Environmentally Relevant Antibiotic Concentrations Exert Stronger Selection Pressure on River Biofilm Resistomes than AMR-Reservoir Effluents.

Freshwater environments are primary receiving systems of wastewater and effluents, which carry low concentrations of antibiotics and antimicrobial-resistant (AMR) bacteria and genes. Aquatic microbial communities are thus exposed to environmentally relevant concentrations of antibiotics (ERCA) that presumably influence the acquisition and spread of environmental AMR. Here, we analyzed ERCA exposure with and without the additional presence of municipal wastewater treatment plant effluent (W) and swine manure run-off (M) on aquatic biofilm resistomes. Microscopic analyses revealed decreased taxonomic diversity and biofilm structural integrity, while metagenomic analysis revealed an increased abundance of resistance, virulence, and mobile element-related genes at the highest ERCA exposure levels, with less notable impacts observed when solely exposed to W or M effluents. Microbial function predictions indicated increased gene abundance associated with energy and cell membrane metabolism and heavy metal resistance under ERCA conditions. In silico predictions of increased resistance mechanisms did not correlate with observed phenotypic resistance patterns when whole communities were exposed to antimicrobial susceptibility testing. This reveals important insight into the complexity of whole-community coordination of physical and genetic responses to selective pressures. Lastly, the environmental AMR risk assessment of metagenomic data revealed a higher risk score for biofilms grown at sub-MIC antibiotic conditions.

Submerged fermentation of lentil protein isolate and its impact on protein functionality, nutrition, and volatile profiles.

Fermentation of pulses as a clean processing technique has been reported to have a favorable impact on the functional and nutritional quality of the starting materials. Compared to commonly fermented pulses such as peas and chickpeas, limited information is available on the effect of fermentation on lentils, especially when using a high protein isolate (>80% protein) as compared to seeds or flours. Therefore, in the present work, lentil protein isolate was used as a feedstock for submerged fermentation with Aspergillus niger, Aspergillus oryzae, or Lactobacillus plantarum. After 48 h, the samples showed increased protein content with enhanced solubility and oil-holding capacity. Controlled fermentation, as opposed to spontaneous fermentation, maintained the high foaming capacity; however, all fermented samples had lower foam and emulsion stabilizing properties and reduced water-holding capacity compared to the control. The fermented proteins were also less digestible, possibly due to an increase in phenolics and saponins. New volatile compounds were identified in fermented samples that show promise for improved sensory attributes. Significant differences were observed in specific quality attributes depending on the microbial strain used. Further research is required to better understand the fermentative metabolism of microbial communities when provided high-protein lentil ingredients as growth substrates. PRACTICAL APPLICATION: Fermented lentil protein isolate has promising flavor profiles that may improve its sensory properties for food application.

Sub-MIC antibiotics influence the microbiome, resistome and structure of riverine biofilm communities.

The effects of sub-minimum inhibitory concentrations (sub-MICs) of antibiotics on aquatic environments is not yet fully understood. Here, we explore these effects by employing a replicated microcosm system fed with river water where biofilm communities were continuously exposed over an eight-week period to sub-MIC exposure (1/10, 1/50, and 1/100 MIC) to a mix of common antibiotics (ciprofloxacin, streptomycin, and oxytetracycline). Biofilms were examined using a structure-function approach entailing microscopy and metagenomic techniques, revealing details on the microbiome, resistome, virulome, and functional prediction. A comparison of three commonly used microbiome and resistome databases was also performed. Differences in biofilm architecture were observed between sub-MIC antibiotic treatments, with an overall reduction of extracellular polymeric substances and autotroph (algal and cyanobacteria) and protozoan biomass, particularly at the 1/10 sub-MIC condition. While metagenomic analyses demonstrated that microbial diversity was lowest at the sub-MIC 1/10 antibiotic treatment, resistome diversity was highest at sub-MIC 1/50. This study also notes the importance of benchmarking analysis tools and careful selection of reference databases, given the disparity in detected antimicrobial resistance genes (ARGs) identity and abundance across methods. Ultimately, the most detected ARGs in sub-MICs exposed biofilms were those that conferred resistance to aminoglycosides, tetracyclines, ß-lactams, sulfonamides, and trimethoprim. Co-occurrence of microbiome and resistome features consistently showed a relationship between Proteobacteria genera and aminoglycoside ARGs. Our results support the hypothesis that constant exposure to sub-MICs antibiotics facilitate the transmission and promote prevalence of antibiotic resistance in riverine biofilms communities, and additionally shift overall microbial community metabolic function.

