Relative Abundance Of Acinetobacter Research Articles

Study on the fate of per- and polyfluoroalkyl substances during thermophilic anaerobic digestion of sewage sludge and the role of granular activated carbon addition

Limited information is available on the removal of per- and polyfluoroalkyl substances (PFAS) in anaerobic digestion (AD). Τhe fate of six PFAS was studied in thermophilic bioreactors in the presence of granular activated carbon (GAC) and voltage application. Reactors with GAC exhibited lower concentrations of volatile fatty acids and higher methane production compared to those with and without the application of voltage. Analysis of PFAS in dissolved and solid phase showed that their distribution was dependent on perfluorocarbon chain length and functional group. Mass balances showed that PFAS were not removed during conventional AD or after applying voltage; however, significant removal (up to 61 ± 8 %) was observed in bioreactors with GAC for perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorooctane sulfonate (PFOS). Biomass characterization showed that in these bioreactors, the relative abundance of Acinetobacter and Pseudomonas was higher, indicating their potential role in PFAS biotransformation.

Heterogeneous changes in gut and tumor microbiota in patients with pancreatic cancer: insights from clinical evidence

BackgroundPancreatic cancer is the foremost contributor to cancer-related deaths globally, and its prevalence continues to rise annually. Nevertheless, the underlying mechanisms behind its development remain unclear and necessitate comprehensive investigation.MethodsIn this study, a total of 29 fresh stool samples were collected from patients diagnosed with pancreatic cancer. The gut microbial data of healthy controls were obtained from the SRA database (SRA data number: SRP150089). Additionally, 28 serum samples and diseased tissues were collected from 14 patients with confirmed pancreatic cancer and 14 patients with chronic pancreatitis. Informed consent was obtained from both groups of patients. Microbial sequencing was performed using 16s rRNA.ResultsThe results showed that compared with healthy controls, the species abundance index of intestinal flora in patients with pancreatic cancer was increased (P < 0.05), and the number of beneficial bacteria at the genus level was reduced (P < 0.05). Compared with patients with chronic pancreatitis, the expression levels of CA242 and CA199 in the serum of patients with pancreatic cancer were increased (P < 0.05). The bacterial richness index of tumor microorganisms in patients with pancreatic cancer increased, while the diversity index decreased(P < 0.05). Furthermore, there was a change in the species composition at the genus level. Additionally, the expression level of CA242 was found to be significantly positively correlated with the relative abundance of Acinetobacter(P < 0.05).ConclusionOver all, the expression levels of serum tumor markers CA242 and CA19-9 in patients with pancreatic cancer are increased, while the beneficial bacteria in the intestine and tumor microenvironment are reduced and pathogenic bacteria are increased. Acinetobacter is a specific bacterial genus highly expressed in pancreatic cancer tissue.

Characteristics of intestinal microbiota in preterm infants and the effects of probiotic supplementation on the microbiota.

In this study, we investigated the characteristics of the intestinal microbiota of preterm infants, and then analyzed the effects of probiotics supplementation on intestinal microbiota in preterm infants. This study enrolled 64 infants born between 26 and 32 weeks gestational age (GA) and 22 full-term infants. 34 premature infants received oral probiotic supplementation for 28 days. Stool samples were obtained on the first day (D1) and the 28th day (D28) after birth for each infant. Total bacterial DNA was extracted and sequenced using the Illumina MiSeq Sequencing System, specifically targeting the V3-V4 hyper-variable regions of the 16S rDNA gene. The sequencing results were then used to compare and analyze the composition and diversity index of the intestinal microbiota. There was no significant difference in meconium bacterial colonization rate between premature and full-term infants after birth (p > 0.05). At D1, the relative abundance of Bifidobacterium, Bacteroides, and Lactobacillus in the stool of preterm infants was lower than that of full-term infants, and the relative abundance of Acinetobacter was higher than that of full-term infants. The Shannon index and Chao1 index of intestinal microbiota in preterm infants are lower than those in full-term infants (p < 0.05). Supplementation of probiotics can increase the relative abundance of Enterococcus and Enterobacter, and reduce the relative abundance of Escherichia and Clostridium in premature infants. The Chao1 index of intestinal microbiota decreased in preterm infants after probiotic supplementation (p < 0.05). The characteristics of intestinal microbiota in preterm infants differ from those in full-term infants. Probiotic supplementation can reduce the relative abundance of potential pathogenic bacteria and increase the abundance of beneficial microbiota in premature infants.

