Average Well Color Development Research Articles

Combined effects of border irrigation and super-absorbent polymers on enzyme activity and microbial diversity of poplar rhizosphere soil.

Fast-growing poplar plantations are considered a great benefit to timber production, but water availability is a key factor limiting their growth and development, especially in arid and semi-arid ecosystems. Super-absorbent polymers facilitate more water retention in soil after rain or irrigation, and they are able to release water gradually during plant growth. This study aimed to examine the effects of reduced irrigation (60% and 30% of conventional border irrigation) co-applied with super-absorbent polymers (0, 40 kg/ha) on root exudates, enzyme activities, microbial functional diversity in rhizosphere soil, and volume increments in poplar (Populus euramericana cv. 'Neva'). The results showed that 60% border irrigation co-applied with super-absorbent polymers significantly increased the content of organic acids, amino acids and total sugars in the root exudates, and the activities of invertase, urease, dehydrogenase, and catalase in the rhizosphere soil in comparison to conventional border irrigation without super-absorbent polymers. Meanwhile, this treatment also enhanced the average well-color development, Shannon index, and McIntosh index, but decreased the Simpson index. Additionally, the average volume growth rate and relative water content of leaves reached their maximum using 60% irrigation with super-absorbent polymers, which was significantly higher than other treatments. However, using 30% irrigation with super-absorbent polymers, had a smaller effect on rhizosphere soil and volume growth than 60% irrigation with super-absorbent polymers. Therefore, using an appropriate water-saving irrigation measure (60% conventional border irrigation with super-absorbent polymers) can help to improve enzyme activities and microbial diversity in the rhizosphere soil while promoting the growth of poplar trees.

Bacillus tequilensis influences metabolite production in tomato and restores soil microbial diversity during Fusarium oxysporum infection.

This study evaluates cellular damage, metabolite profiling, and defence-related gene expression in tomato plants and soil microflora during Fusarium wilt disease after treatment with B. tequilensis PBE-1. Histochemical analysis showed that PBE-1 was the primary line of defence through lignin deposition and reduced cell damage. GC-MS revealed that PBE-1 treatment ameliorated stress caused by F. oxysporum infection. PBE-1 also improved transpiration, photosynthesis, and stomatal conductance in tomato. qRT-PCR suggested that the defence-related genes FLS2, SERK, NOS, WRKYT, NHO, SAUR, and MYC2, which spread infection, were highly upregulated during F. oxysporum infection, but either downregulated or expressed normally in PBE-1 + P treated plants. This indicates that the plant not only perceives the bio-control agent as a non-pathogen entity but its presence in normal metabolism and gene expression within the host plant is maintained. The study further corroborated findings that application of PBE-1 does not cause ecological disturbances in the rhizosphere. Activity of soil microflora across four treatments, measured by Average Well Colour Development (AWCD), showed continuous increases from weeks 1 to 4 post-pathogen infection, with distinct substrate usage patterns like tannic and fumaric acids impacting microbial energy source utilization and diversity. Principal Component Analysis (PCA) and diversity indices like McIntosh, Shannon, and Simpson further illustrated significant microbial community shifts over the study period. In conclusion, our findings demonstrate that B. tequilensis PBE-1 is an ideal bio-agent for field application during Fusarium wilt disease management in tomato.

Urea promoted soil microbial community and reduced the residual ciprofloxacin in soil and its uptake by Chinese flowering cabbage.

Antibiotics in agricultural soil can be accumulated in crops and might pose a potential risk to human health. Nevertheless, there is a lack of knowledge about the impact of nitrogen fertilizers on the dissipation and uptake of antibiotics in soils. Therefore, our aim in this study is to investigate the effects of urea fertilizer on the residues of ciprofloxacin and its uptake by Chinese flowering cabbage (Brassica parachinensis L.) as affected by the associated changes on the soil microbial community. A pot experiment has been conducted using spiked soil with 20 mg ciprofloxacin /kg soil and fertilized with urea at dosages equal to 0, 0.2, 0.4, 0.8 t/ha. Application urea especially at 0.4 t/ha decreased the residue of ciprofloxacin in the soil and its uptake by the roots and its translocation to the shoots of Chinese flowering cabbage. The translocation factors (TFs) for ciprofloxacin were significantly decreased (P < 0.05) only at the treatment of 0.4 t/ha, while no significant difference of bio-concentration factors (BCFs). The average well color development (AWCD) values, Shannon diversity, and richness index were higher in the fertilized than the un-fertilized soils, and all such indicators were greater at the treatment of 0.4 t/ha than at 0.2 and 0.8 t/ha. The carbon substrate utilization of phenolic acids at the treatments of 0.4 t/ha were greater than with other levels of urea fertilizer. In conclusion, moderate urea addition significantly increased soil microbial activity and abundance, which in turn promoted the ciprofloxacin dissipation in soil and plant tissue. The present study provides an economical and operational strategy for the remediation of ciprofloxacin contaminated soils.

