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This study was performed to develop and validate a predictive growth model of pathogenic Escherichia coli to ensure the safety of fresh‐cut produce. Samples were inoculated with a cocktail of seven E. coli strains of five pathotypes (EHEC, Enterohemorrhagic E. coli; ETEC, Enterotoxigenic E. coli; EPEC, Enteropathogenic E. coli; EIEC, Enteroinvasive E. coli, and EAEC, Enteroaggregative E. coli) and stored at 4, 10, 12, 15, 25, 30, and 37°C. Growth of pathogenic E. coli was observed above 12°C. The primary growth model for pathogenic E. coli in fresh‐cut produce was developed based on the Baranyi model. The secondary model was developed as a function of temperature for lag phase duration (LPD) and maximum specific growth rate (μmax) based on the polynomial second‐order model. The primary and secondary models for pathogenic E. coli were fitted with a high degree of goodness of fit (R2 ≥ 0.99). The bias factor (Bf), accuracy factor (Af), and root mean square error (RMSE) were 0.995, 1.011, and 0.084, respectively. The growth model we developed can provide useful data for assessing the quantitative microbial risk of pathogenic E. coli in fresh‐cut produce intended for human consumption. In addition, it is thought to be widely available in industries that produce, process, distribute, and sell fresh‐cut produce., Primary model of the growth of pathogenic Escherichia coli in fresh‐cut produce. (A) 4°C, (B) 10°C, (C) 12°C, (D) 15°C, (E) 25°C, (F) 30°C, (G) 37°C.

The diverse microbial communities in kimchi are dependent on fermentation period and temperature. Here, we investigated the effect of enterotoxigenic Escherichia coli (ETEC) during the fermentation of kimchi at two temperatures using high-throughput sequencing. There were no differences in pH between the control group, samples not inoculated with ETEC, and the ETEC group, samples inoculated with ETEC MFDS 1009477. The pH of the two groups, which were fermented at 10 and 25°C, decreased rapidly at the beginning of fermentation and then reached pH 3.96 and pH 3.62. In both groups, the genera Lactobacillus, Leuconostoc, and Weissella were predominant. Our result suggests that microbial communities during kimchi fermentation may be affected by the fermentation parameters, such as temperature and period, and not enterotoxigenic E. coli (ETEC).

Contamination of foodstuffs by potentially enteropathogenic Arcobacter spp. is becoming a concern worldwide. However, few studies have examined virulence-associated genes in isolates of Arcobacter spp. from food. Here, we investigated the prevalence of three pathogenic Arcobacter species, A. butzleri, A. cryaerophilus, and A. skirrowii, in chicken, pork, and leafy green vegetables (n = 323) in South Korea. Samples were examined using two different protocols selected from a literature review: Acrobacter selective broth (ASB) II + Arcobacter selective medium (ASM) II (protocol A), and ASB II + modified charcoal cefoperazone deoxycholate agar supplemented with CAT (protocol B). Overall, Arcobacter spp. were detected in 45.8% of food samples, and the recovery rate of protocol B (37.8%) was significantly higher than that of protocol A (30.7%) (p 0.05). Refrigerated chicken gizzard samples showed the highest detection rate (100%), followed by refrigerated chicken wing (79.5%), intestine (77.3%), neck skin (63.3%), pork (55.6%), frozen chicken legs (5.0%), and leafy green vegetables (4.4%) (p 0.05). All isolates from chicken and leafy green vegetables were identified as A. butzleri, whereas A. cryaerophilus and A. skirrowii were mainly detected in pork. Most samples (95.8%) harbored more than one of nine putative virulence factors (cadF, ciaB, cj1349, hecA, hecB, mviN, pldA, irgA, and tlyA), and 91.3% harbored more than two. Isolates harboring all nine putative virulence genes were obtained from 1.9% of samples: five pork and one chicken. This study provides comprehensive and de facto evidence regarding prevalence of an emerging pathogen, Arcobacter spp., in various foods, along with their virulence potential. The results justify further research with respect to their role in food safety.

