Utilization Of Microbial Resources Research Articles

GCM and gcType in 2024: comprehensive resources for microbial strains and genomic data.

Microbial culture collections play a crucial role in the collection, maintenance, and distribution of quality-assured living microbial strains, along with their associated phenotypic and omics data. To enhance the find-able, accessible, interoperable, and re-usable (FAIR) data utilization of microbial resources, the World Data Center for Microorganisms (WDCM) has developed the Global Catalogue of Microorganisms (GCM) and the Global Catalogue of Type Strains (gcType). These platforms provide interactive interfaces for cataloging the holdings of collections, along with detailed annotations of type strain genomes and curated metadata, including ecosystems, growth conditions, and collection locations. The system maximizes the scientific impact of microbial resources and culture collections through an integrated data mining tool that links strain- and species-related information from various public resources. Currently, the GCM and gcType include 574422 strains from 154 culture collections across 51 countries and regions, along with 25980 genomes from type species. Additionally, 2702655 articles and 103337 patents are integrated with these microbial resources.The system supports microbial taxonomic research and provides evidence for implementing the Nagoya Protocol in the field of microbial resources and their digital sequence information (DSI). Access is freely available at gcm.wdcm.org and gctype.wdcm.org.

Improvement of Saline–Alkali Soil and Straw Degradation Efficiency in Cold and Arid Areas Using Klebsiella sp. and Pseudomonas sp.

Corn straw is an important renewable resource, which could improve the quality of saline–alkali cultivated land. However, the slow decomposition of crop residues in cold, arid, and saline–alkali soils can lead to serious resource waste and ecological crises. The use of beneficial microorganisms with degradation functions could solve these problems. In this study, three types of saline–alkali soil with low, medium, and high salinity levels were used in the straw-returning experiment. The experiment was conducted with four treatments: GF2 (Klebsiella sp.), GF7 (Pseudomonas sp.), GF2+GF7, and CK (control without bacteria). Microbial characteristics, straw degradation efficiency, element release rate, and soil factors were compared, and random forest linear regression and partial least squares path modeling analysis methods were utilized. The results indicated that the degradation of bacterial metabolites, the efficiency of corn stover degradation, the efficiency of component degradation, and the release rates of elements (C, N, P, and K) initially increased and then decreased with the increase in salinity. At the maximum value of moderately saline–alkali soil, the effect of GF2+GF7 treatment was significantly better than that of other treatments (p < 0.05). Given the interactive effects of saline–alkali soil and microbial factors, the application of exogenous degrading bacteria could significantly increase soil enzyme activity and soil available nutrients, as well as regulate the salt–alkali ion balance in soil. The cation exchange capacity (9.13%, p < 0.01) was the primary driving force for the degradation rate of straw in saline–alkali soil with different degrees of salinization under the influence of exogenous degrading bacteria. Straw decomposition directly affected the soil chemical properties and indirectly affected soil enzyme activity. The results of this study would provide new strategies and insights into the utilization of microbial resources to promote straw degradation.

Characterization and Antioxidant Activity of the Polysaccharide Hydrolysate from Lactobacillus plantarum LPC-1 and Their Effect on Spinach (Spinach oleracea L.) Growth.

This study presents a comparison between two hydrolysis systems (MnO2/H2O2 and ascorbic acid (VC)/H2O2) for the depolymerization of exopolysaccharide (EPS) from Lactobacillus plantarum LPC-1. Response surface methodology (RSM) was used to optimize these two degradation systems, resulting in two H2O2-free degradation products, MEPS (MnO2/H2O2-treated EPS) and VEPS (VC/H2O2-treated EPS), where H2O2 residues in the final products and their antioxidant activity were considered vital points. The relationship between the structural variations of two degraded polysaccharides and their antioxidant activity was characterized. Physicochemical tests showed that H2O2 had a notable impact on determining the total and reducing sugars in the polysaccharides, and both degradation systems efficiently eliminated this effect. After optimization, the average molecular weight of EPS was reduced from 265.75kDa to 135.41kDa (MEPS) and 113.11kDa (VEPS), improving its antioxidant properties. Characterization results showed that the two hydrolysis products had similar major functional groups and monosaccharide composition as EPS. The crystal structure, main chain length, and branched chain number were crucial factors affecting the biological activity of polysaccharides. In pot testing, two degraded polysaccharides improved spinach quality more than EPS due to their lower molecular weights, suggesting the advantages of low-molecular-weight polysaccharides. In summary, these two degradation techniques offer valuable insights for further expanding the utilization of microbial resources.

