Dominant Flora Research Articles

Effect of EDDS on the rhizosphere ecology and microbial regulation of the Cd-Cr contaminated soil remediation using king grass combined with Piriformospora indica

The negative impacts of soil heavy metals composite pollution on agricultural production and human health are becoming increasingly prevalent. The applications of green chelating agents and microorganisms have emerged as promising alternate methods for enhancing phytoremediation. The regulatory effects of root secretion composition, microbial carbon source utilization, key gene expression, and soil microbial community structure were comprehensively analyzed through a combination of HPLC, Biolog EcoPlates, qPCR, and high-throughput screening techniques. The application of EDDS resulted in a favorable rhizosphere ecological environment for the king grass Piriformospora indica, characterized by a decrease in soil pH by 0.41 units, stimulation of succinic acid and fumaric acid secretion, and an increase in carbon source metabolic activity of amino acids and carbohydrates. Consequently, this improvement enhanced the bioavailability of Cd/Cr and increased the biomass of king grass by 25.7%. The expression of dissimilatory iron-reducing bacteria was significantly upregulated by 99.2%, while there was no significant difference in Clostridium abundance. Furthermore, the richness of the soil rhizosphere fungal community (Ascomycota: 45.8%, Rozellomycota: 16.7%) significantly increased to regulate the proportion of tolerant microbial dominant groups, promoting the improvement of Cd/Cr removal efficiency (Cd: 23.4%, Cr: 18.7%). These findings provide a theoretical basis for the sustainable development of chelating agent-assisted plants-microorganisms combined remediation of heavy metals in soil.

Evaluation of the Impact of Herbicidal Weed Management Practices on Weed Density, Yield Attributes and Yield of Irrigated Chickpea (Cicer arietinum L.)

In the Rabi season of 2021-22, an experiment was conducted at the Agronomy Research Farm of CCS Haryana Agricultural University in Hisar. The aim was to examine how herbicidal weed management affects irrigated chickpea. The experiment was laid out in Randomised Block Design (RBD) with thirteen treatments, each repeated three times. The treatments included various herbicides applied at different stages, such as pre-plant incorporation (PPI), pre-emergence (PRE), and post-emergence (POE). Interestingly, the Ready mix (RM) herbicide application of pendimethalin + imazethapyr (RM) @ 1000 g a.i ha-1, applied both as PPI and PRE, outperformed the herbicides applied solely as PPI, PRE, or POE. Among the herbicidal treatments, the combined during PPI and PRE stages exhibited excellent control over a diverse weed population, leading to a significant increase in chickpea yield compared to the weedy check. The number of seeds per pod, pods per plant, and branches per plant varied significantly with different weed control treatments. Weed-free plots showed the highest values in these parameters. The uncontrolled growth of weeds in the weedy check resulted in a 55.2% reduction in seed yield as compared to weed-free plots. The maximum seed yield (1968 kg ha-1) and favorable yield attributes were observed in the weed- free treatment, statistically comparable to the yield obtained from two hand weeding at 30 and 50 days after sowing (1940 kg ha-1). Among herbicidal treatments, the highest seed yield was achieved with the PRE application of pendimethalin + imazethapyr (RM) @ 1000 g a.i. ha-1 (1827 kg ha-1). The dominant weed flora consisted of Chenopodium album, Fumaria parviflora and Anagallis arvensis. Density of different weed species was significantly influenced by different weed control treatments. All the weed control treatments significantly reduced the total weed density and dry matter accumulation by weeds in comparison to weedy check. Weed free and two hand hoeing reduced the weed population drastically which was statistically at par with PRE application of pendimethalin + imazethapyr (RM) at 1000 g a.i. ha-1. Chenopodium album, Fumaria parviflora and Anagallis arvensis were effectively controlled by RM irrespective of its time of application.

Glycerol tributylate (Triacylglycerol tributanoate) promoted the liver lipid metabolism by cultivating the intestinal flora of grass carp (Ctenopharyngodon idellus).

