Microbial Diversity Analysis Research Articles

Bacteria from nodules of Abrus mollis Hance: genetic diversity and screening of highly efficient growth-promoting strains.

Abrus mollis Hance. (AM) is an important species used in southern Chinese medicine. It is mainly found in Guangdong and Guangxi provinces in China, and it is effective in the treatment of hepatitis. Endophytic bacteria are known to affect the growth and quality of medicinal plants. However, there are limited reports describing endophytic bacteria related to AM. In the present study, Illumina-based 16S rRNA gene sequencing was used to investigate the endophytic bacterial communities of root nodules of AM at five sampling sites in Guangxi. In addition, 179 strains of endophytic bacteria were isolated and categorized into 13 haplotypes based on recA sequence analysis. The phylogeny of the 16S rRNA gene sequences revealed a predominance of nonrhizobial endophytes. Microbial diversity analysis showed that Proteobacteria was the dominant phylum in all samples, while Bradyrhizobium was the dominant genus in different samples. An efficient strain, Rhizobium tropici FM-19, was screened and obtained through greenhouse experiments. The AM plants inoculated with this strain showed the best growth performance and high nitrogen fixation and nodulation capacity. Notably, total phenols and total flavonoids, important active components in AM, increased by 30.9 and 42.7%, respectively, after inoculation with Rhizobium tropici FM-19. This study provides insights into the complex microbial diversity of AM nodules and provides strain information for the efficient cultivation of AM.

Effect of Cucumber Continuous Monocropping on Traditional Chinese Medicine Residue through Analysis of Physicochemical Characteristics and Microbial Diversity

The use of traditional Chinese medicine (TCM) residue as a crop culture substrate has unique advantages in alleviating the obstacles associated with continuous monocropping, such as increasing production, improving quality and alleviating pests and diseases. However, the effect of TCM residue application on substrates in continuous monocropping practices has not been determined. In this study, the cucumber variety “Jinyou No. 10” was used as the material, and fermented TCM residue, vermiculite and perlite were used as organic substrates (3:1:1). The cucumbers were cultivated on substrates for different durations of continuous monocropping, which were the first cropping cycle (A1), second cropping cycle (A2), third cropping cycle (A3) and fourth cropping cycle (A4). The control (A0) was the substrate sample without any crop planted in it. After the cucumbers were harvested, substrate samples (areas around the cucumber roots) were collected. The physiochemical properties of the cultivated substrates were determined, and the microbial community structures were analyzed through 16S rRNA and ITS sequencing. The physiochemical indices of the substrates with different durations of continuous monocropping (A1–A4) were significantly different than those of the control (A0) substrate. Moreover, the continuous cropping of cucumber had greater effects on fungal communities than on bacterial communities. Bacterial community structure analysis revealed a greater proportion of important bacterial taxa (Proteobacteria, Chloroflexi, and Nitrospirae) in the continuous monocropping substrates than in the A0 substrate. For the fungal community, Ascomycota accounted for the largest percentage of the fungal community in all the samples. The diversity of the microbial community was found to be influenced primarily by electrical conductivity, organic matter content, pH and total potassium content according to the correlation analysis of physicochemical properties and relative abundance of the microbial community. Our study would provide a basis for addressing persistent challenges in continuous cropping and for obtaining the utmost benefit from using TCM organic residue waste.

Abstract 2804: Comparative analysis of microbial diversity and abundance in colorectal cancer patients before and after surgery

