Search Results (12)

Wheat grain serves as the primary raw material for producing medium-high temperature (MT)-Daqu, a fermentation starter crucial for Chinese Baijiu production, characterized by spontaneous fermentation without the inoculation of exogenous substances. However, the interactions among wheat varieties, cultivation environments, and the resulting Daqu quality remain poorly understood. This study evaluates three wheat varieties harvested from three distinct cultivation environments, examining wheat grain quality, grain-associated endophytes, and physicochemical properties and microbial communities of MT-Daqu at 0, 9, and 90 days of fermentation. The results revealed the cultivation environment had the most pronounced impact on wheat fungal endophytes. The physicochemical properties of Daqu were primarily impacted by variety, namely, the enzyme activity impacted by environmental factors. Pantoea, Aspergillus, and Stephylium are key microbial genera shared between wheat grains and MT-Daqu. Redundancy analysis highlighted the critical roles of moisture content, starch content, and amino acid nitrogen levels in driving microbial succession in Daqu. Mantel analysis demonstrated significant correlations between the abundance of dominant fungal endophytes in wheat grains and Daqu quality parameters, including starch content (r = 0.45; p < 0.01), saccharifying activity (r = 0.41), liquefying activity (r = 0.31), and esterifying activity (r = 0.30) (p < 0.05). Spearman correlation analysis indicated that Nesterenkonia, Aspergillus, Cryptococcus, Dioszegia, Golubevia, Udeniomyces and Stemphylium are the dominant wheat-derived bacterial genera associated with the abundance of microorganisms in MT-Daqu. This study elucidated the “cultivation environment–grain endophyte–Daqu microorganism” microbial transmission pathway, providing a theoretical foundation for breeding wheat varieties optimized for Daqu production and identifying suitable production regions. Full article

Post-harvest storage loss in sugar beets due to root rot and respiration can cause >20% sugar loss. Breeding strategies focused on factors contributing to improved post-harvest storage quality are of great importance to prevent losses. Using 16S rRNA and ITS sequencing and sugar beet mutational breeding lines with high disease resistance (R), along with a susceptible (S) commercial cultivar, the role of root microbiome and metabolome in storage performance was investigated. The R lines in general showed higher abundances of bacterial phyla, Patescibacteria at the M time point, and Cyanobacteria and Desulfobacterota at the L time point. Amongst fungal phyla, Basidiomycota (including Athelia) and Ascomycota were predominant in diseased samples. Linear discriminant analysis Effect Size (LEfSe) identified bacterial taxa such as Micrococcales, Micrococcaceae, Bacilli, Glutamicibacter, Nesterenkonia, and Paenarthrobacter as putative biomarkers associated with resistance in the R lines. Further functional enrichment analysis showed a higher abundance of bacteria, such as those related to the super pathway of pyrimidine deoxyribonucleoside degradation, L-tryptophan biosynthesis at M and L, and fungi, such as those associated with the biosynthesis of L-iditol 2-dehydrogenase at L in the R lines. Metabolome analysis of the roots revealed higher enrichment of pathways associated with arginine, proline, alanine, aspartate, and glutamate metabolism at M, in addition to beta-alanine and butanoate metabolism at L in the R lines. Correlation analysis between the microbiome and metabolites indicated that the root’s biochemical composition, such as the presence of nitrogen-containing secondary metabolites, may regulate relative abundances of key microbial candidates contributing to better post-harvest storage. Full article

