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Background The Paenibacillus srains exhibit diverse abilities to secrete hydrolases capable of degrading biomacromolecules and to act as plant growth-promoting bacteria (PGPB) through the degradation of fungal cell walls and promotion the nutrient cycling of nitrogen (N) and phosphorus (P). Despite the well-acknowledged attributes of Paenibacillus , only limited studies have identified strains of it concurrently produce multiple hydrolytic enzymes and display strong phytobeneficial characteristics. The objective of this study was to isolate and functionally characterize a novel Paenibacillus strain that combines hydrolytic capabilities with plant growth-promoting potential. Methods Strain TH7-28 T was isolated and taxonomically classified through a polyphasic identification approach based on 16S rRNA gene phylogeny, genome analysis, and physiological and biochemical characteristics. Its metabolic capabilities were characterized using CAZy and KEGG pathway annotations, supplemented by Kofam-KOALA functional profiling. Genomic relatedness to reference strains was determined using OGRIs: ANI, dDDH, and tetra-nucleotide frequency signature analyses. Biophysical and biochemical properties were evaluated through enzymatic activity assays, antimicrobial susceptibility testing, respiratory quinone system identification, fatty acid methyl ester profiling, and polar lipid composition analysis. The wheat germination test was used to verify the plant growth-promoting ability. Results Strain TH7-28 T was Gram-stain-positive, aerobic, white and rod-shaped. Phylogenetic analysis based on the 16S rRNA gene and genomic sequence indicated that strain TH7-28 T was classified within the genus Paenibacillus . The ANI values of strain TH7-28 T with the closest related strains P . macerans ATCC 8244 T and P. oralis KCOM 3021 T were 91.00% and 92.85%, respectively. The dDDH values of strain TH7-28 T with P . macerans ATCC 8244 T and P. oralis KCOM 3021 T were 44.60% and 52.40%, respectively. The respiratory quinone was menaquinone 7 (MK-7). The major cellular fatty acids (> 10%) comprised anteiso-C 15:0 , anteiso-C 17:0 , iso-C 16:0 and C 16:0 . The genomic DNA G + C content was 52.1%. Phosphatidylethanolamine, two amino lipids and three phospholipids were the main polar lipids. Genomic sequencing revealed multifunctional gene clusters encoding carbohydrate-active enzymes (cellulase and amylase), proteases, and phospholipases, alongside antifungal chitinase and endo-β-1,3-glucanase. The biomolecular metabolic gene types and gene copy numbers of strain TH7-28 T were significantly higher than those of other Paenibacillus genus, indicating its robust capacity for macromolecule degradation. The nitrogen-fixing potential of strain TH7-28 T was confirmed via nifH/D/K genes. Phosphorus activation capacity was demonstrated through ps t S/C/A/B -mediated inorganic uptake and phospholipase-driven organic solubilization. Experimental assays further demonstrated significant enzymatic activities of chitinase (8.12 ± 0.66 × 10 –3 U/mL), β-1,3-glucanase (0.023 ± 0.004 U/mL), and nitrogenase (0.164 ± 0.006 U/mL), with concurrent hydrolysis of cellulose, starch, casein, chitin and lecithin. Through the wheat germination experiment, it has been confirmed that this strain significantly enhanced both the seed germination rate and stem length, thereby establishing a solid foundation for subsequent research on its practical applications. Conclusion Strain TH7-28 T , isolated from lake sediment, was identified to represent a novel species designated Paenibacillus lacisediminis sp. nov. The strain exhibits multifunctional hydrolase activities, antifungal enzyme synthesis, nitrogen fixation, phosphorus solubilization and plant growth promoting. The findings confirm Paenibacillus lacisediminis sp. nov. as a biotechnologically promising strain for sustainable agriculture, furthermore enriching the functional repertoire of Paenibacillus genus.

Cecina de León is a traditional Spanish dry-cured beef product whose surface, as in other similar meat products, becomes heavily colonised by fungi during ripening, raising concerns related to possible mycotoxin contamination. This study aimed to characterise the mycobiota associated with cecina and its production environment, with particular emphasis on mycotoxigenic Penicillium species. Seventy-eight cecina samples and 26 air samples were collected from meat-processing plants and local markets in the province of León (Spain) and analysed for fungal counts, water activity and pH. A total of 101 mould isolates and 16 yeasts were recovered, with Penicillium accounting for 88% of all moulds. Sixteen Penicillium species were identified using a polyphasic approach integrating macro- and micromorphological analysis, extrolite production, molecular markers (BenA, CaM and ITS), and MALDI-TOF MS. Mycotoxin screening by HPTLC and HPLC-PDA targeted cyclopiazonic acid, ochratoxin A, patulin, citrinin, griseofulvin and mycophenolic acid, revealing that 51% of the Penicillium isolates were mycotoxin producers, mainly P. commune. The proposed polyphasic strategy, including MALDI-TOF MS as a rapid complementary tool, offers a practical framework for the surveillance of fungal communities and mycotoxin risk in meat-processing environments.

