scholarly journals Application of Lactobacillus helveticus CNRZ 32 to Control the Microbial Contaminants in Cheese by Addition of Bacterial Extracts or by In Situ Production of Bioactive Metabolites

2021 ◽  
pp. 12-19
Author(s):  
Mohamed F. El-Sayad ◽  
Gamal A. Ibrahim ◽  
Osama M. Sharaf ◽  
Nadia M. Dabiza

Microbial spoilage of cheese represents a major concern from both health and economic views. The addition of food preservatives is considered the most applied strategy to ensure food quality and to control microbial contamination. It well established that natural preservatives such as Nisin and Natamycin are of great effectiveness against a wide range of microbial concerns, but the lack of wide spectrum effect induces looking for more efficient alternatives. This research suggests alternative treatments to be evaluated side by side with both Nisin and Natamycin within real cheese models to control microbial contamination during the storage period. To evaluate this, two varieties of cheese were manufactured and inoculated with a set of pathogen and cheese spoiling microorganisms. Talaga cheese batches were separately treated with extract of MRS that previously fermented by Lactobacillus helveticus CNRZ 32, Nisin and Natamycin at Free State and Chitosan Nanoparticles-loaded state to become 6 treatments (T1 – T6) other than the control (C). The same treatments were applied to Karish cheese batches, in addition to inoculation of Lactobacillus helveticus CNRZ 32 1% (v/v) in the seventh batch. Upon microbiological analyses, results show that T2; the extract loaded on Chitosan Nanoparticles completely reduced the count of all pathogens and spoiling populations after two weeks of cold storage (2 – 6oC) in Talaga cheese. In the case of Karish cheese, the 7th batch treated with Lactobacillus helveticus CNRZ 32 inoculation had no pathogenic nor spoiler growth after one week of cold storage (2 – 6oC). These results suggest that Lactic acid bacteria especially Lactobacillus helveticus CNRZ 32 can efficiently ensure the safety and quality of cheese if applied in appropriate form.

2020 ◽  
Vol 11 (1) ◽  
pp. 7677-7688

There is no previous work that utilizes the multi-solvent extraction and structure elucidation of Lactobacillus helveticus cell-free supernatant (CFS). In this study, the CFS of Lb. helveticus CNRZ 32 was extracted by ethyl acetate, diethyl ether, dichloromethane, and n-hexane solvents. The extracts of considerable antimicrobial activities were characterized through GC/MS clarify metabolic profiles, TLC for compounds separation, and bio-autography to determine the number and Rf of effective compounds. Ethyl acetate extract possessed the strongest effect on all tested pathogens with inhibition diameter reached 38 mm in the case of Staphylococcus sciuri, while Diethyl ether and Dichloromethane extracts came secondly. The extract of Ethyl acetate mainly included butyl lactate with area % (59.45), while 9,12-Octadecadienoic acid (Z,Z)-, methyl ester and different health beneficial compounds were identified in both Diethyl ether and Dichloromethane extracts. Due to the strong synergism among Chitosan Nanoparticles and different extracts, the MIC values were lowered by about 20 – 50%.


2021 ◽  
Vol 8 (1) ◽  
pp. 132-139
Author(s):  
Rajreepa Talukdar ◽  
Kumananda Tayung

Zanthoxylum oxyphyllum Edgew. is a medicinal plant widely been used by the local tribal communities of Assam as an alternative source of medicine for the treatment of various diseases. In the present study, endophytic fungi associated with Z. oxyphyllum were undertaken with an aim to investigate the isolates for their antimicrobial potential. The endophytic fungi were recovered using four different media, namely, Malt Extract Agar (MEA) media, Potato Dextrose Agar (PDA) media, Water Agar (WA) media and media amended with the Plant Extract (PEA) from samples collected from three sites. Altogether, 18 isolates of endophytic fungi were isolated from 150 surface sterilized and healthy leaf fragments. Colletotrichum was found to be dominant endophytic genus with 7 different species. Other isolated endophytic fungal genera were Fusarium, Curvularia, Aspergillus, Corynespora and isolates belonging non-sporulating fungi categorised as Mycelia Sterilia. The endophytic fungi were determined for antimicrobial activity against selected clinically significant human pathogenic test organisms. Ethyl acetate crude extracts of all endophytic fungi exhibited antimicrobial activity by inhibiting a minimum of one of the four test pathogens. Amongst the isolates, crude extracts obtained from Fusarium sp. and five Colletotrichum spp. showed wide-spectrum antimicrobial activity against all the test organisms. The study indicated that Z. oxyphyllum harbours a wide range of endophytes capable of producing secondary metabolites with antimicrobial properties. Further detailed investigation of their bioactive metabolites might lead to discovery of compounds with potential therapeutic applications as a new source of medicine.


2019 ◽  
Vol 14 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Hidayat Hussain ◽  
Ivan R. Green ◽  
Muhammad Saleem ◽  
Khanzadi F. Khattak ◽  
Muhammad Irshad ◽  
...  