Snapshot of proteomic changes in Aspergillus oryzae during various stages of fermentative processing of pea protein isolate.

Pea (Pisum sativum) is one of the most abundant and sustainable alternate source of protein. Although pea proteins have good quantities of most of the essential amino acids, they have a limited supply of tryptophan, methionine and cysteine. Moreover, pea proteins have poor techno-functional properties compared to proteins from animal sources, limiting their use in certain food applications. Bioprocessing techniques like solid-state fermentation (SSF) and enzymatic processing have been explored to improve the nutrient profile and functionality of pea proteins. However, there is a lack of information about proteomic changes in the food matrix during fermentation of the pea substrate. In this research, samples during SSF of pea protein isolate with Aspergillus oryzae were used for shotgun mass spectrometry (LC-MS/MS) analysis to identify the underlying functional pathways which play direct or indirect roles in enabling the colonization of the substrate leading to potential improvement of functional and nutritional value of pea protein. Results revealed the identity of A. oryzae proteins involved in different metabolic pathways that differed during various stages of SSF. Among them, methionine synthase was identified as an abundant protein, which catalyzes methionine biosynthesis. This might suggest how fermentation processes could be used to improve the presence of sulfur containing amino acids to rebalance the essential amino acid profile and improve the nutritional quality of pea proteins.

Impact of Raised without Antibiotics Measures on Antimicrobial Resistance and Prevalence of Pathogens in Sow Barns.

The growing concern over the emergence of antimicrobial resistance (AMR) in animal production as a result of extensive and inappropriate antibiotic use has prompted many swine farmers to raise their animals without antibiotics (RWA). In this study, the impact of implementing an RWA production approach in sow barns on actual on-farm antibiotic use, the emergence of AMR, and the abundance of pathogens was investigated. Over a 13-month period, fecal and nasopharynx samples were collected at 3-month intervals from sows raised in RWA barns and sows in conventional barns using antibiotics in accordance with the new regulations (non-RWA). Whole genome sequencing (WGS) was used to determine the prevalence of AMR and the presence of pathogens in those samples. Records of all drug use from the 13-month longitudinal study indicated a significant reduction in antimicrobial usage in sows from RWA barns compared to conventional non-RWA barns. Antifolates were commonly administered to non-RWA sows, whereas ß-lactams were widely used to treat sows in RWA barns. Metagenomic analyses demonstrated an increased abundance of pathogenic Actinobacteria, Firmicutes, and Proteobacteria in the nasopharynx microbiome of RWA sows relative to non-RWA sows. However, WGS analyses revealed that the nasal microbiome of sows raised under RWA production exhibited a significant increase in the frequency of resistance genes coding for ß-lactams, MDR, and tetracycline.

Optimization of Atmospheric Cold Plasma Treatment with Different Gases for Reduction of Escherichia coli in Wheat Flour.

