Efficacy of pH elevation as a bactericidal strategy for treating ballast water of freight carriers

Journal of Advanced Research

Noel L. Bassett¹  Deborah D. Iwanowicz²  Clifford E. Starliper²  Cynthia R. Adams²  Phyllis A. Green³  Barnaby J. Watten⁴ 

[1] American Steamship Company, 500 Essjay Road, Williamsville, NY 14221, USA;Fish Health Research Laboratory, Leetown Science Center, United States Geological Survey, 11649 Leetown Road, Kearneysville, WV 25430, USA;Isle Royale National Park, National Park Service, 800 East Lakeshore Drive, Houghton, MI 49931, USA;S.O. Conte Anadromous Fish Research Center, Leetown Science Center, United States Geological Survey, One Migratory Way, Turners Falls, MA 01376, USA;

关键词: Ballast water;    Nonindigenous;    Bacteria;    pH;    Treatment;   

DOI  :  10.1016/j.jare.2015.02.005

来源: DOAJ

【 摘 要 】

Treatment of ship ballast water with sodium hydroxide (NaOH) is one method currently being developed to minimize the risk to introduce aquatic invasive species. The bactericidal capability of sodium hydroxide was determined for 148 bacterial strains from ballast water collected in 2009 and 2010 from the M/V Indiana Harbor, a bulk-freight carrier plying the Laurentian Great Lakes, USA. Primary culture of bacteria was done using brain heart infusion agar and a developmental medium. Strains were characterized based on PCR amplification and sequencing of a portion of the 16S rRNA gene. Sequence similarities (99+ %) were determined by comparison with the National Center for Biotechnology Information (NCBI) GenBank catalog. Flavobacterium spp. were the most prevalent bacteria characterized in 2009, comprising 51.1% (24/47) of the total, and Pseudomonas spp. (62/101; 61.4%) and Brevundimonas spp. (22/101; 21.8%) were the predominate bacteria recovered in 2010; together, comprising 83.2% (84/101) of the total. Testing was done in tryptic soy broth (TSB) medium adjusted with 5 N NaOH. Growth of each strain was evaluated at pH 10.0, pH 11.0 and pH 12.0, and 4 h up to 72 h. The median cell count at 0 h for 148 cultures was 5.20 × 106 cfu/mL with a range 1.02 × 105–1.60 × 108 cfu/mL. The TSB adjusted to pH 10.0 and incubation for less than 24 h was bactericidal to 52 (35.1%) strains. Growth in pH 11.0 TSB for less than 4 h was bactericidal to 131 (88.5%) strains and pH 11.0 within 12 h was bactericidal to 141 (95.3%). One strain, Bacillus horikoshii, survived the harshest treatment, pH 12.0 for 72 h.

【 授权许可】

Unknown