List-method directed forgetting: Do critical findings generalize from short to long retention intervals?

People can purposefully forget information that has become irrelevant, as is demonstrated in list-method directed forgetting (LMDF). In this task, participants are cued to intentionally forget an already studied list (list 1) before encoding a second list (list 2); this induces forgetting of the first-list items. Most research on LMDF has been conducted with short retention intervals, but very recent studies indicate that such directed forgetting can be lasting. We examined in two experiments whether core findings in the LMDF literature generalize from short to long retention intervals. The focus of Experiment 1 was on the previous finding that, with short retention interval, list-2 encoding is necessary for list-1 forgetting to arise. Experiment 1 replicated the finding after a short delay of 3 min between study and test and extended it to a longer delay of 20 min. The focus of Experiment 1 was on the absence of list-1 forgetting in item recognition, previously observed after short retention interval. Experiment 1 replicated the finding after a short delay of 3 min between study and test and extended it to longer delays of 20 min and 24 h. Implications of the results for theoretical explanations of LMDF are discussed.

Prospective Evaluation of Changes in Pain Levels, Quality of Life and Functionality After Low Dose Radiotherapy for Epicondylitis, Plantar Fasciitis, and Finger Osteoarthritis.

Background: The objective benefits of low dose radiotherapy (LDRT) for non-malignant joint disorders are controversial. This study evaluated changes in pain, quality of life (QoL) and function after LDRT for epicondylitis, plantar fasciitis, and finger osteoarthritis. Materials and Methods: Patients over 40 years old with epicondylitis, plantar fasciitis, and finger osteoarthritis were had pain following at least 6 months of conservative therapy. Patients received 0.5 Gy LDRT twice weekly for 4 weeks repeated once after 8 weeks in patients who failed to achieve complete pain relief. Patients assessed their pain according to the visual analog scale. Handgrip strength was measured with an isometric dynamometer and the fast self-paced walking test was used in patients with plantar fasciitis. QoL was evaluated according to the EQ-5D and HAQ-DI questionnaires. Results: Outcomes for 157 patients (204 sites) were documented at 2, 6, and 12 months after last LDRT. Pain reduction at rest (p < 0.001), during activity (p < 0.001) and increase in handgrip strength (extension p < 0.001, flexion p = 0.002) were highly significant for patients with lateral epicondylitis. Patients with medial epicondylitis reported pain relief at rest (p = 0.041) and during activity (p = 0.041) and significant increase in handgrip strength (p = 0.022). Patients with plantar fasciitis reported pain reduction at rest (p < 0.001), during activity (p < 0.001) and faster walking times (p < 0.001). A trend toward improved QoL was observed. Patients with finger osteoarthritis reported significant pain relief during activity (p < 0.001) and a gain in handgrip strength (p = 0.004), with a trend to both pain relief at rest (p = 0.056) and stronger pinch grip (p = 0.099). Conclusions: LDRT achieved significant pain relief at rest and during activity and a corresponding objective improvement in handgrip strength in patients with epicondylitis. Pain relief at rest, during activity and improvement in walking time were demonstrated in patients with plantar fasciitis. LDRT achieved pain relief during activity, and handgrip strength was improved in patients with finger osteoarthritis. No significant effect was seen on quality of life measures for these conditions. The observed benefits were maintained 12 months after LDRT for all 3 indications and we recommend this low cost, safe intervention for patients over 40 who have failed prior conservative therapy.

Comparative Genomics of Completely Sequenced Lactobacillus helveticus Genomes Provides Insights into Strain-Specific Genes and Resolves Metagenomics Data Down to the Strain Level.