In this study we aimed to derive the response surface models for Escherichia coli reduction in wheat flour using atmospheric cold plasma (ACP) with three types of gas. The jet-type atmospheric cold plasma wand system was used with a 30 W power supply, and three gases (argon, air, and nitrogen) were applied as the treatment gas. The operating parameters for process optimization considered were wheat flour mass (g), treatment time (min), and gas flow rate (L/min). The wheat flour samples were artificially contaminated with E. coli at a concentration of 9.25 ± 0.74 log CFU/g. ACP treatments with argon, air, and nitrogen resulted in 2.66, 4.21, and 5.55 log CFU/g reduction of E. coli, respectively, in wheat flour under optimized conditions. The optimized conditions to reduce E. coli were 0.5 g of the flour mass, 15 min of treatment time, and 0.20 L/min of nitrogen gas flow rate, and the predicted highest reduction level from modeling was 5.63 log CFU/g.

Huddling together to survive: Population density as a survival strategy of non-spore forming bacteria under nutrient starvation and desiccation at solid-air interfaces.

Acclimation and flexible response mechanisms are survival adaptations allowing prokaryotic cells to colonize diverse habitats and maintain viability in nature. Lack of water significantly impacts cellular response, which can be partially compensated for through community interactions and accessing survival means beyond the cell's boundaries. In the present study, higher numbers of cultivable Gram-positive Arthrobacter sp. and Gram-negative Pseudomonas stutzeri cells were found on surfaces when high population density was used after prolonged periods of desiccation and nutrient starvation. Total cell counts during desiccation periods decreased slower than culturable cell counts independently from initial population density. The presence of homogenate, prepared by filtering homogenized cultures through a 0.2 µm filter, extended culturability of Arthrobacter sp. cells, while intact heat-killed cells extended the culturability of Arthrobacter sp. and P. stutzeri. Our results suggest very slow cell membrane breakdown for desiccated bacterial cells at solid-air interfaces over extended time spans, which may serve as reservoirs of nutrients, and may potentially provide trace amounts of water for surviving cells. Higher initial population density and recycling of resources from "zombie"-like cells, may support growth in a similar fashion as access to cell lysates or the contents of heat-killed cells analogous to dead-phase cultures where some cells experience cryptic growth.

Draft Genome Sequence of Polaromonas eurypsychrophila AER18D-145, Isolated from a Uranium Tailings Management Facility in Northern Saskatchewan, Canada.

The 4.8-Mbp draft genome sequence of Polaromonas eurypsychrophila AER18D-145, isolated from a uranium tailings management facility, is reported. The sequence may provide insights into the mechanisms of the hypertolerance of this strain to extreme conditions and help determine its potential for bioremediation applications.

Multilayer photonic films based on interlocked chiral-nematic cellulose nanocrystals in starch/chitosan.

In this study, a new approach to employ and control cellulose nanocrystal (CNC) chiral nematic structure as a biodegradable, intelligent material was investigated. Tuned CNC self-assembled films were interlocked between two layers of citric acid, cross-linked starch/chitosan (1:1) films through the solvent casting process. This method increased the mechanical properties of produced films and created a selective reflection band from UV to near-IR depending on the helical pitch of the chiral nematic CNC layer. The features of these intelligent films have potential for different applications, from UV protective packaging to biomedical uses. The water vapor permeability (WVP) of the produced films decreased considerably by adding a CNC layer into the cross-linked starch/chitosan structure. Also, the WVP was different for the different helical pitches of the CNC layer. The starch/chitosan (outer layer) also showed a remarkable antibacterial property against E. coli, P. fluorescens, S. Enteritidis, and S. aureus which could be useful for biomedical applications or antibacterial packaging.

Environmental Biofilms as Reservoirs for Antimicrobial Resistance.

Characterizing the response of microbial communities to a range of antibiotic concentrations is one of the strategies used to understand the impact of antibiotic resistance. Many studies have described the occurrence and prevalence of antibiotic resistance in microbial communities from reservoirs such as hospitals, sewage, and farm feedlots, where bacteria are often exposed to high and/or constant concentrations of antibiotics. Outside of these sources, antibiotics generally occur at lower, sub-minimum inhibitory concentrations (sub-MICs). The constant exposure to low concentrations of antibiotics may serve as a chemical "cue" that drives development of antibiotic resistance. Low concentrations of antibiotics have not yet been broadly described in reservoirs outside of the aforementioned environments, nor is the transfer and dissemination of antibiotic resistant bacteria and genes within natural microbial communities fully understood. This review will thus focus on low antibiotic-concentration environmental reservoirs and mechanisms that are important in the dissemination of antibiotic resistance to help identify key knowledge gaps concerning the environmental resistome.

