Further studies should be conducted to find the target position and the sequence characteristics of activating siRNAs that could enhance the promoter activities of the genes without the TATA-box motif. Florfenicol Antibiotics are abundant in various environmental habitats such as seawater, plants, sludge, and soils. Because antibiotics affect our ecosystem, which includes the microbial diversity and abundance in the environment, they are widely considered to act as key pollutants. Although antibiotics contaminate the environment, how antibiotics affect environment-originated bacteria and their evolution remains poorly understood. Because most antibiotics used for treating infections are produced by environmental microorganisms, antibiotic resistance genes and mechanisms could exist in nonclinical habitats. In natural environments, antibiotic production and resistance might be considered as biochemical warfare to eliminate competing organisms because antibiotics suppress bacterial growth and metabolism. Antibiotics of distinct classes act on different targets Olsalazine Disodium through specific mechanisms: b-lactams lead to autolysis by interfering with cell wall biosynthesis; aminoglycosides cause mistranslation by targeting the 30S subunit of the ribosome; tetracycline inhibits protein synthesis by disrupting the binding of aminoacyl tRNA to the mRNA-ribosome complex; and fluoroquinolones inhibit DNA replication by binding with DNA gyrase and topoisomerase. Antibiotic resistance could be acquired through several ways: i) the action of antimicrobial-inactivating enzymes, ii) reduced access of antimicrobials to bacterial targets, and iii) mutations that change targets or cellular functions. Many clinical and environmental bacteria have multiple antibiotic-resistance mechanisms. The diesel-degrading A. oleivorans DR1 was isolated from the rice paddy soil and its genome was completely sequenced. Our previous studies demonstrated that quorum sensing and biofilm formation are important for diesel-degradation in DR1 cells. Most antibiotic resistance studies of Acinetobacter species have largely focused on pathogenic Acinetobacter such as Acinetobacter baumannii owing to high level of multidrug resistance.