Identification and Potential Biotechnological Characterization of Lactic Acid Bacteria Isolated from White Cheese Samples

In this study, the isolation of lactic acid bacteria was carried out from one hundred white cheese samples collected from different regions of Turkey. Subsequently, phenotypic and genotypic characterization of the isolates was performed. Biochemical characteristics of the isolates were determined by API 50CHL. Furthermore, the biotechnological enzyme production potential of the isolates was screened. Genomic fingerprint profiles of the test isolates were detected by using rep-PCR (BOX-PCR), which has been used successfully in the differentiation of microorganisms at the species, subspecies, and even strain levels. The results showed that a total of forty-one bacteria were isolated and seventeen of which are found to be different species. The isolates generally grew at 4-6 pH values, 0-8% NaCl and 30-40°C. Later, isolates thought to be different species were identified by 16S rRNA gene sequence analyses. According to 16S rRNA sequence results, MA56 showed a 96.41% similarity match to Lentilactobacillus buchneri, it is thought to be a new species. In addition, MA19, MA25, MA43, and MA47 were determined to have multi-enzyme production potential. MA43 has a plantaricin gene and it showed a high antagonistic effect on Escherichia coli O157:H7 ATCC 43888 and Pseudomonas aeruginosa ATCC 9027. Inhibition zones were measured at 19 mm and 16 mm respectively

A novel endo-beta-1,4-xylanase from Pediococcus acidilactici GC25; purification, characterization and application in clarification of fruit juices

GENC, BERNA/0000-0002-2790-9578; Adiguzel, Ahmet/0000-0001-8848-6647WOS: 000466621200059PubMed: 30753879A novel extracellular xylanase was purified and characterized from Pediococcus acidilactici GC25 (GenBank number: MF289522). the purification was 4.6-fold with a yield of 43.61% through acetone precipitation, Q-Sepharose, and CM-Sepharose ion change chromatography. the molecular weight of the enzyme was 48.15 kDa, and the optimum pH and temperature were 7.0 and 40 degrees C, respectively. the maximum activity was observed between 20 and 50 degrees C. Although it was active within a wide pH range (pH 2.0-9.0), it retained over 85% of its activity after 24 h incubation; and over 70% of its activity after 168 h incubation in neutral and alkaline pH. It was observed that the enzyme showed high stability with K+, Ba2+, Cd2+, Co2+, Sr2+, Mg2+, Ca2+, Al3+, Zn2+, and Ni2+ ions. the K-m and V-max for the xylanase were 3.10 mg mL(-1) and 4.66 U/mg protein, respectively. It was determined that treatment of different fruit juices with P. acidilactici GC25 xylanase improved the clarification. the highest increase in the reducing sugar amount and decrease in the turbidity was 24.47 +/- 1.08 and 21.22 +/- 0.58 for peach juice at 0.15 U/mL enzyme concentration. These results showed that the xylanase purified from P. acidilactici GC25 may have a wide potential in biotechnological processes of the food and baking industry. (C) 2019 Elsevier B.V. All rights reserved.Research Development Center of Ataturk UniversityAtaturk University [2015/54, FAD-2018-6352]; Ataturk University, TurkeyAtaturk UniversityThis research was conducted under the projects numbered 2015/54 and FAD-2018-6352 supported by the Research Development Center of Ataturk University. the authors acknowledged the support of Ataturk University, Turkey for this work

Bacteriocin Producing Bacteria Isolated from Turkish Traditional Sausage Samples

In this study, traditional sausage samples from different provinces of Turkey (Gaziantep, Antalya, Erzurum and Kahramanmaras) were obtained and one hundred three isolates were collected. Using the (GTG)5 -PCR genomic fingerprint analysis method, seven of them were observed to be different and conventional tests of these isolates were performed. Molecular identification of two isolates carrying the bacteriocin gene and having antimicrobial activity by agar disc diffusion method was performed by 16S rRNA sequence analysis. As a result, the seven isolates were identified as Aerococcus urinaeequi (EK1), Streptococcus salivarius (EK2), Leuconostoc mesenteroides (EK3), Macrococcus caseolyticus (EK4), Lactococcus garvieae (EK5), Staphylococcus saprophyticus (EK6) and Lactobacillus sakei (EK7). Among these strains, it has been determined that Ln. mesenteroides and L. sakei carried the mecentericin and sacacin genes. When antimicrobial activity against different strains was examined, inhibition formations of Ln. mesenteroides and L. sakei on Enterococcus faecalis, Shigella dysenteriae and Escherichia coli O157: H7 were observed