Activity Of Lactoferrin Research Articles

Antifungal and Antiparasitic Activities of Lactoferrin

The first function attributed to lactoferrin, an iron-binding protein belonging to the non-immune natural de- fences, was antimicrobial activity related to its capability of sequestering iron. Many other antimicrobial and antiviral functions have been ascribed to lactoferrin. In vitro activity towards human pathogenic fungi on the part of both human and bovine lactoferrin has been well documented as well. The antifungal activity appears to be related to lactoferrin inter- ference with the fungal cell surface rather than iron deprivation and some host-mediated mechanisms of action cannot be ruled out. Lactoferrin also displays anti-parasitic activity, although the molecular mechanisms of such activity are even more complex.

Human lactoferrin but not lysozyme neutralizes HSV-1 and inhibits HSV-1 replication and cell-to-cell spread

The frequent oral shedding of herpes simplex virus type 1 (HSV-1) in the absence of clinical disease suggests that symptomatic HSV-1 recurrences may be inhibited by the mucosal environment. Indeed, saliva has been shown to contain substances with anti-HSV activity. In the current study, we investigated the anti-HSV-1 activity of human lactoferrin (hLf) and lysozyme (hLz), two highly cationic polypeptides of the mucosal innate defence system.HLf blocked HSV-1 infection at multiple steps of the viral replication cycle, whereas lysozyme displayed no anti-HSV-1 activity. Preincubation of HSV-1 virions and presence of hLf during or after viral absorption period or for the entire HSV-1 infection cycle inhibited HSV-1 infection by reducing both the plaque count and plaque size in a dose- and virus strain-dependent manner. Cell-to-cell spread of wild-type HSV-1 and the strain gC-39, deleted of glycoprotein C, was dramatically reduced, but the cell-to-cell spread of HSV-1 Rid1, harboring a mutated gD and thus unable to react with the cellular HVEM receptor, remained unchanged. This suggests that the inhibition of cell-to-cell spread is mediated by effects on gD or its cellular counterparts.Our results show that the cationic nature is not a major determinant in the anti-HSV action of mucosal innate cationic polypeptides, since whereas hLf inhibited HSV-1 infection efficiently, hLz had no HSV-1 inhibiting activity. Our results show that in addition to inhibiting the adsorption and post-attachment events of HSV-1 infection, hLf is also able to neutralize HSV-1 and that the inhibition of cell-to-cell spread involves viral gD. These results suggest that Lf may have a significant role in the modulation of HSV-1 infection in the oral cavity as well as in the genital mucosa, the major sites of HSV-1 infection.

Bactericidal Effect of Lactoferrin and Its Amidated and Pepsin-Digested Derivatives on Pseudomonasfluorescens: Influence of Environmental and Physiological Factors

The influence of environmental and physiological factors such as substrate composition and inoculum characteristics on the bactericidal activity of bovine lactoferrin (LF) and its amidated and pepsin-digested derivatives against Pseudomonasfluorescens was investigated. Amidated LF (AMILF) exerted the most potent bactericidal activity, with a 5.8-log decrease in P.fluorescens counts, and LF the lowest, with just a 1-log decrease, whereas pepsin-digested LF (PDLF) reduced bacterial counts by 2.7 log, after 1 h at 30°C. Amidation of PDLF increased effectiveness by 1.2 log, whereas pepsin digestion of AMILF decreased effectiveness by 2.8 log. Bactericidal activity of LF and its derivatives was higher in Tris buffer than in phosphate buffer. The bactericidal effect of AMILF and PDLF was enhanced as medium pH was increased from 5.5 to 8.5, whereas LF showed higher activity under acidic or basic conditions than at neutral pH. The presence of cations affected the activity of LF and its derivatives, from a concentration of 10mM for K+, 1mM for Na+, and 0.1mM for Ca2+,Co2+,Cu2+, Mg2+,Zn2+, and Fe3+. Bactericidal effectiveness diminished as the bacterial inoculum was increased. Log-phase cultures (10-h incubation) were less sensitive to the bactericidal activity of LF and its derivatives than stationary cultures (20- and 30-h incubation). All these factors should be considered when applications of LF and its derivatives in foods and other complex systems are investigated.