A total of 364 samples of vegetable- and meat-based meals were collected at three processing steps: step I, preparation of raw ingredients; step II, processing and cooking; and step III, finished meals. Microbiological quality was evaluated by using data for the prevalence and concentration of the aerobic plate counts, total coliforms (TC), fecal coliforms (FC), and Escherichia coli. The data were analyzed for differences between cafeterias, seasons, raw materials, and processing steps. Fourteen (15.2%) of the 92 finished meal samples were microbiologically unsatisfactory. Neither cafeteria nor season was significantly associated with microbiological quality ( P > 0.05). However, the type of raw ingredients and processing steps were significantly associated with differences in microbiological quality. Vegetable-based meals had higher TC concentrations than meat-based meals because salad and seasoned and fermented vegetables are not cooked, unlike heat-processed meat products. Microbial counts tended to decrease through the processing steps, and E. coli, which could only be enumerated on uncooked chicken breast (1.6 log CFU/g) and sliced pork (2.6 log CFU/g), was totally eliminated by boiling and roasting. However, the presence of FC was not completely eliminated, even by cooking, and so this group of organisms should be considered as an important indicator of hygienic meal preparation in cafeterias. Although pathogenic E. coli was not isolated in this study, continuous microbiological monitoring of composite foods served in cafeterias should be performed as the presence of TC and FC in finished meals indicates the potential for contamination by pathogenic E. coli.

The aims of this study was to determine the actual levels of microbial contamination in cereal and Saeng-sik products and establish new microbial criteria for cereal and Saeng-sik products for the “Korea Food Code”. Monitoring microbial indicator organisms (i.e., total aerobic, coliform, and Escherichia coli counts) and food-borne pathogens (i.e., Bacillus cereus, Staphylococcus aureus, and Clostridium perfringens) revealed that the total aerobic counts of cereal and Saeng-sik products were not detected (ND)–2.48 and 4.00–7.88 log10 CFU/g, respectively, whereas coliform bacteria were only detected in Saeng-sik (ND–5.24 log10 CFU/g). Cereals and Saeng-sik products were also contaminated with B. cereus (ND–2.95 log10 CFU/g and −0.40–3.30 log10 CFU/g, respectively). However, S. aureus, C. perfringens and E. coli were not detected in any of the cereal or Saeng-sik products. Based on this study, a revision was proposed for microbial criteria in cereal and Saeng-sik products.

Quantitative triplex real-time PCR (qPCR) offers an alternative method for detection of bacterial contamination. It provides quantitation of the number of gene copies. In our study, we established a qPCR assay to detect and quantify the specificity towards Bacillus cereus and B. thuringiensis. The assay was designed to detect a 280 bp fragment of motB gene encoding the flagellar motor protein, specific for detection of B. cereus and B. thuringiensis, excluding other group species B. pseudomycoides, B. mycoides and B. weihenstephanensis. Specificity of the assay was confirmed with 111 strains belonging to Bacillus cereus group and performed against 58 B. cereus, 50 B. thuringiensis, 3 other Bacillus bacteria and 9 non-Bacillus bacteria. Detection limit was determined for each assay. Direct analysis of samples revealed the specificity towards identification and characterization of B. cereus group cultured in nutrient media. Based on results, it was observed that motB showed 97% specificity towards B. cereus strains, 98% for B. thuringiensis but other B. cereus group showed less sensitivity (0%), thus, provides an efficient tool to identify B. cereus and B. thuringiensis. Further, environmental and food samples do not require band isolation, re-amplification or sequence identification. Thus, reducing the time and cost of analysis.

An effective bactericidal cold-marinating method for beef products is described, exploiting the synergism between soy sauce and natural compounds (carvacrol, CV or thymol, TM) to reduce microbiological risks. Beef slices inoculated with Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium (3.1-3.5logCFU/g) were marinated in a teriyaki sauce with or without CV and TM (0.3 and 0.5%). After 1, 3, and 7days at 4°C, indigenous microflora population, color, lipid oxidation, marinade uptake, and pH of marinated beef and leftover marinade samples were examined. Teriyaki sauce alone did not reduce or inhibit any of the target pathogens or indigenous bacteria, while 0.5% CV- or TM-containing teriyaki sauce inactivated all inocula without recovery within 7days (p0.05). The pathogens relocated from the beef into the leftover marinade (3.0-3.4logCFU/mL) were also completely inactivated. The treatment inhibited growth of indigenous aerobic bacteria (p0.05) and inactivated coliform bacteria. Physicochemical parameters were not significantly affected (p0.05).