The microbiota and metabolome dynamics and their interactions modulate solid-state fermentation process and enhance clean recycling of brewers' spent grain.

The massive yield of brewers' spent grain (BSG) waste inevitably threaten environmental health. Here, solid-state fermentation (SSF) technology featuring multi-strain (MS) inoculation and high-throughput sequencing technology were employed to facilitate the sustainable and clean recycling of BSG waste while revealing the associated underlying microbiological and metabolic mechanisms. MS inoculation displayed a lower pH value (3.91 vs. 4.12) and neutral detergent fiber content (446.24 vs. 476.23 g/kg DM), a higher levels of lactic acid (86.64 vs. 33.07 g/kg DM), acetic acid (6.13 vs. 4.87 g/kg DM), propionic acid (2.78 vs. 2.18 g/kg DM) and crude protein (307.5 vs. 289.15 g/kg DM) than those in the control group. Moreover, MS inoculation inhibited the formation of non-protein-N and ammonia-N, and spoilage microorganism resuscitation, while enhanced substrate preservation. Microbiologically, during the SSF, the group treated with MS inoculation exhibited an increase in the relative abundance of Leuconostoc (0.58%∼6.60%), Weissella (6.22%∼15.42%), Enterococcus (3.15%∼9.08%), Bacillus (17.63%∼31.29%), Lactobacillus (12.89%∼8.29%), Pseudoalteromonas (12.87%∼16.29%), and a decrease in the relative abundance of Acinetobacter (0.79%∼0.02%) and Enterobacteriaceae (0.78%∼0.24%). Metabolically, starch and sucrose metabolism, arginine and proline metabolism, and phenylalanine metabolism significantly influenced the quality of extruded BSG fermented by MS during SSF. The examination of the correlation between the microbiota, metabolites, and fermentation parameters revealed that complex interactions between microbes and the environment factors impact metabolite production. Collectively, inoculating with MS improved fermentation quality and stability, facilitated the clean recycling of BSG, which is linked to complex interactions among microbes, the environment factors and metabolite production.

Nitrogen removal characteristics of heterotrophic nitrification-aerobic denitrification bacterium Acinetobacter ZQ-A1 and community characteristics analysis of its application in pig farm wastewater.

A heterotrophic nitrifying aerobic denitrifying (HN-AD) strain ZQ-A1 with excellent denitrification performance, identified as Acinetobacter, was isolated from simultaneous nitrification and denitrification (SND) craft. ZQ-A1 was capable of removing NH4+, NO2-, and NO3-; the 21-hour removal rates were 84.84%, 87.13%, and 92.63%. ZQ-A1 has the ability to treat mixed nitrogen sources. In addition, ZQ-A1 can be well applied to actual sewage. According to the analysis of microbial community characteristics, the relative abundance of Acinetobacter in the experimental group increased from 0.06% to 2.38%, which is an important reason for the removal rate of NH4+ exceeding 99% within 30 days. The results of KEGG function prediction showed that with the addition of ZQ-A1, the relative abundance of pathways related to bacterial metabolism, such as tricarboxylic acid cycle metabolism, was higher. The research expanded the thinking of HN-AD bacteria in actual production and laid a foundation for its application in sewage treatment.