Analysis on metabolic functions of rhizosphere microbial communities of Pinus massoniana provenances with different carbon storage by Biolog Eco microplates.

Rhizosphere microorganisms are influenced by vegetation. Meanwhile, they respond to vegetation through their own changes, developing an interactive feedback system between microorganisms and vegetation. However, it is still unclear whether the functional diversity of rhizosphere soil microorganisms varies with different carbon storage levels and what factors affect the functional diversity of rhizosphere soil microorganisms. In this study, the Biolog-Eco microplate technique was used to analyze the metabolic diversity of carbon source of rhizosphere soil microorganisms from 6 Pinus massoniana provenances with three levels of high, medium and low carbon storage. The results showed that the average well color development(AWCD) value of rhizosphere microorganisms was significantly positive correlated with carbon storage level of Pinus massoniana (p < 0.05). The AWCD value, Simpson and Shannon diversity of high carbon sequestrance provenances were 1.40 (144h incubation) 0.96 and 3.24, respectively, which were significantly higher (p < 0.05) than those of other P. massoniana provenances. The rhizosphere microbial AWCD, Shannon and Simpson diversity of the 6 provenances showed the same variation trend (SM>AY>QJ>SX>HF>SW). Similarly, microbial biomass carbon (MBC) content was positively correlated with carbon storage level, and there were significant differences among high, medium and low carbon storage provenances. The PCA results showed that the differences in the carbon source metabolism of rhizosphere microorganisms were mainly reflected in the utilization of amino acids, carboxylic acids and carbohydrates. Pearson correlation analysis showed that soil organic carbon (SOC), total nitrogen (TN) and pH were significantly correlated with rhizosphere AWCD (p < 0.05). Soil properties are important factors affecting rhizosphere microbial carbon source metabolism. The study confirmed that the microorganisms of high carbon storage provenances had relatively high carbon metabolic activity. Among them, the carbon metabolic activity of rhizosphere microorganisms of SM provenance was the highest, which was the preferred provenances in effective ecological service function.

Test of polystyrene toxicity on Aeromonas-sobria and staphylococcus-homini bacteria

The spread of nano-plastic particles arising from the decomposition of plastic has become a global problem because it poses a threat to primary products in food chains, and thus threatens the entire system. We tested the apparent effects on the metabolism of Gram-negative and Gram-positive bacteria after exposure to nano-plastics (nanocpolystyrene) by using carbon as an energy source. After diagnosis bacteria samples and then exposed to nanopolystyrene solution with different concentrations (200, 500 and 1000) ppm. Biology Eco Microplate (BEMP) was used to determine changes in bacteria after uptake of a carbon source. Average well-color development (AWCD) was used for data analysis, the result showed there are increase in size of bacteria and in absorption of carbon sources.

Effects of repeated afidopyropen treatment on the structure and function of the soil microbial community

Chemical insecticides are the most effective pest control agents. Afidopyropen is a novel insecticide used against sap-sucking insects, such as aphids. However, the effects of repeated afidopyropen application on the structure and function of soil microorganisms remain unknown. In this study, the changes in the enzyme activities, community structure and function, and relative abundance of antibiotic resistance ontology (ARO) of soil microorganisms were investigated during three repeated afidopyropen applications under laboratory conditions at the maximum recommended dosage (M1) and 10 times the M1 (M10). The neutral phosphatase (NPA) and catalase (CAT) activities in the soil were significantly suppressed after afidopyropen treatment. The Simpson diversity index (1/D) and Shannon–Wiener diversity index (H) also decreased in both the M1 and M10 afidopyropen-treated soils, indicating a remarkable decrease in soil microorganism diversity. The average well color development (AWCD) first increased and subsequently recovered to normal levels after the third application of the insecticide, suggesting that afidopyropen application could increase the metabolic activity of soil microorganisms. Metagenomic analysis showed that repeated afidopyropen application in both the M1 and M10 treatment groups altered the community structure of soil microorganisms, albeit in different ways. Furthermore, repeated afidopyropen application significantly increased the relative ARO abundance, especially in the M10 treatment, with the most dominant AROs being adeF, baeS, and IND-6. These findings reveal the effects of excessive afidopyropen application on soil microorganisms and lay an important foundation for the comprehensive evaluation of the impact of this insecticide on the environment.