Abstract Background: Previous studies have indicated differing patterns of the microbiome in colorectal cancer (CRC) patients compared to healthy individuals. Yet, the changes in microbial features of CRC patients before and after surgery remain underexplored. This study aims to investigate the impact of surgical intervention on the gut microbial diversity and abundance at the patient level. Methods: This hospital-based study analyzed data from 36 CRC patients who underwent CRC surgery at the Department of Surgery, Seoul National University Hospital between January 2020 and May 2022. Fecal samples from these patients were collected twice, both before surgery and during the post-surgery follow-up period. DNA extraction from stool specimens was performed using the MAG-Bind Universal Pathogen kit. This was followed by amplification and sequencing of the 16S rRNA gene V3-V4 region, with subsequent bioinformatics analyses conducted using QIIME 2. To compare the alpha diversity indices of patients before and after surgery, we employed both the paired t-test and the Wilcoxon signed-rank test. Results: Out of the 36 patients, 21 were male and 15 were female, with a mean age of 63.8 years. The average duration between surgery and post-surgery fecal sample collection was 2.3 years. Post-surgery, the alpha diversity indices decreased compared to pre-surgery, but the differences were not significant, except for Faith's PD. At the phylum level, Firmicutes and Actinobacteriota, both recognized as beneficial bacteria, increased in abundance after surgery, while Bacteriodota, typically considered harmful, significantly decreased. At the genus level, variations in microbial abundance also showed an increase in Blautia, Bifidobacterium, and Collinsella, and a decrease in Enterococcus, Romboutsia, and Faecalibacterium. The rise in Bifidobacterium abundance following surgery suggests a gut environment altered by the surgery to favor beneficial bacteria. However, a specific species decline in Bifidobacterium adolescentis was observed, highlighting that CRC surgery may have distinct impacts on different bacterial species. Conclusions: Our study indicates a slight decline in gut microbiome diversity following surgery. At the phylum level, there was an observed increase in beneficial bacteria and a decrease in harmful bacteria post-surgery, suggesting potential health improvements in CRC patients. Further research, particularly with a larger sample size and encompassing a broader range of bacteria, is needed to better understand the patterns and implications of microbiome variation in relation to surgical outcomes. Such insights could be pivotal in optimizing patient care and recovery strategies post-surgery. Citation Format: Hyeree Park, Min Jung Kim, Ji Won Park, Seung-Yong Jeong, Aesun Shin, Sung-Yup Cho, Eun Sung Jung, Dong Ho Suh, Sunyoung Lee, Yu Jin Park. Comparative analysis of microbial diversity and abundance in colorectal cancer patients before and after surgery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2804.

Microbial community dynamics and spatial distribution of flavor compound metabolism during solid-state fermentation of Baijiu enhanced by Wickerhamomyces anomalus

Biofortification of Baijiu fermentation process using exogenous functional strains can change the microbial community structure in the fermentation system, which in turn affects the flavor of Baijiu. In this study, we used a simulated solid-state fermentation of Baijiu to investigate the effects of the addition of Wickerhamomyces anomalus strain YM001 on the improvement of Baijiu flavor compounds and its mechanism. The results of microbial diversity analysis showed that Wickerhamomyces and Lactiplantibacillus were the dominant genera in the biofortified fermentation system. In addition, W. anomalus YM001 drove the change of bacteria with moisture and alcohol content, which will synthesise esters using ethanol and moisturet as substrates. The addition of W. anomalus YM001 increased the content of total esters in fermentation samples, especially ethyl acetate, and other compounds such as acetic acid and phenylethyl ester to some extent. W. anomalus YM001 altered the correlation between microorganisms and flavor compounds, with Latilactobacillus and Pediococcus showing a significant positive correlation with ethyl acetate and Weissella showing a significant negative correlation with ethyl caproate and ethanol. In addition, the metabolic properties of ethyl acetate, ethyl decanoate and phenethyl acetate were also altered. In summary, biofortification with W. anomalus YM001 altered the microbial community composition and the physicochemical properties of the fermented grains in the Baijiu brewing system, while elevating the contents of ethyl acetate, ethyl decanoate and phenyl acetate. These findings suggest that biofortification during Baijiu brewing improves Baijiu flavor and contributes to the overall quality of Baijiu.