Study on Metabolic Effects of protein for Microbial Metabolic Engineering

Microbial metabolic engineering is a new bioengineering technology, which can improve the yield of compounds, optimize energy utilization and solve various problems faced by human beings by changing the genetic information, metabolic pathway and metabolic flux of microorganisms. Protein is the main undertaker of life activities, and its metabolic process involves complex biochemical reactions and cell regulation mechanisms. Protein metabolism plays an important role and application in microbial metabolic engineering. The purpose of this paper is to explore the metabolic effects of protein for microbial metabolic engineering, so as to deeply understand the metabolic characteristics and regulation mechanism of microorganisms. Microbial metabolic engineering has important applications in improving the yield of compounds, optimizing energy utilization, environmental treatment and medicine. The research and application of protein metabolism can provide more in-depth theoretical basis and technical support for microbial metabolism engineering, thus promoting the development and utilization of microbial resources.

Cultivation strategies for prokaryotes from extreme environments.

The great majority of microorganisms are as-yet-uncultivated, mostly found in extreme environments. High-throughput sequencing provides data-rich genomes from single-cell and metagenomic techniques, which has enabled researchers to obtain a glimpse of the unexpected genetic diversity of "microbial dark matter."However, cultivating microorganisms from extreme environments remains essential for dissecting and utilizing the functions of extremophiles. Here, we provide a straightforward protocol for efficiently isolating prokaryotic microorganisms from different extreme habitats (thermal, xeric, saline, alkaline, acidic, and cryogenic environments), which was established through previous successful workand our long-term experience in extremophile resource mining. We propose common processes for extremophile isolation at first and then summarize multiple cultivation strategies for recovering prokaryotic microorganisms from extreme environments and meanwhile provide specific isolation tips that are always overlooked but important. Furthermore, we propose the use of multi-omics-guided microbial cultivation approaches for culturing these as-yet-uncultivated microorganisms and two examples are provided to introduce how these approaches work. In summary, the protocol allows researchers to significantly improve the isolation efficiency of pure cultures and novel taxa, which therefore paves the way for the protection and utilization of microbial resources from extreme environments.

Comparative analysis of bacterial diversity in two hot springs in Hefei, China

Hot springs are extreme ecological environments of microbes. The study is the first comparative analysis of bacterial diversity of Tangchi and Bantang hot spring water samples collected in Hefei, China, which is conducive to the further development and utilization of microbial resources in hot springs. Illumina MiSeq system was utilized to sequence and analyze the bacterial 16S rRNA gene from hot spring water samples by bioinformatics, to probe into the bacterial abundance and diversity of two hot springs in Hefei. Results revealed that prevalent bacterial phyla in Tangchi hot spring were Bacillota and Aquificota, and the prevalent bacterial genus was Hydrogenobacter; prevalent phyla in Bantang hot spring were Pseudomonadota followed by Actinobacteriota, and prevalent genera were CL500-29_marine_group and Polynucleobacter. More species and higher evenness in Bantang hot spring than those in Tangchi hot spring. In MetaCyc pathway analysis, the major pathways of metabolism existed in the bacteria from the two hot springs were ‘pyruvate fermentation to isobutanol (engineered)’, ‘acetylene degradation’, ‘carbon fixation pathways in prokaryotes’, ‘nitrate reduction I (denitrification)’, ‘methanogenesis from acetate’, ‘superpathway of glucose and xylose degradation’, etc.

Identification and Surveys of Promoting Plant Growth VOCs from Biocontrol Bacteria Paenibacillus peoriae GXUN15128.