THE EFFECT OF NISIN AND BOVINE LACTOFERRIN ON THE MICROBIOLOGICAL QUALITY OF TURKISH‐STYLE MEATBALL (TEKIRDAĞ KÖFTE)

ABSTRACT Tekirdağ köfte, a Turkish‐style meatball, is one of the most popular ground meat products in Turkey. The aim of this study was to evaluate the effect of different nisin and lactoferrin (Lf) concentrations and their combinations on the microbiological quality of Turkish‐style meatball (Tekirdağ köfte). For this purpose, the meatball dough was divided into six equal groups, and each of the groups was treated separately with different nisin and/or Lf concentrations (0, 100 and 200 µg/g). Analyses were performed on each meatball group at 0, 1, 3, 5, 7, 10 and 12 days for microbiological parameters (total mesophilic aerobic bacteria, lactic acid bacteria, coliforms, Escherichia coli, total staphylococcae, Staphylococcus aureus, total psychrophilic bacteria, Pseudomonas spp., sulfite‐reducing anaerobic bacteria, and yeast and mold) and physicochemical analyses (pH, water activity and moisture). Treatment with Lf alone and its combination with nisin significantly reduced (P < 0.05) the total aerobic bacteria, coliform, E. coli, total psychrophilic bacteria, Pseudomonas spp., and yeast and mold counts in meatballs. The largest reduction in these counts occurred on the meatballs treated with a mixture of Lf (200 µg/g) and nisin (100 µg/g). This combination prolonged the refrigerated shelf life of naturally contaminated Turkish‐style meatballs to 10 days compared to 3 days for nontreated control.PRACTICAL APPLICATIONSMeatballs are prepared from ground meat in Turkey. Studies have shown that total bacteria, coliform, and yeast and mold counts were usually high in meatball samples in Turkey, and these products were also usually contaminated with pathogenic bacteria. Therefore, this product mostly poses a risk to consumer health and has a short shelf life (about 3–4 days). In order to control the growth of spoilage microorganisms, the use of natural antimicrobial preservatives has been preferred in the food industry. For this purpose, nisin and lactoferrin were preferred in this study. Although there are many reports on the use of nisin to inhibit pathogenic bacteria, especially Listeria monocytogenes and Staphylococcus aureus in food, research on the antimicrobial activity of lactoferrin in food systems is limited.According to the results of our study, treatment with lactoferrin alone and its combination with nisin significantly reduced spoilage bacteria counts and extended the refrigerated shelf life of Turkish‐style meatballs. Therefore, the use of these natural compounds in meatballs may be useful for consumer health, and may also be a practical application for the producer because of the short shelf life of this product.

Antimicrobial activity of recombinant human lactoferrin from Aspergillus awamori, human milk lactoferrin and their hydrolysates

The antibacterial activity of human lactoferrin from milk (hLF), recombinant human lactoferrin from Aspergillus awamori (rhLF) and their hydrolysates obtained with pepsin was investigated against Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes. The minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) were determined for all the bacteria and the proteins assayed. Taking into account the MICs found for both lactoferrins studied, we can say that they behave very similarly, except for L. monocytogenes for which rhLF was more active. We studied the effect that heat treatments exerted on the antibacterial activity of the two types of lactoferrin and the only heat treatment that had a negative effect on that activity was 85 °C for 10 min. The activity of hLF and rhLF in UHT milk and whey against E. coli O157:H7 and L. monocytogenes, was also assayed. Our results showed a reduction in the number of viable cells for both microorganisms when were incubated with rhLF or hLF, but this decrease was lower than in broth media.

Bactericidal activity of LFchimera is stronger and less sensitive to ionic strength than its constituent lactoferricin and lactoferrampin peptides

The innate immunity factor lactoferrin harbours two antimicrobial moieties, lactoferricin and lactoferrampin, situated in close proximity in the N1 domain of the molecule. Most likely they cooperate in many of the beneficial activities of lactoferrin. To investigate whether chimerization of both peptides forms a functional unit we designed a chimerical structure containing lactoferricin amino acids 17–30 and lactoferrampin amino acids 265–284. The bactericidal activity of this LFchimera was found to be drastically stronger than that of the constituent peptides, as was demonstrated by the need for lower dose, shorter incubation time and less ionic strength dependency. Likewise, strongly enhanced interaction with negatively charged model membranes was found for the LFchimera relative to the constituent peptides. Thus, chimerization of the two antimicrobial peptides resembling their structural orientation in the native molecule strikingly improves their biological activity.