Research Note: Analysis of microbial diversity on the shell surface of eggs collected from geographically distinct farms in China

Micro-organisms on the eggshell surface of affect the quality of the egg. Sometimes, these microbes even pose a serious threat to the health of the egg's consumer. Bacterial 16S rDNA and fungal internal transcribed spacer region were sequenced to analyze the microbial diversity on the shell surface of the eggs collected from 4 distinct regions of China: Guyuan (GY; 1.5 million hens), Langfang (LF; 0.1 million hens), Beihai (BH; 1.2 million hens), and Dongguan (DG; 0.2 million hens). The results showed a higher bacterial and fungal abundance on the eggs collected from the northern and southern China farms, respectively. The dominant bacterial phylum detected across all egg samples was Firmicutes. In addition, the shell surfaces of the DG and LF samples harbored abundant levels of Proteobacteria. The dominant fungal phyla detected across all egg samples were Ascomycota and Basidiomycota. The bacterial compositions on eggshell surfaces differed significantly across all geographic regions, and the fungal composition differed significantly between samples collected from the southern and northern farms (P < 0.05). The abundance and composition of microbial colonies on the eggshell surface varied based on their geographical location (climate and environment) and farming scale (management). Our findings provide an important reference for optimizing the cleaning and disinfection methods for fresh eggs collected from different sources.

Combined hydrothermal pretreatment of agricultural and forestry wastes to enhance anaerobic digestion for methane production

The dense structure and significant differences in the properties of agricultural and forestry wastes make it difficult to achieve anaerobic conversion. This study employed hydrothermal pretreatment (HTP) and combined hydrothermal pretreatment (CHTP) to enhance the anaerobic digestion (AD) performance of agricultural and forestry organic wastes. At a specific hydrothermal condition of 140℃ for 30 mins, the cumulative methane production of garden waste (GW), chicken manure (CM), duck manure (DM), and pig manure (PM) increased by 14.70%, 14.18%, 27.48%, and 21.81%, respectively. Under the same conditions, CHTP of garden waste with livestock and poultry manures showed noticeable synergistic effects, resulting in the methane production potential of garden waste mixed with chicken manure, duck manure, and pig manure increased by 28.82%, 36.59%, and 37.56%, respectively, compared with the untreated group. Metabolomic analysis showed that CHTP could significantly promote the decomposition of biomass carbohydrates, proteins, and lipids, leading to increased levels of small molecular metabolites. Analysis of microbial community diversity showed that HTP and CHTP increase the abundance of specific functional microbial communities, such as hydrolysis bacteria and methanogens, thereby promoting the anaerobic production of methane from biomass waste. Energy balance analysis shows that HTP-AD and CHTP-AD have a positive net energy benefit. This study provides an efficient CHTP technology and theoretical support for the resource utilization and energy conversion of agricultural and forestry wastes.

Analysis of Microbial Diversity and Community Structure of Rhizosphere Soil of Three Astragalus Species Grown in Special High-Cold Environment of Northwestern Yunnan, China.

Astragalus is a medicinal plant with obvious rhizosphere effects. At present, there are many Astragalus plants with high application value but low recognition and resource reserves in the northwestern area of Yunnan province, China. In this study, metagenomics was used to analyze the microbial diversity and community structure of rhizosphere soil of A. forrestii, A. acaulis, and A. ernestii plants grown in a special high-cold environment of northwestern Yunnan, China, at different altitudes ranging from 3225 to 4353 m. These microbes were taxonomically annotated to obtain 24 phyla and 501 genera for A. forrestii, 30 phyla and 504 genera for A. acaulis, as well as 39 phyla and 533 genera for A. ernestii. Overall, the dominant bacterial phyla included Proteobacteria, Actinobacteria, and Acidobacteria, while the dominant fungal ones were Ascomycota and Basidiomycota. At the genus level, Bradyrhizobium, Afipia, and Paraburkholderia were the most prevalent bacteria, and Hyaloscypha, Pseudogymnoascus, and Russula were the dominant fungal genera. Some of them are considered biocontrol microbes that could sustain the growth and health of host Astragalus plants. Redundancy analysis revealed that pH, TN, and SOM had a significant impact on the microbial community structures (p < 0.05). Finally, triterpene, flavonoid, polysaccharide, and amino acid metabolisms accounted for a high proportion of the enriched KEGG pathways, which possibly contributed to the synthesis of bioactive constituents in the Astragalus plants.