The role of microbial volatile organic compounds (MVOCs) in promoting plant growth has received much attention. We isolated Paenibacillus peoriae from mangrove rhizosphere soil, which can produce VOCs to promote the growth of Arabidopsis thaliana seedlings, increase the aboveground biomass of A. thaliana, and increase the number of lateral roots of A. thaliana. The effects of different inoculation amounts and different media on the composition of MVOCs were studied by solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) and headspace sampler/GC-MS. We found that the growth medium influences the function and composition of MVOCs. To survey the growth-promoting functions, the transcriptome of the receptor A. thaliana was then determined. We also verified the inhibitory effect of the soluble compounds produced by P. peoriae on the growth of 10 pathogenic fungi. The ability of P. peoriae to produce volatile and soluble compounds to promote plant growth and disease resistance has shown great potential for application in the sustainability of agricultural production. IMPORTANCE Microbial volatile organic compounds (MVOCs) have great potential as "gas fertilizers" for agricultural applications, and it is a promising research direction for the utilization of microbial resources. This study is part of the field of interactions between microorganisms and plants. To study the function and application of microorganisms from the perspective of VOCs is helpful to break the bottleneck of traditional microbial application. At present, the study of MVOCs is lacking; there is a lack of functional strains, especially with plant-protective functions and nonpathogenic application value. The significance of this study is that it provides Paenibacillus peoriae, which produces VOCs with plant growth-promoting effects and broad-spectrum antifungal activity against plant-pathogenic fungi. Our study provides a more comprehensive, new VOC component analysis method and explains how MVOCs promote plant growth through transcriptome analysis. This will greatly increase our understanding of MVOC applications as a model for other MVOC research.

Sediment microbial community structure, enzymatic activities and functional gene abundance in the coastal hypersaline habitats

Salt marsh vegetation, mudflat and salt production are common features in worldwide coastal areas; however, their influence on microbial community composition and structure has been poorly studied and rarely compared. In the present study, microbial community composition (phospholipid fatty acid (PLFA) profiling and 16S rRNA gene sequencing (bacterial and archaeal)) and structure, enzymatic activities and abundance of functional genes in the sediments of salt ponds (crystallizer, condenser and reservoir), mudflat and vegetated mudflat were determined. Enzyme activities (β-glucosidase, urease and alkaline phosphatase) were considerably decreased in saltpan sediments because of elevated salinity while sediment of vegetated mudflat sediments showed the highest enzyme activities. Concentrations of total microbial biomarker PLFAs (total bacterial, Gram-positive, Gram-negative, fungal and actinomycetes) were the highest in vegetated mudflat sediments and the lowest in crystallizer sediments. Nonmetric-multidimensional scaling (NMDS) analysis of PLFA data revealed that the microbial community of crystallizer, mudflat and vegetated mudflat was significantly different from each other as well as different from condenser and reservoir. The most predominant phyla within the classified bacterial fractions were Proteobacteria followed by Firmicutes, Bacteroidetes and Planctomycetes, while Euryarchaeota and Crenarchaeota phyla dominated the classified archaeal fraction. Cyanobacterial genotypes were the most dominant in the condenser. Mudflat and vegetated mudflat supported a greater abundance of Bacteroidetes and Actinobacteria, respectively. The results of the present study suggest that salt ponds had significantly decreased the microbial and enzyme activities in comparison to mudflat and vegetated mudflat sediments due to very high salinity, ionic concentrations and devoid of vegetation. The present study expands our understanding of microbial resource utilization and adaptations of microorganisms in a hypersaline environment.