Background: The present study examined the changes in microbiological composition during the production process of crab marinated in soy sauce, potential microbial hazards, potential contamination routes and effective critical control points. Crab and soy sauce samples were obtained from six different manufacturing plants at different stages, and their microbiological content was comprehensively assessed by quantitative and qualitative analyses.; Results: The results revealed the following: (1) the final products contained 4.0 log colony-forming units (CFU) g-1 aerobic plate counts (APCs) and 1.1 log CFU g-1 coliforms, which may have been introduced from the raw materials (the level of APCs in raw crab and soy sauce mixed with other ingredients was 3.8 log CFU g-1 and 4.0 log CFU mL-1 respectively); (2) marination of crab in soy sauce may allow cross-contamination by coliforms; (3) only Bacillus cereus and Staphylococcus aureus were qualitatively detected in samples at different stages of manufacture (detection rate of 28 and 5.6% respectively), and these bacteria may impact the microbiological quality and safety of crab marinated in soy sauce; and (4) bacterial counts were either maintained or increased during the manufacturing process (suggesting that no particular step can be targeted to reduce bacterial counts).; Conclusion: Proper management of raw materials and the marination process are effective critical control points, and alternative interventions may be needed to control bacterial quantity. The results provide important basic information about the production of crab marinated in soy sauce and may facilitate effective implementation of sanitary management practices in related industries and research fields. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.

This study examined the prevalence of seven species of Enterococcus in foodstuffs (n = 500) retailed in South Korea and identified the potential virulence of isolates. The overall detection rate of Enterococcus spp. was 68.2%, and the bacteria were most prevalent in refrigerated chicken (84.1%), followed by refrigerated pork (71.0%), frozen chicken (60.0%), leafy vegetables (56.0%), and refrigerated beef (53.0%). The prevalence differed by sample type: E. faecalis and E. faecium were the most or second most frequently identified species in foods of animal origin, while a large portion of the leafy vegetable isolates were confirmed as E. casseliflavus. The presence of virulence genes was apparent in all species except E. durans; approximately half of the isolates (46.3%) had more than one virulence determinant, especially gelE (gelatinase) (88.1%). One of the interesting findings was that even non-E. faecalis and non-E. faecium enterococci also had virulence determinants. However, none of the Enterococcus isolates were resistant to vancomycin. These results provide comprehensive data on the prevalence of the genus Enterococcus in South Korea and empirical evidence regarding the virulence potential; thus, the findings herein call for further studies about the relevance of these bacteria to food safety.

The objectives of the current study were to investigate the fate of microbial indicators [aerobic plate counts (APC), total coliforms (TC), and lactic acid bacteria (LAB)] in commercial salted napa cabbages during storage conditions at different temperatures (5, 22, and 30 °C, for up to 72 h) and to develop a predictive growth model using the modified Gompertz equation to determine shelf life. Microbial population sizes (initial log CFU g −1 : APC, 5.1; TC, 3.0; LAB, 3.7) remained stable at 5 °C, but rapidly increased by 2–4 log CFU g −1 within 12 h at 22 and 30 °C; furthermore, the pH of salted napa cabbages decreased significantly ( P 2 ≧ 0.97), the highest μ max was observed for LAB at 30 °C [0.61 log CFU h −1 ], while the lowest was noted for TC at 5 °C [0.04 log CFU h −1 ]. Shelf-life was determined using APC (7.7 log CFU g −1 ) and LAB (6.0 log CFU g −1 ) limits; the microbiological acceptability period of salted napa cabbage was predicted to be 12.6 and 9.3 h at 22 and 30 °C, respectively. Thus, consumers should use the product within 12 h of storage at room temperature (more quickly in the summer (9 h)), or store it in a refrigerator. The presented research proposes a shelf-life modeling of commercial salted napa cabbages, which may be used as a scientific basis for product quality control and issuing appropriate guidance for consumer use at home.

Microbiological quality of laver, one of the edible seaweeds, has not been reported in a real processing line. Laver or supplements were collected from six manufacturers (A to F) to assess potential microbiological hazards and the critical control points in commercial processing lines. Aerobic plate counts (APC), coliform counts, Bacillus cereus, Staphylococcus aureus, and Vibrio parahaemolyticus were enumerated, and the presence of B. cereus, Listeria monocytogenes, Salmonella, S. aureus, and V. parahaemolyticus were confirmed during processing. The raw material, i.e., dried laver, had a high initial APC level (4.4 to 7.8 log CFU/g), which decreased gradually during processing (final products, 1.3 to 5.9 log CFU/g). Coliforms and B. cereus were not detected in any of the final products, but they were present in some raw materials and semiprocessed products in quantitative analysis. After enrichment for recovery of stress-injured cells, E. coli and foodborne pathogens were not detected in any samples, with the exception of B. cereus. Heat-injured and spore-forming B. cereus isolates were occasionally obtained from some of the raw materials and products after enrichment, thus B. cereus may be a potential microbiological hazard that should be controlled using strategic intervention measures. Secondary roasting (260 to 400°C, 2 to 10 s) significantly reduced the APC (maximum log reduction, 4.7 log CFU/g), and this could be a key intervention step for controlling microbiological hazards during processing (critical control point). When this step was performed appropriately, according to the processing guide for each plant, the microorganisms were inactivated more successfully in the products. This study provides scientific evidence that may facilitate the development of strategies for microbiological hazard control and hygienic management guidelines for real manufacturing plants.

