Microbial species playing roles for the production of traditional Kasar cheese during pre-maturation period

The microbial flora of traditional Kaşar cheese samples obtained from six dairy plants during pre-maturation period of Kaşar maturation was analysed. In total, 500 isolates of none-starter lactic acid bacteria (NSLAB) and 80 fungi isolates were isolated, and they were subjected to molecular discrimination by RAPD-PCR and rep-PCR analysis. Genotypic characterization of these isolates revealed the presence of 45 distinct strains belonging to 13 different NSLAB species with Lactobacillus paracasei as the dominant species. A rich yeast microflora in Kaşar samples was also observed with the presence of 19 distinct strains belonging to 8 different species with Pichia kudriavzevii as the dominant species. During this period, only two Penicillium species were found in Kaşar samples. This study confirmed the biodiversity of NSLAB and fungi microflora of Kaşar cheese during pre-maturation period, and these results are important for the development of starter cultures for Kaşar production at industrial level. © 201

EpsA is an essential gene in exopolysaccharide production in Lactobacillus johnsonii FI9785

Lactobacillus johnsonii FI9785 has an eps gene cluster which is required for the biosynthesis of homopolymeric exopolysaccharides (EPS)-1 and heteropolymeric EPS-2 as a capsular layer. The first gene of the cluster, epsA, is the putative transcriptional regulator. In this study we showed the crucial role of epsA in EPS biosynthesis by demonstrating that deletion of epsA resulted in complete loss of both EPS-1 and EPS-2 on the cell surface. Plasmid complementation of the epsA gene fully restored EPS production, as confirmed by transmission electron microscopy and nuclear magnetic resonance (NMR) analysis. Furthermore, this complementation resulted in a twofold increase in the expression levels of this gene, which almost doubled amounts of EPS production in comparison with the wild-type strain. Analysis of EPS by NMR showed an increased ratio of the heteropolysaccharide to homopolysaccharide in the complemented strain and allowed identification of the acetylated residue in EPS-2 as the (1,4)-linked ?Glcp unit, with the acetyl group located at O-6. These findings indicate that epsA is a positive regulator of EPS production and that EPS production can be manipulated by altering its expression. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology

Optimization of pectin extraction from orange pulp and characterization of compositional and steady shear properties [Portakal posasından modifiye pektin eldesi ve optimizasyonu, kompozisyonel ve yatışkan faz özelliklerinin karakterizasyonu]

Pectin, which is one of the most important wastes of fruit juice industry, was extracted from orange pulp at optimum conditions (pH, time and temperature) and modified using pectinase. The effect of modification on the structural properties of pectin was monitored using Fourier transformed infrared spectroscopy (FTIR) and high performance liquid chromatography (HPLC) analyses. The bands at 1600-1800 cm-1 which indicate the specific region and quality of pectin were detected using FTIR while galacturonic acid content was determined using HPLC. The results showed that the galacturonic acid content of pectin from orange pulp was determined to be 406.44 mg/g powder pectin while that of the modified pectin from the orange pulp was determined to be 465,34 mg/g powder pectin. In addition, flow properties of the pectin samples were determined using rheological analysis. The viscosity and viscoelastic properties of the modified pectin samples were revealed to be different from those of non-modified pectin samples. The consistency index values of unmodified and modified pectin samples were determined to be 0.0559 Pa.sn and 0.0046 Pa.sn, respectively. © 2017 Namik Kemal University - Agricultural Faculty. All Rights Reserved

A novel antifungal surface-coating application to limit postharvest decay on coated apples: Molecular, thermal and morphological properties of electrospun zein–nanofiber mats loaded with curcumin