Functional diversity and behavioral changes of microbial communities under salt affected soils

Salt-affected soils (SASs) are globally distributed especially in the arid and semi-arid regions of the world which highly affect the crop growth and productivity. The soil physico-chemical and biological properties largely vary with different types of SASs which trigger the crop yield, nutrient imbalance and soil quality. Therefore, to understand the changes in soil microbiology in relation to soil characteristics, a micro plot study was conducted to evaluate the impact of soil salinity/sodicity on physical, chemical properties at surface (0–15 cm) and subsurface (15–30 cm) soils in relation to soil microbial population, activities and functional diversity with focusing on community-level physiological profiling (CLPP) study. Five types of soils based on pH, electric conductivity (EC) and salt concentration maintained for last 25 years - highly saline, moderately saline, highly sodic, moderately sodic and normal were evaluated in micro plots to understand the changes in soil biological properties in relation to salt concentration. The results revealed that the highest value of pHs, ECe (EC of soil saturated paste extract), cation exchange capacity (CEC), exchangeable sodium percentage (ESP), sodium adsorption ratio (SAR), anions and cations concentrations, bulk density (BD), infiltration rate (IR), penetration resistance (PR) were observed in highly saline and highly sodic soils at surface and subsurface soil layer. In surface and subsurface layers, organic carbon (0.67 and 0.52 %) and available N (110 and 195 kg ha−1) were found higher under normal soils than SASs (% OC: 0.20–0.34 and 0.17–0.38; available N: 75–80 and 47–77 kg ha−1), respectively. In relation to changes in soil physicochemical properties, average well color development (AWCD) was found highest with normal soils followed by moderately saline and moderately sodic soils and lowest was found in highly sodic soils at surface soils which indicates interference of salts in metabolic activities of microbes. The utilization of amino acids, amines, carboxylic acids, phenolic compounds and polymers was highest for normal soils followed by moderately saline and lowest was recorded for highly sodic soils. But AWCD for carbohydrates was highest in highly saline soils, followed by highly sodic soils in contrast to normal soil and lowest was found under moderately sodic soils. Shannon diversity index (H) and substrate richness (SR) were found higher (3.19 and 24.07) in normal soils than SASs. Similarly, effect of salt load was also reflected on less soil enzymatic activities such as dehydrogenase, aryl sulfatase, invertase, etc. under varying types of SASs. Thus, with the increasing salt load, chemical and physical properties of soils were found to deteriorate and directly affected the microbial population, activities and their diversity in soil. This study indicated that soil physico-chemical properties, functional diversity, population and community of microbes were highly influenced by nature of salts and their concentration that may affect the soil quality and crop yield.

Physico-Chemical Quality and Physiological Profiles of Microbial Communities in Freshwater Systems of Mega Manila, Philippines

Studying the quality of freshwater systems and drinking water in highly urbanized megalopolises around the world remains a challenge. This article reports data on the quality of select freshwater systems in Mega Manila, Philippines. Water samples collected between 2020 and 2021 were analyzed for physico-chemical parameters and microbial community metabolic fingerprints, i.e., carbon substrate utilization patterns (CSUPs). The detection of arsenic, lead, cadmium, mercury, polyaromatic hydrocarbons (PAHs), and organochlorine pesticides (OCPs) was carried out using standard chromatography- and spectroscopy-based protocols. Physiological profiles were determined using the Biolog EcoPlate™ system. Eight samples were free of heavy metals, and none contained PAHs or OCPs. Fourteen samples had high microbial activity, as indicated by average well color development (AWCD) and community metabolic diversity (CMD) values. Community-level physiological profiling (CLPP) revealed that (1) samples clustered as groups according to shared CSUPs, and (2) microbial communities in non-drinking samples actively utilized all six substrate classes compared to drinking samples. The data reported here can provide a baseline or a comparator for prospective quality assessments of drinking water and freshwater sources in the region. Metabolic fingerprinting using CSUPs is a simple and cheap phenotypic analysis of microbial communities and their physiological activity in aquatic environments.

