alternative to dairy-based fermented beverages. It is prepared by fermenting a sucrose solution with fresh and dried fruits using water kefir grains, and demineralized whey can be used in water kefir production. This review describes current knowledge on water kefir production and its health effects. The main aims of this paper are to focus on the microbial composition, potential health-promoting properties, limitations in human consumption, and challenges in the production of water kefir. Water kefir grains and substrates, including brown sugar, dried and fresh fruits, vegetables, and molasses, used in the production influence the fermentation characteristics and composition of water kefir. Lactic acid bacteria, acetic acid bacteria, and yeasts are the microorganisms involved in the fermentation process. Lactobacillus species are the most common microorganisms found in water kefir. Water kefir contains various bioactive compounds that have potential health benefits. Water kefir may inhibit the growth of certain pathogenic microorganisms and food spoilage bacteria, resulting in various health-promoting properties, including immunomodulatory, antihypertensive, anti-inflammatory, anti-ulcerogenic, antiobesity, hypolipidemic, and hepatoprotective activities.

Effect of harvesting season and location on the microbial quality and community composition of the edible sea urchin (Echinus esculentus) gonads.

Despite the crucial role of microbial community composition in the quality and stability of seafood, little emphasis has been given to the microbiota profile of sea urchin gonads. This study investigates the microbial quality and community composition of sea urchin gonads (Echinus esculentus) as a function of harvesting season (autumn, winter, spring, and summer) and location (one site proximal to urban activity areas while the other is located in open water close to the coastline). Significant season-dependent variations were found in psychrotrophic and aerobic plate counts, with higher counts in summer, followed by autumn, spring, and winter. H2S-producing bacteria and Pseudomonas spp. counts were unaffected by harvesting season or location. Sea urchin gonad microbial composition proved resilient and dynamic, primarily shaped by seasonal variations, and minimally influenced by location. Winter and spring samples exhibited higher diversity than autumn and summer. Key genera like Pseudomonas, Psychromonas, Vibrio, Chryseobacterium, Shewanella, and Photobacterium varied seasonally. Pseudomonas, Vibrio, and Photobacterium are crucial in assessing microbial quality and safety due to their roles as specific spoilage organisms (SSOs) and, in some cases, human pathogens. Though relative abundances differed slightly between locations, harvesting location did not notably impact microbial community shaping in gonads. However, the results suggest that harvesting locations near areas with urban activity may lead to contamination with specific bacterial species, possibly due to water quality variations. These findings emphasize the importance of considering seasonality when evaluating sea urchin gonad microbial quality. Identifying key genera enhances insights into potential SSOs and human pathogens, enhancing food safety considerations in the consumption of raw or lightly processed sea urchin gonads and guiding the development of preservation methods to extend shelf life.

Nutritional and microbial profiles of ripened plant-based cheese analogs collected from the European market.

Plant-based cheese analogs have emerged as a novel global market trend driven by sustainability concerns for our planet. This study examines eleven soft ripened plant-based cheese analogs produced in Europe, primarily with bloomy rinds and cashew nuts as the main ingredient. First, we focused on exploring the macronutrients and salt content stated on the labels, as well a detailed fatty acid analysis of the samples. Compared to dairy cheeses, plant-based cheeses share similarities in lipid content, but their fatty acid profiles diverge significantly, with higher ratio of mono- and polyunsaturated fatty acids such as oleic and linoleic acids. We also investigated the microbiota of these analog products, employing a culture-dependent and -independent approaches. We identified a variety of microorganisms in the plant-based cheeses, with Lactococcus lactis and Leuconostoc mesenteroides being the dominant bacterial species, and Geotrichum candidum and Penicillium camemberti the dominant fungal species. Most of the species characterized are similar to those present in dairy cheeses, suggesting that they have been inoculated as culture starters to contribute to the sensorial acceptance of plant-based cheeses. However, we also identify several species that are possibly intrinsic to plant matrices or originate from the production environment, such as Pediococcus pentosaceus and Enterococcus spp. This coexistence of typical dairy-associated organisms with plant associated species highlights the potential microbial dynamics inherent in the production of plant-based cheese. These findings will contribute to a better understanding of plant-based cheese alternatives, enable the development of sustainable products, and pave the way for future research exploring the use of plant-based substrates in the production of cheese analogues.

New insights into assembly processes and driving factors of urban soil microbial community under environmental stress in Beijing.

Rapid urbanization leads to drastic environmental changes, directly or indirectly affecting the structure and function of soil microbial communities. However, the ecological response of soil microbes to environmental stresses has not yet been fully explored. In this study, we used high-throughput sequencing to analyze the assembly mechanism and driving factors of soil microbial community under environmental stresses. The results indicated that environmental stresses significantly affected soil properties and the levels of beryllium, cobalt, antimony, and vanadium contamination in soil generally increased from the suburban areas toward the city core. The composition and distribution of soil microbial communities demonstrated clear differences under different levels of environmental stress, but there was no significant difference in microbial diversity. Random forest and partial least squares structural equation modeling results suggested that multiple factors influenced microbial diversity, but antimony was the key driver. The influence of environmental stress led to deterministic processes dominating microbial community assembly processes, which promoted the regional homogenization of soil microbes. Therefore, this study provides new insights into urban soil microbial management under environmental stresses.