Aspergillus niger, Penicillium citrinum, and Cladosporium cladosporioides are the primary spoilage molds of dried fishery food products. This study investigated the effects of different doses of ultraviolet (UV) light (260 nm) on the reduction of A. niger, P. citrinum, and C. cladosporioides on experimentally contaminated dried filefish (Stephanolepis cirrhifer) fillet surfaces and the effect on the quality of the fillets. All three strains counts were significantly (p 0.05) between the nontreated (control) and UV-treated fillets, the flavor and overall acceptability significantly (p

The effects of freezing (−20 °C and −40 °C for 6 h, 12 h, and 1–21 days), salting (5, 10, 15, and 20% NaCl for 3 h, 6 h, 12 h, and 1–7 days), and a combined treatment with chlorine (500, 1000, 1500, and 2000 ppm) and ultrasound (37 kHz frequency and 1200 W for 5, 10, 15, 20, and 30 min) were investigated to observe the inactivation of Anisakis larvae in salt-fermented squid and pollock tripe or in the test tube. All larvae inoculated in squid and pollock tripe were inactivated after 48 h at −20 °C and 24 h at −40 °C. The average recovery rates of the larvae inoculated in squid and pollock tripe were 94.4% and 95.2%, respectively. The viabilities of larvae were 81.7% in 5% NaCl and 26.7% in 10% NaCl after 7 days of storage. However, all larvae were inactivated when submerged in 15% NaCl after 7 days of storage and 20% NaCl after 6 days of storage. Viability was reduced from 43.3% to 13.3% when ultrasound alone was used to treat live larvae in test tubes for 15–20 min. Furthermore, although no reduction effect on viability of larvae was observed when chlorine alone was used for treatment, 0% viability was observed using the combined treatment of 1500 ppm chlorine and ultrasound for 30 min. Interestingly, when the viscera of heavily parasitized conger eels were treated with chlorine and ultrasound, there was no reduction effect on viability of the larvae on the viscera. These results could be used to provide more specific guidelines for manufacturers and consumers about the freezing and salting conditions necessary to kill Anisakis larvae in salt-fermented squid and pollock tripe.

This study was performed to evaluate antimicrobial resistance of food-borne pathogens isolated from retail meat in Korea. A total of 157 samples of beef, pork, and chicken were collected and analyzed for E. coli, Salmonella, Campylobacter. Resistances to tetracycline were declined in accord with reduced usage of tetracycline in live stock production. E. coli stains from chicken meat had higher multi-drug resistance ratio than strains from other meat. One extended spectrum beta lactamase (ESBL) producing E. coli and two ESBL producing Salmonella were identified in this study. ESBL producing Salmonella strains were confirmed to carry CTX-M-1 type genes.

Pathogenic Escherichia coli (PEc) is a leading cause of both foodborne and waterborne illness. In September 2012, a major foodborne outbreak with PEc occurred, affecting approximately 1,200 students and food handlers from 7 schools in Gyeonggi province, South Korea caused by contaminated kimchi. For detection of PEc in kimchi, real-time polymerase chain reaction (RT-PCR) and traditional culture methods were used. EAEC and ETEC genotypes were identified in samples from individuals with the illness and in kimchi using conventional PCR. Bacteria in stool samples were genetically similar to bacteria from kimchi (98% homology). PEc from kimchi was identified as the causative agent of a foodborne outbreak in South Korea. A significant link between kimchi and individuals with foodborne illnesses after consuming kimchi was demonstrated.