To investigate the effects of glycerol tributyrin (TB) (Triacylglycerol tributanoate) on the regulation of liver lipid metabolism by intestinal flora of grass carp (Ctenopharyngodon idellus). The compound feed with soybean oil 2.8% + fish oil 1.8%, soybean oil 6.3% + fish oil 1.8%, and soybean oil 6.2% + fish oil 1.8% + TB 0.1% was added to the basal diet as a fat source and fed to the basal (control) group, high lipid (HL) group, and tributyrin (TB) group for 12weeks. We tested the growth performance, fat content, diversity, and abundance of gut flora and other related indexes of grass carp by Soxhlet extraction, liver tissue enzyme activity, oil red O staining, and 16S rRNA high-throughput sequencing. The results showed that the liver fat number and liver fat content of grass carp in the TB group were lower than those in the HL group, while the fattening degree was significantly higher than those in the other two groups; according to the indices such as Shannon, Ace, and Coverage, it was found that the grass carp in the TB group had the highest abundance and diversity of intestinal microflora; at the portal level, Proteobacteria and Fusobacteria were the main dominant flora in the TB group, with the number of unique OUTs accounting for about 59. 9% of the total number measured; at the genus level, the relative abundance of lipase-producing, short-chain fatty acid-associated bacteria, such as Bacillus-Lactobacillus and Bifidobacterium, was significantly lower (p < 0.05). Thus, we conclude that the addition of TB to high-fat diets can alter the structure of the intestinal microbial community and promote hepatic lipid metabolism in grass carp. TB can alleviate fatty liver in grass carp by increasing the relative abundance of short-chain fatty acids in the intestine. Meanwhile, TB inhibits the conversion of primary bile acids to secondary bile acids in the host, which can block intestinal FXR signaling and the hepatic FXR-SHP pathway, thus slowing down fat synthesis and alleviating the accumulation of liver lipids in grass carp.

Altered metabolome and microbiome features provide clues in predicting recurrence of ulcerative colitis

PurposeMany studies have shown that the imbalance of the intestinal flora and metabolite can lead to the development of ulcerative colitis (UC), but their role in recurrent-UC is still unclear. We studied the intestinal flora and metabolites associated with recurrent-UC to elucidate the mechanism and biomarkers of recurrent-UC. MethodsUlcerative colitis (UC) models in active, remission, and recurrence stages were established, and the abundance of intestinal flora was determined by 16 S rRNA sequencing. The changes in the metabolites present in feces and serum were analyzed by UPLC-MS/MS. ResultsWe identified 24 metabolites in feces and serum, which might be used as diagnostic and predictive biomarkers of recurrent-UC. The dominant flora of recurrent-UC included Romboutsia, UCG-005, etc. The results of a network analysis found that long-chain fatty acids and phenylalanine were strongly correlated with Firmicutes and Proteobacteria, which indicated that the recurrence of UC might be closely related to metabolites and microorganisms. ConclusionThe changes in intestinal microbiota and metabolites are closely related to the development of UC. Microbiota is an important inducer of UC, which can regulate metabolites through the 'microorganism-gut-metabolite' axis. It may provide a new method for the prediction and treatment of UC.

Microbial Profile of Fresh and Semicooked Nile Tilapia (Oreochromis niloticus) and Hygienic Practice of Fish Handlers in Hawassa, Ethiopia.

Despite its high nutritional quality, fish is a highly perishable food item. This study aimed at assessing the microbial quality and safety of fresh and semicooked Nile tilapia fish fillets and the food safety practices of fish handlers in Hawassa City. The microbial load of 40 for each of raw and semicooked fillet samples was estimated by the standard plate count method, and the dominant flora as well as common bacterial pathogens were identified following phenotypic procedures. Moreover, a survey was conducted to assess the hygienic conditions and food safety practices of 30 fish handlers. The mean microbial load of the raw fillet samples in log10CFUg-1 was 8.42 for aerobic mesophilic bacteria (AMBC), 2.52 for total coliforms (TCC), and 3.41 for a count of staphylococci (CS). On the other hand, the respective parameters for the semicooked fillets in log10CFUg-1 were 6.68 (AMBC), 2.52 (TCC), and 3.17 (CS). The mean AMBC of all the fresh raw fillet samples exceeded the recommended maximum permissible limits. The mean SC of raw fillets from three of the eight vendors and one semicooked fillet were at a potentially hazardous level (>4 log units). Moreover, Salmonella species were isolated from 30% to 25% of raw and semicooked samples, respectively. The mesophilic bacterial flora of both types of samples was dominated by Bacillus species, Salmonella species, E coli, and Staphylococcus species. Most fish handlers did not practice hygienic food handling and lacked basic sanitation amenities like clean water and soap for hand washing. Moreover, nearly all the fish handlers did not have any formal education. These findings call for public health intervention measures like the provision of training in good hygienic practices and certification for fish vendors in the chain.

Prickly Ash Seeds improve immunity of Hu sheep by changing the diversity and structure of gut microbiota.