Although complete genome sequences hold particular value for an accurate description of core genomes, the identification of strain-specific genes, and as the optimal basis for functional genomics studies, they are still largely underrepresented in public repositories. Based on an assessment of the genome assembly complexity for all lactobacilli, we used Pacific Biosciences' long read technology to sequence and de novo assemble the genomes of three Lactobacillus helveticus starter strains, raising the number of completely sequenced strains to 12. The first comparative genomics study for L. helveticus-to our knowledge-identified a core genome of 988 genes and sets of unique, strain-specific genes ranging from about 30 to more than 200 genes. Importantly, the comparison of MiSeq- and PacBio-based assemblies uncovered that not only accessory but also core genes can be missed in incomplete genome assemblies based on short reads. Analysis of the three genomes revealed that a large number of pseudogenes were enriched for functional Gene Ontology categories such as amino acid transmembrane transport and carbohydrate metabolism, which is in line with a reductive genome evolution in the rich natural habitat of L. helveticus. Notably, the functional Clusters of Orthologous Groups of proteins categories "cell wall/membrane biogenesis" and "defense mechanisms" were found to be enriched among the strain-specific genes. A genome mining effort uncovered examples where an experimentally observed phenotype could be linked to the underlying genotype, such as for cell envelope proteinase PrtH3 of strain FAM8627. Another possible link identified for peptidoglycan hydrolases will require further experiments. Of note, strain FAM22155 did not harbor a CRISPR/Cas system; its loss was also observed in other L. helveticus strains and lactobacillus species, thus questioning the value of the CRISPR/Cas system for diagnostic purposes. Importantly, the complete genome sequences proved to be very useful for the analysis of natural whey starter cultures with metagenomics, as a larger percentage of the sequenced reads of these complex mixtures could be unambiguously assigned down to the strain level.

Amplicon Sequencing of the slpH Locus Permits Culture-Independent Strain Typing of Lactobacillus helveticus in Dairy Products.

The advent of massive parallel sequencing technologies has opened up possibilities for the study of the bacterial diversity of ecosystems without the need for enrichment or single strain isolation. By exploiting 78 genome data-sets from Lactobacillus helveticus strains, we found that the slpH locus that encodes a putative surface layer protein displays sufficient genetic heterogeneity to be a suitable target for strain typing. Based on high-throughput slpH gene sequencing and the detection of single-base DNA sequence variations, we established a culture-independent method to assess the biodiversity of the L. helveticus strains present in fermented dairy food. When we applied the method to study the L. helveticus strain composition in 15 natural whey cultures (NWCs) that were collected at different Gruyère, a protected designation of origin (PDO) production facilities, we detected a total of 10 sequence types (STs). In addition, we monitored the development of a three-strain mix in raclette cheese for 17 weeks.

Chemokine-Like Receptor 1 mRNA Weakly Correlates with Non-Alcoholic Steatohepatitis Score in Male but Not Female Individuals.

The chemokine-like receptor 1 (CMKLR1) ligands resolvin E1 and chemerin are known to modulate inflammatory response. The progression of non-alcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH) is associated with inflammation. Here it was analyzed whether hepatic CMKLR1 expression is related to histological features of NASH. Therefore, CMKLR1 mRNA was quantified in liver tissue of 33 patients without NAFLD, 47 patients with borderline NASH and 38 patients with NASH. Hepatic CMKLR1 mRNA was not associated with gender and body mass index (BMI) in the controls and the whole study group. CMKLR1 expression was similar in controls and in patients with borderline NASH and NASH. In male patients weak positive correlations with inflammation, fibrosis and NASH score were identified. In females CMKLR1 was not associated with features of NAFLD. Liver CMKLR1 mRNA tended to be higher in type 2 diabetes patients of both genders and in hypercholesterolemic women. In summary, this study shows that hepatic CMKLR1 mRNA is weakly associated with features of NASH in male patients only.

Ceramide and polyunsaturated phospholipids are strongly reduced in human hepatocellular carcinoma.

