ABSTRACT
Myxococcus xanthus is a Gram-negative soil bacterium capable of performing sophisticated cellular behaviors and growing one of the most intricate bacterial single-species biofilms in nature. During the process of biofilm formation, social behaviors of M. xanthus cells dominate key steps of the biofilm establishment, e.g., cellular motility on solid surface, predatory behavior by the grouped cells, kin recognition in the community, fruiting body development, myxospore differentiation, and programmed cell death. This review introduces the recent research progress about the M. xanthus biofilms.
ABSTRACT
10.3969/j.issn.2095-4344.2013.25.016
ABSTRACT
<p><b>OBJECTIVE</b>To optimize a simple and effective method for total RNA extraction from bulblet of Fritillaria anhuiensis.</p><p><b>METHOD</b>Four methods, i. e. guanidine isothiocyanate, bentonite, modified SDS/phenol and the RNAiso plus, were used to extract total RNA from bulblet of F. anhuiensis. Then the results of the extraction were compared and analyzed by electrophoresis detection and RT-PCR verification.</p><p><b>RESULT</b>The total RNA extracted by bentonite method were clear and no dispersion, the integrity of the RNA was well, and there was no obvious contamination with DNA and other impurities, was suitable for RT-PCR test.</p><p><b>CONCLUSION</b>The bentonite method is quick, economic, and efficient for total RNA extraction from bulblet of F. anhuiensis.</p>
Subject(s)
Bentonite , Chemistry , DNA, Complementary , Electrophoresis , Fritillaria , Genetics , Guanidines , Chemistry , Isothiocyanates , Chemistry , Phenol , Chemistry , Plant Roots , Genetics , Plants, Medicinal , Genetics , RNA, Plant , Reverse Transcriptase Polymerase Chain Reaction , Sodium Dodecyl Sulfate , Chemistry , Time FactorsABSTRACT
Eight high-effective decolorization strains were isolated by enrichment using Direct Fast Scarlet 4BS as sole source of carbon and energy. The optimal microbial consortium consisting of fungus 8-4(*) and bacterium 1-10 was selected by optimizing combination decolorization experiments with these eight freely suspended strains, whose decolorization activity was higher than individual strains due to synergistic reaction with each other. The optimal microbial consortium was also immobilized using polyvinyl alcohol (PVA) as the carrier. This paper optimized the immobilization and operational conditions, investigated the effect of the environmental factors (temperature, pH and dissolved oxygen (DO)) and initial dye concentration on the rate of decolorization by immobilized microbial consortium. The results showed that the optimal decolorization activity was observed in pH range (5-8), temperature range (25-40 degrees C) under shaking culture of high DO level. Decolorization with the optimal microbial consortium gave a relatively high maximum decolorization activity (ca. 81.25 mgl(-1)h(-1)), which occurred at a dye concentration of 1000 mgl(-1), suggesting the applicability of the strains in remediation of wastewater containing high azo dye concentrations. The immobilized beads could be reused for more than 30 cycles, without losing any degradation capacity. The changes of UV-visible spectra and the change curve of COD of 4BS solution before and after decolorization cultivation and the proliferation and distribution of microbial consortium in gel beads were also microscopically observed, which could be used for conferring the decolorization mechanisms of dye 4BS.