Piglet Gut and in-Barn Manure from Farms on a Raised without Antibiotics Program Display Reduced Antimicrobial Resistance but an Increased Prevalence of Pathogens.

In response to new stringent regulations in Canada regarding the use of antibiotics in animal production, many farms have implemented practices to produce animals that are raised without antibiotics (RWA) from birth to slaughter. This study aims to assess the impact of RWA production practices on reducing the actual total on-farm use of antibiotics, the occurrence of pathogens, and the prevalence of antimicrobial resistance (AMR). A 28-month longitudinal surveillance of farms that adopted the RWA program and conventional farms using antibiotics in accordance with the new regulations (non-RWA) was conducted by collecting fecal samples from 6-week-old pigs and composite manure from the barn over six time points and applying whole-genome sequencing (WGS) to assess the prevalence of AMR genes as well as the abundance of pathogens. Analysis of in-barn drug use records confirmed the decreased consumption of antibiotics in RWA barns compared to non-RWA barns. WGS analyses revealed that RWA barns had reduced the frequency of AMR genes in piglet feces and in-barn manure. However, metagenomic analyses showed that RWA barns had a significant increase in the frequency of pathogenic Firmicutes in fecal samples and pathogenic Proteobacteria in barn manure samples.

Prediction of bacterial functional diversity in clay microcosms.

Microorganisms in clay barriers could affect the long-term performance of waste containers in future deep geological repositories (DGR) for used nuclear fuel through production of corrosive metabolites (e.g., sulfide), which is why clay materials are highly compacted: to reduce both physical space and access to water for microorganisms to grow. However, the highly compacted nature of clays and the resulting low activity or dormancy of microorganisms complicate the extraction of biomarkers (i.e., PLFA, DNA etc.) from such barriers for predictive analysis of microbial risks. In order to overcome these challenges, we have combined culture- and 16S rRNA gene amplicon sequencing-based approaches to describe the functional diversity of microorganisms in several commercial clay products, including two different samples of Wyoming type MX-80 bentonite (Batch 1 and Batch 2), the reference clay for a future Canadian DGR, and Avonlea type Canaprill, a clay sample for comparison. Microorganisms from as-received bentonites were enriched in anoxic 10% w/v clay microcosms for three months at ambient temperature with addition of 10% hydrogen along with presumable indigenous organics and sulfate in the clay. High-throughput sequencing of 16S rRNA gene fragments indicated a high abundance of Gram-positive bacteria of the phylum Firmicutes (82%) in MX-80 Batch 1 incubations. Bacterial libraries from microcosms with MX-80 Batch 2 were enriched with Firmicutes (53%) and Chloroflexi (43%). Firmicutes also significantly contributed (<15%) to the bacterial community in Canaprill clay microcosm, which was dominated by Gram-negative Proteobacteria (>70%). Sequence analysis revealed presence of the bacterial families Peptostreptococcaceae, Clostridiaceae, Peptococcaceae, Bacillaceae, Enterobacteriaceae, Veillonellaceae, Tissierellaceae and Planococcaceae in MX-80 Batch 1 incubations; Bacillaceae, along with unidentified bacteria of the phylum Chloroflexi, in MX-80 Batch 2 clay microcosms, and Pseudomonadaceae, Hydrogenophilaceae, Bacillaceae, Desulfobacteraceae, Desulfobulbaceae, Peptococcaceae, Pelobacteraceae, Alcaligenaceae, Rhodospirillaceae in Canaprill microcosms. Exploration of potential metabolic pathways in the bacterial communities from the clay microcosms suggested variable patterns of sulfur cycling in the different clays with the possible prevalence of bacterial sulfate-reduction in MX-80 bentonite, and probably successive sulfate-reduction/sulfur-oxidation reactions in Canaprill microcosms. Furthermore, analysis of potential metabolic pathways in the bentonite enrichments suggested that bacteria with acid-producing capabilities (i.e., fermenters and acetogens) together with sulfide-producing prokaryotes might perhaps contribute to corrosion risks in clay systems. However, the low activity or dormancy of microorganisms in highly compacted bentonites as a result of severe environmental constraints (e.g., low water activity and high swelling pressure in the confined bentonite) in situ would be expected to largely inhibit bacterial activity in highly compacted clay-based barriers in a future DGR.