Glycosaminoglycans are not indispensable for the anti-herpes simplex virus type 2 activity of lactoferrin

Lactoferrin has been recognized as a potent inhibitor of human herpetic viruses, such as herpes simplex type 1 (HSV-1) and 2 (HSV-2). In particular, bovine lactoferrin (bLf) has been found to prevent viral infection by binding to heparan sulphate (HS) glycosaminoglycans (GAGs) that in turn can act as cell receptors for human herpetic viruses. In this study we further investigate the mechanism of inhibiting activity of both human lactoferrin (hLf) and bLf against HSV-2. The antiviral effect of these proteins towards HSV-2 strain 333 and its glycoprotein C (gC)-truncated derivative HSV-2 gC-neg1 has been tested in monkey kidney cells. Our results indicate that the antiviral activity of bLf does not involve gC–HS interaction as there was no difference in its effectiveness towards wild type and mutant virus. As regards hLf, the mutant virus HSV-2 gC-neg1 was more sensitive compared to the wild type, suggesting that the human protein might interact with some viral structures that in wild-type viruses are masked by gC. When the modulation of HSV-2 infection by bLf and hLf was investigated under different experimental conditions, the bovine protein proved more effective than the human protein. Moreover, we found that, differently from what observed with HSV-1, bLf inhibited HSV-2 plaque-forming activity also in cells devoid of GAG expression. These results suggest that bLf may block a virus receptor of non-GAG nature and add new information on the anti-herpes virus activity of this protein, confirming it as an outstanding candidate for the treatment of herpetic infections.

ANTIBACTERIAL ACTIVITY AND BINDING ABILITY OF BOVINE LACTOFERRIN AGAINST PSEUDOMONAS SPP.

ABSTRACT The antibacterial activity of bovine lactoferrin was tested against Pseudomonas fluorescens and Pseudomonas syringae. The activity was studied by monitoring the growth of a Pseudomonas spp. in the presence or absence of bovine apo‐lactoferrin, bovine holo‐lactoferrin or native‐lactoferrin in liquid media at different concentrations. Lactoferrin‐binding proteins in the membrane fractions of Pseudomonas spp. were detected using far‐Western blot analysis. The addition of bovine lactoferrin to the medium inhibited the growth of all tested strains. Furthermore, the growth of P. fluorescens and P. syringae was strongly inhibited by bovine apo‐lactoferrin. The estimated molecular weights of lactoferrin‐binding proteins in P. fluorescens were 70, 49, 47 and 25 kDa, and 70, 48 and 28 kDa in P. syringae.PRACTICAL APPLICATIONS Pseudomonas fluorescens is an important psychrotrophic bacterium responsible for undesirable flavors in milk and dairy products. Thus, flavor and texture defects, such as bitterness and running paste, were also reported. In addition, Pseudomonas syringae causes various diseases on many different susceptible plant species, generally producing chlorotic and necrotic lesions on leaves and fruits. The resultant bacterial spoilage causes considerable economic losses for the food and dairy industries. At present, antiseptics and agricultural chemicals are used for defense of foods and vegetables from these bacteria, but such substances are known to deleteriously affect the human body. The results of this study demonstrate that bovine lactoferrin significantly inhibits the growth of P. fluorescens and P. syringae. The results indicate that the incorporation of bovine lactoferrin is expected to protect dairy products, food and fruits from pathogenic bacteria.