Non-photosynthetic chemoautotrophic CO2 assimilation microorganisms carbon fixation efficiency and control factors in deep-sea hydrothermal vent

Non-photosynthetic chemoautotrophic microorganisms in deep-sea hydrothermal vent can obtain energy by oxidation reducing substances and synthesize CO2 into organic carbon, and the development and utilization of microbial resources in this environment for CO2 fixation under ordinary environmental conditions is of great significance to understand the carbon cycle and microbial carbon fixation in deep-sea hydrothermal vent. In this study, a set of spiral-stirred bioreactor (SSB) was developed to cultivate a group of non-photosynthetic chemoautotrophic CO2 assimilation microorganisms (NPCAM), mainly Sphingomonadaceae (unclassified, the mean of which was 31.16 %), from deep-sea hydrothermal vent sediments, which have the characteristics of halophilic, acid-base and heavy metal resistant. The maximum carbon fixation efficiency (calculated by CO2) was 6.209 mg·CO2/(L·h) after 96 h of incubation in the presence of mixed electron donors (MEDs, 0.46 % NaNO2, 0.50 % Na2S2O3 and 1.25 % Na2S, w/v), mixed inorganic carbon sources (CO2, Na2CO3 and NaHCO3) and aerobic conditions. The detection of NPCAM synthetic organic fraction in SSB system, the study of single bacteria culturability and carbon fixation efficiency, the analysis of CO2 fixation pathway and the development of coupled carbon fixation technology are the prospective works that need to be further developed.

Influence of Rosaceous Species and Driving Factors on Differentiation of Rhizospheric Bacteria in a Deciduous Broad-Leaved Forest.

Understanding plant-microbe interactions could provide the basis for improved phytoremediation, microbial resource utilization, and secondary metabolite production. Rhizosphere bacterial communities are strongly influenced by abiotic factors such as soil nutrient availability and the composition of such communities exhibits differentiation under different host plants. In a deciduous broad-leaved forest in Anhui Province, eastern China, the rhizospheric bacteria of three different tree species of the Rosaceae family (Sorbus alnifolia, Cerasus serrulata, and Photinia beauverdiana) were studied, with the bacteria of the bulk soil as controls. Bacterial community composition was determined using the Illumina platform for high-throughput sequencing of 16S rRNA genes. The results showed that the bacterial community composition varied between rhizospheric and bulk soils, and dominant bacterial phyla as Proteobacteria, Actinobacteria, and Acidobacteria were found in both soils. Information on predicted functional genes and pathways revealed significant differences between rhizospheric and bulk soil bacteria. It provided ample evidence for the different metabolic characteristics of the rhizosphere bacterial communities of the three tree species. Electrical conductivity (22.72%), total phosphorus concentration (21.89%), and urease activity (22%) were the main drivers for changes in the composition of the rhizosphere bacterial communities from the three tree species.

Forage mixed planting can effectively improve soil enzyme activity and microbial community structure and diversity in agro-pastoral interlacing arid zone

Aiming at the problems of serious soil desertification and continuous reduction of effective soil nutrients in the agricultural and animal husbandry interlaced arid area in Inner Mongolia, this study used Aohan alfalfa, old awn wheat, and fodder oats at the Siziwang Banner, Ulanchabu City, Inner Mongolia Autonomous Region. There were a total of five treatments, namely, single seeding alfalfa, single seeding old awn wheat, single seeding fodder oats, alfalfa and old awn wheat mixed sowing, and control. The results showed that the urease activity and microbial biomass nitrogen content of mixed planting were higher than other treatments. With the advancement of the growth period, the bacteria α-diversity index showed an upward trend; β-diversity analysis showed that planting method was the main factor affecting bacteria diversity and sampling time was the main factor affecting fungi diversity. In summary, mixed planting treatment was more helpful to improve soil enzyme activity, microbial biomass, and enrich soil microbial diversity, which was of great significance to maintain the balance of soil ecosystem. It is hoped that this study will contribute to the theoretical basis and practical experiences for efficient utilization of microbial resources in the field of soil improvement.

