Effects Of Environmental And Dynamic Succession Of Shewanella Loihica ECSMB14101 Biofilms On The Plantigrade Settlement Of The Mussel Mytilus Coruscus

Marine multiple-species and single-species biofilms have been known to play an important role in the settlement of plantigrades of the mussel Mytilus coruscus,but the effects of environmental factors on the formation of single bacterial biofilms and the subsequent settlement of plantigrades of the M.coruscus remains unknown.1.Effects of temperature and salinity factors on bacterial biofilms and settlement of the M.coruscus plantigradesIn order to study the effect of environmental factors on the biofilms of Shewanella loihica ECSMB14101 and subsequent effect on the settlement of plantigrades of M.coruscus,the environmental factors in this experiment were designed under the salinity conditions of 10,20,30 in 18 ? and the temperature conditions of 8 ?,18 ?,28 ? in salinity of 30.The results showed that the final density of the S.loihica ECSMB14101 biofilm formed with the same initial density were variety under the different environmental conditions.The inducing activities of biofilms were different under those conditions of temperature and salinity.The amount of bacteria in the biofilm increased with the increase of temperature,and the settlement rate of M.coruscus in 8? and 18 ?,were 31% and 66%,respectively.In contrast,the inducing activity of S.loihica ECSMB14101 biofilms were not difference between 18 ? and 28 ?.In addition,the biofilm thickness increased with the increasing temperature and salinity.Thus,the temperature and salinity altered the biofilm characteristics and ultimately led to the settlement behavior of M.coruscus.This study explored the interplay among environmental factors,biofilm formation,and mussel settlement,which also provided the theoretical basis for the future study of the settlement mechanism of M.coruscus.2.Effects of marine bacterial biofilms succession on settlement of plantigrades of the M.coruscus.In order to know the processing of biofilm succession and the effect of biofilms succession on the settlement of plantigrades of the M.coruscus,this paper investigated the biological characteristics and inducing activity on settlement of M.coruscus plantigrades of three marine bacterial biofilms,which formed in different periods.We found that the bacterial density,thickness and colonization of biofilms will increase as the time increases.The induction activity of the biofilm formed by 3 marine bacterias in 48 h on the M.coruscus plantigrades was increased with the increase of time.In 48 h,biofilm formed by Shewanella loihica ECSMB14101 showed high induction activity to M.coruscus,whereas Pseudoalteromonas atlantica ECSMB14103 and Vibrio splendidus ECSMB14105 showed moderately inducible activity.Bacterial density showed significantly inducing activity on settlement of M.coruscus plantigrades and the biofilms showed a regulate dynamic characteristics.In conclusion,this study investigated the effects of marine bacterial biofilms succession and their effects on the settlement of plantigrades of the M.coruscus.These findings are important to understand the mechanism of forming of biofilm and provide theoretical basis for the aquaculture of M.coruscus.