Biological Characteristics and Pathogenicities of Shewanella algae and Shewanella abalone from Babylonia

[Objective] The biological characteristics and pathogenicities of Shewanella algae and Shewanella abalone from Babylonia were studied in this paper. [Method]The hemolytic bacteria were isolated from the hepatopancreas of Babylonia suffered from proboscis edema with blood agar plate. The dominant bacterial community in the ill Babylonia was identified by 16 S r DNA sequence analysis, and the bacterial cultural and biochemical characteristics and pathogenicities were studied. [Result]The Shewanella bacteria, including Shewanella algae and Shewanella abalone, are the dominant bacterial community in Babylonia suffered from proboscis edema.The colony characteristics of Shewanella algae in nutrient agar medium, TCBS agar medium and CHROMagar vibrio colored medium were similar to those of Shewanella abalone. Shewanella algae possessed β-hemolysis and Shewanella abalone possessed α-hemolysis in the blood agar plate. The biochemical reaction of Shewanella algae and Shewanella abalone was all of non-fermentation type. The results of artificial infection test showed that half lethal dose（LD50） of the test strains of Shewanella algae was 10-5.50/0.1 ml. The test strains of Shewanella algae have strong toxicity, and could cause mice and chickens to die of sepsis with mortality of100%. The mortality of Babylonia infected with Shewanella algae was 10%; while the survived Babylonia lost the ability of moving and intaking for a long time, but they were not suffered from proboscis edema. There was no death in mice or chicks infected with Shewanella abalone, but their livers and spleens were slightly hyperemic and swelling. There was also no death in Babylonia infected with Shewanella abalone, but their intaking and moving ability was lost for a short time.[Conclusion] Although Shewanella algae and Shewanella abalone were the dominant bacteria in Babylonia suffered from proboscis edema, they were not the main pathogenic bacteria for proboscis edema. Shewanella algae had strong pathogenicity to mice, chicks and Babylonia, while Shewanella abalone showed no marked pathogenicity to those experimental animals in this study.

希瓦氏菌Shewanella algae CCU101高效降解甲基橙

为了评估Shewanella algae CCU101降解甲基橙的性能,研究甲基橙初始质量浓度、乳酸钠浓度、菌液吸光度和金属离子浓度4种因素对S.algae CCU101降解甲基橙能力的影响。结果表明,S.algae CCU101降解甲基橙呈一级反应,最大降解速率常数为1.0122 h^(−1)。在甲基橙初始质量浓度为300 mg×L^(−1)时,S.algae CCU101降解甲基橙的速度比Shewanella oneidensis MR^(−1)高2.13倍。推测S.algae CCU101高效降解甲基橙的能力源于S.algae CCU101具有高生长速率及高团聚成膜能力。由于S.algae CCU101与模式菌株S.oneidensis MR^(−1)相比,具有更高的甲基橙降解速率,可作为染料降解的潜在工程菌株。