Lipid composition affects membrane function, cell proliferation and cell death and is changed in cancer tissues. Hepatocellular carcinoma (HCC) is an aggressive cancer and this study aimed at a comprehensive characterization of hepatic and serum lipids in human HCC. Cholesteryl ester were higher in tumorous tissues (TT) compared to adjacent non-tumorous tissues (NT). Free cholesterol exerting cytotoxic effects was not changed. Phosphatidylethanolamine, -serine (PS) and -inositol but not phosphatidylcholine (PC) and lysophosphatidylcholine (LPC) were reduced in HCC tissues. Saturated species mostly increased and polyunsaturated species were diminished in all of these phospholipids. Ceramide (Cer) was markedly reduced in HCC tissues and higher levels of sphingomyelin suggest impaired sphingomyelinase activity as one of the underlying mechanisms. Importantly, ceramide in NT increased in HCC stage T3. Ceramide released from hepatocytes attracts immune cells and a positive association of the macrophage specific receptor CD163 with NT ceramide was identified. HCC associated lipid changes did not differ in patients suffering from type 2 diabetes. Protein levels of p53 were induced in TT and negatively correlated with Cer d18:1/16:0 and PS 36:1. Of the lipid species changed in HCC tissues only TT Cer d18:1/16:0, Cer d18:1/24:1, PC 38:6 and LPC 22:6 correlated with the respective serum levels. Our study demonstrates a considerably altered hepatic lipidome in HCC tissues. Ceramide was markedly reduced in HCC tissues, and therefore, raising ceramide levels specifically in the tumor represents a reasonable therapeutic approach for the treatment of this malignancy.

Circulating lipocalin 2 is neither related to liver steatosis in patients with non-alcoholic fatty liver disease nor to residual liver function in cirrhosis.

Lipocalin 2 (LCN2) is induced in the injured liver and associated with inflammation. Aim of the present study was to evaluate whether serum LCN2 is a non-invasive marker to assess hepatic steatosis in patients with non-alcoholic fatty liver disease (NAFLD) or residual liver function in patients with liver cirrhosis. Therefore, LCN2 was measured by ELISA in serum of 32 randomly selected patients without fatty liver (controls), 24 patients with ultrasound diagnosed NAFLD and 42 patients with liver cirrhosis mainly due to alcohol. Systemic LCN2 was comparable in patients with liver steatosis, those with liver cirrhosis and controls. LCN2 negatively correlated with bilirubin in both cohorts. In cirrhosis, LCN2 was not associated with more advanced liver injury defined by the CHILD-PUGH score and model for end-stage liver disease score. Resistin but not C-reactive protein or chemerin positively correlated with LCN2. LCN2 levels were not increased in patients with ascites or patients with esophageal varices. Consequently, reduction of portal pressure by transjugular intrahepatic portosystemic shunt did not affect LCN2 levels. Hepatic venous blood (HVS), portal venous blood and systemic venous blood levels of LCN2 were similar. HVS LCN2 was unchanged in patients with end-stage liver cirrhosis compared to those with well-compensated disease arguing against increased hepatic release. Current data exclude that serum LCN2 is of any value as steatosis marker in patients with NAFLD and indicator of liver function in patients with alcoholic liver cirrhosis.

The adaptor protein alpha-syntrophin regulates adipocyte lipid droplet growth.

The scaffold protein alpha-syntrophin (SNTA) regulates lipolysis indicating a role in lipid homeostasis. Adipocytes are the main lipid storage cells in the body, and here, the function of SNTA has been analyzed in 3T3-L1 cells. SNTA is expressed in preadipocytes and is induced early during adipogenesis. Knock-down of SNTA in preadipocytes increases their proliferation. Proteins which are induced during adipogenesis like adiponectin and caveolin-1, and the inflammatory cytokine IL-6 are at normal levels in the mature cells differentiated from preadipocytes with low SNTA. This suggests that SNTA does neither affect differentiation nor inflammation. Expression of proteins with a role in cholesterol and triglyceride homeostasis is unchanged. Consequently, basal and epinephrine induced lipolysis as well as insulin stimulated phosphorylation of Akt and ERK1/2 are normal. Importantly, adipocytes with low SNTA form smaller lipid droplets and store less triglycerides. Stearoyl-CoA reductase and MnSOD are reduced upon SNTA knock-down but do not contribute to lower lipid levels. Oleate uptake is even increased in cells with SNTA knock-down. In summary, current data show that SNTA is involved in the expansion of lipid droplets independent of adipogenesis. Enhanced preadipocyte proliferation and capacity to store surplus fatty acids may protect adipocytes with low SNTA from lipotoxicity in obesity.