In this experiment, we explored the chemical composition and community structure of Mulberry “Wuhedashi” (Morus alba L., hereinafter referred to as WHDS) in different stages and obtained data support for its resource utilisation. Five ripening stages were established: S1, deep-red stage; S2, red with black stage; S3, black with red stage; S4, black stage; S5, overripe stage. The results showed that there were significant differences in the indicators of WHDS in the different stages. Immature WHDS contains high levels of amino acids (2.14 ± 0.15 mg/g), organic acids (43.10 ± 0.75 mg/g), K (3019.52 ± 78.00 mg/L), and Ca (1617.86 ± 24.45 mg/L) and is an important source of amino acid and mineral supplementation for the body. Total phenolic compounds (26.15 ± 0.43 g/L), total flavonoids (2.46 ± 0.03 g/L), total anthocyanins (587.60 ± 7.38 mg/L), the ABTS radical scavenging rate (94.20 ± 2.18%), the DPPH radical scavenging rate (95.13 ± 1.44%), and total flavour compounds (1279.09 ± 33.50 mg/L) peaked at S4, which is the optimal stage for the consumption and processing of WHDS. High-throughput sequencing identified 10 dominant genera, including Bacillus, Brevibacterium, Pseudomonas, and Tatumella. Nesterenkonia was the most highly associated micro-organism. Bacterial genera such as Pantoea and Pseudomonas were significantly positively correlated with esters, enhancing the floral and fruity flavours of wine. The results of the study revealed the characteristics of WHDS in different stages, which can help to target the development of nutritious mulberry derivatives and provide a reference for enhancing the added value of mulberry. Full article

Bacterial endophytes (120) were isolated from six halophytes (Distichlis spicata, Cynodon dactylon, Eragrostis obtusiflora, Suaeda torreyana, Kochia scoparia, and Baccharis salicifolia). These halophiles were molecularly identified and characterized with or without NaCl conditions. Characterization was based on tests such as indole acetic acid (IAA), exopolysaccharides (EPS), and siderophores (SID) production; solubilization of phosphate (P), potassium (K), zinc (Zn), and manganese (Mn); mineralization of phytate; enzymatic activity (acid and alkaline phosphatase, phytases, xylanases, and chitinases) and the mineralization/solubilization mechanisms involved (organic acids and sugars). Moreover, compatibility among bacteria was assessed. Eleven halophiles were characterized as highly tolerant to NaCl (2.5 M). The bacteria isolated were all different from each other. Two belonged to Bacillus velezensis and one to B. pumilus while the rest of bacteria were identified up to the genus level as belonging to Bacillus, Halobacillus, Halomonas, Pseudomonas, Nesterenkonia, and three strains of Oceanobacillus. The biochemical responses of nutrient solubilization and enzymatic activity were different between bacteria and were influenced by the presence of NaCl. Organic acids were involved in P mineralization and nutrient solubilization. Tartaric acid was common in the solubilization of P, Zn, and K. Maleic and vanillic acid were only detected in Zn and K solubilization, respectively. Furthermore, sugars appeared to be involved in the solubilization of nutrients; fructose was detected in the solubilization tests. Therefore, these biochemical bacterial characteristics should be corroborated in vivo and tested as a consortium to mitigate saline stress in glycophytes under a global climate change scheme that threatens to exacerbate soil salinity. Full article

Soil salinization is negatively affecting soils globally, and the spread of this problem is of great concern due to the loss of functions and benefits offered by the soil resource. In the present study, we explored the diversity of halophilic and halotolerant microorganisms in the arable fraction of a sodic–saline soil without agricultural practices and two soils with agricultural practices (one sodic and one saline) near the geothermal area “Los Negritos” in Villamar, Michoacán state. This was achieved through their isolation and molecular identification, as well as the characterization of their potential for the production of metabolites and enzymes of biotechnological interest under saline conditions. Using culture-dependent techniques, 62 halotolerant and moderately halophilic strains belonging to the genera Bacillus, Brachybacterium, Gracilibacillus, Halobacillus, Halomonas, Kocuria, Marinococcus, Nesterenkonia, Oceanobacillus, Planococcus, Priestia, Salibactetium, Salimicrobium, Salinicoccus, Staphylococcus, Terribacillus, and Virgibacillus were isolated. The different strains synthesized hydrolytic enzymes under 15% (w/v) of salts, as well as metabolites with plant-growth-promoting (PGP) characteristics, such as indole acetic acid (IAA), under saline conditions. Furthermore, the production of biopolymers was detected among the strains; members of Bacillus, Halomonas, Staphylococcus, and Salinicoccus showed extracellular polymeric substance (EPS) production, and the strain Halomonas sp. LNSP3E3-1.2 produced polyhydroxybutyrate (PHB) under 10% (w/v) of total salts. Full article