Prickly Ash Seeds (PAS), as a traditional Chinese medicinal herb, have pharmacological effects such as anti-asthma, anti-thrombotic, and anti-bacterial, but their impact on gut microbiota is still unclear. This study used a full-length 16 s rRNA gene sequencing technique to determine the effect of adding PAS to the diet on the structure and distribution of gut microbiota in Hu sheep. All lambs were randomly divided into two groups, the CK group was fed with a basal ration, and the LZS group was given a basal diet with 3% of PAS added to the ration. The levels of inflammatory factors (IL-10, IL-1β, and TNF-α) in intestinal tissues were measured by enzyme-linked immunosorbent assay (ELISA) for Hu sheep in the CK and LZS group. The results indicate that PAS can increase the diversity and richness of gut microbiota, and can affect the community composition of gut microbiota. LEfSe analysis revealed that Verrucomicrobiota, Kiritimatiella, WCHB 41, and uncultured_rumen_bacterium were significantly enriched in the LZS group. KEGG pathway analysis found that LZS was significantly higher than the CK group in the Excretory system, Folding, sorting and degradation, and Immune system pathways (p < 0.05). The results of ELISA assay showed that the level of IL-10 was significantly higher in the LZS group than in the CK group (p < 0.05), and the levels of TNF-α and IL-1β were significantly higher in the CK group than in the LZS group (p < 0.05). LEfSe analysis revealed that the dominant flora in the large intestine segment changed from Bacteroidota and Gammaproteobacteria to Akkermansiaceae and Verrucomicrobiae after PAS addition to Hu sheep lambs; the dominant flora in the small intestine segment changed from Lactobacillales and Aeriscardovia to Kiritimatiellae and WCHB1 41. In conclusion, the addition of PAS to sheep diets can increase the number and types of beneficial bacteria in the intestinal tract, improve lamb immunity, and reduce intestinal inflammation. It provides new insights into healthy sheep production.

The dual role of potassium ferrate in promoting primary sludge hydrolysis and acidogenesis in anaerobic fermentation

Potassium ferrate (PF), a green disinfectant has been widely used in drinking water disinfection and has drawn immense attention for its application in sludge treatment. This research study has investigated the effects of PF on the hydrolysis and acidification of primary sludge (PS) to promote the short chain fatty acids (SCFAs) recovery, while achieving solid waste treatment and carbon emission reduction. The results showed that PF could effectively promote the accumulation of SCFAs, and maximum SCFAs yield of 4686.56 mg COD/L was achieved by PF assisted PS fermentation at a PF dosage of 0.4 g/g VSS, which was 2.05 times higher than the control. Substance transformation and enzyme activity analysis indicated that PF significantly promoted the release and hydrolysis of insoluble organic matters from PS through chemical oxidation and alkaline hydrolysis. Furthermore, high doses of PF could also inhibit the growth of methanogens and alter the dominant fermentation flora responsible for SCFAs production. Under the influence of high-dose PF, the foremost acidogenic bacteria were shifted into Trichococcus, Enterococcus, Streptococcus and Gallicola, which might be selectively enriched under the stress of residual Fe (Ⅲ) in the system. The PS fermentation liquid produced after PF pretreatment exhibited a higher C/N ratio and lower phosphorus concentration, which enhanced its suitability as carbon sources for denitrification in WWTPs. This study offered an environmentally friendly method for recovering SCFAs from PS and provided a viable approach to addressing the issue of carbon source shortage in wastewater treatment processes.

Lactobacillus plantarum Zhang-LL Inhibits Colitis-Related Tumorigenesis by Regulating Arachidonic Acid Metabolism and CD22-Mediated B-Cell Receptor Regulation.

Colorectal cancer (CRC) is a significant health concern and is the third most commonly diagnosed and second deadliest cancer worldwide. CRC has been steadily increasing in developing countries owing to factors such as aging and epidemics. Despite extensive research, the exact pathogenesis of CRC remains unclear, and its causes are complex and variable. Numerous in vitro, animal, and clinical trials have demonstrated the efficacy of probiotics such as Lactobacillus plantarum in reversing the adverse outcomes of CRC. These findings suggest that probiotics play vital roles in the prevention, adjuvant treatment, and prognosis of CRC. In this study, we constructed a mouse model of CRC using an intraperitoneal injection of azomethane combined with dextran sodium sulfate, while administering 5-fluorouracil as well as high- and low-doses of L. plantarum Zhang-LL live or heat-killed strains. Weight changes and disease activity indices were recorded during feeding, and the number of polyps and colon length were measured after euthanasia. HE staining was used to observe the histopathological changes in the colons of mice, and ELISA was used to detect the expression levels of IL-1β, TNF-α, and IFN-γ in serum. To investigate the specific mechanisms involved in alleviating CRC progression, gut microbial alterations were investigated using 16S rRNA amplicon sequencing and non-targeted metabolomics, and changes in genes related to CRC were assessed using eukaryotic transcriptomics. The results showed that both viable and heat-killed strains of L. plantarum Zhang-LL in high doses significantly inhibited tumorigenesis, colon shortening, adverse inflammatory reactions, intestinal tissue damage, and pro-inflammatory factor expression upregulation. Specifically, in the gut microbiota, the abundance of the dominant flora Acutalibacter muris and Lactobacillus johnsonii was regulated, PGE2 expression was significantly reduced, the arachidonic acid metabolism pathway was inhibited, and CD22-mediated B-cell receptor regulation-related gene expression was upregulated. This study showed that L. plantarum Zhang-LL live or heat-inactivated strains alleviated CRC progression by reducing the abundance of potentially pathogenic bacteria, increasing the abundance of beneficial commensal bacteria, mediating the arachidonic acid metabolism pathway, and improving host immunogenicity.