Annexin A6 protein is downregulated in human hepatocellular carcinoma.

Annexin A6 (AnxA6) is a lipid-binding protein highly expressed in the liver, regulating cholesterol homeostasis and signaling pathways with a role in liver physiology. Here, we analyzed whether hepatic AnxA6 levels are affected by pathological conditions that are associated with liver dysfunction and liver injury. AnxA6 levels in the fatty liver of mice fed a high-fat diet, in ob/ob and db/db animals and in human fatty liver are comparable to controls. Similarly, AnxA6 levels appear unaffected in murine nonalcoholic steatohepatitis and human liver fibrosis. Accordingly, adiponectin, lysophosphatidylcholine, palmitate, and TGFbeta, all of which have a role in liver injury, do not affect AnxA6 expression in human hepatocytes. Likewise, adiponectin and IL8 do not alter AnxA6 levels in primary human hepatic stellate cells. However, in hepatic tumors of 18 patients, AnxA6 protein levels are substantially reduced compared to nontumorous tissues. AnxA6 mRNA is even increased in the tumors suggesting that posttranscriptional mechanisms are involved herein. Lipidomic analysis shows trends toward elevated cholesteryl ester and sphingomyelin in the tumor samples, yet the ratio of tumor to nontumorous AnxA6 does not correlate with these lipids. The current study shows that AnxA6 is specifically reduced in human hepatocellular carcinoma suggesting a role of this protein in hepatocarcinogenesis.

Hepatic scavenger receptor BI is associated with type 2 diabetes but unrelated to human and murine non-alcoholic fatty liver disease.

Scavenger receptor, class B type I (SR-BI) is a physiologically relevant regulator of high density lipoprotein (HDL) metabolism. Low HDL is a common feature of patients with non-alcoholic fatty liver disease (NAFLD). Here, hepatic SR-BI expression was analyzed in human and murine NAFLD. In primary human hepatocytes NAFLD relevant factors like inflammatory cytokines, lipopolysaccharide and TGF-ß did not affect SR-BI protein. Similarly, oleate and palmitate had no effect. The adipokines chemerin, adiponectin, leptin and omentin did not regulate SR-BI expression. Accordingly, hepatic SR-BI was not changed in human and murine fatty liver and non-alcoholic steatohepatits. SR-BI was higher in type 2 diabetes patients but not in those with hypercholesterolemia. The current study indicates a minor if any role of SR-BI in human and murine NAFLD.

Resolvin E1 and chemerin C15 peptide do not improve rodent non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is a progressive liver disease more commonly diagnosed in obesity. Therapeutic options to treat NASH are limited. Liver inflammation is a hallmark of NASH, and here it was tested whether the lipid mediator resolvin E1 (RvE1) and chemerin derived C15 peptide, which both exert potent anti-inflammatory activities, ameliorate NASH pathology. Male mice fed an atherogenic diet for 12 weeks, well described to induce NASH, received intraperitoneal injections of RvE1, C15 peptide or PBS as control for four days. Both treatments did not affect body weight or serum ALT. Liver triglycerides were neither reduced by the lipid nor the peptide. Hepatic expression of the macrophage marker F4/80 and the inflammatory mediators TNF and CCL2 was not changed. Further, fibrotic genes including TGFbeta, alphaSMA and CTGF were not affected by RvE1 or C15 injections. Serum adiponectin was comparable in the three groups. RvE1 and C15 are ligands of CMKLR1 whose expression was not reduced upon feeding the NASH inducing diet. This excludes low receptor levels as reason for therapeutic failure. In summary, current data demonstrate that RvE1 and chemerin derived C15 peptide do not ameliorate murine NASH.