Fungal community composition and diversity in the rhizosphere soils of Argentina (syn. Potentilla) anserina, on the Qinghai Plateau

Fungal communities and diversity in the rhizosphere soil of Argentina (syn . Potentilla ) anserina were investigated by high-throughput sequencing. Soil fungal communities changed seasonally; nitrogen, phosphorus, and potassium contents in the soil were highly correlated with specific fungal groups and distributions. At the class level, the fungal community of A. anserina rhizosphere was mainly composed of Sordariomycetes, Pezizomycetes, Dothideomycetes, and Leotiomycetes. Moreover, rhizosphere soil was dominated by Ascomycota and characterized by a relatively high percentage of saprotrophic, parasitic, endophytic, and arbuscular mycorrhizal fungi: Mortierella (3.95 %), Fusarium (3.11 %), Cadophora (2.19 %), Phoma (2.01 %), Preussia (1.18 %) and Glomerales (0.37 %). FUNGuild analysis revealed different fungal ecotypes in rhizosphere soil, including symbiotic, saprotrophic, and pathogenic fungi. The structure and quantity of different ecotypes of fungi showed dynamic changes and may have different functions in the agro-ecosystem. These results provide a theoretical framework for further development and utilization of microbial resources to improve sustainable management strategies. • The rhizosphere fungi of Argentina anserina contain several functional groups. • The fungal OTUs was significantly correlated with environmental factors. • The samples from summer accounted for the lowest diversity than other three seasons. • More than 50 % of fungal OTUs vary with the seasons.

Habitat specificity and co-occurrence network of bacterial communities in the Xincuntun Cave, Guilin, Guangxi

<p indent=0mm>Although karst systems comprise approximately 5%−20% of the Earth’s ice-free land surface, only 10% of them have so far been explored. Karst caves are important components of karst systems and represent one of the most unique and poorly understood ecosystems on Earth. They are extreme environments in terms of nutrition deficiency, permanent darkness, and isolation from other ecosystems, and serve as a natural laboratory to study the deep biosphere. Caves are also ideal places to discover microbial dark matter such as microbial biodiversity and novel metabolic pathways and metabolites. Microorganisms in caves have been demonstrated to be involved in the dissolution and formation of minerals, biogeochemical cycles, and degradation of organic matter and thus have a fundamental role in sustaining the cave ecosystems. However, knowledge about microbial distribution, diversity, potential functions, and interactions in subsurface caves has remained limited to date particularly in different niches, which limits the utilization of microbial resources and hampers our understanding of biogeochemical processes in the deep biosphere. To address these issues, bacterial communities from seven different niches including cave wall, weathered crust, loose sediments, biofilms from the wet surface of stalagmite, biofilms from the dry surface of stalagmite, microbial mat on rock surface, and overlying soils in the Xincuntun Cave, Southwest China, were investigated via high-throughput sequencing and bioinformatics. Alpha diversities of bacterial communities significantly differed from one niche to the other. Specifically, bacterial diversity was the highest in the overlying soil, followed by those in weathering crust, sediments, wet surface of stalagmite, cave wall, dry surface of stalagmite, and microbial mat. Bacterial communities were dominated by <italic>Actinobacteria</italic> and <italic>Proteobacteria</italic> and showed high specificity for their niches as indicated by principal coordinates analysis (PCoA) and bacterial indicator groups identified by the linear discriminant analysis effect size (LEfSe) method. <italic>Nitrospira </italic>and <italic>Polycyclovoran </italic>were indicator genera on the dry surface of stalagmite. <italic>Candidatus </italic>Udaeobacter, <italic>Vicinamibacter</italic>, <italic>Bacillus</italic>, and <italic>Longimicrobium </italic>were indicator genera in overlying soils, microbial mat, sediments, and weathering crust, respectively. Redundancy analysis was conducted to investigate the relationship between environmental factors and bacterial communities. Results showed that pH, TOC, and Mg/Si (chemical weathering index) were of significance to construct bacterial communities. The pH had significantly positive association with<italic> Gammaproteobacteria</italic>,<italic> Rokubacteria</italic>, and <italic>Nitrospirae</italic>, whereas it was negatively related with<italic> Actinobacteria</italic>. TOC had a significantly positive correlation with <italic>Alphaproteobacteria</italic>,<italic> Gammaproteobacteria</italic>,<italic> </italic>and <italic>Planctomycetes</italic> and negative correlation with <italic>Acidobacteria</italic>. Bacterial interactions among different groups were analyzed via co-occurrence networks. The results indicated a high-modularity network with <italic>Gammaproteobacteria</italic>, <italic>Candidatus</italic> Udaeobacter, and <italic>Thermoleophilia</italic>, being the top-three keystone members, which may contribute to the stability of microbial network. The high proportion of positive links between nodes inferred fundamental cooperation among different microbial groups surviving under the extreme conditions in karst caves. Our results revealed habitat specificity of bacterial communities, microbial interactions, and environmental driving forces for bacterial communities in the Xincuntun Cave, enhancing our understanding of the deep terrestrial biosphere.