An exploration of mechanism of high quality and yield of Gastrodia elata Bl. f. glauca by the isolation, identification, and evaluation of Mycena

Gastrodia elata Bl. f. glauca is an important traditional Chinese medicinal plant. The yield and quality of Gastrodia elata Bl. have significantly decreased due to multigenerational asexual reproduction. Therefore, it is necessary to have sexual reproduction of Gastrodia elata Bl. to supplement the market supply. Seeds of G. elata Bl. have no endosperm, and their sexual reproduction depends on the nutrients provided by the embryo cells infected by Mycena fungi to complete seed germination. However, Mycena fungi are small and have many species, and not all Mycena fungi can promote the germination of G. elata Bl. seeds. Therefore, it is of great significance to isolate and identify suitable germination fungi and explore the mechanism for improving the production performance and yield, and quality of G. elata Bl. Six closely related Mycena isolates, JFGL-01, JFGL-02, JFGL-03, JFGL-04, JFGL-05, and JFGL-06, were isolated from the leaves and protocorms of G. elata Bl. f. glauca and were identified as Mycena purpureofusca. The mycelial state and number of germinating protocorms were used as indicators to preferentially select Mycena fungi, and it was concluded that JFGL-06 had the best mycelial state and ability to germinate G. elata Bl. seeds. Finally, a mechanism to increase the yield of G. elata Bl. was explored by comparing the changes in nutrient elements and microbial diversity in the soil around G. elata Bl. with different strains. JFGL-06 proved to be an excellent Mycena fungal strain suitable for G. elata Bl. f. glauca. Compared with the commercial strain, JFGL-06 significantly increased the C, N, Na, Mg, S, Cl, K, Ca, and Fe contents of the soil surrounding the protocorms of G. elata Bl. f. glauca. JFGL-06 improved the composition, diversity, and metabolic function of the surrounding soil microbial community of G. elata Bl. f. glauca protocorms at the phylum, class, and genus levels, significantly increased the relative abundance of bacteria such as Acidobacteria and fungi such as Trichoderma among the dominant groups, and increased the abundance of functional genes in metabolic pathways such as nucleotide metabolism and energy metabolism. There was a significant reduction in the relative abundance of bacteria, such as Actinomycetes, and fungi, such as Fusarium, in the dominant flora, and a reduced abundance of functional genes, such as amino acid metabolism and xenobiotic biodegradation and metabolism. This is the main reason why the JFGL-06 strain promoted high-quality and high-yield G. elata Bl. f. glauca in Changbai Mountain.

Oropharyngeal administration of colostrum targeting gut microbiota and metabolites in very preterm infants: protocol for a multicenter randomized controlled trial

BackgroundOropharyngeal administration of colostrum (OAC) has an immune-stimulating effect on oropharyngeal-associated lymphoid tissue, and can promote the maturation of the gastrointestinal tract. However, how OAC promotes intestinal maturation in preterm infants by altering gut microbiota remains unclear. We aim to assess changes in gut microbiota and metabolites after OAC in very preterm infants.MethodsA multicenter, double-blind, randomized controlled trial will be conducted in three large neonatal intensive care units in Shenzhen, China, with preterm infants with gestational age less than 32 weeks at birth and birth weight less than 1500 g. It is estimated that 320 preterm infants will be enrolled in this study within one year. The intervention group will receive oropharyngeal administration of 0.2 ml colostrum every 3 h, starting between the first 48 to 72 h and continued for 5 consecutive days. Following a similar administration scheme, the control group will receive oropharyngeal administration of sterile water. Stool samples will be collected at the first defecation, as well as on the 7th, 14th, 21st and 28th days after birth for analysis of effect of OAC on gut microbiota and metabolites through 16sRNA gene sequencing and liquid chromatography-mass spectrometry.DiscussionThis proposal advocates for the promotion of OAC as a safe and relatively beneficial protocol in neonatal intensive care units, which may contribute to the establishment of a dominant intestinal flora. Findings of this study may help improve the health outcomes of preterm infants by establishment of targeted gut microbiota in future studies.Trial registrationNCT05481866 (registered July 30, 2022 on ClinicalTrials.gov).