Lipid abnormalities in alpha/beta2-syntrophin null mice are independent from ABCA1.

The syntrophins alpha (SNTA) and beta 2 (SNTB2) are molecular adaptor proteins shown to stabilize ABCA1, an essential regulator of HDL cholesterol. Furthermore, SNTB2 is involved in glucose stimulated insulin release. Hyperglycemia and dyslipidemia are characteristic features of the metabolic syndrome, a serious public health problem with rising prevalence. Therefore, it is important to understand the role of the syntrophins herein. Mice deficient for both syntrophins (SNTA/B2-/-) have normal insulin and glucose tolerance, hepatic ABCA1 protein and cholesterol. When challenged with a HFD, wild type and SNTA/B2-/- mice have similar weight gain, adiposity, serum and liver triglycerides. Hepatic ABCA1, serum insulin and insulin sensitivity are normal while glucose tolerance is impaired. Liver cholesterol is reduced, and expression of SREBP2 and HMG-CoA-R is increased in the knockout mice. Scavenger receptor-BI (SR-BI) protein is strongly diminished in the liver of SNTA/B2-/- mice while SR-BI binding protein NHERF1 is not changed and PDZK1 is even induced. Knock-down of SNTA, SNTB2 or both has no effect on hepatocyte SR-BI and PDZK1 proteins. Further, SR-BI levels are not reduced in brown adipose tissue of SNTA/B2-/- mice excluding that syntrophins directly stabilize SR-BI. SR-BI stability is regulated by MAPK and phosphorylated ERK2 is induced in the liver of the knock-out mice. Blockage of ERK activity upregulates hepatocyte SR-BI showing that increased MAPK activity contributes to low SR-BI. Sphingomyelin which is well described to regulate cholesterol metabolism is reduced in the liver and serum of the knock-out mice while the size of serum lipoproteins is not affected. Current data exclude a major function of these syntrophins in ABCA1 activity and insulin release but suggest a role in regulating glucose uptake, ERK and SR-BI levels, and sphingomyelin metabolism in obesity.

Prevalence of antibiotic resistance in coagulase-negative staphylococci from spontaneously fermented meat products and safety assessment for new starters.

To provide new meat starter strains lacking antibiotic (AB) resistances, we explored the AB susceptibility in 116 coagulase-negative Staphylococcus (CNS) isolates from traditionally fermented sausages (n=40) manufactured with meat from conventional animal breeding, and from meat products (n=76) made from meat of animals raised in natural habitats under low- or no-antibiotic pressure. Less than 50% of these CNS isolates showed phenotypic resistances to at least one antibiotic (AB) by using microdilution assay. Resistances to penicillins and tetracycline were most often observed and could be traced back to blaZ and tet(K) genes. Prevalence of AB resistances was species-dependent and mainly found in isolates of Staphylococcus warneri (78%), Staphylococcus capitis (75%) and Staphylococcus epidermidis (67%), but only sporadically detected in Staphylococcus carnosus (27%) and Staphylococcus equorum (18%). AB resistances were more often observed in S. xylosus isolates originating from natural habitats compared to traditionally fermented sausages made from conventional meat. A selection of 101 isolates belonging to S. xylosus (n=63), S. carnosus (n=21) and S. equorum (n=17) were subsequently grouped by pulsed-field gel electrophoresis (PFGE) into strain clusters. No S. carnosus and only five S. xylosus strains were lacking AB resistances and exhibited a PFGE genotype different from commercial starters. These strains, together with 17 S. equorum strains, were further studied for safety and technological characteristics. The ability to produce biogenic amines was not detected in any strain. PCR amplifications for enterotoxin encoding genes seg-sej were detected in one, and for δ-hemolysin encoding gene hld in four S. equorum strains, but phenotypic hemolytic activity was visible for three S. xylosus and 15 S. equorum strains. Catalase and nitrate reductase activity was observed in all isolates tested; particularly S. equorum showed high nitrate reduction. In conclusion, we were able to select four new meat starter strains (two S. xylosus and two S. equorum strains) out of 116 investigated CNS, fulfilling all safety criteria including the absence of AB resistances, production of biogenic amines and genes encoding virulence factors but exhibiting high nitrate reductase and catalase activity as suitable technological characteristics. Thus, S. equorum isolates, often the dominant species in spontaneously fermented meat products, provided a prospective meat starter species exhibiting high nitrate reduction and low prevalence of AB resistances.