Antimicrobial Biodegradable Food Packaging Based on Chitosan and Metal/Metal-Oxide Bio-Nanocomposites: A Review.

Finding a practical alternative to decrease the use of conventional polymers in the plastic industry has become an acute concern since industrially-produced plastic waste, mainly conventional food packaging, has become an environmental crisis worldwide. Biodegradable polymers have attracted the attention of researchers as a possible alternative for fossil-based plastics. Chitosan-based packaging materials, in particular, have become a recent focus for the biodegradable food packaging sector due to their biodegradability, non-toxic nature, and antimicrobial properties. Chitosan, obtained from chitin, is the most abundant biopolymer in nature after cellulose. Chitosan is an ideal biomaterial for active packaging as it can be fabricated alone or combined with other polymers as well as metallic antimicrobial particles, either as layers or as coacervates for examination as functional components of active packaging systems. Chitosan-metal/metal oxide bio-nanocomposites have seen growing interest as antimicrobial packaging materials, with several different mechanisms of inhibition speculated to include direct physical interactions or chemical reactions (i.e., the production of reactive oxygen species as well as the increased dissolution of toxic metal cations). The use of chitosan and its metal/metal oxide (i.e., titanium dioxide, zinc oxide, and silver nanoparticles) bio-nanocomposites in packaging applications are the primary focus of discussion in this review.

Draft Genome Sequence of Arthrobacter sp. Strain 260, Isolated from a Uranium Tailings Management Facility in Northern Saskatchewan, Canada.

The 3.9-Mbp draft genome sequence of Arthrobacter sp. strain 260, which was isolated from a uranium tailings management facility, is reported. The sequence may help determine the bioremediation potential of this strain and facilitate further research aimed at a better understanding of the hypertolerance of this genus to extreme conditions.

Impact of sample collection on prokaryotic and eukaryotic diversity of niche environments of the oil-sand mining impacted Athabasca River.

Microbial communities are an important aspect of overall riverine ecology; however, appreciation of the effects of anthropogenic activities on unique riverine microbial niches, and how the collection of these samples affects the observed diversity and community profile is lacking. We analyzed prokaryotic and eukaryotic communities from surface water, biofilms, and suspended load niches along a gradient of oil sands-related contamination in the Athabasca River (Alberta, Canada), with suspended load or particle-associated communities collected either via Kenney Sampler or centrifugation manifold. At the phylum level, different niche communities were highly similar to each other and across locations. However, there were significant differences in the abundance of specific genera among the different niches and across sampling locations. A generalized linear model revealed that use of the Kenney Sampler resulted in more diverse bacterial and eukaryotic suspended load community than centrifugal collection, though suspended load communities collected by any means remained stably diverse across locations. Although there was an influence of water quality parameters on community composition, all sampled sites support diverse bacterial and eukaryotic communities regardless of the degree of contamination, highlighting the need to look beyond ecological diversity as a means of assessing ecological perturbations, and consider collecting samples from multiple niche environments.

Transcriptomics reveal core activities of the plant growth-promoting bacterium Delftia acidovorans RAY209 during interaction with canola and soybean roots.