Bacterial diversity and functional characteristics of natural rainwater lakes in Saihanba artificial forest farm as revealed by 16S rRNA sequencing

The Saihanba Mechanical Forest is an artificial national forest park with a forest-steppe landscape. The flora and fauna have been extensively studied, but a comprehensive understanding of the bacterial community composition and structure of the natural rainwater lakes present in the area has rarely been reported. In this study, the structure and functional characteristics of bacterial communities in lake sediments and water samples in the Saihanba artificial forest were investigated using 16s rRNA high-throughput sequencing. Microbial diversity analyses revealed that Proteobacteria, Acidobacteria, Bacteroidota and Verrucomicrobiota microbiota dominated. The abundance of Proteobacteria and Actinobacteriota was significantly higher (p < .05) in water samples compared to sediment samples. PICRUSt2 functional analysis predicted genes associated with the degradation of xenobiotics and the execution of essential metabolic processes. Here, we report differences in the composition of native bacterial communities in sediments and water under the Saihanba artificial forest and make functional gene predictions. This study provides a reference for further exploring the structure and functional characteristics of microbial communities in water samples and sediment environments of lakes under planted forests.

Effects of soyhulls with different particle size on the growth performance, blood indices and gut microbiota of yellow feather broilers

ABSTRACT 1. The objective of this study was to determine the effects of soyhulls with different particle sizes on the growth performance, blood indices and gut microbiota of yellow feather broilers. 2. Total of 240 healthy, one-day-old, yellow feather broilers were randomly divided into four groups, with six pen replicates within each group and ten birds per pen. The control group birds were fed the basal diet (Control). For the treatment groups, 5% soyhulls with different particle sizes were included in the basal diet. The particle size geometric mean diameters (d gw) of the soyhulls in the three treatment groups were 299.69 μm (LowPS), 489.85 μm (MediumPS) and 734.83 μm (HighPS) with geometric standard deviation (S gw) 1.75 μm, 1.62 μm and 1.67 μm, respectively. 3. Results showed that the growth performance variables and organ indices were not different among the four groups. The MediumPS group had increased TG, T-CHO, ALT, HDL-C, and GSH-PX levels and decreased T-AOC levels, whereas LowPS and HighPS groups had increased HDL-C and GSH-PX levels (p < 0.05). Microbial diversity analysis showed that the intestinal microbiota of yellow feather broilers mainly included Firmicutes and Bacteroidetes. Inclusion of 5% soyhulls with different particle size had no effect on alpha diversity indices of caecal microbiota. The HighPS group had significantly higher relative abundance of Firmicutes spp. and lower Bacteroidetes spp. compared with the LowPS and MediumPS group but this was not different from the Control group. The relative abundance of Cyanobacteria spp. was significantly higher in the HighPS group than the other three groups. LEfSe analysis showed that there were more enriched biomarker taxa in the groups with soyhulls than the control group. 4. Overall, the inclusion of soyhulls with different particle sizes had limited effects on growth performance, blood indices and caecal microbiota composition of yellow feather broilers.

Effects of Designed Herbal Formula on Growth Performance, Blood Indices, Organ Traits, and Cecum Microbiology in Broilers.

The objective of this study was to investigate the effect of the designed herbal formula (DHF) on growth performance, blood indices, organ traits, and cecum microbiology in broilers. A total of 96 male broilers of 1 d were selected and randomly assigned to two groups with six replicates of eight broilers each. The control (CON) and the basal diet containing 1.0% DHF (Astragali radix, Atractylodes macrocephala Koidz., Isatis tinctoria Linnaeus, and Citri reticulatae pericarpium, 2:1:1:2) were fed separately. The experiment was conducted for 35 days. The results showed that the DHF diet increased body weight and decreased the feed conversion ratio (FCR) (p < 0.05). At 21 days, the spleen, thymus, lymphocytes, and thrombocytes were increased (p < 0.05), and pancreas, duodenum, heterophils, and mean corpuscular hemoglobin (MCH) were decreased (p < 0.05). At 35 days, the heart, pancreas, white blood cell, heterophils, hemoglobin, MCH and mean corpuscular hemoglobin concentration (MCHC) were decreased, while lymphocytes and middle cells were increased (p < 0.05). The results of microbial diversity analysis showed that the DHF diet decreased the microbial diversity of the cecum. Firmicutes and Bacteroidetes were the dominant phyla, where the DHF diet increased the relative abundances of Bacteroides uniformis, Bacteroides vulgatus, and Faecalibacterium prausnitzii, and then decreased the relative abundance of Shigella sonnei. In conclusion, DHF played a positive role in improving the growth performance, immune performance, and relative abundance of Bacteroides uniformis, Bacteroides vulgatus, and Faecalibacterium prausnitzii in cecum microbiology in broilers, and has the potential to be used as a novel feed additive.