Ecosystem type and species’ traits help explain bird responses to spatial patterns of fire

BackgroundUnderstanding how temporal and spatial attributes of fire regimes, environmental conditions, and species’ traits interact to shape ecological communities will help improve biodiversity conservation in fire-affected areas. We compared the influence of time since the last fire at a site, and the area and diversity of post-fire successional vegetation surrounding a site (i.e., the “spatial context” of fire), on bird species and functional groups in two ecosystems in south-eastern Australia. These ecosystems, semi-arid “mallee” woodlands and temperate “foothill” forests, differ in stand-regeneration patterns, climate, and topography. For 22 bird species in mallee woodlands, 33 species in foothill forests and four functional groups of birds in both ecosystems, we fitted non-linear models that differed in fire regime predictor variables.ResultsIn foothill forests, models that included both time since fire and a spatial context variable explained more variation in bird abundances than models that included only time since fire or a spatial variable. In mallee woodlands, the addition of spatial attributes of fire helped explain the occurrence of several species, but this finding was muted when measured across all species. There were key differences between ecosystems in functional group responses to fire regimes. Canopy/upper-midstorey foragers were positively associated with the amount of late-successional vegetation in mallee woodlands, but not in foothill forests. Lower-midstorey foragers showed a decline response to the amount of late-successional vegetation in mallee woodlands and a contrasting incline response in foothill forests. However, lower-midstorey foragers showed a similar response to the amount of surrounding early-successional vegetation in both ecosystems—decreasing in abundance when > 50% of the surrounding vegetation was early-successional.ConclusionsThe influence of fire regimes on birds varies among species within sites, across landscapes and between ecosystems. Species’ foraging traits influence bird associations with fire regimes, and help to make sense of a myriad of relationships, but are usefully understood in the context of ecosystem types and the regeneration patterns of their dominant flora. The spatial context of fire regimes is also important—the amount of successional vegetation surrounding a site influences bird abundance. Fire management strategies that incorporate the spatial contexts of fire regimes, as well as the temporal and ecological contexts of fire regimes, will have the greatest benefits for biodiversity.

The multidrug-resistant Pseudomonas fluorescens strain: a hidden threat in boar semen preservation.

Although the bacterial composition of boar ejaculate has been extensively studied, the bacterial composition of extended boar semen is often overlooked, despite the potential risks these microorganisms may pose to the long-term preservation of extended boar semen at 15-17°C. In this study, we characterized the bacterial community composition of extended semen and discovered that Pseudomonas spp. was the dominant flora. The dominant strains were further isolated and identified as a potential new species in the Pseudomonas fluorescens group and named GXZC strain, which had adverse effects on sperm quality and was better adapted to growth at 17°C. Antimicrobial susceptibility testing showed that the GXZC strain was resistant to all commonly used veterinary antibiotics. Whole-genome sequencing (WGS) and genome annotation revealed the large genetic structure and function [7,253,751 base pairs and 6,790 coding sequences (CDSs)]. Comparative genomic analysis with the closest type strains showed that the GXZC strain predicted more diversity of intrinsic and acquired resistance genes to multi-antimicrobial agents. Taken together, our study highlights a problem associated with the long-term storage of extended boar semen caused by a P. fluorescens group strain with unique biological characteristics. It is essential to develop a new antibacterial solution for the long-term preservation of boar semen.

Microbial denitrification characteristics of typical decentralized wastewater treatment processes based on 16S rRNA sequencing.

