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A novel Streptomyces strain, designated TRM43335 T , was isolated from the Taklimakan desert in Alar City, Xinjiang, north-west China. The strain was found to exhibit an inhibitory effect on biofilm formation by Candida albicans and Staphylococcus epidermidis. A polyphasic approach was used to determine its taxonomic status. The strain was observed to form abundant aerial mycelium, occasionally twisted and which differentiated into spiral spore chains. Spores of TRM43335 T were observed to be oval-shaped, with a smooth surface. Strain TRM43335 T was found to grow optimally at 37 °C, pH 8 and in the presence of 1% (w/v) NaCl. The major sugars were identified as ribose, xylose, glucose, mannose and galactose, and the principal phospholipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannoside and phosphatidylinositol. The diagnostic cell wall amino acid was identified as LL-diaminopimelic acid. The predominant menaquinone was found to be MK-9(H 6 ). The major cellular fatty acids were identified as iso-C 16:1 H, anteiso-C 15:0 , iso-C 16:0 , anteiso-C 17:0 , anteiso-C 17:1 w9c and iso-C 15:0 . Analysis of the 16S rRNA sequence showed that strain TRM43335 T exhibits high sequence similarity to Streptomyces desertarenae SYSU D8023 T 98.69%. A multilocus sequence analysis of five house-keeping genes (atpD, gyrB, rpoB, recA and trpB) also illustrated that strain TRM43335 T should be assigned to the genus Streptomyces. The DNA G + C content of the strain was determined to be 72.8 mol%. The average nucleotide identity relatedness between strain TRM43335 T and the phylogenetically related strain S. desertarenae SYSU D8023 T was found to be 89.23%, and the in silico DNA-DNA hybridization value to be 36.70%. Therefore, it is concluded that strain TRM43335 T represents a novel species of the genus Streptomyces, for which the name Streptomyces taklimakanensis sp. nov is proposed. The type strain is TRM43335 T (CCTCC AA 2018052  T  = KCTC 49254  T ).

• The chemical composition of Fingered Citron essential oil was investigated by GC-MS. • Fingered Citron essential oil significantly inhibited the biofilm formation of L. monocytogenes • Fingered Citron essential oil significantly destroyed the preformed L. monocytogenes biofilm. • Fingered Citron essential oil increased the metabolic activity of L. monocytogenes biofilm. • Fingered Citron essential oil changed the architecture of L. monocytogenes biofilm. Listeria monocytogenes is an important foodborne pathogen that could cause listeriosis and poses potential threats to human health. Citrus medica L. var. sarcodactylis Swingle , also known as Fingered Citron, is a citrus species widely cultivated in South China. The aim of this work was to investigate the anti-biofilm efficacy of essential oil from Fingered Citron (FCEO) against L. monocytogenes. The crystal violet assay showed that FCEO exhibited strong anti-biofilm activity on both inhibiting biofilm formation and eradicating preformed biofilm. XTT assay indicated that FCEO significantly increased the metabolic active cells in the biofilm. Confocal scanning laser microscopy images and COMSTAT assay revealed that FCEO destroyed the intact architecture of biofilm, reduced biofilm biomass, thickness and substratum coverage. The morphological changes of cells in the biofilm were observed by scanning electron microscopy, which showed that FCEO could cause the wrinkle, collapse, lysis and cytoplasmic content leakage of cells. Our results also indicated that FCEO displayed its anti-biofilm activity through both biofilm dispersal and cell killing. Our findings provide evidence that FCEO exhibits strong anti-biofilm activity and might be used as a potential agent to control L. monocytogenes biofilm. [ABSTRACT FROM AUTHOR]

A high slime-producing Lactobacillus fermentum strain (named as L. fermentum S1) was isolated from traditional fermented Fuyuan pickle, which was made of white turnip and collected from Fuyuan county, Yunnan province, China. We extracted and purified the exopolysaccharides from L. fermentum S1, and investigated their preliminary structure characteristics and biological activities. Three purified exopolysaccharide fractions, designated as EPS1, EPS2 and EPS3, were obtained from the culture supernatant of L. fermentum S1 by ethanol precipitation, anion exchange and gel filtration chromatography. The EPS2 and EPS3 were homogeneous with molecular weights of 4.45 × 10 6 and 2.82 × 10 6  Da, respectively. All the purified EPS fractions were composed of glucose, galactose, mannose and arabinose, but with different molar ratios. EPS1, EPS2 and EPS3 presented different surface morphologies and their degradation temperatures were 302.7°C, 316.3°C and 316.9°C, respectively. Bioactivity research showed that L. fermentum S1 EPS elicited free radical scavenging capacity and ferric reducing antioxidant power, and 1 mg/mL of EPS significantly improved the gastrointestinal transit tolerance of non EPS-producing strain L. fermentum LG1. Moreover, S1 EPS had a favorable anti-biofilm activity against Escherichia coli and Staphylococcus aureus. These results indicated that S1 EPS could be explored as a promising functional adjunct for application in foods., (Copyright © 2019 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)