Comparing Methods of Separating Bacterial Biofilms on the Surface of Water Transportation Pipes and Equipment of Milking in the Farms

Document Type : Ruminant Nutrition


1 Ferdowsi University of Mashhad

2 Ferdwosi University of Mashhad


Introduction Bacterial biofilms can be both useful and harmful based on their combination and locations. Biofilm formation occurs as a stepwise process. Their formation in liquid transportation pipes used for milking system and drinking water in animal farms may create some problems and is a potential source of pollution. Speed of biofilm formation depends on many factors including: construction and functional characteristics of bacteria, the composition and culture conditions such as temperature and substratum. In this research the Bacillus subtillis bacteria with special characteristics was selected due to its capability for biofilm creation. Bacillus subtillis bacteria is mobility and a stronger connection than other bacteria levels are created. In the research conducted in the biofilm there are many resources on biofilm formation by Bacillus subtillis bacteria. Bacillus subtillis is saprophytic in the soil, water and air. There is also the ability to form spores of Bacillus subtillis.
Materials and Methods Firstly the possibility of creating biofilms on different Plastic (polyvinilchlorid, polypropylene, polyethylengelycole), alluminum and glass surfaces in three temperatures of 4°C, 30°C and 37°C were studied. Two different methods of biofilms separation including separating swap and vortex were tested and their efficienceies were calculated. After biofilm formation on parts of the vortex separation method after washing parts in sterile conditions in a tube containing normal saline for 4 minutes was vortex. The bacterial suspension decreasing dilution series was created. Pour plate in medium using agar plate count agar and was cultured at 30°C for 24-48 hours. Numbers of colonies were counted. The numbers of biofilm cells were calculated. In swap method after biofilm formation on parts using a cotton swap was isolated biofilms. The swap was transferred to tube containing normal saline and the bacterial suspension decreasing dilution series was created. Pour plate in medium using agar plate count agar and was cultured at 30°C for 24-48 hours. Numbers of colonies were counted. The numbers of biofilm cells were calculated.
Results and Discussion Bacillus subtillis biofilms were formed on all studied surfaces. Total count of bacteria detached from biofilm indicates that these bacteria can develop on the polypropylene surface much more than the other surfaces. 10 days later, the formation of biofilm reached the maximum level. The optimum temperature was 30°C. The vortex method was more efficient in comparison to other methods. The bacterial attachment was highest with the plastic surface, specially the propylene surface; whereas the lowest attachment was detected in the glass surfaces. Synthetic materials based on hydrocarbons are more susceptible to the formation of biofilm and infection. Generally lower levels are microscopic pores and also less likely to form a biofilm. Rusty pipes, old, worn-out and scratched plastic furniture raised the possibility of contamination and could cause problems.
Conclusion It was concluded that glass pipes are the best materials for liquid transportation in different forms of animal farms. According to this study, basic methods of removing biofilm and enable ranchers to make good use of the equipment and the practical methods of removing contaminants help.


1- Bailey, C.P., and A. Vonholy. 1993. Bacillus Spore Contamintion associated with commerical bread manufacture. Journal Food Microbiology, 10:287-294.
2- Bob, F.B. 1997.Text book of microbiology. 12 thed. Philadelphia USA. WB Saunder Company;p.631.
3- Costerton, J.W., Z. Lewandowski., D. E. Caldwell., and E. Korber. 1995. Microbial biofilm in the nature.Journal Microbiology, 49:711-745.
4- Duguid, I. G., E. Evans., M. R. Brown., and P. Gilbert. 1992. Effect of biofilm culture upom the susceptibility of staphyloccus epidermidis to tobramycim. Journal of Antimicrobial Chemotherapy, 30:803-810.
5- Lindsay, D., and A. Vonholy .1997. Evaluation of disloading methods for laboratory- grown bacterial biofilms. Journal Food Microbiology, 14:383-390.
6- Marshall, K. C., and G. W. Characklis. 1990. Biofilms a basis for an interd is ciplinary approach. In: Characklis, G.W. and K.C. Marshall editor. Biofilms.3 thed.USA.Wiley, P.3-15.
7- Mcfeters, G. A., K.C.Marshall., and W. G. Characklis. 1990. The microbial cell physiological ecology in biofilm systems. In : Characklis G.W. and K.C. Marshall editor. biofilms .3 the.USA.wiley, p.42-45.
8- Writanen, G., and T. Sandholm. 1993. Epifluorescence image analysis and cultiration of foodborne biofilme bacteria grown on stainless steel surface. Journal of Food Protection, 56:678-683.
9- Zheng, Z., and P. S. Stewart. 2002. Penetration of rifampin through staphylococcus epidermidis biofilms.Journal of Antimicrobial Chemotherapy, 49:900-903.
10- Zottola, E. A. 1994.Microbial attachment and biofilm formation: a new problem in food industry. Journal Food Technology, 48:107-114.
11- Zulfiqar, A. M., A. Mubashir., M. Naseem khan., I. Lai., N. Hassan., and S. I. Kan. 2013. Biofilm formation and dispersal of staphylococcus aureus under the influence of oxacillin. Journal Microbial Pathogenesis, 62:66-72.