Despite the widespread application of decentralized wastewater treatment (WWT) facilities in China, relatively few research has used the multi-media biological filter (MMBF) facilities to investigate the microorganism characteristics. This study utilizes 16S rRNA high-throughput sequencing (HTS) technology to examine the microbial biodiversity of a representative wastewater treatment (WWT) system in an expressway service area. The pathways of nitrogen removal along the treatment route were analyzed in conjunction with water quality monitoring. The distribution and composition of microbial flora in the samples were examined, and the dominant flora were identified using LEfSe analysis. The FAPROTAX methodology was employed to investigate the relative abundance of genes associated with the nitrogen cycle and to discern the presence of functional genes involved in nitrogen metabolism. On average, the method has a high level of efficiency in removing COD, TN, NH3-N, and TP from the effluent. The analysis of the microbial community identified a total of 40 phyla, 111 classes, 143 orders, 263 families, and 419 genera. The phyla that were predominantly observed include Proteobacteria, Acidobacteria, Chloroflexi, Actinobacteria, Nitrospirae, Bacteroidetes. The results show that the system has achieved high performance in nitrogen removal, the abundance of nitrification genes is significantly higher than that of other nitrogen cycle genes such as denitrification, and there are six nitrogen metabolism pathways, primarily nitrification, among which Nitrospirae and Nitrospira are the core differentiated flora that can adapt to low temperature conditions and participate in nitrification, and are the dominant nitrogen removal flora in cold regions. This work aims to comprehensively investigate the diversity and functional properties of the bacterial community in decentralized WWT processes.

Microbiome Reveals the Effects of Biogas Fertilizer on Soil Microbial Community Structure and Diversity in Perennial Apple Orchards

Fruit trees are perennial crops that grow in one place for their whole lives, which leads to the deterioration of the soil as well as a decline in fruit quality and yield. Microbial diversity and community structure are important soil factors affecting stress resistance and the quality of fruit trees. Additionally, biogas fertilizer also plays an important role in improving fruit quality. Whether biogas fertilizer can improve continuous cropping barriers by affecting microbial diversity and community structure remains to be further investigated. Therefore, 7-year-old Fuji apples were used as material, and biogas fertilizer was applied continuously for three years. The results show that the contents of soil organic matter (SOM), available nitrogen (AN), available phosphorus (AP), and soil porosity (SP) increased by 0.712, 0.217, 1.089, and 0.401 after applying biogas fertilizer, respectively. The concentrations of vitamin C, titratable acid, and soluble solids also significantly increased. We also found that the relative abundance of dominant soil flora significantly increased, such as Sphingomonas (g_Sphingomonas), Chlamydomonas (g_Chlamydomonas), and Stachybotry (g_Stachybotry), while the relative abundance of inferior flora significantly decreased, such as Cryptococcus (g_Cryptococcus) and Alternaria (g_Alternaria). In summary, biogas fertilizer can improve the physicochemical properties of the soil as well as the structure and diversity of the microbial communities in rainfed orchards, resulting in higher fruit quality.

A comparison of digestive strategies for fishes with different feeding habits: Digestive enzyme activities, intestinal morphology, and gut microbiota.

Fish feeding habit determines the digestive tract structure and intestinal microflora. However, the relationship between feeding habit, digestive intestinal morphology, and microbial diversity of omnivorous, herbivorous, plankton feeder, and carnivorous fish from the same environment has not been compared. This study compared the digestive enzyme activities, intestinal morphology, and intestinal microflora of omnivorous (Carassius auratus), herbivorous (Ctenopharyngodon idellus), carnivorous (Siniperca chuatsi), and plankton feeder (Schizothorax grahami) fishes and predicted the potential functions of specific microflora on different nutrients. Twelve intestine samples were collected from each of the four fishes from Dianchi Lake. The composition and diversity of microbial communities were determined by using high-throughput sequencing of 16S rDNA. The results showed that the carnivorous fish (S. chuatsi) had higher trypsin and pancrelipase activities in the hepatopancreas and enteropeptidase in the intestine, but lower amylase activities in the intestine. The carnivorous fish intestine had more microvilli branches and complex structures than other fish species in the order carnivorous > herbivorous > plankton feeder > omnivorous. The intestinal microflora diversity was higher in the omnivorous fish and followed the order omnivorous > herbivorous > plankton feeder > carnivorous. Acinetobacter species and Bacteroides species were the most dominant flora in the carnivorous and herbivorous fishes, respectively. Acinetobacter species and Pseudomonas species might help the host to digest protein, while Bacteroidetes species may help the host to digest cellulose. Taken together, feeding habit determines the digestive enzyme activities, intestinal tissue morphology, and differential colonization of fish intestinal flora. The knowledge obtained is useful in feed formulation and feeding practices for the studied fish species.