Combined effects of microplastics and cadmium on the soil-plant system: Phytotoxicity, Cd accumulation and microbial activity

Microplastics (MPs), an emerging pollutant of concern, widely cooccurred with heavy metals in soil, however, little is known about the combined effects of the interactions of MPs and cadmium (Cd) on the soil-plant system. In this study, the combined effects of several types of MPs and soil Cd contamination on Brassica juncea growth, Cd uptake, and soil microbial carbon metabolism were investigated in a 50-day pot experiment. Aged polyethylene (PE), aged polypropylene (PP), biodegradable polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) displayed moderate phytotoxicity, with reductions in leaf chlorophyll content and shoot biomass. Compared with the control treatment without MPs or B. juncea, B. juncea growth significantly increased the soil pH by 0.3 pH units, and the growth of B. juncea in the presence of biodegradable PBAT or PLA MPs increased the soil pH by an additional 0.4 or 0.6 pH units, respectively. The presence of PBAT or PLA MPs greatly reduced soil diethylenetriamine pentaacetic acid (DTPA)-extractable Cd concentrations and plant Cd accumulation. The Cd bioconcentration factor was higher in roots than shoots in all treatments except the treatment containing PBAT MPs. The average well color development (AWCD), an indicator of metabolic activity, was highest in the treatment with B. juncea alone and was reduced by both biodegradable and conventional MPs. The microbial utilization efficiency of esters and alcohols was enhanced in the treatment with PBAT MPs, whereas carboxylic acids were preferentially utilized in the treatment with PLA MPs. These findings indicate that co-exposure to MPs and Cd may alter soil microenvironmental characteristics such as soil pH, leading to changes in Cd bioavailability, plant growth and Cd accumulation, and the microbial community's capacity to metabolize carbon. These effects of MPs in soil warrant further exploration.

New insights into the effects of antibiotics and copper on microbial community diversity and carbon source utilization.

Residual antibiotics (ABs) and heavy metals (HMs) are continuously released from soil, reflecting their intensive use and contamination of water and soil, posing an environmental problem of great concern. Relatively few studies exist of the functional diversity of soil microorganisms under the combined action of ABs and HMs. To address this deficiency, BIOLOG ECO microplates and the Integrated Biological Responses version 2 (IBRv2) method were used to comprehensively explore the effects of single and combined actions of copper (Cu) and enrofloxacin (ENR), oxytetracycline (OTC), and sulfadimidine (SM2) on the soil microbial community. The results showed that the high concentration (0.80mmol/kg) compound group had a significant effect on average well color development (AWCD) and OTC showed a dose-response relationship. The results of IBRv2 analysis showed that the single treatment group of ENR or SM2 had a significant effect on soil microbial communities, and the IBRv2 of E1 was 5.432. Microbes under ENR, SM2, and Cu stress had more types of available carbon sources, and all treatment groups were significantly more enriched with microorganisms having D-mannitol and L-asparagine as carbon sources. This study confirms that the combined effects of ABs and HMs can inhibit or promote the function of soil microbial communities. In addition, this paper will provide new insights into IBRv2 as an effective method to evaluate the impacts of contaminants on soil health.

Application of the Biolog EcoPlate™ technique for assessing the microbial metabolic diversity in moss profiles of continental Antarctica

Little is known about metabolic capabilities of microbial assemblages in continental Antarctic to utilize diverse carbon sources within moss profiles consisting of live, senescent, and dead moss tissues in different stages of decomposition. In the present study, microbial metabolic diversity was determined using Biolog EcoPlate™ for samples of Bryum pseudotriquetrum/B. archangelicum complex collected at five sites located in coastal outcrops of the Lützow-Holm Bay area (Queen Maud Land), East continental Antarctica, and effects of chemical, biological, and physical properties of the moss tissues were explored. The average well-color development, the number of substrates utilized, Simpson's diversity index and equitability of the microbial substrate utilization, and the utilization of carbohydrates, amino acids/amines, carboxylic acids, and polymers varied significantly among the five sites and among four layers of moss profiles. Principal component analysis showed that the utilization of L-asparagine, L-arginine, D-galacturonic acid, Tween 40, Tween 80, and D-mannitol mainly contributed to the variance in the microbial metabolic diversity between sites and moss profiles. The linear mixed models indicated that the relative content of recalcitrant organic components, the number of fungal species, and the water content of moss tissues affected the diversity of microbial utilization of carbon sources.