Microbiological quality of 206 raw ready-to-eat seafood samples was investigated according to species (gizzard shad, halibut, rockfish, tuna, oyster and squid) and distribution channels (fishery, hyper and online market). Enumeration of aerobic plate count and total coliforms (TC) and pathogenic bacteria (Bacillus cereus, Staphylococcus aureus and Vibrio parahaemolyticus) was performed, and level of microbiological quality was classified into four groups: satisfactory, acceptable, unsatisfactory and unacceptable. Qualitative analysis was also performed for Escherichia coli and eight foodborne pathogens (B. cereus, E. coli O157:H7, Listeria monocytogenes, Salmonella spp., S. aureus, Vibrio cholerae, V. parahaemolyticus, and Vibrio vulnificus). Raw ready-to-eat seafood products revealed 0·5% at an unsatisfactory level and 4·9% at an unacceptable level due to ≥4 log CFU g−1 of TC in squid and ≥3 log CFU g−1 of V. parahaemolyticus in gizzard shad respectively. Gizzard shad was shown to be potentially hazardous, as its sashimi is eaten with its skin attached. Bacillus cereus, E. coli, S. aureus, V. parahaemolyticus and V. vulnificus were qualitatively detected. Samples from the fishery market showed higher detection rate especially in V. parahaemolyticus (21·6%) and V. vulnificus (1·7%) which indicates the need to improve microbiological safety of raw ready-to-eat seafood products in fishery market. Significance and Impact of the Study Raw ready-to-eat seafood products like sashimi can be easily contaminated with various bacteria from aquatic environments and human reservoirs, which subsequently bring about a risk in food poisoning due to no heating process before consumption. The results of this study provide comprehensive microbiological data on various species of raw ready-to-eat seafood from various distribution channels. It may contribute to establish reasonable standard and effective strategies to ensure a good microbiological quality of raw ready-to-eat seafood for the safety of meals, like sashimi and sushi.

Ethnopharmacological relevance : Lonicera japonica Thunb and Anemarrhena asphodeloides BUNGE have been used for the treatment of a variety of inflammatory diseases, cold and infective diseases in many countries, including Korea and China. Aim of the study : This study aimed to assess the anti-nociceptive and anti-inflammatory activities of n-butanol fraction (WIN-34B) prepared from dried flowers of Lonicera japonica and dried roots of Anemarrhena asphodeloides as potential novel treatment of osteoarthritis. Materials and methods : Anti-nociceptive activities of WIN-34B (100, 200 and 400 mg/kg, p.o.) were measured using acetic acid-induced writhing response, formalin-induced paw licking, hot plate, radiant heat tail-flick, carrageenan-induced paw pressure, and Hargreaves tests, respectively. Anti-inflammatory activities of WIN-34B (100, 200 and 400 mg/kg, p.o.) were assessed using acetic acid-induced vascular permeability, carrageenan-induced paw edema, and croton oil-induced ear edema. Anti-osteoarthritis effect of WIN-34B was analyzed using monosodium iodoacetate (MIA)-induced osteoarthritis animal model. Results : WIN-34B exhibited better anti-inflammatory activity than that of celecoxib in carrageenan at the dose of 200 mg/kg and croton oil-induced paw edema and ear edema at the doses of 200 and 400 mg/kg. WIN-34B exhibited significant anti-inflammatory effects on vascular permeability. WIN-34B also exhibited significant anti-nociceptive activities in the late phase of formalin-induced paw licking and writhing response model in mice. In radiant heat tail-flick and carrageenan-induced paw pressure tests, WIN-34B at the dose of 400 mg/kg and at the doses of 200 and 400 mg/kg presented similar activities to indomethacin and celecoxib. Compared to indomethacin WIN-34B at 400 mg/kg showed similar or better anti-nociceptive activities after 1 and 2 h of theraphy in the hot plate test and better anti-nociceptive activity than that of celecoxib in Hargreves test. In the MIA-induced osteoarthritis animal models, WIN-34B at 400 mg/kg exhibited similar or better anti-nociceptive property than that of celecoxib throughout the pain measurement periods. Conclusion : When compared to celecoxib, WIN-34B exhibited similar or better anti-nociceptive and anti-inflammatory activities in osteoarthritic animal models, which may become a potential novel treatment for osteoarthritis.