Antimicrobial Activity of Lactoferrin against Foodborne Pathogenic Bacteria Incorporated into Edible Chitosan Film

The objectives of this research were to develop and characterize edible chitosan film containing lactoferrin as a natural antimicrobial agent, and to investigate the combination effects of lactoferrin with lysozyme in chitosan film against the growth of Escherichia coli O157:H7 and Listeria monocytogenes. Chitosan films containing lactoferrin, lysozyme, or nisin were fabricated, and the antimicrobial concentrations were 0.5, 1, or 2 mg in a circular disc of chitosan film. Three concentrations of lactoferrin or EDTA (0.28, 0.56, or 1.12 mg per disc) were also incorporated into the chitosan film containing lysozyme to investigate the combination effects of lactoferrin. The water barrier properties of the chitosan films containing lactoferrin were characterized. The antimicrobial activities against E. coli O157:H7 and L. monocytogenes were determined using the agar diffusion assay and cell count assay. The chitosan films containing lactoferrin less than 1 mg per disc did not alter the water vapor permeability of the chitosan film. Although the film containing lysozyme exhibited significant antimicrobial activity, the incorporation of lactoferrin alone into chitosan film did not exhibit significant antimicrobial activity against both E. coli O157:H7 and L. monocytogenes. However, the combination of lactoferrin with lysozyme-containing chitosan film significantly decreased the growth of E. coli O157:H7, exhibiting a comparable effect to that of the combination of EDTA with lysozyme (P < 0.05). Furthermore, the combination of lactoferrin with lysozyme in chitosan film exhibited greater reduction in the growth of L. monocytogenes than did the combination EDTA with lysozyme, resulting in an approximate 3-log reduction.

IsdA ProtectsStaphylococcus aureusagainst the Bactericidal Protease Activity of Apolactoferrin

An important facet of the Staphylococcus aureus host-pathogen interaction is the ability of the invading bacterium to evade host innate defenses, particularly the cocktail of host antimicrobial peptides. In this work, we showed that IsdA, a surface protein of S. aureus which is required for nasal colonization, binds to lactoferrin, the most abundant antistaphylococcal polypeptide in human nasal secretions. The presence of IsdA on the surface of S. aureus confers resistance to killing by lactoferrin. In addition, the bactericidal activity of lactoferrin was inhibited by addition of phenylmethylsulfonyl fluoride, implicating the serine protease activity of lactoferrin in the killing of S. aureus. Recombinant IsdA was a competitive inhibitor of lactoferrin protease activity. Reciprocally, antibody reactive to IsdA enhanced killing of S. aureus. Thus, IsdA can protect S. aureus against lactoferrin and acts as a protease inhibitor.

Lactoferrin from canine neutrophils: Isolation and physicochemical and antimicrobial properties

Lactoferrin has been isolated from canine leukocytes for the first time. Lactoferrin was identified by N-terminal amino acid sequence and by capability to capture ferric cations resulting in a complex with absorbance maximum at 460-470 nm. It is demonstrated that canine lactoferrin resembles the human homolog in some physicochemical properties, i.e. molecular weight, carbohydrate presence, and conditions of protein-iron complex dissociation. Bactericidal activity of dog lactoferrin was demonstrated on the gram-negative bacterium Escherichia coli and gram-positive bacterium Listeria monocytogenes. Bactericidal activity of canine lactoferrin is similar to that of human lactoferrin.

Ovotransferrin expression and release by chicken cell lines infected with Marek’s disease virus

Mammals posses both serum transferrin and lactoferrin, whose functions are taken over in birds by ovotransferrin, displaying both iron transport and antibacterial activities. Ovotransferrin also exerts antiviral activity towards Marek's disease virus, an avian member of the herpes family of viruses. This virus infects lymphoid organs and induces the transcription of ovotransferrin in infected chicken embryo fibroblasts. However, it has not yet been established whether ovotransferrin gene transcription is linked to the release of the protein outside the cells or whether ovotransferrin expression and release also occurs in chicken lymphoblastoid cells in which the Marek's disease viral genome is integrated. Our results indicate that both serum and egg-white isoforms of ovotransferrin are expressed and released in the supernatants of chicken embryo fibroblast and lymphoblastoid cells in the absence of infection. Viral infection of chicken embryo fibroblasts caused a slight increase of ovotransferrin release, whereas viral reinfection of lymphoblastoid cells caused a remarkable ovotransferrin release in a virus concentration-dependent manner. These findings suggest that ovotransferrin release in vivo may play a crucial role in protecting the whole organism from viral infection spreading, and support the hypothesis that the antiviral activity of ovotransferrin is an important part of the innate immune response in birds, resembling the antiviral activity of lactoferrin in mammals.