(1) Background: Organic food produced in environmentally friendly farming systems has become increasingly popular. (2) Methods: We used a DNA metabarcoding approach to investigate the differences in the microbial community between organic and conventional ‘Huangguan’ pear fruit; and (3) Results: Compared to a conventional orchard, the fruit firmness in the organic orchard had significantly lowered after 30 days of shelf-life storage at 25 °C, and the soluble solids content (SSC), titratable acid (TA), and decay index were higher. There were differences in the microbial diversity between organic and conventional orchards pears. After 30 days of storage, Fusarium and Starmerella became the main epiphytic fungi in organic fruits, while Meyerozyma was dominant in conventional fruits. Gluconobacter, Acetobacter, and Komagataeibacter were dominant epiphytic bacteria on pears from both organic and conventional orchards after a 30-day storage period. Bacteroides, Muribaculaceae, and Nesterenkonia were the main endophytic bacteria throughout storage. There was a negative correlation between fruit firmness and decay index. Moreover, the abundance of Acetobacter and Starmerella were positively correlated with fruit firmness, while Muribaculaceae was negatively correlated, implying that these three microorganisms may be associated with the postharvest decay of organic fruit; (4) Conclusions: The difference in postharvest quality and decay in organic and conventional fruits could potentially be attributed to the variation in the microbial community during storage. Full article

The members of the Nesterenkonia genus have been isolated from various habitats, like saline soil, salt lake, sponge-associated and the human gut, some of which are even located in polar areas. To identify their stress resistance mechanisms and draw a genomic profile across this genus, we isolated four Nesterenkonia strains from the lakes in the Tibetan Plateau, referred to as the third pole, and compared them with all other 30 high-quality Nesterenkonia genomes that are deposited in NCBI. The Heaps’ law model estimated that the pan-genome of this genus is open and the number of core, shell, cloud, and singleton genes were 993 (6.61%), 2782 (18.52%), 4117 (27.40%), and 7132 (47.47%), respectively. Phylogenomic and ANI/AAI analysis indicated that all genomes can be divided into three main clades, named NES-1, NES-2, and NES-3. The strains isolated from lakes in the Tibetan Plateau were clustered with four strains from different sources in the Antarctic and formed a subclade within NES-2, described as NES-AT. Genome features of this subclade, including GC (guanine + cytosine) content, tRNA number, carbon/nitrogen atoms per residue side chain (C/N-ARSC), and amino acid composition, in NES-AT individuals were significantly different from other strains, indicating genomic adaptation to cold, nutrient-limited, osmotic, and ultraviolet conditions in polar areas. Functional analysis revealed the enrichment of specific genes involved in bacteriorhodopsin synthesis, biofilm formation, and more diverse nutrient substance metabolism genes in the NES-AT clade, suggesting potential adaptation strategies for energy metabolism in polar environments. This study provides a comprehensive profile of the genomic features of the Nesterenkonia genus and reveals the possible mechanism for the survival of Nesterenkonia isolates in polar areas. Full article

In this study, we examined the effect of salinity and alkalinity on the metabolic potential and taxonomic composition of microbiota inhabiting the sodic soils in different plant communities. The soil samples were collected in the Pannonian steppe (Hungary, Central Europe) under extreme dry and wet weather conditions. The metabolic profiles of microorganisms were analyzed using the MicroResp method, the bacterial diversity was assessed by cultivation and next-generation amplicon sequencing based on the 16S rRNA gene. Catabolic profiles of microbial communities varied primarily according to the alkali vegetation types. Most members of the strain collection were identified as plant associated and halophilic/alkaliphilic species of Micrococcus, Nesterenkonia, Nocardiopsis, Streptomyces (Actinobacteria) and Bacillus, Paenibacillus (Firmicutes) genera. Based on the pyrosequencing data, the relative abundance of the phyla Proteobacteria, Actinobacteria, Acidobacteria, Gemmatimonadetes and Bacteroidetes also changed mainly with the sample types, indicating distinctions within the compositions of bacterial communities according to the sodic soil alkalinity-salinity gradient. The effect of weather extremes was the most pronounced in the relative abundance of the phyla Actinobacteria and Acidobacteria. The type of alkali vegetation caused greater shifts in both the diversity and activity of sodic soil microbial communities than the extreme aridity and moisture. Full article