Impact of Dissolved Oxygen on the Performance and Microbial Dynamics in Side-Stream Activated Sludge Hydrolysis Process

Dissolved oxygen (DO) plays an important role in the performance of biological wastewater treatment systems. This study investigated the effect of the DO concentration on nutrient removal performance and microbial community structure in side-stream activated sludge hydrolysis (SSH) and conventional anaerobic/anoxic/aerobic (A2O) processes. The results showed that the change in DO had little effect on the removal performance of chemical oxygen demand (COD), and the removal efficiencies were about 90% for both reactors. Compared with the high DO level (4.1–6.9 mg/L), the A2O and SSH reactors had better nitrogen removal performance at low (0.5–2.2 mg/L) and moderate (2.2–3.9 mg/L) DO levels, with ammonia (NH4+-N) removal efficiencies of 88–89% and 89–91%, respectively, and total nitrogen (TN) removal efficiencies of 74–76% and 75–81%, respectively. Directly reducing the DO concentration from high to low reduced the phosphate removal efficiencies of the A2O and SSH reactors from 80.2% and 86.2% to 63.1% and 70.6%, respectively, while re-elevating the DO concentration to moderate levels significantly improved the phosphate removal efficiencies to 94.6% and 96.0%, respectively. Compared to the A2O reactor, the SSH reactor had more stable and better nutrient removal performance under different DO conditions, partly due to the additional carbon sources produced through the sludge fermentation in the side-stream reactor. The decrease in the DO concentration resulted in a decrease in the relative abundance of Acinetobacter but an increase in the relative abundance of Competibacter, potentially leading to the deterioration in phosphorus removal.

Identification of an Acinetobacter lwoffii strain isolated from diseased hybrid sturgeon (Acipenser baerii♀× Acipenser schrenckii♂)

Members of the genus Acinetobacter are important opportunistic pathogens responsible for various nosocomial infections. However, Acinetobacter spp. are rarely isolated from fish. In this study, we isolated a dominant bacterial strain named I-702 from diseased hybrid sturgeons (Acipenser baerii♀ × Acipenser schrenckii♂) bred at a farm in Yichang City, Hubei Province, China. We identified the strain as Acinetobacter lwoffii based on morphological, physiological and biochemical, and 16S rRNA gene sequence analyses. Regression infection experiments using strain I-702 showed that the symptoms of the artificially infected fish were the same as those of natural diseased sturgeons, such as abdominal congestion and redness and swelling of cloaca. We calculated that the median lethal dose (LD50) of strain I-702 for hybrid sturgeons was 1.22 × 102 ± 0.11 colony forming units/g fish. We also compared the proportion of different leukocytes between healthy and diseased fish; the proportion of neutrophils (30.89%) and monocytes (36.68%) in infected fish increased significantly, whereas that of lymphocytes (30.17%) decreased. Histopathological examination revealed that strain I-702 caused damage to the liver, and intestine tissues of sturgeons. Gut microbial analysis revealed that I-702 infection caused dysbiosis in sturgeons. The relative abundance of Acinetobacter in the diseased group (54.4%) was significantly higher than that in the healthy group (10.7%), whereas the relative abundance of Cetobacterium decreased significantly (healthy sturgeon: 25.6%, diseased sturgeon: 1.5%). Strain I-702 was susceptible to aminoglycosides (neomycin sulfate, amikacin, and gentamycin) and tetracyclines (minocycline and doxycycline). These results suggest that A. lwoffii is an important pathogen of sturgeons. Moreover, the study provides a scientific basis for the control and prevention of A. lwoffii infection in fish.

Effect of Citrus aurantium juice as a disinfecting agent on quality and bacterial communities of striped catfish steaks stored at -20 °C.