有机肥施用对红壤原生生物与微生物互作的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 有机肥施用对红壤原生生物与微生物互作的影响 DOI: 10.5846/stxb202112253651 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家优秀青年基金（41922048）；国家面上基金（42107336，42177298） Impacts of manure application on interaction between protists community and microorganisms in red soil Author: Affiliation: Fund Project: National Science Fund for Excellent Young Scholars of China (41922048), National Natural Science Foundation of China (42177298, 42107336) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为明确不同施肥处理对土壤原生生物群落、微生物碳代谢活性的影响，以南方典型旱地红壤为研究对象，基于中国科学院鹰潭红壤生态实验站玉米单作系统有机培肥长期定位试验，选取不施肥（M0）、低量猪粪（M1）、高量猪粪（M2）、高量猪粪+石灰（M3）4个处理，利用高通量测序技术研究不同猪粪处理下红壤原生生物多样性、群落结构的变化，揭示原生生物与微生物互作对土壤微生物碳代谢活性和玉米产量的影响。结果表明：①长期施用猪粪处理下，土壤pH、有机质（SOM）、全氮（TN）、全磷（TP）、速效磷（AP）和速效钾（AK）的含量显著提高；②与M0处理相比，施肥处理显著提高了原生生物生物量和多样性，并且显著改变了其群落结构，其中土壤TP、pH、AP、TN、SOM和AK是原生生物群落结构变化的重要驱动因子；③施肥处理显著提高了土壤细菌和真菌生物量，增加了微生物碳代谢活性（Average well color development，AWCD）；④土壤pH和AP通过影响原生生物多样性和群落结构，间接提高了微生物碳代谢活性和玉米产量。本研究结果为提升旱地红壤的生物多样性，保障土壤健康和维持生态系统服务功能提供了科学依据。 Abstract:The purpose of this study was to investigate the protist community and soil microbial carbon metabolism with pig manure application in the dryland red soil of south China. The long-term field experiment was conducted in maize mono-cropping system at the National Agro-Ecosystem Observation and Research Station in Yingtan, Jiangxi Province. Four treatments included no manure (M0), low manure (M1), high manure (M2), and high manure with lime addition (M3). The high-throughput sequencing of 18S rRNA gene was used to explore the diversity and structure of soil protist community, and to estimate the effect of protists-microorganisms interaction on microbial carbon metabolism and maize yield. Our results showed that soil chemical properties significantly varied under the four fertilization treatments. Soil pH, soil organic matter (SOM), total nitrogen (TN), total phosphorus (TP), available phosphorus (AP), and available potassium (AK) were significantly increased under manure treatments. Compared with M0 treatment, manure treatments (M1, M2, and M3) significantly enhanced the biomass and diversity of protist, and remarkably modified the protist community structure. The protist community composition was mainly affected by soil TP, pH, AP, TN, SOM, and AK. Manure application significantly improved the bacterial and fungal biomasses, and consequently promoted microbial carbon metabolism indicated by the values of average well color development (AWCD). Structural equation modelling indicated that soil pH and AP could indirectly increase microbial carbon metabolism and maize yield through regulating the diversity and structure of protist community. Taken together, we provide the scientific basis for promoting the microbial diversity in the dryland red soil, and maintaining soil health and ecosystem service functioning. 参考文献 相似文献 引证文献

Functional Diversity of Soil Microorganisms and Influencing Factors in Three Typical Water-Conservation Forests in Danjiangkou Reservoir Area

As a key part of the forest ecosystem, soil microorganisms play extremely important roles in maintaining the ecological environment and the security of water quality in reservoir areas. However, it is not clear whether there are differences in the functional diversity of soil microorganisms in different types of water-conservation forests in reservoir areas, and which factors affect the functional diversity of soil microorganisms. In our study, the Biolog-Eco microplate technique was used to analyze the carbon source metabolic characteristics of soil microbial communities in three typical water-conservation forests and a non-forest land: Pinus massoniana-Quercus variabilis mixed forest (MF), Pinus massoniana forest (PF), Quercus variabilis forest (QF) and non-forest land (CK). The results showed that the average well color development (AWCD), the Shannon diversity index (SDI) and the richness index (S) of the three forest lands was significantly greater than that of the non-forest land (p &lt; 0.05). The mean values of AWCD, SDI and S of the three forests had the same order (QF &gt; PF &gt; MF), but there was no significant difference among different types of forests. The microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) of QF and PF were higher than those of MF and CK, but the microbial biomass C/N ratio (MBC/MBN) was lower. The variance partitioning analysis (VPA) showed that 86.4% of the variation was explained by plant (community) diversity, soil physical and chemical properties and soil microbial biomass, which independently explained 10.0%, 28.9%, and 14.9% of the variation, respectively. The redundancy analysis (RDA) showed that total phosphorus (TP), microbial biomass carbon (MBC), total nitrogen (TN), number of plant species (Num) and alkali-hydro nitrogen (Wn) were the key factors affecting the functional diversity of soil microorganisms. This study confirmed that forest ecosystem is better than non-forest land in maintaining soil microbial function diversity. Moreover, Quercus variabilis forest may be a better stand type in maintaining the diversity of soil microbial functions in the study area.

