Study On Environmental Impact Factors Of Biological Characteristics Of Common Pathogenic Bacteria In Ship Ballast Water

Revealing the dynamic changes of the biological characteristics of marine invasive species and reducing the risks of pest invasion are the hotspots of ship ballast water control and management.In this paper,three kinds of indicators of microorganism(Escherichia coli,Vibrio parahaemolyticus and Vibrio cholerae)are investigated on the basis of the research of ballast water.Combine the field sampling and laboratory simulation as our research method,we first analyze the actual situation such as the vertical distribution,the environmental impact factors as well as the age of ballast water of three pathogens in ballast tanks.And then,we study the dynamic changes of three pathogens under the influence of single environmental factors respectively.Finally,based on the orthogonal experiment,we screen out the environmental factors which have significant effects on the three pathogens,and we further optimize to study the dynamic changes of the three pathogens under the influence of multiple environmental factors and we find out that the best condition of the growth of the three pathogens.And the results indicate that:Firstly,when the age of the ballast water is more than 10 days,the number of the three pathogens is significantly positively correlated with the water depth,and when the age is less than 13 days,such correlation will enhance with the increase of the age.Secondly,the results of single environmental factors show that when the temperature is 32?,pH value is 7 and the dissolved oxygen is 12mg/L,the three pathogens have the best growth condition.Escherichia coli and Vibrio cholerae are under the best growth condition when the salinity is 20 ‰,and when the salinity is 30 ‰,Vibrio parahaemolyticus has its best condition.Thirdly,The results of multi-environmental factors show that the optimal combination of Escherichia coli growth is when the temperature is 32 ?,pH value is 7,the salinity is 30 ‰ and the dissolved oxygen is 12 mg / L,the most influential factor is dissolved oxygen;the optimal combination of Vibrio parahaemolyticus is similar to Escherichia coli except the most influential factor is temperature;The optimal combination of Vibrio cholerae growth is when the temperature is 28 ?,pH value is 6,salinity is 30 ‰,dissolved oxygen is 12 mg / L,the greatest impact to Vibrio cholerae growth is the dissolved oxygenIn order to get fully understanding of the origin,habits and distribution of the intrusion organisms in ballast water and screen the environmental factors which affect its temporal and spatial distribution are helpful to establish a database of intrusion species of ballast water.It can also provide theoretical support for the risk assessment of biological invasion and the rapid detection of species and the research and development of ballast water treatment equipment.