Functional implications of the microbial community structure of undefined mesophilic starter cultures

This review describes the recent advances made in the studies of the microbial community of complex and undefined cheese starter cultures. We report on work related to the composition of the cultures at the level of genetic lineages, on the presence and activity of bacteriophages and on the population dynamics during cheese making and during starter culture propagation. Furthermore, the link between starter composition and starter functionality will be discussed. Finally, recent advances in predictive metabolic modelling of the multi-strain cultures will be discussed in the context of microbe-microbe interactions

Community dynamics of complex starter cultures for Gouda-type cheeses and its functional consequences

Lactic acid bacteria (LAB) are used as starter and adjunct cultures for the production of artisanal and industrial fermented milk products such as yoghurt and cheese. Artisanal fermentations is propagated with the transfer of an inoculum from old batch of fermented food to the new batch (back-slopping) to initiate the fermentation with the activity of the indigenous microbiota present in the inoculum. In industrial production, these inocula with indigenous microbiota are replaced with the starter cultures that contain lower numbers of LAB species for better controlled fermentation process and consistent final product quality. Cheese manufacturing is still performed in both artisanal ways and with the use of starter cultures. Gouda cheese starter cultures constitute several strains from the subspecies of Lactococcus lactisand Leuconostocs mesenteroidesin different combinations. The mixed and undefined type of starter culture may harbour variable number of strains that contribute unique functionalities to the cheese manufacturing process. Therefore, understanding, controlling and predicting the cheese manufacturing processes require the determination of strain level diversity in the starter culture, their collective and specific metabolic complement, and their activity throughout the cheese manufacturing process, including the interactions between the strains. The first two studies that are covered in this thesis describes the development of a high resolution AFLP fingerprinting tool allowing the discrimination of closely related strains in the starter culture and the subsequent analysis of the microbial community of Gouda cheese starter with this implemented technique and with metagenomics. Furthermore, the thesis includes the development of another tool to selectively amplify DNA only from live fraction of the microbial community in cheese using propidium monoazide (PMA), which is required to study community dynamics with culture independent approaches. The last study in the thesis describes the effects of the variation in propagation regime on the community composition of a mixed starter culture and connects the composition change to the functionalities that impact on flavour development during cheese manufacturing. Overall, the approaches presented in this thesis are intended to eventually enable accurate prediction and control of the cheese manufacturing process using (un)defined starter cultures, but may also allow rational design and development of new starter cultures.</p

in rats

The aim of this study was to investigate the efficacy of ibuprofen on the healing of esophagus and the prevention of stricture development after esophageal caustic injuries in rats.Rats were divided into three groups as: group 1(sham), group 2(esophageal burn injury), group 3(injury + ibuprofen). In groups 2 and 3, a standard esophageal burn injury was created by applying 10% NaOH solution to distal esophagus of about 3 cm. To rats in the sham group, isotonic solution was given instead of NaOH. Ibuprofen (90 mg/kg/day) was given via oral route to group 3 rats. Normal saline as placebo was given via the same route to rats in groups 1 and 2. 28 days later, all the live rats were killed. The distal esophageal segments of all rats were removed and divided into two equal parts for biochemical and histopathologic examination. In the tissue samples, biochemically hydroxyproline and histopathologically collagen content and stenosis indices were evaluated for efficacy of treatment.The hydroxyproline level (mu g/mg wet tissue) in the groups was 1.54 +/- A 0.08, 4.82 +/- A 0.60, and 3.28 +/- A 0.27, respectively. The hydroxyproline level increased significantly in group 2 compared with group 1 (P < 0.01). Although the hydroxyproline level was significantly increased in group 3 compared with group 1, it decreased significantly in group 3 compared with group 2 (P < 0.05) by treatment of ibuprofen. In group 3, the collagen content score (1.50 +/- A 0.26) was significantly lower than in group 2 (2.62 +/- A 0.37) (P < 0.05). The stenosis index was found as 0.37 +/- A 0.02 in group 1, 0.84 +/- A 0.02 in group 2, and 0.67 +/- A 0.03 in group 3. The stenosis index in group 2 was significantly higher than group 1 and group 3 (P < 0.01). Although the stenosis index was significantly higher than in group 1, a significant decrease in stenosis index was found in group 3 compared with group 2, by ibuprofen treatment (P < 0.01).Based on these results, we concluded that the treatment with ibuprofen in acute phase esophageal burn injury has beneficial effects on healing of esophagus and may decrease the stricture formation. For these reasons, ibuprofen may effectively be used in the acute phase treatment of caustic esophagus injury and after esophageal dilatation procedures