Sodium hypochlorite is generally used as a disinfectant in washing of freshwater fishes where the safety aspect of health is of concern. Although plant-based essential oils and synthetic chemical agents have been applied, they might contain toxic substances, are expensive and can cause undesirable quality. This research aims to fill the knowledge gap necessary to validate Citrus aurantium juice as a disinfecting agent for preserving striped catfish steaks at -20 °C for 28 days. Fifty (50) ppm sodium hypochlorite was used as a commercial disinfectant (control). The results showed that a negative color characteristic (higher a* and increased b*) was found in the control but not in striped catfish steaks immersed in C. aurantium juice (TM) on days 14 and 28. No significant differences were found in the peroxide value among the treatments on days 14 and 28 (P > 0.05). A lower accumulation of trichloroacetic acid soluble peptides was detected in TM but not in control, while total volatile basic nitrogen of all treatments was up to standard of fish quality during storage. Contrastingly, the total viable count of both treatments increased to >7.0 log CFU/g on day 28 which did not meet the edible limit of standard for freshwater fishes. The spoilage microbial community was observed on days 0 and 28 of storage which showed a decrease in relative abundance of Acinetobacter, Pseudomonas, Brochothrix, Lactococcus, Carnobacterium, Psychrobacter, and Vagococcus as found in TM on day 28, when compared to the control. Thus, these results implied that C. aurantium juice could replace sodium hypochlorite as an alternative disinfecting agent to control the microbiological spoilage and physico-chemical quality of striped catfish steaks.

Special tissue microbiota such as Cyanobacteria are associated with the immune microenvironment of lung adenocarcinoma.

Lung cancer is the leading prevalent form of human cancer and has the highest mortality rate among all cancer types. The role and potential mechanism of the lung microbiome in lung cancer is still unknown. This study aims to investigate the microbiomes of lung cancer patients possessing different levels of infiltrated CD8+ T cells and programmed cell death-1 (PD-1) receptors, and further assess the correlation between specific microbes and the immune environment of lung tumor. We analyzed the microbiomes of lung cancer tissues from patients with different levels of infiltrated CD8+ T cells and PD-1 expression using 16S rRNA gene sequencing. The relative abundance of dominant phyla and genera was compared, and the correlation between microbial composition and immune markers was explored. Our results showed that lung cancer tissues displayed similar microbiome profiles, including Proteobacteria, Bacteroidetes, and Actinobacteria as the dominant phyla; and Chryseobacterium, Triticum aestivum (bread wheat), and Acinetobacter as the dominant genera. We found that the relative abundance of Chryseobacterium was positively correlated with CD8+ T cell infiltration and the level of PD-1 expression, while the relative abundance of Acinetobacter was negatively associated with the PD-1 level. In addition, higher beta diversity was identified in samples with low CD8+ T cell infiltration, but no significant correlation between beta diversity and PD-1 expression was observed. Furthermore, the relative abundance of Cyanobacteria was significantly higher in both the CD8 high and PD-1 high groups. Our study indicated that the lung microbiota played an indispensable role in the CD8+ T cell-mediated tumor immune response. These findings shed light on valuable insights into the intricate interplay between the lung microbiome and the immune system in the progression of lung cancer, offing potential therapeutic strategies targeting the lung microbiome.

Translocation and Dissemination of Gut Bacteria after Severe Traumatic Brain Injury.

Enterobacteriaceae are often found in the lungs of patients with severe Traumatic Brain Injury (sTBI). However, it is unknown whether these bacteria come from the gut microbiota. To investigate this hypothesis, the mice model of sTBI was used in this study. After sTBI, Chao1 and Simpson index peaking at 7 d in the lungs (p < 0.05). The relative abundance of Acinetobacter in the lungs increased to 16.26% at 7 d after sTBI. The chao1 index of gut microbiota increased after sTBI and peaked at 7 d (p < 0.05). Three hours after sTBI, the conditional pathogens such as Lachnoclostridium, Acinetobacter, Bacteroides and Streptococcus grew significantly. At 7 d and 14 d, the histology scores in the sTBI group were significantly higher than the control group (p < 0.05). The myeloperoxidase (MPO) activity increased at all-time points after sTBI and peaked at 7 d (p < 0.05). The LBP and sCD14 peaking 7 d after sTBI (p < 0.05). The Zonulin increased significantly at 3 d after sTBI and maintained the high level (p < 0.05). SourceTracker identified that the lung tissue microbiota reflects 49.69% gut source at 7 d after sTBI. In the small intestine, sTBI induced gastrointestinal dysfunction with increased apoptosis and decreasing antimicrobial peptides. There was a negative correlation between gut conditional pathogens and the expression level of antimicrobial peptides in Paneth cells. Our data indicate that gut bacteria translocated to the lungs after sTBI, and Paneth cells may regulate gut microbiota stability and translocation.

