• Title/Summary/Keyword: Microbial stability

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Physicochemical and Microbiological Characterization of Protected Designation of Origin Ezine Cheese: Assessment of Non-starter Lactic Acid Bacterial Diversity with Antimicrobial Activity

  • Uymaz, Basar;Akcelik, Nefise;Yuksel, Zerrin
    • Food Science of Animal Resources
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    • v.39 no.5
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    • pp.804-819
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    • 2019
  • Ezine cheese is a non-starter and long-ripened cheese produced in the Mount of Ida region of Canakkale, Turkey, with a protected designation of origin status. Non-starter lactic acid bacteria (NSLAB) have a substantial effect on the quality and final sensorial characteristics of long-ripened cheeses. The dominance of NSLAB can be attributed to their high tolerance to the hostile environment in cheese during ripening relative to many other microbial groups and to its ability to inhibit undesired microorganisms. These qualities promote the microbiological stability of long-ripened cheeses. In this study, 144 samples were collected from three dairies during the ripening period of Ezine cheese. Physicochemical composition and NSLAB identification analyses were performed using both conventional and molecular methods. According to the results of a 16S rRNA gene sequence analysis, 13 different species belonging to seven genera were identified. Enterococcus faecium (38.42%) and E. faecalis (18.94%) were dominant species during the cheese manufacturing process, surviving 12 months of ripening together with Lactobacillus paracasei (13.68%) and Lb. plantarum (11.05%). The results indicate that NSLAB contributes to the microbiological stability of Ezine cheese over 12 months of ripening. The isolation of NSLAB with antimicrobial activity, potential bacteriocin producers, yielded defined collections of natural NSLAB isolates from Ezine cheese that can be used to generate specific starter cultures for the production of Ezine cheese (PDO).

Antimicrobial Characteristic of Methanolic Extracts from Prunus mune Byproducts Against Food Spoilage Microorganisms (매실박 메탄올 추출물의 항균 특성)

  • Ha, Myung-Hee;Park, Woo-Po;Lee, Seung-Cheol;Heo, Ho-Jin;Cho, Sung-Hwan
    • Food Science and Preservation
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    • v.14 no.2
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    • pp.183-187
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    • 2007
  • The antimicrobial properties of methanolic extract (PML) from Prunus nune byproducts after liquor manufacturing weremeasured using various putrefactive and food spoilage microorganisms. PML showed remarkable antimicrobial effects against various putrefactive and food spoliage microorganisms when used at 500g/mL. The antimicrobial properties were stable for 30 min at 100C and at pH 3 11. PML seems to be a natural antimicrobial agent with high effectiveness, and shows both thernal and pH stability. In addition, the mode of antimicrobial action suggests that the active components may synergistically perturb microbial membrane functions.

Photostability evaluation of Jawarishe Jalinoos

  • Shahnawaz, Shahnawaz;Rahman, Khaleequr;Sultana, Arshiya;Sultana, Shabiya
    • CELLMED
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    • v.11 no.4
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    • pp.18.1-18.8
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    • 2021
  • Jawarishe Jalinoos (JJ) is an orally used formulation available in semisolid dosage form, prepared with powdered plant materials mixed in honey or sugar syrup. It has many admirable pharmacological effects and used in Unani medicine to treat various acute and chronic disorders since ancient times. The ICH Harmonised Tripartite Guideline stated that photostability testing should be an essential part of stability testing to confirm that light exposure does not result in an unacceptable change in drugs substance and finished products. To date, the effect of light on JJ is not studied, in this study photostability evaluation of JJ was carried out. The test sample was manufactured with genuine ingredients in the in-door pharmacy of the National Institute of Unani Medicine. JJ was packed in two transparent polyethylene terephthalate airtight containers. The first sample was analysed at zero-day and the second sample was placed in a stability chamber subjected to light challenge with an overall illumination of 1.2 million lux hours combined with near ultraviolet energy of 200-watt hours per square meter by using option 2, along with 30±2℃ temperature and relative humidity 70±5%. Analysis of both finished products showed no considerable changes in organoleptic characters. Less than 5% variation was observed in physicochemical parameters. HPTLC fingerprinting showed justifiable variation. Microbial load and specific counts were within the limit prescribed by WHO. As no unacceptable changes were noted in JJ subjecting to light challenge, it is concluded that JJ is a photostable Unani compound formulation.