Coating surfaces of fruit with electrospun zein mats with functionalized antimicrobial properties can be a novel strategy to prevent fungal colonization on fruit surfaces. In this study, we tested curcumin-loaded electrospun zein nanofibers (CLZN) in terms of limitation of postharvest decay on CLZN–coated apples infected with Botrytis cinerea and Penicillium expansum. Mixtures of zein and curcumin (the curcumin amounts of 2.5 and 5 wt% based on the weight of zein powder) were electrospun to yield cylindrical and ultrafine (< 350 nm in diameter) polymeric nanofibers. In addition, molecular, thermal, zeta potential and morphological properties of the CLZN as well as their encapsulation efficiency and releasing kinetics were determined, revealing that the developed zein-based scaffolds showed high encapsulation efficiency, molecular interactions with curcumin within nanofibers, alterations in physical states of these components, smooth beadless structure and good thermal (an endothermic peak at 152 °C) and dispersion stability (? 24 mV of ? potential) properties. In vitro antifungal activity tests conducted at 27 °C for six days showed that CLZN were effective against growth of the tested fungal pathogens, exhibiting almost 40–50% inhibition of mycelial growth of the fungal pathogens; but the antifungal effect against P. expansum was but two-fold higher than that against B. cinerea. In vivo tests conducted at 23 °C with 75% humidity for six days confirmed in vitro test results in terms of both visual inspections on uncoated and coated apples, revealing almost 50% reduction in lesion diameter measured on coated apples infected with Penicillium expansum. Our results suggest that CLZN mats open up new opportunities for a novel application of edible and biodegradable antifungal coating material with the ability to hinder fungal proliferation on coated apples during storage period. Industrial relevance We coated the surfaces of fruits with electrospun mats with functionalized antimicrobial properties to prevent fungal colonization on fruit surface. The coating of apples with curcumin-loaded zein nanoparticles (CLZNs) limited the postharvest decay caused by the fungal pathogens, Penicillium expansum and Botrytis cinerea. This study showed that by encapsulation of curcumin into zein-based nanofibers considerably increased the antifungal effectiveness of curcumin. Our results highlighted the potential use of the CLZN as an effective fungicidal coating material against P. expansum and B. cinerea and suggested that CLZNs can be promising tools to compete with synthetic fungicide counterparts of curcumin. The results of this study should be of great importance to industrial applications in terms of development of natural, but effective preservatives as alternative to synthetic ones. © 2016 Elsevier Lt

Effects of Lactobacillus Reuteri E81 Added into Rations of Chukar Partridges (Alectoris Chukar) Fed Under Heat Stress Conditions on Fattening Performance and Meat Quality

BAYRAKTAR, BULENT/0000-0002-2335-9089; Kaya, Hacer/0000-0001-9024-8525; GUL, MEHMET/0000-0001-5477-1773; kamiloglu, aybike/0000-0002-6756-0331; TEKCE, EMRE/0000-0002-6690-725XWOS: 000569515700011This study investigated the effects of the addition of Lactobacillus reuteri E81 (LRE) into rations of chukar partridges (Alectoris chukar) fed under heat stress (HS) conditions on fattening performance and meat quality. This study included 256 chukar partridges aged 1 day. the study comprised an adaptation period of 7 days and a fattening period of 35 days and included 8 different groups with 32 animals in each group. Each group was further divided into four subgroups with eight animals in each subgroup. At the end of the study, the best results in terms of fattening performance in the non-HS groups were obtained in the LRE 600 ppm group and in the HS groups, SLRE 200 ppm had the best effect on average live weight and average live weight increase, whereas SLRE 400 ppm had the best effect on FCR (p<0.05). the analysis of the samples collected from chukar partridges on day 21 showed that, there was no effect on the colour parameters and Thiobarbituric acid reactive substances (TBARS) level in the LRE in the HS and non-HS groups, whereas the meat pH level decreased in the SLRE 400 ppm group (p<0.05). the analysis of the samples collected on day 42 showed that there was no effect on colour parameters in the HS and non-HS groups. TBARS level decreased at the dose of LRE 200 ppm in the non-HS group, and the meat pH level decreased in both HS and non-HS groups (p<0.05).scientific research projects commission of Bayburt University, Bayburt, Turkey [2018/02-69001-02]This study was conducted pursuant to the approval (dated 12.11.2019 and numbered 2019/15) of the Local Ethics Board for Animal Experiments of Directorate of Veterinary Control Center Research Institute. This study was funded and supported by the scientific research projects commission of Bayburt University, Bayburt, Turkey (Project code: 2018/02-69001-02). the authors declare that they have no conflict of interest