Oil Degrading Ability and Characterization of Oil Degrading Bacteria Isolated from Digestive Gland in Mytilus galloprovincialis.

从褐贻贝（Mytilus galloprovincialis）的消化腺中分离出4种油降解菌（ODB），渔港周围海水中分离出3种油降解菌是褐贻贝的栖息地。然后我们尝试表征它们并测量它们的油降解率。【研究结果】特征：各类细菌均呈非活动棒状。这些细菌的最佳生长温度为30℃。从16SrRNA基因的DNA序列、SDS-PAGE图谱和精细结构观察，鉴定各组细菌属Alcanivorax sp.。SDS-PAGE图谱显示，7株Alcanivorax sp.的图谱相似，但也有细微差异。由此推测，7个Alcanivorax sp.是Alcanivorax sp.的不同种或菌株。降解率：它们降解油的能力是通过与它们孵育的重油干重的变化来检验的。产自褐毛霉的细菌降解率在10% ~ 30%之间，产自海水的细菌降解率在10%以下。与不含重油的培养基相比，含有重油的培养基使细胞密度增加了约10倍或更多。这表明这些细菌可以利用稠油组分。3.油的降解机理：我们观察到重油被Alcanivorax sp.浓缩培养基乳化，SDS-PAGE显示最突出的组分带是脂多糖，我们推测脂多糖作为生物表面活性剂进行了降解。

We have isolated 4 kinds of oil degrading bacteria(ODB) from the digestive gland of Mytilus galloprovincialis and 3 kinds of ODB from the sea water around fishery harbors are habitats of M.galloprovincialis. Then we tried to characterize them and to measure their oil degradation rate.【RESEARCH RESULTS】1.Characterization : All kinds of bacteria showed non-motile rod shape. Optimum growth temperature of these bacteria was 30℃. From DNA sequence of the 16SrRNA gene, band-pattern of SDS-PAGE and the observation of fine structures, the species of bacteria in each group were identified as Alcanivorax sp. SDS-PAGE showed that the band-patterns of 7 Alcanivorax sp. were similar, but there were some minor differences. From this result, we speculated that 7 Alcanivorax sp. are distinct species or strains of Alcanivorax sp. 2.Degradation rates : Their abilities to degrade oil were examined by the change in the dry weight of the heavy oil with which they were incubated. The degradation rates of bacteria from M.galloprovincialis were about 10%-30%, and the degradation rates of bacteria from the sea water were below 10%. The culture medium with heavy oil increased cell densities about 10 times or more in comparison with it without heavy oil. This result indicates that these bacteria can utilize heavy oil component(s). 3.Mechanisms of oil degradation : We have observed the heavy oil was emulsified by the concentrated culture medium of Alcanivorax sp. SDS-PAGE showed that the most prominent component band was a lipopolysaccharide, and then we have speculated that the lipopolysaccharide acts as a bio-surfactant for the degradation.