The plant growth-promoting rhizobacterium Delftia acidovorans RAY209 is capable of establishing strong root attachment during early plant development at 7 days post-inoculation. The transcriptional response of RAY209 was measured using RNA-seq during early (day 2) and sustained (day 7) root colonization of canola plants, capturing RAY209 differentiation from a medium-suspended cell state to a strongly root-attached cell state. Transcriptomic data was collected in an identical manner during RAY209 interaction with soybean roots to explore the putative root colonization response to this globally relevant crop. Analysis indicated there is an increased number of significantly differentially expressed genes between medium-suspended and root-attached cells during early soybean root colonization relative to sustained colonization, while the opposite temporal pattern was observed for canola root colonization. Regardless of the plant host, root-attached RAY209 cells exhibited the least amount of differential gene expression between early and sustained root colonization. Root-attached cells of either canola or soybean roots expressed high levels of a fasciclin gene homolog encoding an adhesion protein, as well as genes encoding hydrolases, multiple biosynthetic processes, and membrane transport. Notably, while RAY209 ABC transporter genes of similar function were transcribed during attachment to either canola or soybean roots, several transporter genes were uniquely differentially expressed during colonization of the respective plant hosts. In turn, both canola and soybean plants expressed genes encoding pectin lyase and hydrolases - enzymes with purported function in remodelling extracellular matrices in response to RAY209 colonization. RAY209 exhibited both a core regulatory response and a planthost-specific regulatory response to root colonization, indicating that RAY209 specifically adjusts its cellular activities to adapt to the canola and soybean root environments. This transcriptomic data defines the basic RAY209 response as both a canola and soybean commercial crop and seed inoculant.

A health metadata-based management approach for comparative analysis of high-throughput genetic sequences for quantifying antimicrobial resistance reduction in Canadian hog barns.

New Canadian regulations have required that all use of antibiotics in livestock animal production should be under veterinary prescription and oversight, while the prophylactic use and inclusion of these agents in animal feed as growth promoters are also banned. In response to this new rule, many Canadian animal producers have voluntarily implemented production practices aimed at producing animals effectively while avoiding the use of antibiotics. In the swine industry, one such program is the 'raised without antibiotics' (RWA) program. In this paper, we describe a comprehensive investigative methodology comparing the effect of the adoption of the RWA approach with non-RWA pig production operations where antibiotics may still be administered on animals as needed. Our experimental approach involves a multi-year longitudinal investigation of pig farming to determine the effects of antibiotic usage on the prevalence of antimicrobial resistance (AMR) and pathogen abundance in the context of the drug exposures recorded in the RWA versus non-RWA scenarios. Surveillance of AMR and pathogens was conducted using whole-genome sequencing (WGS) in conjunction with open source tools and data pipeline analyses, which inform on the resistome, virulome and bacterial diversity in animals and materials associated with the different types of barns. This information was combined and correlated with drug usage (types and amounts) over time, along with animal health metadata (stage of growth, reason for drug use, among others). The overarching goal was to develop a set of interconnected informatic tools and data management procedures wherein specific queries could be made and customized, to reveal statistically valid cause/effect relationships. Results demonstrating possible correlations between RWA and AMR would support the Canadian pig industry, as well as regulatory agencies in new efforts, focused on reducing overall antibiotics use and in curbing the development and spread of AMR related to animal agriculture.

Production of glycerol by Lactobacillus plantarum NRRL B-4496 and formation of hexamine during fermentation of pea protein enriched flour.