Intra- and inter-observer reliability of Laredo classification system in Legg–Calvé–Perthes Disease

PubMed ID: 30788596The purpose of the current study was to investigate intra- and inter-observer reliability of arthrographic Laredo classification system in Perthes disease. Forty-seven patients were included in this cross-sectional descriptive study. Patients’ age, gender, physical findings and hip arthrographs were collected from hospital medical records. Two different sets of power point slides were prepared in which the order of cases was randomized and blinded. Observers were divided into three groups according to their surgical experience (9 residents, 10 seniors, 10 pediatric orthopedists), and they assessed two times 1 month’s intervals. Statistical analysis was performed by using the SPSS v21. Inter- and intra-observer reliabilities were calculated using intra-class correlation coefficient, weighted kappa and percentage agreement. Percentage agreement of Laredo classification was about 50% for all groups (residents, seniors and pediatric orthopedists); intra-observer reliabilities were excellent, excellent and fair, respectively. Inter-observer reliability of Laredo classification for each set was found to be excellent for all groups. Length of experience did not correlated significantly with the level of intra-observer agreement. As a conclusion, our results showed that Laredo’s arthrographic classification system’s intra-observer reliability is at least at a fair level and inter-observer reliability is at an excellent level. We believe that this classification system is valuable for an orthopedic surgeon who deals with the treatment of Perthes disease. © 2019, Springer-Verlag France SAS, part of Springer Nature

Protective effect of pentoxifyllin on alcohol induced gastric mucosal damage in rats: Relation with prostoglandin and nitric oxide

Pentoxifylline (PTX) has been shown to increase tissue oxygen tension and improve tissue oxygen delivery. Early microcirculatory stasis is a major factor in gastric mucosal injury induced by ethanol in rats, PTX a methyl xanthine derivate prevents microcirculatory stasis and protects tissue by reducing tumour necrosis factor (TNF-α). This study investigated whether ptx induced protection involves nitric oxide mediated pathways or endogenous prostaglandins (PGs') production. Fifty-eight Swiss-Albino rats were divided into six groups and 2 ml of ethanol 98% was administered orogastrically to induce gastric mucosal injury. The animals were killed 30 minutes after gastric injury by cervical dislocation. In all groups, gastric mucosal injury was evaluated/measured by macroscopic and microscopic methods and glutathion ratio (GSH/GSSG) and malondialdehyde (MDA) levels in gastric tissue. One hour prior to ethanol administration the following were also administered Group 1: serum physiologic (SF) intraperitoneally (ip) 1 ml, Group 2:100 mg/kg PTX ip, Group 3:100 mg/kg PTX ip one hour following 1 ml SF subcutan (sc), Group 4: 100 mg/kg PTX ip one hour following 5 mg/kg indomethacin sc, Group 5: 100 mg/kg PTX ip one hour following 1 ml SF ip, Group 6:100 mg/kg PTX ip one hour after 60 mg/kg L-NAME (Nitric oxide synthesis inhibitor) ip subcutaneously. Results: PTX pretreatment prior to ethanol administration significantly reduced macroscopic and microscopic scores of gastric mucosal injury (10.6 ± 3.7 mm versus 27.5 ± 19.5, 0.88 ± 0.60 versus 1.87 ± 0.83, p < 0.05) respectively. PTX pretreatment also reduced MDA levels in gastric tissue 351.1 ± 94.0 versus 624.3 ± 234 mmol/gwettissue, (p < 0.01) but did not effect GSH/GSSG ratio. The experimental results of inhibition of endogenous PGs' synthesis was not affected by indomethacin, but administration of L-NAME significantly increased the gastric mucosal injury. Conclusion: PTX prevents ethanol induced gastric mucosal injury in rats. This effect is not related to the synthesis of prostaglandins, but does seem to be related to nitric oxide mediated pathways

Leuconostoc mesenteroides subsp. cremoris TIFN8 Genome sequencing and assembly

Leuconostoc mesenteroides subsp. cremoris isolated from a natural starter culture used in cheese manufacturing

Lactococcus cremoris subsp. cremoris TIFN6 Genome sequencing and assembly

Lactococcus lactis subsp. cremoris isolated from a natural starter culture used in cheese manufacturing