Structural and functional characteristics of soil microbial communities in response to different ecological risk levels of heavy metals.

The potential ecological risk index (RI) is the most commonly used method to assess heavy metals (HMs) contamination in soils. However, studies have focused on the response of soil microorganisms to different concentrations, whereas little is known about the responses of the microbial community structures and functions to HMs at different RI levels. Here, we conducted soil microcosms with low (L), medium (M) and high (H) RI levels, depending on the Pb and Cd concentrations, were conducted. The original soil was used as the control (CK). High-throughput sequencing, qPCR, and Biolog plate approaches were applied to investigate the microbial community structures, abundance, diversity, metabolic capacity, functional genes, and community assembly processes. The abundance and alpha diversity indices for the bacteria at different RI levels were significantly lower than those of the CK. Meanwhile, the abundance and ACE index for the fungi increased significantly with RI levels. Acidobacteria, Basidiomycota and Planctomycetes were enriched as the RI level increased. Keystone taxa and co-occurrence pattern analysis showed that rare taxa play a vital role in the stability and function of the microbial community at different RI levels. Network analysis indicates that not only did the complexity and vulnerability of microbial community decrease as risk levels increased, but that the lowest number of keystone taxa was found at the H level. However, the microbial community showed enhanced intraspecific cooperation to adapt to the HMs stress. The Biolog plate data suggested that the average well color development (AWCD) reduced significantly with RI levels in bacteria, whereas the fungal AWCD was dramatically reduced only at the H level. The functional diversity indices and gene abundance for the microorganisms at the H level were significantly lower than those the CK. In addition, microbial community assembly tended to be more stochastic with an increase in RI levels. Our results provide new insight into the ecological impacts of HMs on the soil microbiome at different risk levels, and will aid in future risk assessments for Pb and Cd contamination.

Community Level Physiological Profiling of Microbial Communities Influencing Mine Spoil Genesis in Chronosequence Coal Mine Overburden Spoil

Ecological restoration through mine spoil genesis should be dogmatic and the strategies involved a holistic approach, which emphasizes the role of microbial community composition that varies in accordance with the physiological and nutritional status of mine spoil profiles. This is because the patterns observed aboveground is being driven by the belowground diversity and processes. Thus, the relationship between microbial community structure and mine spoil genesis in chronosequence coal mine spoil has attracted considerable research attention. The occurrence of higher microbial diversity and difficulties in culturing microbes necessitate the use of a culture-independent approach through community-level physiological profiling based on the patterns of carbon source utilization using BIOLOG Ecoplate and thereby the functional diversity of microbial communities in different age series coal mine spoil was determined. The average well-color development exhibited an increasing trend with a minimum in OB0 (0.0640) and a maximum in OB15 (0.5060) over time. The patterns of substrate utilization (carbohydrates, carboxylic and ketonic acids, amino acids, polymers, amines, and amides) reflect the shift in microbial community composition in different age series coal mine spoil over time. Gradual increase in species richness and Shannon diversity index with the increase in age of mine spoil substantiated relatively higher microbial diversity reflecting the sign of mine spoil genesis. Principal component analysis and redundancy analysis based on the differential patterns of substrate utilization discriminate different age series coal mine spoil into independent clusters, which evaluated the broad-scale patterns of microbial community dynamics influencing the pace and progress of mine spoil genesis.