Effects of corn particle size on growth performance, gastrointestinal development, carcass indices and intestinal microbiota of broilers

This experiment was conducted to investigate the effects of different corn particle sizes on growth performance, gastrointestinal development, carcass processing yields and intestinal microbiota of caged broilers. One-day-old Ross 308 broilers were randomly divided into 8 treatments with 10 replicates per treatment and 30 birds per replicate pen. The experiment lasted 37 d. Feed and water were provided ad libitum. The results showed as follows: birds fed diets with the FG corn between d 1 and 13 and CG corn between d14 to 37 had increased body weight, daily gain, and feed intake (P < 0.05). Birds fed diets with CG corn between d 24 to 37 had a heavier relative weight of gizzard at d 38 (P < 0.05). Birds fed diets with FG corn from d 1 to 13 and the CG corn from d 14 to 37 had a higher carcass yield and a relative thigh weight at d 38 (P < 0.05). The intestinal microbiota was significantly affected by different corn particle sizes. The relative abundance of Lactobacillaceae was significantly decreased, whereas that of Peptostreptococcaceae was increased (P < 0.05) in birds fed with the CG corn between d1 to 37. The relative abundance of Acinetobacter was significantly increased in birds fed the FG corn between d1 to 37 (P < 0.05). In conclusion, the use of FG corn in the starter phase and CG corn in the grower and finisher phases was beneficial to growth performance, gastrointestinal development and intestinal microbial structure of broilers reared in cages.

Exploring the effect of wilting on fermentation profiles and microbial community structure during ensiling and air exposure of king grass silage.

In order to better understand the effect of wilting treatment on silage, we study analyzed the fermentation quality of unwilted (CK) and wilted (WT) king grass silage, and the dynamic changes of microorganisms in silage and aerobic exposure. After 30 days of silage, WT silage significantly reduced the pH of the silage (p < 0.05) and increased the contents of lactic acid and acetic acid (p < 0.05), but did not reduce the content of Ammonia-N (p > 0.05). Wilting treatment increased bacterial and fungal diversity during silage but decreased fungal diversity during aerobic exposure. The relative abundance of Lactococcus and Enterococcus in wilting silage increased. In the aerobic exposure stage, the relative abundance of Klebsiella decreased, but the relative abundance of Enterobacter increased in wilting treatment silage. In addition, the relative abundance of Acinetobacter and Ignatzschineria increased after 5 days of aerobic exposure. In contrast with unwilted silage, wilting treatment silage after aerobic exposure had no Candida, but the relative abundance of Wickerhamomyces increased. The results showed that wilting treatment could raise the silage quality of king grass. However, WT silage did not inhibit the reproduction of harmful microorganisms during aerobic exposure and did not significantly improve the aerobic stability of silage.

The role of attached bacteria in the formation of Microcystis colony in Chentaizi River.

To further understand the role of attached bacteria in the formation of Microcystis colonies, we conducted a field investigation in Chentaizi River in Tianjin, China, which frequently suffers Microcystis blooms in summer. The results showed the average cell density of Microcystis was 2.31 × 107 cell/L from July 19 to July 27, 2021. Free-living and attached bacteria communities shared similar phylum diversity, but the abundance changed obviously. The colony size of Microcystis and attached bacterial number in the colony showed an increasing trend during the whole sampling period. There was a significant positive correlation between Microcystis colonial size and attached bacterial density (P < 0.01), indicating attached bacteria could contribute the colony formation of Microcystis. The genus composition in attached bacterial community varied in colonies of different sizes. The relative abundance of Acinetobacter, Cloacibacterium, Sphingobacterium, and Ralstonia in >90 μm colonies were significantly higher than those in 8-20 μm and 20-90 μm colonies (P < 0.05). These genera might have positive effects on the colony formation of Microcystis during sampling.