Comparison of microbial communities and nitrite formation in two different beet sugar extraction systems

This study investigated nitrite formation in beet sugar factories, crucial due to tightening European Union directives for contaminants in feed material. Comparing two extraction systems (trough and tower), the trough system exhibited dynamic nitrite formation processes resulting in an average nitrite content of 14.35 mg/kg in raw juice. In the tower system, high nitrite levels and rapid degradation occurred in hot extraction areas, leading to an average nitrite content of 30.89 mg/kg in raw juice during sampling period. Microbial diversity analysis revealed a community shift, with Firmicutes dominating in hot extraction regions. Highly abundant amplicon sequence variants (ASVs) predominantly belonged to the genera Tuberibacillus and Geobacillus in both systems (Tuberibacillus: trough: 73%, tower: 67%; Geobacillus: trough: 41%, tower: 30%). Sequences related to bacteria relevant for nitrite metabolism varied between the two systems. Limosilactobacillus fermentum was more prevalent in the trough extraction system (6% relative abundance in raw juice), than in the tower system (0.5% relative abundance in raw juice). Similarly, Parageobacillus caldoxylolyticus was more abundant in tower extraction, especially in high-temperature zones like the countercurrent mixer (7% relative abundance). These findings provide insights into microbial processes, community structure, and potential strategies for early nitrite reduction in the extraction process.

Microbiome-Metabolomic Analysis Revealed the Immunoprotective Effects of the Extract of Vanilla planifolia Andrew (EVPA) on Immunosuppressed Mice.

This study investigated the immunoprotective effects of the extract of Vanilla planifolia Andrew (EVPA) on cyclophosphamide (Cy)-induced immunosuppression in mice. The results show that EVPA administration significantly alleviated the immune damage induced by Cy, as evidenced by an improved body weight, organ index, and colonic injury. A further analysis of microbial diversity revealed that the EVPA primarily increased the abundance of the beneficial bacteria Verrucomicrobiota, Lactobacillaceae, and Lactobacillus while decreasing Akkermansiaceae, Akkermansia, Romboutsia, and Lactococcus, thereby ameliorating the microbial dysbiosis caused by Cy. A metabolomic analysis revealed significant alterations in the microbial metabolite levels after EVPA treatment, including urobilinogen, formamidopyrimidine nucleoside triphosphate, Cer (d18:1/18:0), pantetheine, and LysoPC (15:0/0:0). These altered metabolites are associated with pathways related to sphingolipid metabolism, carbapenem biosynthesis, pantothenate and CoA biosynthesis, glycerophospholipid metabolism, and porphyrin metabolism. Furthermore, significant correlations were observed between certain microbial groups and the differential metabolites. These findings provide new insights into the immunomodulatory effects of EVPA on the intestinal microbiota and metabolism, laying the foundation for more extensive utilization.

Denitrification Characteristics of the Low-Temperature Tolerant Denitrification Strain Achromobacter spiritinus HS2 and Its Application.