Effects of Simulated Nitrogen Deposition on Soil Microbial Carbon Metabolism in Calamagrostis angustifolia Wetland in Sanjiang Plain

Atmospheric nitrogen deposition has a crucial impact on the structure and function of soil microorganisms of wetland ecosystems. Therefore, carrying out a study on the effects of soil carbon metabolism capacity has a great significance for the protection and utilization of wetland ecosystems. In this study, the effects of simulated nitrogen deposition on the carbon metabolic capacity of soil microorganisms in Calamagrostis angustifolia wetland for five consecutive years was investigated using Biolog-Eco technology. The results showed:① soil water content (SMC), pH, nitrate nitrogen (NO3-), ammonium nitrogen (NH4+), dissolved organic carbon (DOC), and total nitrogen (TN) contents were significantly different (P<0.05) under different nitrogen deposition conditions. ② The average well color development (AWCD) values of soil microorganisms within different N depositions were in the order of CK (control)>HN (high nitrogen treatment)>LN (low nitrogen treatment). LN significantly reduced the Shannon diversity index of soil microorganisms, and HN significantly reduced the Pielou index of soil microorganisms (P<0.05). ③ LN significantly inhibited the intensity of the utilization of carbohydrates, alcohols, amines, and acids by soil microorganisms (P<0.05); HN significantly promoted the utilization of esters by microorganisms, but HN caused soil microorganisms to inhibit the carbon sources of carbohydrates, amines, and acids (P<0.05). ④ Redundancy analysis showed that NH4+, DOC, and pH were the main environmental factors affecting the functional diversity of soil microbial communities in Calamagrostis angustifolia wetland in the Sanjiang Plain. Long-term nitrogen deposition will lead to the reduction in soil microbial functional diversity; the microbial activity related to the utilization of carbon source substrates is also significantly reduced, and the ability of microorganisms to utilize a single carbon source substrate also changes.

Influence of Bacillus subtilis strain Z-14 on microbial communities of wheat rhizospheric soil infested with Gaeumannomyces graminis var. tritici.

Wheat take-all disease caused by Gaeumannomyces graminis var. tritici (Ggt) spreads rapidly and is highly destructive, causing severe reductions in wheat yield. Bacillus subtilis strain Z-14 that significantly controlled wheat take-all disease effectively colonized the roots of wheat seedlings. Z-14 increased the metabolic activity and carbon source utilization of rhizospheric microorganisms, thus elevating average well-color development (AWCD) values and functional diversity indexes of soil microbial communities. Z-14 increased the abundance of Bacillus in the rhizosphere, which was positively correlated with AWCD and functional diversity indexes. The Z-14-treated samples acquired more linkages and relative connections between bacterial communities according to co-occurrence network analyses. After the application of Ggt, the number of linkages between fungal communities increased but later decreased, whereas Z-14 increased such interactions. Whole-genome sequencing uncovered 113 functional genes related to Z-14’s colonization ability and 10 secondary metabolite gene clusters in the strain, of which nine substances have antimicrobial activity. This study clarifies how bacterial agents like Z-14 act against phytopathogenic fungi and lays a foundation for the effective application of biocontrol agents.

Microbial Community Structure and Metabolic Characteristics of Intestine and Gills of Dwarf-Form Populations of Sthenoteuthis oualaniensis in South China Sea

Sthenoteuthis oualaniensis is an important biological resource in the South China Sea. However, the microbiological characteristics of this squid, especially those of the dwarf-form, are poorly understood. This study was conducted to analyze the microbial community structure and metabolic characteristics of the intestinal and gill tissues of dwarf-form populations of S. oualaniensis. The dwarf-form squids of different sexes and gonadal maturities were collected from South China Sea in spring 2020. Results showed that Mycoplasma was the most dominant group of bacteria in the intestinal samples of the females with immature gonads (FN), females at sexual maturity (FY), and males at sexual maturity (MY) and the second-highest relative abundance group in males with immature gonads (MN). The microbial community structure in squid gills differed from that of intestinal flora. The BD1-7 clade was the dominant genus in gill samples of all groups. Furthermore, the microbial community activities in gills were higher than in intestinal groups, especially FYG. The larger dwarf-form populations had microbial communities with more robust utilization of carbon sources, assessed via average well color development (AWCD). Correlation and redundancy analysis determined that AWCD significantly positively correlated with the relative abundance of BD1-7 clade (p &lt; 0.05). The results indicated that the dominant group of bacteria and microbial community structure were different between the intestinal and gill microbial communities in the dwarf-form S. oualaniensis populations of different sexes and maturities. Moreover, the metabolic potential of the gill microbial community was higher than that of the intestinal microbial community in the dwarf-form populations.