南极海洋生物肠道微生物研究进展

生物的胃肠道微生物数量众多，各种菌群之间互相制约，与宿主共同进化。南大洋作为一个巨大的生物资源库，繁衍生存着大量的生物，其生活环境的多样性及特殊性，使得其胃肠道微生物较为特殊，肠道微生物群落也进化到适应宿主的各种营养生活方式。从不同营养级具有代表性的南极海洋生物出发，以南极磷虾，鱼类，企鹅，海豹为主线，综述这些生物胃肠道微生物的研究概况以及相关研究方法的优势与局限性，以期揭示肠道微生物与宿主的关系，为更加有效开发利用微生物资源提供借鉴。;The number of microbes in the stomach and gut of animals is huge, and various microbial communities constrain each other. Those microbes co-evolve with their hosts. The Southern Ocean, as a huge biological resource bank, supports a large number of animals. The diversity and specialty of its living environment make the gut microbes of animals extremely special. The gut microbial community has evolved to adapt to various nutritional life styles of host species. From the perspective of representative Antarctic organisms in different trophic levels, this review summarizes gut microbe composition of those species. The advantages and disadvantages of research approaches related to those studies are also analyzed. This review is expected to reveal the relationship between the gut microbes and their hosts, and further to provide a reference for more effective development and utilization of microbial resources in this region.

Nghiên cứu đa dạng vi khuẩn trong trầm tích biển tại quần đảo Trường Sa bằng phương pháp truyền thống kết hợp kỹ thuật điện di biến tính

The denaturing gradient gel electrophoresis (DGGE) is an effective culture-independent technique for assessing diversity of microbial communities. In this study, the PCR-DGGE technique was applied for analyzing the diversity of bacterial communities in marine sediment in the Truong Sa archipelago (Spratly Islands), Vietnam, and a comparison with cultivable bacterial fraction was performed. Three sediment samples taken from different depths were used in the study. A total of 17 bacterial strains were isolated and divided into 6 groups based on their colony and cell morphologies. Comparative analyses of nearly full-length 16S rDNA sequences retrieved from six representative strains of these morphologically distinguished groups indicated that they were most closely related to Bacillus amyloliquefaciens, Bacillus filamentosus, Bacillus endophyticus, Bacillus licheniformis, Pseudomonas balearica, and Raoultella ornithinolytica. The PCR-DGGE analyses carried out with the three sediment samples showed relatively diverse bacterial communities with 9 distinct bands, 6 of which were related to the isolated representatives, whereas the other three were identified as Vibrio proteolyticus, Priestia filamentosa, and Clostridium halophilum. Thus, by applying the PCR-DGGE technique, more thorough information on bacterial communities in the sediment of Truong Sa archipelago could be elucidated, providing useful information for further studies on the conservation and utilization of microbial resources in this ecosystem.

Microbial diversity of representative traditional fermented sausages in different regions of China.