Spoilage-related bacterial diversity of vacuum-packed plant-based meat as affected by essential oil and preservative

ABSTRACT Plant-based meat products have the potential to alleviate meat shortages, and has a limited shelf life of a few days under refrigeration. The main cause of food spoilage is the microorganism growth. In order to investigate which bacteria caused the spoilage and spoilage of plant-based meat, high-throughput sequencing technology was used to determine the predominant spoilage bacterial flora in untreated vacuum-packed (Placed for 14 days) plant-based meat and vacuum-packed plant-based meat treated with a composite essential oil (Placed for 112 days) or composite preservative (Placed for 70 days). The dominant flora in vacuum-packed plant-based meat was Enterococcus (accounting for 86.2%). The main bacterial families in the compound essential oil treatment group were norank_chloroplast and Lactobacillaceae (accounting for 74.2% and 14.23% of total abundance), and in the compound preservative treatment group were norank_chloroplast, Pseudomonadaceae, and Carnobacteriaceae (accounting for 35.98%, 33.19%, and 17.96% of total abundance). Treatment with compound essential oil or compound preservative not only prolongs the shelf life of plant-based meat but also modifies the spoilage bacterial flora. Afterwards, research needs to be continued on the molds and fungi that cause the spoilage of plant-based meat, filling the gap in this research direction. Due to provide practical support for the development of the plant-based meat preservation industry.

Effect of Herbicide (Propaquizafop and Imazethapyr) on Weed Flora Associated with Blackgram in Central India

An experiment was conducted at Product Testing Unit, Department of Agronomy, JNKVV, Jabalpur to study the effect of application of propaquizafop and imazethapyr herbicide on weeds associated with blackgram. The experimental field was having mixed weed flora comprising of grassy as well as broad leaved weeds. Nine treatments comprised of four rates of application of propaquizafop+ imazethapyr at 47+70, 50+75, 53+80 and 56+85 g/ha and alone application of propaquizafop (100 g/ha), imazethapyr (100 g/ha), pendimethalin (1500 g/ha) and hand weeding twice at 20 and 40 DAS including weedy check, were laid out in Randomized Block Design with three replications. All herbicide treatments were applied in 500 liters of water per hectare, using flat fan nozzle as per the treatments. The dominant weed flora, species wise weed density, weed biomass, Weed control efficiency and weed index were recorded at different interval. The study revealed that the Echinochloa colona (29.39%) and Dinebra retroflexa (24.30%) were the found as dominant weeds in the field whereas, other monocot weeds like Cyperus iria (18.19%) and dicot weeds like Mullugo pentaphylla (12.23%), Eclipta alba (7.58%) and Alternanthera philoxeroides (8.31%) were also present in less numbers in blackgram under weedy check plots. Among the herbicidal treatments, activity of propaquizafop+imazethapyr mixture at the dose 53+80 and 56+85 g/ha emerged as effective control for the weeds associated with blackgram.

Effects of adding cocoa fermentation medium on cigar leaves in agricultural fermentation stage.

Background and Objective: With the development of the world economy and the integration of cultures, the Chinese cigar market has shown a significant upward trend. However, high-quality cigar leaves are mostly produced in Dominica, Cuba, Nicaragua and other places. In contrast, Chinese cigar leaves have problems such as insufficient aroma, which has become one of the main factors restricting the development of Chinese cigars. Adding medium to ferment is a traditional method in the cigar industry. At present, it mostly relies on manual experience, and lacks systematic and scientific research. At the same time, the addition of medium fermentation is mainly concentrated in the industrial fermentation process, and has not yet begun to be applied in the agricultural fermentation process. In this study, the medium was added to the agricultural fermentation process for the first time to explore the possibility of the application. The effects of adding cocoa medium to ferment on the chemical composition, sensory quality and surface microbial diversity of eggplant core cigar leaves were investigated.wrapper. Method: With Dexue 7' as the experimental material, the changes of main chemical components of wrapper fermented with water and cocoa medium were determined, and microbial community structure on the surface and relative abundance of cigar leaves at different turning periods were analyzed, and the functional genes were predicted. The results of the study were as follows: 1) The results of sensory evaluation showed that the addition of cocoa medium could highlight the aroma of bean, cocoa and coffee, improve the sweetness and fluency and the combustibility of cigar leaves. 2) The addition of cocoa medium increased the contents of proline and malic acid which were positively correlated with sensory quality, and decreased the contents of citric acid, linoleic acid, basic amino acids and aromatic amino acids which were negatively correlated with sensory quality. 3) The addition of cocoa medium increased the total amount of aroma components in cigar leaves, especially carotenoid degradation products, and changed the structural composition of some aroma substances in wrappercigar leaves. 4) The similarity of species composition between the water-added group and the cocoa-added group was higher, but the dominant microorganisms were more concentrated. Staphylococcus and Arthrobacter maintained a high relative abundance throughout the fermentation process, which may be the key microorganisms in the agricultural fermentation stage. 5) The addition of cocoa medium increased the expression abundance of related functional genes in cigar leaves, accelerated the fermentation process of cigar leaves, and bacteria played a major role in the fermentation process. Conclusion: Adding cocoa medium in the agricultural fermentation stage, the changes of bacterial community and dominant flora on the surface of cigar leaves are the main factors affecting their internal chemical components, and the addition of media has a positive effect on tobacco fermentation.

