Dibutyl phthalate (DBP) is used widely as a plasticizer and is thought to negatively affect various organisms. To isolate and investigate DBP-degrading bacteria from hydrospheres in Tokyo, strains were selected on YNB medium containing DBP as the sole carbon source, and candidate strains were identified by zones of clearing around the colonies. Degradation of DBP by the strains was subsequently measured with HPLC, and bacterial identification was accomplished using 16S rDNA sequences. Nineteen strains of DBP degraders were isolated from activated sludge in a sewage treatment plant, from Tokyo Bay, and from the Takahama Canal. These strains degraded 16.8%-88.0% of DBP (0.1%, v/v) for 2 weeks and were identified as several species of Acinetobacter, as well as Tsukamurella tyrosinosolvens, Ochrobactrum anthropi, and Staphylococcus saprophyticus. Commercially available strains of Acinetobacter were also found to degrade DBP.
Three strains, FYK2301M01T, FYK2301M18 and FYK2301M52, all being Gram-negative, spherical, motile and facultatively anaerobic, were isolated from a marine alga (Porphyra sp.) collected on Mikura Island, Japan. Colonies of the strains were circular and pink-pigmented on Marine Agar 2216 (Difco) at 25°C. Cells of the strains reproduced by binary fission. The G+C content of the DNA was 73 mol%. The major isoprenoid quinone was MK-6. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strains are the members of the WPS-1 group (Nogales et al., 2001) comprising no validly described taxa within the phylum Planctomycetes. The highest similarity value of the 16S rRNA gene sequences of the strains to those in the established bacterial taxa was only 78.7% to Planctomyces brasiliensis DSM 5305T. From the taxonomic data obtained in this study, it is proposed that the new marine isolates be placed in a novel genus and species named Phycisphaera mikurensis gen. nov., sp. nov. within a new family, order and class Phycisphaeraceae fam. nov., Phycisphaerales ord. nov. and Phycisphaerae classis nov. in the phylum Planctomycetes. The type strain of Phycisphaera mikurensis is FYK2301M01T (= NBRC 102666T = KCTC 22515T).
The influence of different stress conditions, such as low and high temperatures, the presence of salt or ethanol in the medium, on the growth of Lactobacillus acidophilus IBB801 and the production of acidophilin 801 was investigated in this study. The strain was able to grow at up at to 47°C, while higher temperatures were lethal. A slow growth was detected at 24°C, starting after 24 h of incubation, and the strain was able to survive at 10°C for more than 48 h of incubation. The protein profiles revealed by one dimensional SDS-PAGE showed at least four overexpressed and two repressed bands at low temperatures (10°C and 24°C) compared with the profiles at 37°C and 42°C. The bacteriocin activity was the highest when the producing strain was grown at optimum temperature. However, at 10°C, the inhibitory activity showed a slight increase compared with the one reached at 24°C and 47°C. The same increase in activity was observed in the presence of low amounts of salt (5 to 10 g/L). Higher concentrations of salt or ethanol addition to the growth medium had a negative effect on acidophilin biosynthesis.
An alkalophilic and halotolerant laccase from γ-proteobacterium JB catalyzed in high concentrations of organic solvents and various salts. The enzyme retained 80-100% activity in 10% concentration of dimethylsulfoxide (DMSO), ethanol, acetone or methanol; 100, 85 and 50% activity in 20 mM MgCl2, 5.0 mM MnCl2 and 0.1 mM CuCl2; 140, 120 and 110% activity in 5.0 mM MnSO4, 10 mM MgSO4 and 1mM CaSO4, respectively. Sodium halides inhibited the enzyme in the order: F-> Br-> I-> Cl-. In 0.5 M NaCl, pH 6.0, laccase was ~60% active. Decolorization of indigo carmine by laccase at pH 9.0 was not inhibited even in the presence of 0.5 M NaCl. Release of chromophoric, reducing and hydrophobic compounds during biobleaching of straw rich-soda pulp by laccase was not inhibited when the enzyme was applied in the presence of 1 M NaCl at pH 8.0. Laccase retained 50% residual activity even when incubated with 5% calcium hypochlorite for 30 min.
The DNase test is a simple, economical method that has traditionally been used as a supplemental test to identify pathogenic Staphylococcus. This test also aids in the differentiation of closely-related genera within the Klebsiella-Enterobacter-Serratia division of Enterobacteriaceae and several other pathogens, including screening of C. diphtheriae. Currently DNase activity of microorganisms was tested using DNase agar plate methods. These tests have some drawbacks including the necessity of the extensive time to see the results of DNase activity of bacteria. In here, we developed a new method which is simple, rapid, inexpensive and applicable to examine DNase activity of any bacteria. In this method, simply, bacteria is added to the broth medium containing DNA and followed for the DNA degradation caused by the DNase of bacteria by running in agarose gel. This method we called DNase Tube test showed DNA degradation as fast as in half an hour depending on the DNase activity of the bacteria.