Functional roles of xylanase enhancing intestinal health and growth performance of nursery pigs by reducing the digesta viscosity and modulating the mucosa-associated microbiota in the jejunum.

This study was conducted to investigate the functional roles of an endo-β-1,4-xylanase on the intestinal health and growth performance of nursery pigs. A total of 60 pigs (21 d old, 6.9 ± 0.8 kg body weight [BW]) were allotted based on a randomized complete block design with sex and initial BW as blocks. Dietary treatments had nutrients meeting the requirements with increasing levels of endo-β-1,4-xylanase (0, 220, 440, 880, 1,760 xylanase unit [XU] per kg feed) and fed to pigs in three phases (phases 1, 2, and 3 for 10, 14, and 14 d, respectively). Titanium dioxide (0.4%) was added to the phase 3 diets as an indigestible marker. On day 38, all pigs were euthanized to collect ileal digesta to measure apparent ileal digestibility (AID), jejunal digesta to measure viscosity, and jejunal mucosa to evaluate intestinal health. Data were analyzed using the MIXED procedure for polynomial contrasts and the NLMIXED procedure for broken line analysis of SAS. Increasing xylanase in the nursery diets reduced (linear, P < 0.05) the digesta viscosity in the jejunum. Increasing xylanase tended to reduce the relative abundance of Cupriavidus (P = 0.073) and Megasphaera (P = 0.063); tended to increase the relative abundance of Succinivibrio (P = 0.076) and Pseudomonas (P = 0.060); and had a quadratic effect (P < 0.05) on the relative abundance of Acinetobacter (maximum: 2.01% at 867 XU per kg feed). Xylanase from 0 to 1,087 XU per kg feed reduced (P < 0.05) jejunal malondialdehyde. Xylanase from 0 to 1,475 XU per kg feed increased (P < 0.05) the AID of neutral detergent fiber. Increasing xylanase increased (P < 0.05) the AID of ether extract and tended to increase (P = 0.058) the AID of crude protein. Increasing xylanase did not affect growth performance on overall period, whereas xylanase from 0 to 736 XU per kg feed increased (P < 0.05) average daily gain (ADG) during days 31 to 38. In conclusion, xylanase supplementation showed benefits on intestinal health by reducing digesta viscosity, the relative abundance of potentially harmful bacteria, and the oxidative stress in the jejunal mucosa, collectively enhancing intestinal morphology and the AID of nutrients. Xylanase supplementation at a range of 750 to 1,500 XU per kg feed provided benefits associated with reduced oxidative stress, increased nutrient digestibility, resulting in potential improvement on growth performance of nursery pigs by increasing the average daily feed intake and moderately improving the ADG throughout the last week of feeding.

Producing high-quality cultivation substrates for cucumber production by in-situ composting of corn straw blocks amended with biochar and earthworm casts

In-situ composting is an efficient method for the dispose of crop residues. However, the high organic carbon content and low water-holding capacity of corn (Zea mays L.) straw can easily result in a slow composting process with high nutrient loss. In this study, compressed corn straw blocks was a control (S), straw mixed with earthworm casts (SE), straw mixed with biochar (SB), straw mixed with earthworm casts and biochar (SEB) were treatments to determine their effects on in-situ composting performance. In general, compared with S, the thermophilic period was extended by 14, 13 and 3 days in SE, SB and SEB, respectively, reduced nutrient loss, the water holding porosity of SE and SEB increased by 28.67% and 24.03%. Besides, the bacterial Shannon and Pielou’s indices of SEB increased by 9.42% and 9.33%, respectively, and the relative abundance of Acinetobacter was increased in SB and SEB. Amino acid metabolism and carbohydrate metabolism were the most abundant metabolic processes in composts. SEB showed not only the highest cucumber yields, but also the highest OQI. The OQI of the CCSBs was significantly and positively correlated with cucumber yields (P < 0.001). These results indicated that the combination of earthworm casts and biochar was more effective than each single additive during in-situ composting of corn straw blocks, and emphasized that the overall quality of CCSBs played pivotal roles in determining the agronomic performance of CCSBs. In addition, the in-situ composting of corn straw blocks could be used to produce high-quality cultivation substrates.