The low-temperature environment significantly inhibits the growth and metabolism of denitrifying bacteria, leading to an excessive concentration of ammonia nitrogen and total nitrogen in sewage treatment plants during the cold season. In this study, an efficient denitrifying strain of heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria named HS2 was isolated and screened from industrial sewage of a chemical factory in Inner Mongolia at 8 °C. The strain was confirmed to be Achromobacter spiritinus, a colorless rod-shaped bacterium. When cultured with sodium succinate as the carbon source, a carbon-to-nitrogen ratio of 20-30, a shaking rate of 150-180 r/min, and an initial pH of 6-10, the strain HS2 exhibited excellent nitrogen removal at 8 °C. Through the results of whole-genome sequencing, gene amplification, and gas product detection, the strain HS2 was determined to possess key enzyme genes in both nitrification and denitrification pathways, suggesting a HN-AD pathway of NH4+-N → NH2OH → NO2-N → NO → N2O → N2. At 8 °C, the strain HS2 could completely remove ammonia nitrogen from industrial sewage with an initial concentration of 127.23 mg/L. Microbial species diversity analysis of the final sewage confirmed Achromobacter sp. as the dominant genus, which indicated that the low-temperature denitrifying strain HS2 plays an important role in nitrogen removal in actual low-temperature sewage.

Characterization of bacterial diversity and screening of cellulose-degrading bacteria in the gut system of Glenea cantor (Fabricius) larvae.

The intestinal bacteria of longhorn beetles would be ideal targets for pest control and lignocellulosic resources by destroying or exploiting their cellulose-degrading function. This article aims to investigate the diversity and community structure of intestinal bacteria the oligophagous longhorn beetle Glenea cantor. Additionally, it seeks to identify the presence of lignocellulose-degrading bacteria in the gut, and explore their role in consuming host kapok trees Bombax malabaricum. In this study, the bacterial community from G. cantor was examined by Illumina sequencing of 16S ribosomal RNA (rRNA) targeting the V3 and V4 regions. A total of 563,201 valid sequences and 814 OTUs were obtained. The dominant phyla were Proteobacteria, and the dominant genera were Acinetobacter and Lactococcus. The analysis of microbial diversity revealed a high bacterial diversity in the samples, with the gut bacteria playing a crucial role in the physiological activities of the host, particularly, 9 genera of intestinal bacteria with cellulose degradation function were found, highlighting their vital role in cellulose degradation. Five strains of cellulose-degrading bacteria, belonging to the genus Pseudomonas, were obtained from the intestinal tract of G. cantor larvae using traditional isolation and culture techniques as well as 16S rDNA sequencing. Among these strains, A4 exhibited a cellulase activity of 94.42 ± 0.42U/mL, while A5 displayed the highest filter paper enzyme activity of 127.46 ± 3.54U/mL. These results offered valuable insights into potential targets for pest control through internal attack digestion and cellulose-degrading bacteria in longhorn beetles.

Bacterial diversity in cheese wastewater using Next-Generation Sequencing (NGS)

Abstract. Estikomah SA, Suranto, Susilowati A, Masykuri M. 2024. Bacterial diversity in cheese wastewater using Next-Generation Sequencing (NGS). Biodiversitas 25: 482-490. Cheese wastewater (whey) has a high content of organic substances, including lactose, protein, and fat. The lactose in whey wastewater can also be used as a bacterial growth medium. Bacterial community structure is an essential aspect of microbial water quality. The bacterial diversity data obtained can then be used to evaluate the existence of bacteria that might be useful for making microbiological products. This research employs Next Generation Sequencing (NGS) technology to determine the diversity and abundance of bacteria based on 16S rRNA gene amplicons for further processing of whey wastewater. The NGS-based technique overcomes the limitations of conventional bacterial culture techniques. The effectiveness and accuracy of microbial diversity analysis employing NGS technology are high. The research method includes the steps of sample preparation, DNA extraction using a ZymoBIOMICS DNA Microprep Kit (D4300), PCR amplification of the V3-V4 16S rRNA gene region, DNA sequencing, and a bioinformatics-statistical analysis. The results show that bacterial diversity in whey wastewater was found to have an average number of Operational Taxon Units (OTUs) of 259 tags. The metagenomics study of the microbial community in whey wastewater successfully detected the dominant genus of bacteria, which can benefit the management of whey wastewater. The presence of Lactobacillus and Acetobacter confirms that cheese whey wastewater exists in Yogyakarta Province. Acetobacter can oxidize ethanol to produce acetic acid, a pungent odor characteristic that causes environmental pollution. On the other hand, the presence of Lactobacillus and Acetobacter shows that whey wastewater can be reprocessed to produce fermented beverages, thereby improving their value and minimizing the impact of environmental pollution.