Identification of Distinct Vaginal Microbiota Signatures Contributing Toward Preterm Birth Using an Integrative Computational Approach

  • Sudeepti Kulshreshtha;Priyanka Narad;Brojen Singh;Deepak Modi;Abhishek Sengupta
    • Microbiology and Biotechnology Letters
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    • v.51 no.1
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    • pp.109-123
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    • 2023
  • Preterm birth (PTB) is defined as giving birth prior to the 37th week of pregnancy and is a major cause of infant mortality. Studies have indicated that the vaginal microbiota's composition and its dysbiosis, particularly during pregnancy, may play a major role in PTB. While previous research work concentrated on well-studied microorganisms such as Lactobacillus, Prevotella, Gardnerella, various other microbes, and their significance in the vaginal microbiota's stability remain unknown. Moreover, current studies have focused primarily on the relative abundances of the microbes found, without considering their interactions with other members of the vaginal microbiota. In this work, we developed a novel computational approach and performed taxonomic classification of vaginal microbiota samples stratified longitudinally (Term/PTB) to observe compositional disparities and find underexamined microbes that may be contributing to PTB. Furthermore, we carried out a correlational analysis to build a microbial co-interaction network and investigated the functional implications of the genes present in both Term and PTB samples. The co-occurrence network revealed that Lactobacillus acts in solidarity to maintain the stability of the vaginal microbiota and did not have strong co-interactions with any of the other microbes. Similarly, microbes with strong interactions with Atopobium, a well-known marker microbe of PTB, were also observed. Additionally, several genes such as PTXA, FANCM, GPX, and DUSP were found to be playing an important role in the occurrence of PTB. This study provides a novel conceptual framework revealing distinct vaginal microbiota signatures that could be potential therapeutic targets for the prevention of PTB.

Combined Effect of Gamma Irradiation and Silk Peptide on the Radio-sensitivity of Bacteria and Storage Stability of Ready-to-eat Hamburger Patty (감마선 조사와 실크 펩타이드 병용처리가 세균의 방사선 감수성 및 햄버거 패티의 저장 안정성에 미치는 영향)

  • Kim, Jae-Hun;Park, Jin-Gyu;Song, Beom-Seok;Lee, Ju-Woon;Kim, Wang-Geun;Hwang, Young-Jeong;Byun, Myung-Woo
    • Food Science and Preservation
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    • v.14 no.5
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    • pp.481-486
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    • 2007
  • This study was conducted to evaluate the combined effect of gamma irradiation and silk peptide on the radiosensitivity of bacteria and the storage stability of ready-to-eat hamburger patty. The $D_{10}$ values obtained for Escherichia coli, Listeria ivanovii, Salmonella typhimurium and Clostridium sporogenes by gamma irradiation were 0.25, 0.50, 0.55 and 1.35 kGy, respectively. The inactivation rate of S. typhimurium ($D_{10}=0.53kGy$) inoculated into hamburger patty with 5%(w/w) silk peptide was reduced 6% compared with the control $D_{10}=0.558kGy$). In acceleration storage at $30^{\circ}C$, microorganisms were not observed in samples irradiated with 7 kGy or 10 kGy during storage. However the irradiation at 5 kGy was insufficient to sterilize the contaminated microorganisms in hamburger patty regardless of the addition of silk peptide (5%). These results indicate that the combined treatment of gamma-irradiation and silk peptide admixture could be helpful to ensure storage stability of ready-to-eat hamburger patty, by controlling the preliminary microbial load.

Development of Encapsulated Media for Ammonia Removal (암모니아 가스 제거를 위한 포괄고정화 담체 개발)

  • Jeong, Mi-young;Namgung, Hyeong Kyu;Song, Ji Hyeon;Hwang, Sun-Jin
    • Journal of Korean Society on Water Environment
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    • v.25 no.2
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    • pp.306-310
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    • 2009
  • Packed-bed reactor for removing ammonia was tested at different loading rates. Nitrifiers for ammonia removing was encapsulated in gel media which consisted of polyethlene glycol, alginate and activated carbon. The removal efficiency was nearly 100% when ammonia loading was $12g/m^3/hr$, and the maximum elimination capacity (EC) achieved on this study was $18g/m^3/hr$. The initial microbial portion of nitrifiers in the media was about 82% and it was increased to more than 90% at the end of the operation. Short-term shock loading test was carried out to survey the stability of the media. The inlet loading rates were varied from 2 to $20g/m^3/hr$. The packed-bed reactor overcame the shock loading i.e. removal efficiency recovered rapidly from about 80% to almost 100% within 6 hrs. The results of Live/Dead cell test showed that nitrifiers maintained there activity in the encapsulated media during the test and also against ammonia shock load.

Formation of Flavone Di-O-Glucosides Using a Glycosyltransferase from Bacillus cereus

  • Ahn, Byoung-Chan;Kim, Bong-Gyu;Jeon, Young-Min;Lee, Eun-Jeong;Lim, Yoong-Ho;Ahn, Joong-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.19 no.4
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    • pp.387-390
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    • 2009
  • Microbial UDP-glycosyltransferases can convert many small lipophilic compounds into glycons using uridine-diphosphate-activated sugars. The glycosylation of flavonoids affects solubility, stability, and bioavailability. The gene encoding the UDP-glycosyltransferase from Bacillus cereus, BcGT-3, was cloned by PCR and sequenced. BcGT-3 was expressed in Escherichia coli BL21(DE3) with a glutathione S-transferase tag and purified using a glutathione S-transferase affinity column. BcGT-3 was tested for activity on several substrates including genistein, kaempferol, luteolin, naringenin, and quercetin. Flavonols were the best substrates for BcGT-3. The enzyme dominantly glycosylated the 3-hydroxyl group, but the 7-hydroxyl group was glycosylated when the 3-hydroxyl group was not available. The kaempferol reaction products were identified as kaempferol-3-O-glucoside and kaempferol-3,7-O-diglucoside. Kaempferol was the most effective substrate tested. Based on HPLC, LC/MS, and NMR analyses of the reaction products, we conclude that BcGT-3 can be used for the synthesis of kaempferol 3,7-O-diglucose.