The purpose of this experiment was to study the bacterial diversity of traditional fermented sausages from four typical regions of China (Chengdu, Shenzhen, Changsha and Harbin) and to further evaluate their microbiological safety. The diversity of the microbiota of the sausages was studied using the Illumina HiSeq platform. The results showed that compared with the highest diversity of fermented bacteria in Guangdong, the bacterial diversity of fermented sausage was the lowest in Sichuan. The percentage of dominant phylum (Firmicutes, Cyanophyta, Proteobacter) were 78·39, 13·13 and 7·14% in SC, 35·47, 30·36 and 28·04% in GD, 54·81, 28·91 and 14·00% in HN, 20·20, 58·16 and 17·31% in HB respectively. The main genus distribution of fermented sausages in different regions is varied, but lactic acid bacteria and cyanobacteria are generally the main ones. Traditional fermented sausages using natural fermentation methods have poor microbiological safety, and pathogenic and spoilage micro-organisms such as Acinetobacter, Brochothrix and Pseudomonas have been detected in all four regions. The results in this paper provide a microbiota profile of four typical fermented sausages in China. There is a big difference in the microbiota of sausages in different regions, and the good flavour of traditional Chinese fermented sausage is related closely with the abundant microbial resources, however, the natural fermentation method also expose to the product security threats, including spoilage, pathogenic micro-organisms and biogenic amines, etc. SIGNIFICANCE AND IMPACT OF THE STUDY: The results would offer guidance for industrial fermented sausage production with certain flavour and also improve the microbial resource utilization, and contribute to the control of harmful micro-organisms in traditional fermented sausage.

Microbial transformation of diosgenin to diosgenone by Wickerhamomyces anomalus JQ-1 obtained from Naxi traditional Jiu Qu

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C27H40O3] has been considered as a potential therapeutic alternative remedy for malaria. An efficient and economical approach of microbial transformation with diosgenin to diosgenone by the yeast strain Wickerhamomyces anomalus JQ-1 from Naxi traditional Jiu Qu was developed in this study. Chromatographic analysis confirmed that 85% of 0.1 mM diosgenin was transformed to diosgenone within 72 h. This research demonstrates that diosgenin could be converted to diosgenone through two-step pathway including 3β-hydroxyl oxidation and double bond isomerization rather than through one-step pathway, which prompted a further inference that the oxidation activity in W. anomalus JQ-1 has the same function with the Oppenauer-type oxidation which can convert diosgenin into diosgenone. Gaining specific functional strains from traditional fermented products will be a potential direction and ethnobotanical researches could provide helps with discovery and utilization of microbial resources.

A New Strain of Bacillus tequilensis CGMCC 17603 Isolated from Biological Soil Crusts: A Promising Sand-Fixation Agent for Desertification Control

In arid and semi-arid desert ecosystems, physical, chemical, and vegetative measures were used to prevent wind erosion. However, studies on the utilization of microbial resources for sand fixation are still limited. To fill this gap, a new strain of Bacillus tequilensis CGMCC 17603 with high productivity of exopolysaccharide (EPS) was isolated from biological soil crusts, and its high-density culture technology and sand-fixing ability were studied. The one-factor-at-a-time approach (OFAT) and Box–Behnken design of CGMCC 17603 showed that the optimum culture conditions were pH 8.5, temperature 31 °C, agitation speed 230 rpm, and inoculation quantity 3%, and the optimum medium was 27.25 g/L glucose, 15.90 g/L yeast extract, and 5.61 g/L MgSO4•7H2O. High-density culture showed that the biomass and EPS yield of CGMCC 17603 increased from 9.62 × 107 to 2.33 × 109 CFU/mL, and from 8.01 to 15.61 g/L, respectively. The field experiments showed that CGMCC 17603 could effectively improve the ability of sand fixation and wind prevention. These results indicated that B. tequilensis, first isolated from cyanobacterial crusts, can be considered as an ideal soil-fixing agent to combat desertification in arid and semi-arid areas.