Long-term organic farming aims to reduce synthetic fertilizer and pesticide use in order to sustainably produce and improve soil quality. To do this, there is a need for more information about the soil microbial community, which plays a key role in a sustainable agriculture. In this paper, we assessed the long-term effects of two organic and one conventional cropping systems on the soil microbial community structure using high-throughput sequencing analysis, as well as the link between these communities and the changes in the soil properties and crop yield. The results showed that the crop yield was similar among the three cropping systems. The microbial community changed according to cropping system. Organic cultivation with manure compost and compost tea (Org_C) showed a change in the bacterial community associated with an improved soil carbon and nutrient content. A linear discriminant analysis effect size showed different bacteria and fungi as key microorganisms for each of the three different cropping systems, for conventional systems (Conv), different microorganisms such as Nesterenkonia, Galbibacter, Gramella, Limnobacter, Pseudoalteromonas, Pantoe, and Sporobolomyces were associated with pesticides, while for Org_C and organic cultivation with manure (Org_M), other types of microorganisms were associated with organic amendments with different functions, which, in some cases, reduce soil borne pathogens. However, further investigations such as functional approaches or network analyses are need to better understand the mechanisms behind this behavior. Full article

Nesterenkonia sp. PF2B19, a psychrophile was isolated from 44,800-year-old permafrost soil. This is the first report on comparative genomics of Nesterenkonia sp. isolated from Arctic. Genome of PF2B19 exhibited the presence of a vast array of genetic determinants involved in cold adaptation i.e., response to cold-associated general, osmotic, and oxidative stress. These genomic attributes proved to be valuable in unraveling the adaptive tactics employed by PF2B19 for survival in the cold permafrost soils of the Arctic. Genomic analysis of PF2B19 has given some valuable insight into the biotechnological potential of this strain, particularly as a source of cold-active enzymes, as a bioremediating agent and as plant growth-promoting bacteria. Full article

Marine microorganisms are an important source of natural products with potent bioactivities. Unlike the land, the ocean, especially the deep-sea, is characterized by high pressure, high salinity, low nutrition, and no light among others. Therefore, the biodiversity of marine microorganisms is supposed to be very different from that of the terrestrial ones. Yet, many marine microorganisms can find their counterparts in terrestrial environments. To evaluate their differences, a comparative metabolomics investigation was performed on four strains of Nesterenkonia flava isolated from terrestrial and marine environments. As a result, marine strains were clearly distinguished from terrestrial ones on the principal components analysis (PCA) score plot. Furthermore, by partial least squares discrimination analysis (PLS-DA) and univariate analysis, the characteristic metabolites were figured out and found to be involved in osmotic regulation, redox balancing, and energy metabolism. Our results demonstrated that marine actinomycetes could produce novel secondary metabolites different from their terrestrial relatives because they have special metabolic patterns closely related to the unique features of their living environment. Full article

A novel cyclic ether, nesterenkoniane (1), was isolated from the deep-sea-derived actinomycete Nesterenkonia flava MCCC 1K00610, together with 12 known compounds, including two macrolides (2, 3), two diketopiperazines (4, 5), two nucleosides (6, 7), two indoles (8, 9), three phenolics (10–12), and one butanol derivate (13). Their structures were established mainly on detailed analysis of the NMR and MS spectroscopic data. All 13 compounds were tested for anti-allergic activities using immunoglobulin E (IgE) mediated rat mast RBL-2H3 cell model. Under the concentration of 20 μg/mL, 1 exhibited moderate anti-allergic activity with inhibition rate of 9.86%, compared to that of 37.41% of the positive control, loratadine. While cyclo(d)-Pro-(d)-Leu (4) and indol-3-carbaldehyde (8) showed the most potent effects with the IC₅₀ values of 69.95 and 57.12 μg/mL, respectively, which was comparable to that of loratadine (IC₅₀ = 35.01 μg/mL). To the best of our knowledge, it is the first report on secondary metabolites from the genus of Nesterenkonia. Full article