Modulation of Performance, Plasma Constituents, Small Intestinal Morphology, and Cecum Microbiota in Growing Geese by Dietary Citric Acid Supplementation.

To investigate the efficiency and optimum inclusion level of CA in growing geese diets on performance, plasma constituents, and intestinal health, 240 healthy female geese at the age of 28d were randomly allotted six treatment diets incorporated with 0, 0.8, 1.6, 2.4, 3.2, and 4% CA. Each treatment group consisted of five replicates and eight birds per replicate. The findings demonstrated that 3.2% CA supplementation resulted in improved growth performance (ADG, ADFI, and FBW) (p = 0.001), and geese who received CA also showed lower body fat contents (p < 0.05) than the control group. Moreover, geese from the 2.4% and 3.2% CA group had the highest plasma glutathione peroxidase and insulin-like growth factor 1 levels compared to the other groups (p < 0.05). A microbial diversity analysis of the cecum conducted by 16S rDNA sequencing revealed that 3.2% CA supplementation showed a significantly higher abundance of beneficial bacteria (Muribaculaceae, CHKCI001, Erysipelotricha-ceae_UCG_003, and UCG_009) (p < 0.05) and a lower abundance of harmful bacteria (Atopobiaceae, Streptococcus, Acinetobacter, Pseudomonas, and Alistipes) (p < 0.10). Collectively, our results revealed that dietary supplementation with 3.2% CA had several benefits on the performance and physiological health of growing geese by promoting nutrients metabolism, improving antioxidant capacity, and modulating cecum microbiota.

Effect of commutation on pressure drop and microbial diversity in a horizontal biotrickling filter for toluene removal.

A horizontal biotrickling filter (HBTF) was designed to understand the toluene removal process and microbial community structures. The start-up time of the HBTF, immobilized by the dominant fungi was only about 6 days and the toluene removal efficiency was found to be more than 95% when the inlet toluene concentration remained at around 1560.0 mg/m3. In the stable operation stage of the HBTF, based on not greatly reducing the removal efficiency, a simple and convenient periodic commutation was adopted to reduce the pressure drop (△P) and regulate the distribution of microorganisms in the packing area of the HBTF. The △P decreased from about 90 Pa to 10 Pa after the commutation, which indicated its feasibility. The performance of the HBTF was improved by changing the inlet direction of waste gas flow. When the inlet concentration of toluene was about 640mg/m3, the removal efficiency was nearly 70.0% before commutation and it remained 95.0-98.0% after commutation. Microbial abundance and diversity analysis showed that the corresponding Shannon-Weiner index was 2.73 and 1.84, respectively. The front section of the HBTF, which was exposed to toluene earlier, consistently exhibited higher microbial diversity than that in the back section. Following commutation, microbial diversity decreased in both the front and back sections, with a maximum decline of around 50%. The main fungi treating toluene were Aplanochytrium, Boletellus, and Exophiala.

The distribution characteristics of aerosol bacteria in different types of sheepfolds.