利用PCR-DGGE技术分析内蒙古西部地区土壤细菌的多样性

PDF HTML阅读 XML下载 导出引用 引用提醒 利用PCR-DGGE技术分析内蒙古西部地区土壤细菌的多样性 DOI: 10.5846/stxb201801180138 作者: 作者单位: 内蒙古农业大学,内蒙古农业大学生命科学学院,内蒙古农业大学生命科学学院,内蒙古农业大学生命科学学院,内蒙古农业大学生命科学学院,内蒙古农业大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31370058） Analysis of bacterial diversity of soil in western Inner Mongolia using PCR-DGGE Author: Affiliation: Inner Mongolia Agricultural University,College of Life Sciences of Inner Mongolia Agricultural University,College of Life Sciences of Inner Mongolia Agricultural University,College of Life Sciences of Inner Mongolia Agricultural University,College of Life Sciences of Inner Mongolia Agricultural University,College of Life Sciences of Inner Mongolia Agricultural University Fund Project: 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:为明确内蒙古西部地区土壤细菌的多样性，利用聚合酶链反应-变性梯度凝胶电泳PCR-DGGE（polymerase chain reaction-denaturing gradient gel electrophoresis）技术对170份土壤样品中的细菌丰度和群落结构组成进行了分析，并研究了土壤细菌多样性与肥力参数的关系。结果表明：内蒙古西部地区土壤细菌的多样性是比较丰富的，丰富度指数处于4到60之间，香浓指数处于1.38到4.09之间。不同土壤类型，其细菌的多样性有明显差异。其中，新积土、棕钙土、栗钙土和灰钙土中的细菌多样性指数均高于其他类型土壤，而灰漠土的多样性指数最低。且土壤的不同利用方式也会对土壤细菌多样性有所影响，其中耕地土壤细菌多样性指数最高，而未利用土壤的多样性指数最低。细菌多样性与土壤肥力参数的相关性分析结果显示二者之间并无显著的相关性。内蒙古西部地区土壤中的优势种群包括Proteobacteria（变形菌门）、Bacteroidetes（拟杆菌门）、Firmicutes（厚壁菌门）、Actinobacteria（放线菌门）、Acidobacteria（酸杆菌门）、Gemmatimonadetes（芽单胞菌门）、Nitrospira（硝化螺旋菌门）。可为该地区的土壤生态系统治理与恢复及未来该地区特有微生物资源的开发利用、农业生产指导等提供一定的科学依据。 Abstract:The purpose of this study was to determine bacterial diversity of soil in the western region of Inner Mongolia. The bacterial abundance and community structure of 170 soil samples collected from the western region of Inner Mongolia were tested using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), and the correlation between bacterial community and soil fertility parameters was analyzed. The results showed that the diversity of bacteria in the western region of Inner Mongolia was relatively rich. The richness index was between 4 and 60 and the Shannon index was between 1.38 and 4.09. There were significant differences in the diversity of bacteria among different soil types. The bacterial diversity index of alluvial soil, brown calcic soil, chestnut soil, and sierozem were higher than that of other types of soil. Furthermore, the manner of soil utilization also affected the diversity of bacteria. The Shannon index and richness of cultivated land were the highest and that of unused soil were the lowest. The correlation analysis between bacterial diversity and soil fertility parameters showed that there was no significant correlation between them. The dominant populations of bacteria in soil in the western region of Inner Mongolia include Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria Acinetobacter, Acidobacteria, Gemmatimonadetes, and Nitrospira. This study can provide a scientific basis for the management and restoration of soil ecosystem and the development and utilization of microbial resources and agricultural production guidance in this region. 参考文献 相似文献 引证文献

Characterization of three different types of extracellular vesicles and their impact on bacterial growth

Recently body fluids have been found to contain a class of nanoparticles released from cells, referred to as extracellular vesicles; exosomes are a type of small-diameter extracellular vesicle. We selected three types of sample: milk-derived exosomes, adipose-derived stem cell exosomes, and nanoparticles extracted from coconut water, to investigate their morphology, particle size distribution, protein content, and microRNA expression levels. Among the vesicles investigated, coconut nanoparticles had the greatest size distribution, and the protein content of coconut nanoparticles differed from that of mammalian exosomes. Using fluorescence microscopy, we determined that DiI-labeled extracellular vesicles could be absorbed by bacteria. Prominently, milk-derived exosomes could promote the growth of Escherichia coli K-12 MG1655 and Lactobacillus plantarum WCFS1. The studied extracellular vesicles could alter bacterial gene expression. Overall, this study identified differences in exogenous extracellular vesicles from different sources and revealed their supportive effects on microbial growth to make better utilization of microbial resources.