Associations Between Peripheral Blood Microbiome and the Risk of Hypertension.

Although previous studies have reported the gut microbiome is closely related to hypertension development, whether the change in blood microbiome is associated with the risk of hypertension remains unclear. One hundred and fifty incident hypertension cases and 150 age (± 2 years) and gender (1:1) matched nonhypertension controls included in this nested case-control study were recruited from a prospective cohort study of "135." The composition of the blood microbiome was characterized using bacterial 16S ribosomal RNA gene sequencing. The relative abundance of detected bacteria was converted to a negative logarithm of 10 for the statistical analysis. Totally, 10,689,961 high-quality sequences were acquired. The Chao1 index of the blood microbiome in nonhypertension controls was significantly higher than in hypertensive group (2,302.08 ± 752.78 vs. 1,598.21 ± 500.88, P < 0.001). Compared with the nonhypertension controls, the relative abundance of Proteobacteria phylum was significantly increased (P < 0.001), whereas the relative abundance of phyla Firmicutes and Bacteroidetes were significantly reduced in the hypertensive cases (P < 0.001 and P = 0.039, respectively). At genus level, the risk of hypertension was directly associated with the relative abundance of Acinetobacter (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.01-2.03), Sphingomonas (OR: 1.84, 95% CI: 1.32-2.56), and Staphylococcus (OR: 0.51, 95% CI: 0.36-0.73), respectively. In addition, the relative abundance of Pseudomonas was minor positively correlated with the total cholesterol level. However, the relative Staphylococcus level was minor positively correlated with high-density lipoprotein cholesterol level. The composition of the blood microbiome is significantly associated with the development of hypertension.

SARS-CoV-2 infection in nonhuman primates alters the composition and functional activity of the gut microbiota

ABSTRACT The current pandemic of coronavirus disease (COVID) 2019 constitutes a global public health issue. Regarding the emerging importance of the gut-lung axis in viral respiratory infections, analysis of the gut microbiota’s composition and functional activity during a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection might be instrumental in understanding and controling COVID 19. We used a nonhuman primate model (the macaque), that recapitulates mild COVID-19 symptoms, to analyze the effects of a SARS-CoV-2 infection on dynamic changes of the gut microbiota. 16S rRNA gene profiling and analysis of β diversity indicated significant changes in the composition of the gut microbiota with a peak at 10–13 days post-infection (dpi). Analysis of bacterial abundance correlation networks confirmed disruption of the bacterial community at 10–13 dpi. Some alterations in microbiota persisted after the resolution of the infection until day 26. Some changes in the relative bacterial taxon abundance associated with infectious parameters. Interestingly, the relative abundance of Acinetobacter (Proteobacteria) and some genera of the Ruminococcaceae family (Firmicutes) was positively correlated with the presence of SARS-CoV-2 in the upper respiratory tract. Targeted quantitative metabolomics indicated a drop in short-chain fatty acids (SCFAs) and changes in several bile acids and tryptophan metabolites in infected animals. The relative abundance of several taxa known to be SCFA producers (mostly from the Ruminococcaceae family) was negatively correlated with systemic inflammatory markers while the opposite correlation was seen with several members of the genus Streptococcus. Collectively, SARS-CoV-2 infection in a nonhuman primate is associated with changes in the gut microbiota’s composition and functional activity.

Variations and Potential Factors of Gut Prokaryotic Microbiome During Spawning Migration in Coilia nasus.