Identification of staphylococci and dominant lactic acid bacteria in spontaneously fermented Swiss meat products using PCR-RFLP.

Pathogenic, spoilage, and technologically important microorganisms were monitored in 21 spontaneously fermented Swiss meat products manufactured with meat from wildlife or animals grown in natural habitat. Thereby, PCR-restriction fragment length polymorphism (RFLP) on rpoB and 16S rRNA gene sequences provided a powerful tool for fast and accurate identification of the main microbial population. Lactobacillus sakei and Lactobacillus curvatus dominated in fermented meat products followed by Staphylococcus species, which constituted 88.2% of all Gram-positive, catalase-positive cocci (GCC(+)) with cell counts varying from 2.6 to 7.0 log cfu/g during maturation. Staphylococcus equorum was prevalent in frequency and cell counts during maturation (18.0%; 5.0-7.3 log cfu/g) and in the end products (28.4%; 1.8-6.2 log cfu/g) implicating a new presumptive starter species for meat fermentation. Nine out of 14 end products indicated safety risks to consumers due to the high incidence of Staphylococcus saprophyticus or Staphylococcus epidermidis combined with cell counts of 7.4 and 4.9 log cfu/g, respectively. This fact was supported by the detection of Staphylococcus aureus and Enterobacteriaceae in ready-to-eat products strongly exceeding the tolerable limit of 2 log cfu/g. Spontaneously fermented meat products produced from wildlife or animals grown in natural habitats not only gave rise to hygienic and safety concerns but also provided new presumptive starter strains.

Facultative anaerobic halophilic and alkaliphilic bacteria isolated from a natural smear ecosystem inhibit Listeria growth in early ripening stages.

In vitro and in situ anti-listerial properties of 3 strains of Facultative Anaerobic Halophilic and Alkaliphilic (FAHA) species, i.e. Alkalibacterium kapii ALK 6, Marinilactibacillus psychrotolerans ALK 9 and Facklamia tabacinasalis ALK 1, were investigated. The 3 strains were isolated from a smear ecosystem originating from a commercial Raclette type cheese and exhibiting strong anti-listerial activity in situ on cheese surface. In a first step, strains were tested in vitro for production of antimicrobial compounds against Listeria innocua 81000-1 and Listeria ivanovii HPB 28. M. psychrotolerans ALK 9 inhibited both indicator strains in spot-on-the-lawn tests while A. kapii ALK 6 showed no inhibiting effect. F. tabacinasalis ALK 1 exerted an in vitro inhibition on L. ivanovii HPB 28, but induced the formation of dense ball-shaped microcolonies of L. innocua 81000-1 in the soft agar, a typical biofilm microstructure. The extent of the biofilm zone was enhanced when F. tabacinasalis ALK 1 and M. psychrotolerans ALK 9 were tested together. In a second step, different combinations of strains were applied on Raclette cheeses ripened at pilot scale and contaminated with 50 cfu/cm(2)L. innocua at day 7. A control flora of 6 strains, isolated from ecosystem F and corresponding to species commonly found on smear cheeses, was applied on control and test cheeses. In test cheeses, we investigated the impact on Listeria growth of the addition of the 3 FAHA strains, applied as single or mixed cultures. A 1-log inhibition was obtained at day 15 on cheeses treated with FAHA strains applied either as single or mixed cultures. This 1-log inhibition was correlated with the development of FAHA species that reached their maximal count at day 15. This study suggests that the development of FAHA species in early ripening likely contributes to the initial part of the in situ inhibition exerted by the complex cheese surface ecosystem investigated.