Suspensions of pea protein enriched flour (PP) inoculated with Lactobacillus plantarum NRRL B-4496 and uninoculated PP suspensions were incubated in vials covered with airtight caps. Organic compound compositions of fermented and unfermented PP suspensions (F-PP and U-PP, respectively) were analyzed using solid phase microextraction (SPME) coupled with gas chromatography - mass-spectrometry (GCMS). Acetic acid was detected in all samples; pH dropped from pH 6.5 to pH 4.1 in L. plantarum F-PP and to pH 5.3 in uninoculated F-PP. Abundance of acetic acid and minuscule presence of lactic acid in L. plantarum F-PP suggested that fermentation proceeded preferentially via the pyruvate formate lyase (PFL) pathway. Nonetheless, glycerol appeared to be the most abundant compound in L. plantarum F-PP samples; colorimetric analysis indicated that its average concentration in these samples was 1.05 g/L. A metabolic switch from the PFL pathway to glycerol production might occur due to acidity tolerance limitations of L. plantarum, glycerol production being associated with the release of phosphate, which can act as a buffer. Fermentation of PP by L. plantarum also led to formation of hexamine, which is a known food preservation agent. Presence of naturally formed hexamine and glycerol in food products may render using chemical additives needless.

Metatranscriptomic Insights Into the Response of River Biofilm Communities to Ionic and Nano-Zinc Oxide Exposures.

Manufactured Zn oxide nanoparticle (ZnO-NP) are extensively used world-wide in personal care and industrial products and are important contaminants of aquatic environments. To understand the overall impact of ZnO-NP contamination on aquatic ecosystems, investigation of their toxicity on aquatic biofilms is of particular consequence, given biofilms are known sinks for NP contaminants. In order to assess alterations in the functional activity of river microbial biofilm communities as a result of environmentally-relevant ZnO-NP exposure, biofilms were exposed to ionic zinc salt or ZnOPs that were uncoated (hydrophilic), coated with silane (hydrophobic) or stearic acid (lipophilic), at a total concentration of 188 µg l-1 Zn. ICP-MS analyses of biofilms indicated ZnO-NP concentrated in the biofilms, with hydrophilic, hydrophobic, and lipophilic treatments reaching 0.310, 0.250, and 0.220 µg Zn cm-2 of biofilm, respectively, while scanning transmission X-ray microspectroscopy (STXM) analyses of biofilms confirmed that Zn was extensively- and differentially-sorbed to biofilm material. Microbial community composition, based on taxonomic affiliation of mRNA sequences and enumeration of protozoa and micrometazoa, was not affected by these treatments, and the total transcriptional response of biofilms to all experimental exposures was not indicative of a global toxic-response, as cellular processes involved in general cell maintenance and housekeeping were abundantly transcribed. Transcripts related to major biological processes, including photosynthesis, energy metabolism, nitrogen metabolism, lipid metabolism, membrane transport, antibiotic resistance and xenobiotic degradation, were differentially expressed in Zn-exposures relative to controls. Notably, transcripts involved in nitrogen fixation and photosynthesis were decreased in abundance in response to Zn-exposure, while transcripts related to lipid degradation and motility-chemotaxis were increased, suggesting a potential role of Zn in biofilm dissolution. ZnO-NP and ionic Zn exposures elicited generally overlapping transcriptional responses, however hydrophilic and hydrophobic ZnO-NPs induced a more distinct effect than that of lipophilic ZnO-NPs, which had an effect similar to that of low ionic Zn exposure. While the physical coating of ZnO-NP may not induce specific toxicity observable at a community level, alteration of ecologically important processes of photosynthesis and nitrogen cycling are an important potential consequence of exposure to ionic Zn and Zn oxides.

Scientific Prospects for Cannabis-Microbiome Research to Ensure Quality and Safety of Products.

Cannabis legalization has occurred in several countries worldwide. Along with steadily growing research in Cannabis healthcare science, there is an increasing interest for scientific-based knowledge in plant microbiology and food science, with work connecting the plant microbiome and plant health to product quality across the value chain of cannabis. This review paper provides an overview of the state of knowledge and challenges in Cannabis science, and thereby identifies critical risk management and safety issues in order to capitalize on innovations while ensuring product quality control. It highlights scientific gap areas to steer future research, with an emphasis on plant-microbiome sciences committed to using cutting-edge technologies for more efficient Cannabis production and high-quality products intended for recreational, pharmaceutical, and medicinal use.