Effect of bovine lactoferrin on enamel demineralization and acid fermentation by Streptococcus mutans

The purpose of this study was to evaluate the effects of bovine lactoferrin on acid fermentation and enamel demineralization using Streptococcus mutans in a culture system and an artificial mouth model system. The antibacterial activity of bovine lactoferrin (bLF) against S. mutans was analyzed by a radial diffusion assay. In the culture system, the effect of bLF on the synthesis and adherence of water insoluble glucan (WIG) and the adherence of S. mutans to a glass surface was examined by a batch culture. In the artificial mouth model system, cell suspension of S. mutans , heart infusion broth supplemented with sucrose, and PBS or lactoferrin solution were supplied separately and constantly for 21 hours. The following parameters were determined for evaluation: the amount of artificial biofilm, the changes in pH underneath the biofilm; and the changes in enamel microhardness measured by a Vicker's hardness tester. The antibacterial activity of bLF against S. mutans was observed. The amounts of bacterial cells in the total adherent fractions were inhibited by bLF in a dose dependent manner. The amounts of WIG in a firm-adherent fraction were significantly inhibited by 0.1–1.0% bLF. The changes in microhardness on enamel slabs in the bLF group (2.4 ± 0.8) showed significantly less hardness reduction than those in the control group (22.3 ± 2.5) ( P < 0.001). The artificial biofilm accumulation was not reduced by bLF. The results of this study suggest that bLF might have inhibitory effects against acid fermentation and demineralization of enamel by S. mutans .

Comparison of the effects of acylation and amidation on the antimicrobial and antiviral properties of lactoferrin

To compare amidation and acylation of lactoferrin (LF) from bovine milk, as a means of enhancing its antimicrobial and antiviral properties. LF was chemically modified by amidation with a 1-ethyl-3-[3-(dimethylamino) propyl] carbodiimide (EDC) in the presence of ammonium ions or by acylation with either succinic or acetic anhydride. In the test systems used, amidation substantially enhanced the activity of LF against Pseudomonas fluorescens in comparison with native LF. However, increasing the net negative charge of LF by acylation had no effect on the activity of LF against P. fluorescens, and abrogated the antimicrobial activity of LF against Bacillus subtilis and Saccharomyces cerevisiae. Increasing the net negative charges of LF by acylation eliminated its antimicrobial and antiviral effects against poliovirus and feline calicivirus (nonenveloped viruses). The addition of positive charges to LF via amidation enhanced antimicrobial properties in contrast to increasing the negative charges by acylation, which abolished both the antimicrobial and antiviral properties of LF. The effects of charge alteration of LF determined in this study provides a basis for further development of LF formulations with enhanced antimicrobial effectiveness for use in food process hygiene, veterinary and health-care applications.

The synergistic effect of nisin and lactoferrin on the inhibition of Listeria monocytogenes and Escherichia coli O157:H7

The goal of this study was to determine whether nisin and lactoferrin would act synergistically to inhibit the growth of Listeria monocytogenes and Escherichia coli O157:H7. Lactoferrin and nisin separately or in combination were suspended in peptone yeast glucose broth and following inoculation with L. monocytogenes or E. coli O157:H7 growth inhibition of each pathogen was determined. At 1000 microg ml(-1) lactoferrin L. monocytogenes was effectively inhibited. However, E. coli O157:H7 initially was inhibited and then grew to cell density similar to the control. A combination of 500 microg ml(-1) of lactoferrin and 250 IU ml(-1) of nisin effectively inhibited the growth of E. coli O157:H7, whereas, 250 microg ml(-1) of lactoferrin and 10 IU ml(-1) of nisin were inhibitory to L. monocytogenes. The results suggest that lactoferrin and nisin act synergistically to inhibit the growth of L. monocytogenes and E. coli O157:H7. Natural preservatives that are active against gram-positive and gram-negative pathogens are desirable to the food industry and consumers. This study demonstrates that lactoferrin and nisin work synergistically reducing the levels required independently inhibiting growth of two major foodborne pathogens. Previous reported results indicated a low level of antimicrobial activity; however, this work was not performed in low divalent cation concentration media. It has been suggested that nondivalent cation-limiting medium such as trypticase soy broth (TSB), can reduce or completely eliminate the inhibitory activity. Further knowledge of these interactions can increase the understanding of the antimicrobial activity of lactoferrin. This should make the use of these compounds by industry more attractive.