Aiming at revealing the arsenic (As) resistance of the endophytic Kocuria strains isolated from roots and stems of Sphaeralcea angustifolia grown at mine tailing, four strains belonging to different clades of Kocuria based upon the phylogeny of 16S rRNA genes were screened for minimum inhibitory concentration (MIC). Only the strain NE1RL3 was defined as an As-resistant bacterium with MICs of 14.4/0.0125 mM and 300/20.0 mM for As3+ and As5+, respectively, in LB/mineral media. This strain was identified as K. palustris based upon analyses of cellular chemical compositions (cellular fatty acids, isoprenoides, quinones, and sugars), patterns of carbon source, average nucleotide identity of genome and digital DNA–DNA relatedness. Six genes coding to enzymes or proteins for arsenate reduction and arsenite-bumping were detected in the genome, demonstrating that this strain is resistant to As possibly by reducing As5+ to As3+, and then bumping As3+ out of the cell. However, this estimation was not confirmed since no arsenate reduction was detected in a subsequent assay. This study reported for the first time the presence of phylogenetically distinct arsenate reductase genes in a Kocuria strain and evidenced the possible horizontal transfer of these genes among the endophytic bacteria.

A yeast, isolated from grape juice concentrate by a grape juice processing company in central Washington, was subjected to thermal processing in 52° Brix grape juice concentrate, commercial grape juice, and Yeast-Mold (YM) medium to determine D -values and z -values in the search for an effective means of control. At 50 ℃ in grape juice concentrate the D -value was 33.44 minutes, dropping rapidly as the temperature increased to 52.5 ℃, 55 ℃, 57.5 ℃, and 60 ℃. From this data, a z -value was determined to be 4.38 ℃. Grape juice and YM broth were similarly tested. Commercial grape juice at 45 ℃, 47 ℃, and 50 ℃ showed D -values of 9.80, 7.68, and 1.42, respectively, resulting in a z -value of 5.69 ℃. The isolate heat treated in YM broth at 40 ℃, 45 ℃, 46 ℃, 47.5 ℃, and 50 ℃ showed no effect at 40 ℃ but at higher temperatures, with a D -value of 2.28 at 45 ℃, 1.61 at 46 ℃, 1.05 at 47.5 ℃, and with a z -value of 7.46 ℃. This data suggests that an increase in the concentration of sugars in the environment has a protective effect on the yeast against elevated temperatures. Even so, pasteurization at 90 ℃ for thirty seconds appears to be an effective means of control for the yeast investigated. A yeast with the identical colony and cell morphology was isolated from 52° Brix grape juice concentrate from the same grape juice processing company. Both isolates were subjected to 28S DNA sequencing and FAME analysis for identification and determined to be Zygosaccharomyces rouxii , a known problem yeast in the grape juice and wine-making industry, to this point unknown in the central Washington region.

Background Bioprospecting lipase producers in non-conventional habitats are the way to find special enzymes of diverse applications. Halo-alkaline marshes in Wadi El Natrun in Egypt are some of the most stable ecological systems in the world, and because of the double extremities of alkalinity and salinity, they harbor individual microbes capable of adapting stress conditions. Results Eight strains were recovered from the coastline soil of Al-Beida Lake in Wadi El Natrun and have been tested for lipase production. Among the eight isolates, the strain SBLWN_MH2 was the most active producer of lipase (7.5 U/ml). The crude SBLWN_MH2 lipase showed activity over a wide pH range (3.5 to 13) with an optimum pH at 10.5, and it was able to show more than 75% of its highest activity at pH elevated up to 13. The identification using phenotypic and genotypic methods strongly indicated that the strain SBLWN_MH2 belonged to the genus Streptomyces with a similarity of 99%. Thus, it has been given the suggested name Streptomyces sp. SBLWN_MH2 (MG593538). SBLWN_MH2 produced extracellular lipase in modified starch casein medium supplemented with different oils or Tween-80, and the potential production rate has been attained in the case of linseed oil after 3 days. Further experiments have been carried out to optimize medium composition through Box-Behnken design and response surface methodology, and it was possible to achieve more than 3.5-fold increase in lipase production. Conclusions The present study indicates that Streptomyces sp. SBLWN_MH2 is a potential lipase producer and could be fruitfully employed in the large-scale production of highly alkaline lipase.

