scholarly journals Formation of microbial biofilms on stainless steel with different surface roughness

10.5219/1190 ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 915-924
Author(s):  
Igor Stadnyk ◽  
Ganna Sabadosh ◽  
Tetiana Hushtan ◽  
Yana Yevchuk
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Formation Process ◽  
Dairy Products ◽  
Film Formation ◽  
Dairy Industry ◽  
Spherical Shape ◽  
Technological Equipment ◽  
E Coli ◽  
Dairy Equipment

The physical essence of the formation and influence of bacteria on the surface of technological equipment in the dairy industry is considered as an essential factor leading to contamination of dairy products and is a major hygienic problem. The ability of microorganisms on the surfaces of technological equipment to form biofilm forms and requirements for steel grade, relief, and its roughness were analysed. The effect of surface roughness on promoting or preventing adhesion and reproduction of biofilm forms of bacteria, which reduce the efficiency of sanitary processing of dairy equipment and thereby increase the microbial contamination of dairy products with shortened shelf life, is substantiated. Research about the process of bacterial adhesion to the surface of metals with different roughness depending on the size and shape is presented. It is found that on the surface of stainless steel with roughness 2.687 ±0.014 micron film formation process in Escherichia coli and Staphylococcus aureus are similar from 3 to 24 hours and does not depend on the size of the bacteria, and accordingly allows us to argue that rod-shaped and coccid bacteria attach freely in the hollows of the roughness are the beginning of the process of the first stage of biofilm formation. It is found that on the surface of stainless steel with roughness 0.95 ±0.092 micron film formation process in S. aureus is more intense than in E. coli. Thus, within 3 hours of incubation, the density of biofilms formed S. aureus was 1.2 times bigger than biofilms E. coli, by the next 15 hours of incubation formed biofilms S. aureus were, on average, 1.3 times denser. It is established that S. aureus due to its spherical shape is able to fit in the hollows of the roughness 0.95 ±0.092 μm and faster to adhere to the surface at the same time. E. coli, due to its rod-like shape, with such surface roughness, can adhere to the cavities only over its entire length. It is proved that by surface roughness 0.63 ±0.087 μm film intensity S. aureus was, on average, 1.4 times faster than E. coli, for roughness 0.16 ±0.018 micron film formation process took place equally for S. aureus and E. coli, but biofilms were lower in density than those formed on roughness 0.63 ±0.087 micron. Studies suggest that the use of equipment in the dairy industry with a roughness of less than 0.5 microns will reduce the attachment of microorganisms to the surface and reduce the contamination of dairy products.

scholarly journals STUDY OF THE INFLUENCE OF SAVINASE®EVITY16L ENZYME ON BIOFILMS FORMATION OF STAPHYLOCOCCUS AUREUS ON STAINLESS STEEL WITH DIFFERENT ROUGHNESS

2019 ◽  
Vol 2 ◽  
pp. 26-32 ◽  
Author(s):  
Mykola Kukhtyn ◽  
Khrystyna Kravcheniuk ◽  
Ludmila Beyko ◽  
Yulia Horiuk ◽  
Oleksandr Skliar ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Dairy Products ◽  
Proteolytic Enzyme ◽  
Proteolytic Enzymes ◽  
Dairy Production ◽  
Steel Surfaces ◽  
Dairy Equipment ◽  
Biofilm Matrix

Microbial films formation on the dairy equipment creates a serious problem, because they are difficult to eliminate by washing and disinfecting means that results in contaminating dairy products by microorganisms. The aim of the work was to study the influence of Savinase®Evity 16L proteolytic enzyme on the process of destructing biofilms, formed by Staphylococcus aureus on stainless steel with different surface roughness. It has been established, that surface roughness of stainless steel influences the process of Savinase®Evity 16L enzyme penetration in a hollow and prevents the destruction of the biofilm matrix, created by Staphylococcus aureus. It has been revealed, that after the influence of a proteolytic enzyme on Staphylococcus aureus biofilms, created on steel with roughness 0,16±0,018 mcm, the density decreased in 4,0 times (р≤0,05), comparing with a condition before processing. At roughness 0,63±0,087 mcm the density of formed biofilms decreased at the effect of Savinase®Evity 16L in 3,3times (р≤0,05) and the biofilm was characterized as a weak one. At the same time at stainless steel surfaces with roughness 2,68–0,95mcm, the density of biofilms decreased in 2,3–2,1times (р≤0,05), comparing with a condition before processing, and they were characterized as ones of the middle density. It has been also revealed, that the degradation intensity of biofilms under the influence of Savinase®Evity 16L enzyme at roughness 2,68–0,95 mcm was 1,7–1,9 times (р≤0,05) lower than at the surface with roughness 0,16±0,018 mcm. So, the revealed degradation features of a biofilm, created by Staphylococcus aureus at surfaces of stainless steel of different roughness at the influence of Savinase®Evity 16L proteolytic enzyme give a possibility to substantiate the addition of proteolytic enzymes to the composition of washing means for dairy production. It is also offered to process the surface to the roughness no more than 0,63 mcm for producing food steel for raising the effectiveness of biofilms destruction by enzymes and for the sanitary processing.