Differential modulation of human lactoferrin activity against both R5 and X4-HIV-1 adsorption on epithelial cells and dendritic cells by natural antibodies.

Differential modulation of human lactoferrin activity against both R5 and X4-HIV-1 adsorption on epithelial cells and dendritic cells by natural antibodies.

Differential Modulation of Human Lactoferrin Activity against Both R5 and X4-HIV-1 Adsorption on Epithelial Cells and Dendritic Cells by Natural Antibodies

Human lactoferrin (Lf) is an iron binding glycoprotein that is present in several mucosal secretions. Many biological functions have been ascribed to Lf. In the present study, we showed that Lf limited specifically adsorption of R5- and X4-HIV-1-free particles on endometrial epithelial HEC-1A cells, by inhibiting virus adsorption on heparan-sulfated proteoglycans. But, Lf did not interfere with both R5 and X4-HIV transcytosis. We showed also the efficacy of Lf in preventing R5 and X4-HIV capture by dendritic cells. Conversely, we demonstrated that Lf-reacting natural Abs (NAbs) present within i.v. Ig-enhanced HIV attachment on dendritic cells by forming HIV-Lf-NAbs. HIV particles were able to directly interact with Lf following its interaction with NAbs. We also found Lf-reacting natural Abs within cervicovaginal secretions, suggesting the existence of Lf-NAbs complexes in women genital tract in vivo. In conclusion, this study highlights Lf as a potent microbicides and reports new function for NAbs within the genital compartment that may compartment that may abolish the inhibitory activity of microbicide compounds. Thus, we proposed a model in which Lf would appear as a double-edged sword that could have beneficial or detrimental effects depending on both cellular and molecular environments. This study highlights the use of Lf derivates as microbicide candidates to limit such interferences.

Effects on Escherichia coli O157:H7 and meat starter cultures of bovine lactoferrin in broth and microencapsulated lactoferrin in dry sausage batters

The effects of lactoferrin (LF) alone or with various chelating agents on the growth of 5 strains of Escherichia coli O157:H7 and 7 meat starter cultures were evaluated. E.coli O157:H7 and starter cultures were grown at 13 or 26 °C in Lauria (LB) or All Purpose Tween (APT) broths, respectively, with both broths being supplemented with 2.9% NaCl. LF alone prevented the growth of E. coli O157:H7 strains 0627 and 0628 but other strains grew. The antimicrobial effectiveness of LF was enhanced by EDTA but LF alone did not affect the growth of meat starter cultures in broth. However, when LF plus EDTA and sodium bicarbonate (SB) were used the growth of all meat starter cultures except Lactobacillus curvatus was reduced. During dry sausage manufacture with L. curvatus and Staphylococcus carnosus starter cultures the effects of LF, unencapsulated or microencapsulated in paste-like and dried powder forms, in sausage batters with or without EDTA and SB, on the viability of E. coli O157:H7 were examined. The reduction of E. coli O157:H7 during sausage manufacture was significantly enhanced ( p < 0.05) by all LF treatments. The largest reduction (4.2 log units) was obtained with unencapsulated LF. However, some of the apparent reduction in E.coli O157:H7 numbers with all treatments was due to cell injury rather than lethality, since significantly greater numbers were recovered on APT agar overlaid with the selective medium cefixime-tellurite Sorbitol McConkey agar (ct-SMAC) than on ct-SMAC alone. The narrow spectrum of LF activity and induction of injury rather than inactivation of E. coli O157:H7 limit the effectiveness of this agent against the pathogen in fermented meats.