Effects of Different Native Plants on Soil Remediation and Microbial Diversity in Jiulong Iron Tailings Area, Jiangxi

Phytoremediation is an important solution to heavy metal pollution in soil. However, the impact of plants on microbial communities in contaminated soil also requires attention. Community-level physiological profiling (CLPP) based on the Biolog™ EcoPlate and high-throughput sequencing were used to study the soil microbial community in this article. The rhizosphere and bulk soil samples of six native species were collected from the iron mine tailings on Jiulong Mountain, Jiangxi Province. According to the average well color development (AWCD), all plants improved the activity and diversity of the contaminated soil microbial community to varying degrees. Cunninghamia lanceolate is considered to have good effects and led to the appearance of Cunninghamia lanceolata &gt; Zelkova schneideriana &gt; Toona ciliata &gt; Alnus cremastogyne &gt; Cyclobalanopsis myrsinifolia &gt; Pinus elliottii. The Shannon–Wiener diversity index and principal component analysis (PCA) show that the evenness and dominance of soil microbial communities of several plants are structurally similar to those of uncontaminated soil (UNS). The results of high-throughput sequencing indicated that the bacterial community diversity of C. lanceolata, A. cremastogyne, and P. elliottii is similar to UNS, while fungal community diversity is different from UNS. C. lanceolata has a better effect on soil nutrients, C. myrsinifolia and P. elliottii may have a better effect on decreasing the Cu content. The objective of this study was to assess the influence of native plants on microbial communities in soils and the soil remediation capacity. Mortierellomycota was the key species for native plants to regulate Cu and microbial community functions. Native plants have decisive influence on microbial community diversity.

Effects of dietary supplementation with tropical microfungi Mucor circinelloides and Trichoderma harzianum powder on growth performance, bacterial communities, and the biomass nutritional profile of white shrimp grow-out culture (Litopenaeus vannamei)

Microfungi have been explored further as supplement constituents in shrimp culture due to their rich protein, lipid, essential amino acids, fatty acids, and various bioactive compounds. The researchers have evaluated the effects of two microfungi powders (Mucor circinelloides and Trichoderma harzianum) as feed supplements on growth performance, bacterial communities, and the biomass nutritional profile of white shrimp (Litopenaeus vannamei). The results showed that commercial/artificial feed (Feng-Li) with supplementation microfungi powder had a different effect on white shrimp growth performance than control after 62 days of the grow-out period. Supplementation with 1.5% M. circinelloides powder (M-2) could improve the growth performance of white shrimp, especially the survival rate (81.33%), final body weight (5.21 g), and shrimp biomass (211.35 g). In contrast, supplementation with 1.5% T. harzianum powder (T-2) did not improve the growth performance of white shrimp compared to control (p > 0.05). Furthermore, it also affected the profile of the bacterial community in culture water as well as in shrimp intestines. Supplementation with both microfungi could reduce the total number of bacteria in culture water at the end of the experiment, where the lowest number was obtained in treatment T-2 (3.9 × 10 5 CFU/mL), followed by M-2 (9.9 × 10 5 CFU/mL) and control (4.4 × 10 6 CFU/mL). In the culture water, 20 isolates of culturable bacteria were found during the trial, with the dominant bacteria in M-2: Bacillus cereus, Bacillus velezensis, Gordonia polyisoprenivorans, T-2: Acinetobacter sp., Gordonia polyisoprenivorans, Micrococcus luteus. Based on average well colour development (AWCD), the highest bacterial activity was in the M-2 (0.297–0.707), followed by T-2 (0.226–0.717) and control (0.094–0.694). The highest substrate group utilised in M-2 and T-2 were polymers (0.896 and 1.348) and control: amines (0.100). The highest Shannon diversity index was obtained in the M-2 (2.508), followed by control (2.286) and the T-2 (2.157). As many as 11 isolates of culturable bacteria were found in the shrimp intestine, with dominant bacteria in M-2: Bacillus velezensis, Micrococcus luteus, Bacillus cereus, T-2: Bacillus velezensis, Micrococcus sp.2, Demequina activiva. The highest bacterial activity was in M-2 (2.259), followed by control (2.020) and T-2 (0.050). The highest substrate group utilisation was in M-2: polymers (2.564), T-2: carbohydrates (0.094), and control: polymers (2.185). The highest Shannon diversity index was in the M-2 (3.234), followed by control (3.230) and the T-2 (0.751). In addition, 1.5% M. circinelloides and T. harzianum supplementation increased white shrimp muscle protein content up to 79.21% and 80.40%, respectively, compared to control (76.73%). In conclusion, using Mucor circinelloides powder as a feed supplement can improve the growth performance of white shrimp, increase the functional/probiotic bacteria: B. cereus and B. velezensis in cultur and shrimp's intestine, and increase the protein content in shrimp muscle tissue. However, more in-depth research is needed, especially on anti-nutritional compounds from fungi that affect shrimp growth.