THE CLEANABILITY OF MATERIALS IN CONTACT WITH DAIRY PRODUCTS1

1958 ◽  
Vol 21 (3) ◽  
pp. 68-72 ◽  
Author(s):  
G. L. Hays ◽  
J. D. Burroughs ◽  
D. H. Johns
Keyword(s):  
Stainless Steel ◽  
Dairy Products ◽  
Construction Materials ◽  
Complete Removal ◽  
Radioactive Tracer ◽  
E Coli ◽  
Tracer Techniques ◽  
Equipment Construction ◽  
Dairy Equipment

The removal of air dried soil (dairy products contaminated with E. coli) from the surface of disks of several possible dairy equipment construction materials was determined by both radioactive tracer techniques and bacteriological methods. Both methods showed that cleaning the disks with any of the four types of cleaning compounds effected essentially complete removal of the contaminating soil from the surface of the molded plastics and various finishes of stainless steel which were tested.

scholarly journals Characteristic features of Enterococcus faecalis film formation on the stainless steel AISI 321 depending on the surface roughness

2018 ◽  
Vol 20 (90) ◽  
pp. 58-62
Author(s):  
K. U. Kravcheniuk
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Enterococcus Faecalis ◽  
Steel Surface ◽  
Film Formation ◽  
High Density ◽  
Initial Number ◽  
Steel Aisi ◽  
Aisi 321 ◽  
Stainless Steel Aisi

At the present stage of milk products manufacture, the most important factor affecting their safety and reducing their storage time is a microbiological one. Despite all complex of measures including washing, disinfection, heat processing to eliminate microbes on production equipment and in the finished products it is very difficult to achieve good results. This deals with the fact that microorganisms can survive on the production equipment thanks their ability to form biofilms and also treatment-resistant microorganisms strains appear in the process of continuous sanitary treatment. The aim of the paper was to study the biofilms Enterococcus faecalis formation on the stainless steel AISI 321 depending on their initial quantity and surface roughness. The plates made of the stainless steel AISI 321of surface roughness Rа = 0.955 mkm, Rа = 0.63 mkm and Rа = 0.16 mkm were used for the investigation. It  was found that during 9 hours Enterococcus faecalis was forming the biofilms of weak density less than 0,5 units on the stainless steel surface of AISI 321 of roughness Rа = 0.955 mkm. After the 12th hour the intensive film formation process was noticed in the options with initial number of cells E.f from 2000 to 10 000 and 20–50 thousand/ cm2, the biofilm was getting of high density – 1.246 and 1.415 respectively with initial number of cells less than 1000 per 1 cm2 of steel surface and it was of medium density – 0.672 cells. The process of film formation on the steel surface of roughness 0.63 mkm was rather decelerating, in comparison with the surface of roughness 0.955 mkm. Though, despite this, in the options with initial number of E.f. cells from 2000 to 10 000 and 20–50 thousand/cm2 the biofilms were of high density after the 12th hour of incubation, i.e. it was the same as for the  surface of 0.955 mkm roughness.  The process of film formation at such initial numbers of E.f. on the surface of roughness 0.63 mkm was finishing after the 24th hour while at roughness 0.955 mkm – after the 18th hour of incubation. It was found that on the steel surface of roughness 0.16 mkm the process of film formation was greatly getting slower comparing to the surfaces of roughness 0.955 and 0.63 mkm. During 12 hours of E.f. incubation in case when the initial number of E.f. was less than 1000 per 1 cm2 the film was of weak density but in cases when the initial number was 2000 – 10 000 and 20–50 thousand/cm2 the biofilms were of medium and high density – 0.917 and 1.025 units. After 18 hours of incubation the film was of medium density only in case when the initial number was less than 1000 E.f. per 1 cm2 of the surface. At larger initial number of bacteria it was of high density. Only after 24 hours of E.f. incubation biofilms in all options were of high density. Thus, we came to the conclusion that E.f. biofilms formation on the stainless steel AISI 321 is influenced by the surface roughness and initial number of bacteria. The results have shown that on the plates of roughness 0,16 mkm the film formation process is slower than on the surface of roughness 0.955 and 0.63 mkm.

Surface Roughness of Stainless Steel Influences Attachment and Detachment of Escherichia coli O157

2011 ◽  
Vol 74 (8) ◽  
pp. 1359-1363 ◽  
Author(s):  
REBECCA M. GOULTER-THORSEN ◽  
ELENA TARAN ◽  
IAN R. GENTLE ◽  
KARI S. GOBIUS ◽  
GARY A. DYKES
Keyword(s):  
Escherichia Coli ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Foodborne Pathogen ◽  
Bacterial Attachment ◽  
Epifluorescence Microscopy ◽  
Escherichia Coli O157 ◽  
Force Microscopy ◽  
E Coli ◽  
Blotting Technique