Coilia nasus is influenced by various external pressures during spawning migration and these anadromous transitions can lead to specific gut microbiome characteristics that affecting the host biological process. Therefore, the purpose of this study was to determine the variations of components and functions in the gut prokaryotic microbiome during spawning migration as well as the key factors that triggered the changes. The gut microbiome in C. nasus was mainly consisted of Proteobacteria, Bacteroidetes, Firmicutes, Deinococcus-Thermus and Fusobacteria via 16S rRNA Gene Amplicon Sequencing. The relative abundance of Acinetobacter and Clostridium increased, while Corynebacterium, Actinomyces, Bacillus, Klebsiella and Ochrobactrum decreased after entering freshwater, indicated the preference of C. nasus gut microbial members transferred from seawater to freshwater. Additionally, the proportion of Firmicutes significantly decreased and then increased, as well as the arise of some soil bacteria in gut, corresponding to the phenomenon that C. nasus are fasting during the upstream process and refeeding after entering the spawning grounds. The function prediction of gut microbiome was also consistent with the above results. The present study generally demonstrated the gut microbiome dynamics and the significant correlation between the gut microbiome and salinity and feeding behavior in the spawning migration of C. nasus.

Treatment of Piggery Biogas Slurry by Enhanced Biological Contact Oxidation with HN-AD Bacteria

The conventional pretreatment process for swine wastewater is anaerobic fermentation. This process leads to the formation of high ammonia nitrogen, low carbon, and piggery biogas slurry, which usually results in poor denitrification effect, complicated process flow, and long startup period for the subsequent treatment process. In this study, a novel biological enhanced Biological Contact Oxidation (BCO) process using HN-AD bacteria as microbial inoculants, and PAN activated carbon fiber filler as biofilm carrier was proposed for the treatment of piggery biogas slurry. In the early stage of sludge acclimation, it was found that when NH4+-N concentration was higher than 500 mg·L-1, the nitrification and COD removal in BCO was severely inhibited. When the BCO was enhanced by HN-AD bacteria, however, the tolerance concentration of NH4+-N for bacteria in BCO could reach 600 mg·L-1 and the removal efficiency of NH4+-N, COD, and TN could still remain at a high level. The bio-enhanced BCO process was used to treat the piggery biogas slurry. The average removal rates of NH4+-N, TN, and COD were 86.9%, 70.5%, and 74.4%, respectively, which were higher than the 57.6%, 50.3%, and 50.0% of the traditional treatment process. The concentration of the pollutants mentioned above in the effluent was below the relevant discharge standards. The changes in the microbial community structure during the enrichment process of functional bacteria were studied by high-throughput sequencing technique. The results showed that the dominant bacteria belonging to HN-AD in the biofilm during the sludge acclimation process was Alcaligenes. After the addition of the HN-AD agent, however, the dominant bacteria were Diaphorobacter, Acinetobacter, and Thauer, and the relative abundance of Acinetobacter was much higher than that in the microbial inoculants. The results of scanning electron microscopy further confirmed the existence of bio-enhancement. The surface of the biofilm layer tightly attached to the filler was enriched with rod-like and globular HN-AD functional bacteria.

Remediation of Petroleum-Contaminated Soil Using a Bioaugmented Compost Technique

Bioaugmented compost was created by inoculating petroleum-degrading bacteria into mature compost. The petroleum hydrocarbon degradation efficiencies were investigated by applying this enhanced compost to petroleum-contaminated soil under low temperatures. The results showed that the degrading bacteria can be enriched in the mature compost. After 30 d of remediation, the removal efficiency of TPH, alkanes, and PAHs in the soil was 27.0%, 19.6%, and 10.0%, compared to natural attenuation (CK), which was 4.5%, 9.5%, and 2.3%, respectively. In response to remediation, the relative abundance of Proteobacteria and Actinobacteria phyla decreased from 53.4% and 25.9% to 48.9% and 14.1%, respectively, and Bacteroidetes phylum increased from 5.0% to 24.5%. At the genus level, the relative abundance of Acinetobacter and Pseudomonas increased from 0.02% and 3.4% to 15.2% and 4.6%, respectively. The results indicated that the bioaugmented compost may efficiently facilitate and speed up the bioremediation of petroleum-contaminated soil under low-temperature conditions. Soil microbial diversity and structure of microbial communities are sensitive to the remediation.