The aim of this study was to develop a new salting method using natural phytic acid (PA) to ensure the microbiological safety and quality of salted napa cabbage used for kimchi production. The production of salted napa cabbage involves several stages: trimming, hyper-salting (20% NaCl) for up to 1h, salting (10% NaCl for 10-18 h), three sequential washes in water (30s for each), and draining (2 h). Two separate experiments were performed: one to determine the appropriate treatment conditions and a second to validate applicability under commercial conditions. In Experiment I, the effects of hyper-salting with PA on Escherichia coli O157:H7 numbers were tested in the laboratory. The following variables were monitored: 1) PA concentration (1, 2, 3%, w/w); 2) the ratio of the sample weight to the total volume of the solution (1:1.5, 1:3, or 1:6); 3) the hyper-salting time (30 or 60 min); and 4) the salting time (2, 5, or 8 h). A procedure that achieved a5-log reduction in the E. coli O157:H7 population was then tested in an actual kimchi processing plant (Experiment II). The results from Experiment I showed that bactericidal efficacy increased as all the measured variables increased (p0.05). Hyper-salting with 2% PA at a sample-to-water ratio (w/v) of 1:3 and 1:6 for 60 min resulted in a5-log CFU/g reduction in the E. coli O157:H7 population. Further salting for 5h completely eliminated (1-log CFU/g) all bacteria. Thus, hyper-salting with PA 2% at a sample-to-water ratio of 1:3 for 60 min, followed by salting for 5h, was tested under large-scale production conditions. The results revealed that the initial aerobic plate counts (APC), total coliform counts (TC), and fecal coliform counts (FC) were 6.6, 3.4, and 2.8-log CFU/g, respectively. The selected protocol reduced these values by 3.7-,2.4-, and1.8-log CFU/g, respectively. The 5h salting step maintained the TC and FC at1-log CFU/g; however, the APC recovered somewhat. The pH and salinity of the treated salted napa cabbages were within the ranges required for kimchi production (pH 5.1-5.3 and 1.5-2.0%, respectively). These results suggest that this novel method of salting food ensures microbiological safety and reduces the production time.

We employed Caenorhabditis elegans as a model to study the effectiveness of sanitizers in killing pathogenic Escherichia coli strains ingested by free-living nematodes. Adult worms that had fed on six pathogenic E. coli strains (highly persistent in the nematode intestine) were treated with three chemical solutions. In planktonic cells, none of the H2O2 and acetic acid treatments influenced the survival of the pathogenic E. coli strains, whereas sodium hypochlorite critically decreased the viability of the strains. Importantly, the survival of the E. coli strains was dramatically increased by persistence in the C. elegans gut under 0.1% sodium hypochlorite, and several strains could survive at a concentration of 0.5%. In addition, all pathogenic E. coli strains in the C. elegans gut survived on the lettuce for 5 days even though they were washed with 0.1% sodium hypochlorite. Taken together, our results indicate that pathogenic E. coli ingested by C. elegans may be protected against washing treatment with commercial sanitizers on raw food materials.

A methanolic extract of Lindera obtusiloba (Lauraceae) stems significantly attenuated glutamate-induced oxidative stress in HT22 hippocampal cells. Two new secoisolariciresinol derivatives, characterized as 9,9'- O-di-(E)-feruloyl-meso-5,5'-dimethoxysecoisolariciresinol (1) and 9,9'-O-di-(E)-sinapinoyl-meso-5,5'-dimethoxysecoisolariciresinol (2), were isolated, along with the known compound 9,9'-O-di-(E)-feruloyl-meso-secoisolariciresinol (3), from the methanolic extract of L. obtusiloba stems. Compounds 1, 2, and 3 showed neuroprotective effects on glutamate-induced toxicity in HT22 cells.

Most of the immune response regulators identified to date proved to be products of tumor, of an immune system or of combinations of such systems or to be tumor-induced host products. We have described how the haptoglobin isolated from cancer patients can impose serious hindrance to cell-mediated immune functions in vivo and in vitro under the pathophysiologic concentrations seen in these patients. Because the tumor-associated haptoglobin interferes with the innate and adaptive immune functions, elimination of the haptoglobin by passive removal or by active therapy could be an important adjunct for immunotherapy in cancer patients.

The Nocardia sp. L-417 strain grown with n-hexadecane as a carbon source produced two types of biosurfactant that have different characteristics. These biosurfactants were purified by procedures that included ammonium sulphate fractionation, chilled acetone and hexane treatments, silica-gel column chromatography and Sephadex LH-20 gel filtration. The purified biosurfactants were very stable over a broad range of pHs (2-12) and temperatures (100 degrees C, 3 h). The biosurfactant type I had strong properties as an emulsifying agent and as an emulsion-stabilizing agent, whereas type II had a strong ability to reduce surface tension.