Cloning, Purification, and Characterization of a Heterodimeric β-Galactosidase from Lactobacillus kefiranofaciens ZW3

  • He, Xi;Han, Ning;Wang, Yan-Ping
    • Journal of Microbiology and Biotechnology
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    • v.26 no.1
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    • pp.20-27
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    • 2016
  • Lactobacillus kefiranofaciens ZW3 was obtained from kefir grains, which have high lactose hydrolytic activity. In this study, a heterodimeric LacLM-type β-galactosidase gene (lacLM) from ZW3 was isolated, which was composed of two overlapping genes, lacL (1,884 bp) and lacM (960 bp) encoding large and small subunits with calculated molecular masses of 73,620 and 35,682 Da, respectively. LacLM, LacL, and LacM were expressed in Escherichia coli BL21(DE3) and these recombinant proteins were purified and characterized. The results showed that, compared with the recombinant holoenzyme, the recombinant large subunit exhibits obviously lower thermostability and hydrolytic activity. Moreover, the optimal temperature and pH of the holoenzyme and large subunit are 60℃ and 7.0, and 50℃ and 8.0, respectively. However, the recombinant small subunit alone has no activity. Interestingly, the activity and thermostability of the large subunit were greatly improved after mixing it with the recombinant small subunit. Therefore, the results suggest that the small subunit might play an important role in maintaining the stability of the structure of the catalytic center located in the large subunit.

Standardization and Cooking Properties of Spiced Soy Sauce (조림간장의 표준화와 조리특성)

  • 박승애;신미혜
    • Korean journal of food and cookery science
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    • v.14 no.1
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    • pp.97-105
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    • 1998
  • This study was carried out in order to standardize the processing method of spiced soy sauce, to get the sensory scores for organoleptic properties in different cooking of each food items, and to analyze the microbiological and chemical properties during storage periods. In determining the optimum conditions for standardizing of spiced soy sauce, the best sensory score was found in the ratio of soy sauce to sugar of 1:0.7. In the result of microbial experiment on standardized spiced soy sauce, the stability of storage at 40$^{\circ}C$ up to 6 weeks was proved. The standardized spiced soy sauce which was composed of about 45.5% water, 6% crude protein, 11.7% reducing sugar and 32.1% invert sugar has not shown any significant difference during storage for 6 weeks at 40$^{\circ}C$ compared with the state immediately after processing. In the test of saltiness, specific gravity, viscosity and Hunter's color value, there was no notable change during storage at 40$^{\circ}C$. In the experiment of free amino acid and total amino acid, main amino acids were glutamic acid and aspartic acid, which were not significantly changed during storage compared with processing state. In the analysis of mineral contents, sodium accounts for 95% of the total minerals, followed by phosphorus, magnesium, etc., in order, and there was no change during storage.

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CHARACTERIZATION AND CLASSIFICATION BY NEAR INFRARED SPECTROSCOPY OF WAXES USED IN DAIRY TECHNOLOGY

  • Barzaghi, Stefania;Giardina, Claudia;Cattaneo, Tiziana M.P.;Giangiacomo, Roberto
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1252-1252
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    • 2001
  • The aim of this study was to evaluate the possibility to characterize and classify waxes applied on some type of cheeses to obtain good stability during handling and transportation. Generally, waxes are obtained from the petrochemical industry, nowadays there is the possibility to also use biodegradable waxes produced from microorganisms. Preliminary studies were carried out to optimize sample presentation in NIR analysis, such as melting conditions (influence of temperature) and coat thickness of wax. 12 waxes (biodegradable or not) were analysed by using an InfraAlyzer 500 (Bran+Luebbe). The sample size was performed cutting pieces of 1.5 cm (height) x 1.5 cm (width) x 1.5 mm (thickness), previously melted at 9$0^{\circ}C$. NIR spectra were collected at room temperature, and data were processed by Sesame Software (Bran+Luebbe) to evaluate qualitative differences among samples by cluster analysis. Waxes were gathered on the basis of their origin (petrochemical or microbial). To better understand the significance of the NIRS bands discriminating among waxes, a two-dimensional correlation with FT-IR spectra, collected by a FT-IR/ATR 420 (JASCO) instrument, was made using 2DCORR program (Galactic Industries). On the basis of its classification power, NIRS appears to be a promising tool when used in routine analysis for a qualitative control of raw materials.

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