Effect of gut microbiota homeostasis on hematopoiesis in a neonatal rat model of necrotizing enterocolitis

To study the effect of gut microbiota on hematopoiesis in a neonatal rat model of necrotizing enterocolitis (NEC). Neonatal Sprague-Dawley rats were randomly divided into a control group and a model group (NEC group), with 6 rats in each group. Formula milk combined with hypoxia and cold stimulation was used to establish a neonatal rat model of NEC. Hematoxylin and eosin staining was used to observe the pathological changes of intestinal tissue and hematopoiesis-related organs. Routine blood tests were conducted for each group. Immunohistochemistry was used to observe the changes in specific cells in hematopoiesis-related organs. Flow cytometry was used to measure the changes in specific cells in bone marrow. 16S rDNA sequencing was used to observe the composition and abundance of gut microbiota. Compared with the control group, the NEC group had intestinal congestion and necrosis, damage, atrophy, and shedding of intestinal villi, and a significant increase in NEC histological score. Compared with the control group, the NEC group had significantly lower numbers of peripheral blood leukocytes and lymphocytes (P<0.05), nucleated cells in the spleen, thymus, and bone marrow, and small cell aggregates with basophilic nuclei in the liver (P<0.05). The NEC group had significant reductions in CD71+ erythroid progenitor cells in the liver, CD45+ lymphocytes in the spleen and bone marrow, CD3+ T lymphocytes in thymus, and the proportion of CD45+CD3-CD43+SSChi neutrophils in bone marrow (P<0.05). There was a significant difference in the composition of gut microbiota between the NEC and control groups, and the NEC group had a significant reduction in the abundance of Ligilactobacillus and a significant increase in the abundance of Escherichia-Shigella (P<0.05), which replaced Ligilactobacillus and became the dominant flora. Multi-lineage hematopoietic disorder may be observed in a neonatal rat model of NEC, which may be associated with gut microbiota dysbiosis and abnormal multiplication of the pathogenic bacteria Escherichia-Shigella.

Drug resistance and molecular typing of diarrheagenic escherichia coli from the diarrhea clinics in Qingpu District, Shanghai City from 2015 to 2019

Objective: To analyze the drug resistance and multilocus sequence typing of five types of diarrheagenic Escherichia coli (DEC) isolated from diarrhea outpatients of diarrhea comprehensive monitoring designated hospital in Qingpu District, Shanghai City from 2015 to 2019. Methods: From January 2015 to December 2019, five types of DEC, isolated and identified from diarrhea outpatient cases' anal swabs of the Qingpu branch of Zhongshan Hospital were collected to determine the minimal inhibitory concentration by using the micro broth dilution susceptibility test. The strains, resistant to the third-generation cephalosporins or carbapenems, or producing ESBLs, were selected based on the results of sensitivity tests and determined by WGS. The MLST typing of DEC was analyzed based on the WGS technology and the minimum spanning tree was constructed by BioNumerics 7.6 software to analyze the local dominant flora. Results: A total of 513 strains of DEC were detected and isolated from 4 494 anal swabs, with a detection rate of 11.42%. About 500 strains were tested for drug sensitivity to nine antibiotics in four classes, including 330 strains of enterotoxigenic E.coli (ETEC), 72 strains of enteroaggregative E.coli (EAEC), 95 strains of enteropathogenic E.coli (EPEC), 1 strain of enterohemorrhagic E.coli (EHEC), and 2 strains of enteroinvasive E.coli (EIEC). From 2015 to 2019, the resistance rate of cefotaxime-clavulanic acid was significantly different (P<0.05). The resistance rate of virulence types of DEC to nalixic acid was significantly different (P<0.05). About 71 strains of DEC were determined by WGS, and 77 drug-resistant genes were detected. Strains were classified into 32 ST subtypes, with the dominant genotypes being ST-1491 (29.6%, 21/71) and ST-10 Complex (23.9%, 17/71). All ST-1491 produced ESBLs, which were blaCTX-M gene mutant strains. The dominant type of ST-10 complex was ST-218 (35.3%, 6/17). In addition, 8 strains of EAEC, 14 strains of EPEC and 49 strains of ETEC were classified into 7, 14 and 18 ST subtypes, respectively. Conclusion: The drug resistance of DEC strains from the diarrhea outpatient case of Qingpu District is serious. The ST types of EAEC and EPEC are highly polymorphic. The dominant ST types of DEC are basically consistent with the common genotypes in southeast China.