한우와 젖소 초유로부터 분리한 Lactoferrin과 가수분해물의 항균활성

본 연구는 우리나라 재래종인 한우로부터 초유를 얻어 Lf을 분리정제한 후 한우 Lf와 젖소 Lf의 항균활성을 확인하였다. E. coli O111및 기타 미생물에 대한 항균성은 젖소 Lf가 한우 Lf 보다 높았으며, 젖소 Lf 가수분해물도 한우 Lf 가수분해물보다 마찬가지로 높았다. MIC에서는 E. coli O111 경우 젖소 Lf가 1.5mg/ml, 한우 Lf은 2.75mg/ml이며 젖소 Lf 가수분해물은 0.12mg/ml, 한우 Lf 가수분해물은 0.25mg/ml로 항균성 실험과 동일하게 젖소 Lf 가수분해물의 항균활성이 더 높은 것으로 나타났다. 한편 Lf과 lysozyme의 첨가는 항균활성을 상승시키는 효과를 나타내었다. The purpose of this study is to demonstrate antimicrobial activities of the lactoferrin and its peptic hydrolysates obtained from the colostrums of Hanwoo(Korean native cattle) and Holstein cattle. In the measurement of antimicrobial activity to E. coli O111 and other microorganisms, bovine lactoferrin showed a higher antimicrobial activity than that of Hanwoo cow's lactoferrin . The minimal inhibitory concentration (MIC) of lactoferrin against E. coli O111 was exhibited 1.5mg/ml(Holstein) and 2.75mg/ml (Hanwoo). The same result was also observed between bovine lactoferrin hydrolysate (0.12mg/ml) and Hanwoo cow's lactoferrin hydrolysate (0.25mg/ml). In addition of lysozyme, antimicrobial activity of lactoferrin was increased.

락토페린을 첨가한 저지방/저염 소시지의 품질 및 Escherichia coli O157:H7에 대한 항균 활성에 미치는 효과

기능성 식육제품을 제조하기 위해 첨가한 락토페린의 항균활성을 평가하기 위해 Escherichia coli O157:H7을 일정 수준으로 접종하고 락토페린을 0에서 1%로 달리 첨가한 결과, 농도에 의존적으로 항균활성을 나타냈으며, 특히 0.25% 이상의 농도에서는 접종균에 대한 뚜렷한 항균효과를 나타냈다. 이러한 결과를 근거로 소시지의 저장성 증진을 위해 락토페린을 첨가하여 제조하였으나 저장성 실험 결과에서는 항균효과가 확인되지 않았다. 또한 젖산나트륨을 2% 첨가하고 락토페린을 0.3에서 0.9%로 복합 첨가하여 4℃ 저장 중에 접종한 E. coli O157:H7에 대한 항균활성을 측정한 결과에서는, 젖산나트륨 2% 단독 첨가구는 4주 이후 접종균의 생장이 억제되었으나 젖산나트륨과 락토페린을 복합첨가한 첨가구는 락토페린의 농도가 증가할수록 저장기간 동안 접종균의 성장으로 항균효과가 오히려 감소하였다. 따라서 모델결과에서 보여준 항균효과는 실질적인 식육제품실험에서는 나타나지 않았으며, 이러한 결과는 제조 및 가열 중에 락토페린의 변성과 소시지 제조에 첨가되는 복합첨가물들의 영향으로 첨가된 락토페린의 항균활성이 저해된 것으로 판단된다. 차후의 연구로 락토페린의 항균활성을 높이기 위하여 케이싱의 내면에 필름으로 처리하는 방법으로 항균활성효과를 연구하는 것이 필요할 것으로 사료된다 This study was performed to determine potential antimicrobial activity of lactoferrin, which incorporated into the low-fat/salt sausages during storage either at 30 or 4℃. First, the model study on the antimicrobial activity of lactoferrin was performed. Based on the model study, more than 0.25% of lactoferrin was required to have a distinctive antimicrobial activity for the growth of E. coli O157:H7 in the broth. However, extended shelf-life was not shown in the low-fat/salt sausages manufactured with lactoferrin during refrigerated storage. In addition, no synergistic effects of lactoferrin with sodium lactate were observed in the sausages. These results indicated that the addition of lactoferrin into the low-fat sausages did not have antimicrobial activity of E. coli O157:H7, due to the denaturation of lactoferrin or the complexity of the sausage, even though it had a distinctive antimicrobial effect in the model study.