Population dynamics of two antilisterial cheese surface consortia revealed by temporal temperature gradient gel electrophoresis.

BACKGROUND: Surface contamination of smear cheese by Listeria spp. is of major concern for the industry. Complex smear ecosystems have been shown to harbor antilisterial potential but the microorganisms and mechanisms involved in the inhibition mostly remain unclear, and are likely related to complex interactions than to production of single antimicrobial compounds. Bacterial biodiversity and population dynamics of complex smear ecosystems exhibiting antilisterial properties in situ were investigated by Temporal temperature gradient gel electrophoresis (TTGE), a culture independent technique, for two microbial consortia isolated from commercial Raclette type cheeses inoculated with defined commercial ripening cultures (F) or produced with an old-young smearing process (M). RESULTS: TTGE revealed nine bacterial species common to both F and M consortia, but consortium F exhibited a higher diversity than consortium M, with thirteen and ten species, respectively. Population dynamics were studied after application of the consortia on fresh-produced Raclette cheeses. TTGE analyses revealed a similar sequential development of the nine species common to both consortia. Beside common cheese surface bacteria (Staphylococcus equorum, Corynebacterium spp., Brevibacterium linens, Microbacterium gubbeenense, Agrococcus casei), the two consortia contained marine lactic acid bacteria (Alkalibacterium kapii, Marinilactibacillus psychrotolerans) that developed early in ripening (day 14 to 20), shortly after the growth of staphylococci (day 7). A decrease of Listeria counts was observed on cheese surface inoculated at day 7 with 0.1-1 x 10(2) CFU cm(-2), when cheeses were smeared with consortium F or M. Listeria counts went below the detection limit of the method between day 14 and 28 and no subsequent regrowth was detected over 60 to 80 ripening days. In contrast, Listeria grew to high counts (10(5) CFU cm(-2) on cheeses smeared with a defined surface culture. CONCLUSIONS: This work reports the first population dynamics study of complex smear ecosystems exhibiting in situ antilisterial activity. TTGE revealed the presence of marine lactic acid bacteria that are likely related to the strong Listeria inhibition, as their early development in the smear occurred simultaneously with a decrease in Listeria cell count.

Osmotic stress induced by salt increases cell yield, autolytic activity, and survival of lyophilization of Lactobacillus delbrueckii subsp. lactis.

Growth and stress adaptation of an autolytic strain of Lactobacillus delbrueckii subsp. lactis FAM-10991 was studied during pH-controlled batch fermentations. After an initial growth to an optical density at 650 nm of 0.8 under controlled optimal growth conditions (pH 5.5, 37 degrees C, no salt), exponentially growing cells were exposed to salt at concentrations from 1 to 3.5%, and temperatures between 48 and 53.5 degrees C, without pH control or with pH controlled at 5.5 or 4.5. Autolysis was induced by salt concentrations of 2.5 or 3.5% and suppressed at 53.5 degrees C or pH 4.5. Salt at concentrations of 2.5 or 3.5% or a temperature of 53.5 degrees C, without pH control or with pH controlled at 5.5, significantly enhanced (p<0.05) survival of lyophilization as compared with the survival of cells in control cultures or cultures with salt at concentration of 1 and 1.5%. The former conditions increased survival by 125- and 200-fold, respectively. However, no correlation was found between autolytic activity and survival of lyophilization. Cultures grown with salt at 2.5% gave high yields of viable cells in broths before and after lyophilization, with numbers being 27-fold higher than with control cultures, but with autolytic activity that was 2.5-fold higher than in cells from control cultures.