Bacterial polysaccharides are known to induce the immune response in macrophages. Here we isolated a novel extracellular polysaccharide from the biofilm of Thermus aquaticus YT-1 and evaluated its structure and immunomodulatory effects. The size of this polysaccharide, TA-1, was deduced by size-exclusion chromatography as 500 kDa. GC-MS, high performance anion-exchange chromatography with pulsed amperometric detection, electrospray ionization-MS/MS, and NMR revealed the novel structure of TA-1. The polysaccharide is composed of tetrasaccharide-repeating units of galactofuranose, galactopyranose, and N-acetylgalactosamine (1:1:2) and lacked acidic sugars. TA-1 stimulated macrophage cells to produce the cytokines TNF-α and IL-6. Screening of Toll-like receptors and antibody-blocking experiments indicated that the natural receptor of TA-1 in its immunoactivity is TLR2. Recognition of TA-1 by TLR2 was confirmed by TA-1 induction of IL-6 production in peritoneal macrophages from wild-type mice but not from TLR2^−/− mice. TA-1, as a TLR2 agonist, could possibly be used as an adjuvant and could enhance cytokine release, which increases the immune response. Furthermore, TA-1 induced cytokine release is dependent on MyD88/TIRAP.

Two novel filamentous bacterial isolates, strains WR-30T and WR-220, with an optimum growth temperature of approximately 55-60 degrees C were isolated from Wu-rai hot springs in the northern part of Taiwan. These isolates were aerobic, thermophilic, non-sporulating, red-pigmented and heterotrophic and formed extremely long, filamentous trichomes from cells of different lengths. Phylogenetic analysis of 16S rDNA, DNA-DNA hybridization, morphological and biochemical features and fatty acid composition revealed that the isolates represent a novel species of the genus Meiothermus. The name Meiothermus taiwanensis sp. nov. is proposed for this novel species. The type strain of M. taiwanensis is strain WR-30T (= ATCC BAA-399T = CCRC 17170T = DSM 14542T); strain WR-220 (= ATCC BAA400 = CCRC 17171 = DSM 14543) is a reference strain.

Amphiphilic ionic liquids and ionic liquid crystals, comprising a cationic imidazolium head group (represents as Im), a hydrophobic N-alkyl chain (C_nH_{2n +1}, denoted as C_n, n = 10, 12, 14, 16 and 18), and an amphiphilic N-2-(2-(2-ethoxy)ethoxy)ethanol (3OEG) functional group were synthesized (denoted as [C_n-Im-3OEG][Cl]). While the lipophilicity of [C_n-Im-3OEG][Cl] increases along with the alkyl carbon chain length, the water solubility of these compounds is enhanced with the 3OEG functionality. Compounds with lengths of n = 10, 12 and 14 are room temperature ionic liquids, whereas n = 16 and 18 show thermotropic SmA liquid crystal properties. Meanwhile, compounds of n = 14, 16 and 18 also exhibit lyotropic liquid crystal properties. The ionic and lyotropic liquid crystalline natures of these compounds lead to their superior antimicrobial activity against infectious pathogens. This is especially true for compounds with longer alkyl chains. Rupture of the bioenvelop appears to be operative in the process of antimicrobial activity.