With the development of modern sheep raising technology, the increasing density of animals in sheep house leads to the accumulation of microbial aerosols in sheep house. It is an important prerequisite to grasp the characteristics of bacteria in aerosols in sheep house to solve the problems of air pollution and disease prevention and control in sheep house. In this study, the microorganisms present in the air of sheep houses were investigated to gain insights into the structure of bacterial communities and the prevalence of pathogenic bacteria. Samples from six sheep pens in each of three sheep farms, totaling 18, were collected in August 2022 from Ningxia province, China. A high-volume air sampler was utilized for aerosol collection within the sheep housing followed by DNA extraction for 16S rRNA sequencing. Employing high-throughput 16S rRNA sequencing technology, we conducted an in-depth analysis of microbial populations in various sheep pen air samples, enabling us to assess the community composition and diversity. The results revealed a total of 11,207 operational taxonomic units (OTUs) within the bacterial population across the air samples, encompassing 152 phyla, 298 classes, 517 orders, 853 families, 910 genera, and 482 species. Alpha diversity and beta diversity analysis indicated that differences in species diversity, evenness and coverage between different samples. At the bacterial phylum level, the dominant bacterial groups are Firmicutes, Proteobacteria, and Actinobacteria, among which Firmicutes (97.90-98.43%) is the highest. At the bacterial genus level, bacillus, Bacteroides, Fusobacterium, etc. had higher abundance, with Bacillus (85.47-89.87%) being the highest. Through an in-depth analysis of microbial diversity and a meticulous examination of pathogenic bacteria with high abundance in diverse sheep house air samples, the study provided valuable insights into the microbial diversity, abundance, and distinctive features of prevalent pathogenic bacteria in sheep house air. These findings serve as a foundation for guiding effective disease prevention and control strategies within sheep farming environments.

Incorporating saline microalgae biomass in anaerobic digester treating sewage sludge: Impact on performance and microbial populations

The aim of this study was to acclimate anaerobic prokaryotes to saline microalgae biomass. Semi-continuous experiments were conducted using two 1.5 L mesophilic reactors for 10 weeks, (hydraulic retention time of 21 days). The first reactor was solely fed with sewage sludge (control), while the second received a mixture of sewage sludge and microalgal biomass (80/20 %w/w) cultivated at 70 g·L-1 salinity. The in-reactor salinity reached after the acclimation phase was 14 g·L-1. Biomethane production was comparable between the control and acclimated reactors (205 ± 29 NmLMethane·gVolatileSolids-1). Salinity tolerance assessment of methanogenic archaea revealed that salinity causing 50% inhibition of methane production increased from 10 to 27 g·L-1 after acclimation. Microbial diversity analyses revealed notable changes in methanogenic archaea populations during co-digestion of saline microalgae biomass, particularly methylotrophic (+27%) and acetotrophic (-26%) methanogens. This study has highlighted the possibility of treating efficiently saline microalgae in co-digestion with sewage sludge in future industrial biogas plants.

Integrated Analysis of the Transcriptome and Microbial Diversity in the Intestine of Miniature Pig Obesity Model.

Obesity, a key contributor to metabolic disorders, necessitates an in-depth understanding of its pathogenesis and prerequisites for prevention. Guangxi Bama miniature pig (GBM) offers an apt model for obesity-related studies. In this research, we used transcriptomics and 16S rRNA gene sequencing to discern the differentially expressed genes (DEGs) within intestinal (jejunum, ileum, and colon) tissues and variations in microbial communities in intestinal contents of GBM subjected to normal diets (ND) and high-fat, high-carbohydrate diets (HFHCD). After a feeding duration of 26 weeks, the HFHCD-fed experimental group demonstrated notable increases in backfat thickness, BMI, abnormal blood glucose metabolism, and blood lipid levels alongside the escalated serum expression of pro-inflammatory factors and a marked decline in intestinal health status when compared to the ND group. Transcriptomic analysis revealed a total of 1669 DEGs, of which 27 had similar differences in three intestinal segments across different groups, including five immune related genes: COL6A6, CYP1A1, EIF2AK2, NMI, and LGALS3B. Further, we found significant changes in the microbiota composition, with a significant decrease in beneficial bacterial populations within the HFHCD group. Finally, the results of integrated analysis of microbial diversity with transcriptomics show a positive link between certain microbial abundance (Solibacillus, norank_f__Saccharimonadaceae, Candidatus_Saccharimonas, and unclassified_f__Butyricicoccaceae) and changes in gene expression (COL6A6 and NMI). Overall, HFHCD appears to co-contribute to the initiation and progression of obesity in GBM by aggravating inflammatory responses, disrupting immune homeostasis, and creating imbalances in intestinal flora.