The influence of three commonly used fungicides (iprodione, pyrimethanil and fludioxonil plus cyprodinil) on the density and diversity of yeast populations present on grape berries was evaluated. At the time of harvest, the fungicide residues on grapes were below the maximum permitted levels. In general, larger yeast counts were found on the treated grapes than on the control samples. Among 23 species identified, Cryptococcus magnus, Rhodotorula glutinis and Sporidiobolus pararoseus dominated on sound grape berries. The results showed that the tested fungicides had only a minor impact on the composition of grape berry communities in comparison with the effect of weather conditions and the mode of grape berry sampling. Halo assays using filter discs loaded with fungicides were used as in vitro tests of the sensitivity of grape berry isolates. The fungicide containing pyrimethanil suppressed the growth of all basidiomycetous yeast species, while the sporadically occurring fermentative yeasts were unaffected. Fungicides with fludioxonil plus cyprodinil and iprodione as active substances showed specificity for certain species. Our results suggest that after the safety interval, the presence of fungicides has a minor impact on the composition of grape berry communities, although at the time of fungicide applications, the yeast species composition changes.

Lactic acid bacteria collected from artisanal farmhouses were characterized using a polyphasic approach. Phenotypic methods including biochemical assays, ribosomal DNA restriction analysis and 16S rDNA sequence analysis were performed. This approach provides accuracy for identification, and helps to avoid the loss of natural biodiversity including potentially valuable strains.

The saline-alkaline crater-lake Dziani Dzaha (Mayotte, Indian Ocean) is dominated by the bloom-forming cyanobacterium Arthrospira. However, the rest of the phototrophic community remains underexplored because of their minute dimension or lower biomass. To characterize the phototrophic microorganisms living in this ecosystem considered as a modern analog of Precambrian environments, several strains were isolated from the water column and stromatolites and analyzed using the polyphasic approach. Based on morphological, ultrastructural and molecular (16S rRNA gene, 18S rRNA gene, 16S-23S internal transcribed spacer (ITS) region and cpcBA-IGS locus) methods, seven filamentous cyanobacteria and the prasinophyte Picocystis salinarum were identified. Two new genera and four new cyanobacteria species belonging to the orders Oscillatoriales (Desertifilum dzianense sp. nov.) and Synechococcales (Sodalinema komarekii gen. nov., sp. nov., Sodaleptolyngbya stromatolitii gen. nov., sp. nov. and Haloleptolyngbya elongata sp. nov.) were described. This approach also allowed to identify Arthrospira fusiformis with exclusively straight trichomes instead of the spirally coiled form commonly observed in the genus. This study evidenced the importance of using the polyphasic approach to solve the complex taxonomy of cyanobacteria and to study algal assemblages from unexplored ecosystems.

ABSTRACT Filamentous cyanobacteria belonging to the ‘marine Geitlerinema’ cluster are spread worldwide in saline environments and considered to play an important ecological role. However, the taxonomy of this group remains unclear. Here, we analyzed the phylogeny, ecology and biogeography of the ‘marine Geitlerinema’ cluster representatives and revealed two subclusters: (1) an ‘oceanic’ subcluster containing PCC7105 clade and black band disease (BBD) clade with free-living and pathogenic strains distributed in Atlantic, Indian and Pacific Ocean-related localities, and (2) a Sodalinema subcluster containing free-living strains from marine, hypersaline, saline-alkaline and soda lake habitats from the Eurasian and African continents. Polyphasic analysis using genetic and phenotypic criteria demonstrated that these two groups represent separate genera. Representatives of Sodalinema subcluster were phylogenetically attributed to the genus Sodalinema. Our data expand the ecological and geographical distribution of this genus. We emended the description of the genus Sodalinema and proposed three new species differing in phylogenetic, geographic and ecological criteria: Sodalinema orleanskyi sp. nov., Sodalinema gerasimenkoae sp. nov. and Sodalinema stali sp. nov. Additionally, a new genus and species Baaleninema simplex gen. et sp. nov. was discribed within the PCC7105 clade. By this, we put in order the current confusion of the ‘marine Geitlerinema’ group and highlight its ecological diversity. Phylogenetic relationships among widespread filamentous cyanobacteria from ‘marine Geitlerinema' cluster are systemized; three new Sodalinema species and a new genus Baaleninema are described with the emphasis on their ecological diversity and biogeography.