Determining the influence of surface roughness on Escherichia coli O157 attachment to and detachment from stainless steel (SS) is important for controlling this foodborne pathogen. The aim of this study was to evaluate the interactions of six E. coli strains (four O157:H7, one O157:H12, and one O1:H7) with SS type 304 finishes of various surface roughness: 2B (unpolished surface), 4 (common food grade SS), and 8 (polished smooth surface). In attachment assays (exposure to cell suspensions with periodic swirling), bacteria were enumerated by epifluorescence microscopy, and in detachment assays a blotting technique and atomic force microscopy (AFM) were used. Attachment data suggest that E. coli attach in greater numbers to significantly smoother SS8; however, detachment assays and AFM data suggest cells are more easily removed from this finish. Conversely, attachment to SS2B was lower, and AFM data suggest that E. coli O157 may adhere more strongly to this finish. Attachment and detachment data for SS4 was variable, suggesting complex attachment mechanisms to this type of SS. SS4 is the most common material used in food processing facilities. The data from this study indicate that bacterial interactions with SS4 are complex and less easily predicted than those with SS of other finishes, including 2B and 8. These differences in bacterial attachment may be of concern to the food industry and warrant further investigation.

Technological Aspects of Resistive Film Formation on the Basis of Stainless Steel

2016 ◽  
Vol 30 (2) ◽  
pp. 84-89
Author(s):  
Andrey Moroz ◽  
Nikolay Sushentsov ◽  
Sergey Stepanov ◽  
Elena Mikheeva ◽  
Elena Ryzhova
Keyword(s):  
Stainless Steel ◽  
Film Formation ◽  
Resistive Film

Studying The Effect of a New Mixed Cutting Fluid on Surface Roughness

2020 ◽  
Vol 38 (11A) ◽  
pp. 1593-1601
Author(s):  
Mohammed H. Shaker ◽  
Salah K. Jawad ◽  
Maan A. Tawfiq
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Cutting Parameters ◽  
Machining Process ◽  
Cutting Fluid ◽  
Depth Of Cut ◽  
Cutting Fluids ◽  
Machining Processes ◽  
Dry Cutting ◽  
Cutting Speeds

This research studied the influence of cutting fluids and cutting parameters on the surface roughness for stainless steel worked by turning machine in dry and wet cutting cases. The work was done with different cutting speeds, and feed rates with a fixed depth of cutting. During the machining process, heat was generated and effects of higher surface roughness of work material. In this study, the effects of some cutting fluids, and dry cutting on surface roughness have been examined in turning of AISI316 stainless steel material. Sodium Lauryl Ether Sulfate (SLES) instead of other soluble oils has been used and compared to dry machining processes. Experiments have been performed at four cutting speeds (60, 95, 155, 240) m/min, feed rates (0.065, 0.08, 0.096, 0.114) mm/rev. and constant depth of cut (0.5) mm. The amount of decrease in Ra after the used suggested mixture arrived at (0.21µm), while Ra exceeded (1µm) in case of soluble oils This means the suggested mixture gave the best results of lubricating properties than other cases.

Antimicrobial Effects of Zataria multiflora and Ocimum basilicum on Escherichia coli O157:H7 During Ripening of Traditional Lighvan Cheese

2020 ◽  
Vol 16 (3) ◽  
pp. 373-380
Author(s):  
Mohammad B. Zendeh ◽  
Vadood Razavilar ◽  
Hamid Mirzaei ◽  
Khosrow Mohammadi
Keyword(s):  
Escherichia Coli ◽  
Essential Oils ◽  
Dairy Products ◽  
Antimicrobial Agents ◽  
Escherichia Coli O157 ◽  
Zataria Multiflora ◽  
Antimicrobial Effects ◽  
E Coli ◽  
Common Causes ◽  
Lighvan Cheese

Background: Escherichia coli O157:H7 is one of the most common causes of contamination in Lighvan cheese processing. Using from natural antimicrobial essential oils is applied method to decrease the rate of microbial contamination of dairy products. The present investigation was done to study the antimicrobial effects of Z. multiflora and O. basilicum essential oils on survival of E. coli O157:H7 during ripening of traditional Lighvan cheese. Methods: Leaves of the Z. multiflora and O. basilicum plants were subjected to the Clevenger apparatus. Concentrations of 0, 100 and 200 ppm of the Z. multiflora and 0, 50 and 100 ppm of O. basilicum essential oils and also 103 and 105 cfu/ml numbers of E. coli O157:H7 were used. The numbers of the E. coli O157:H7 bacteria were analyzed during the days 0, 30, 60 and 90 of the ripening period. Results: Z. multiflora and O. basilicum essential oils had considerable antimicrobial effects against E. coli O157:H7. Using the essential oils caused decrease in the numbers of E. coli O157:H7 bacteria in 90th days of ripening (P <0.05). Using from Z. multiflora at concentration of 200 ppm can reduce the survival of E. coli O157:H7 in Lighvan cheese. Conclusion: Using Z. multiflora and O. basilicum essential oils as good antimicrobial agents can reduce the risk of foodborne bacteria and especially E. coli O157:H7 in food products.

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