Background: Cucurbitacins belong to a group of tetracyclic triterpenoids that display a wide range of biological effects. In the past, numerous cucurbitacins have been isolated from natural sources and many active compounds have been synthesized using the privileged scaffold in order to enhance its cytotoxic effects. Objective: his review covers patents on the therapeutic effects of natural cucurbitacins and their synthetic analogs published during the past decade. By far, the majority of patents published are related to cancer and Structure-Activity Relationships (SAR) of these compounds are included to lend gravitas to this important class of natural products. Methods: The date about the published patents was downloaded via online open access patent databases. Results: Cucurbitacins display significant cytotoxic properties, in particular cucurbitacins B and D which possess very potent effects towards a number of cancer cells. Numerous cucurbitacins isolated from natural sources have been derivatized through chemical modification at the C(2)-OH and C(25)- OH groups. Most importantly, an acyl ester of the C(25)-OH and, iso-propyl, n-propyl and ethyl ether groups of the C(2)-OH demonstrated the most increased cytotoxic activity. Conclusion: The significant cytotoxic effects of natural and semi-synthetic cucurbitacins make them attractive as new drug candidates. Moreover, cucurbitacins have the capability to form conjugates with other anticancer drugs which will synergistically enhance their anticancer effects. The authors believe that in order to get lead compounds, there should be a greater focus on the synthesis of homodimers, heterodimers, and halo derivatives of cucurbitacins. In the opinion of the authors the analysis of the published patents on the cucurbitacins indicates that these compounds can be developed into a regimen to treat a wide spectrum of cancers.


2021 ◽  
Vol 9 ◽  
pp. 205031212110225
Author(s):  
Mark A Pianka ◽  
Joseph Serino ◽  
Steven F DeFroda ◽  
Blake M Bodendorfer

Greater trochanteric pain syndrome is a common cause of lateral hip pain, encompassing a spectrum of disorders, including trochanteric bursitis, abductor tendon pathology, and external coxa saltans. Greater trochanteric pain syndrome is primarily a clinical diagnosis, and careful clinical examination is essential for accurate diagnosis and treatment. A thorough history and physical exam may be used to help differentiate greater trochanteric pain syndrome from other common causes of hip pain, including osteoarthritis, femoroacetabular impingement, and lumbar stenosis. Although not required for diagnosis, plain radiographs and magnetic resonance imaging may be useful to exclude alternative pathologies or guide treatment of greater trochanteric pain syndrome. The majority of patients with greater trochanteric pain syndrome respond well to conservative management, including physical therapy, non-steroidal anti-inflammatory drugs, and corticosteroid injections. Operative management is typically indicated in patients with chronic symptoms refractory to conservative therapy. A wide range of surgical options, both open and endoscopic, are available and should be guided by the specific etiology of pain. The purpose of this review is to highlight pertinent clinical and radiographic features used in the diagnosis and management of greater trochanteric pain syndrome. In addition, treatment indications, techniques, and outcomes are described.


Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1831-1853
Author(s):  
Jaeho Jeon ◽  
Yajie Yang ◽  
Haeju Choi ◽  
Jin-Hong Park ◽  
Byoung Hun Lee ◽  
...  

AbstractTwo-dimensional (2D) layers of transition metal carbides, nitrides, or carbonitrides, collectively referred to as MXenes, are considered as the new family of 2D materials for the development of functional building blocks for optoelectronic and photonic device applications. Their advantages are based on their unique and tunable electronic and optical properties, which depend on the modulation of transition metal elements or surface functional groups. In this paper, we have presented a comprehensive review of MXenes to suggest an insightful perspective on future nanophotonic and optoelectronic device applications based on advanced synthesis processes and theoretically predicted or experimentally verified material properties. Recently developed optoelectronic and photonic devices, such as photodetectors, solar cells, fiber lasers, and light-emitting diodes are summarized in this review. Wide-spectrum photodetection with high photoresponsivity, high-yield solar cells, and effective saturable absorption were achieved by exploiting different MXenes. Further, the great potential of MXenes as an electrode material is predicted with a controllable work function in a wide range (1.6–8 eV) and high conductivity (~104 S/cm), and their potential as active channel material by generating a tunable energy bandgap is likewise shown. MXene can provide new functional building blocks for future generation nanophotonic device applications.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 435
Author(s):  
Reham Z. Hamza ◽  
Mohammad S. Al-Harbi ◽  
Munirah A. Al-Hazaa

Aging is a neurological disease that is afforded by incidence of oxidative stress. Chitosan has received global interests due to its wide medical uses. Quercetin (Q) is a bioflavonoid and widely distributed in vegetables and fruits. Resveratrol is considered as a potent antioxidant and is a component of a wide range of foods. The using of either chitosan nanopartciles (CH-NPs), querectin (Q), and resveratrol (RV) to reduce the oxidative stress and biochemical alterations on brain and testicular tissues induced by D-galactose (DG) (100 mg/Kg) were the aim of the present study. This study investigated the probable protective effects of CH-NPs in two doses (140,280 mg/Kg), Q (20 mg/Kg) and RV (20 mg/Kg), against DG induced aging and neurological alterations. Brain antioxidant capacity as malonaldehyde (MDA), catalase (CAT), and glutathione reductase (GRx), as well as histopathological damages of the brain and testicular tissues were measured. The DG treated group had significantly elevated the oxidative stress markers by 96% and 91.4% in brain and testicular tissues respectively and lower significantly the antioxidant enzyme activities of both brain and testicular tissues than those of the control group by 86.95%, 69.27%, 83.07%, and 69.43%. Groups of DG that treated with a combination of CH-NPs in two doses, Q and RV, the levels of oxidative stress marker declined significantly by 68.70%, 76.64% in brain tissues and by 74.07% and 76.61% in testicular tissues, and the enzymatic antioxidants increased significantly by 75.55%, 79.24%, 62.32%, and 61.97% as compared to the DG group. The present results indicate that CH-NPs, Q, and RV have protective effects against DG-induced brain and testis tissue damage at the biochemical and histopathological levels. Mechanisms of this protective effect of used compounds against neurological and testicular toxicity may be due to the enhanced brain and testis antioxidant capacities.


2021 ◽  
Vol 22 (9) ◽  
pp. 4437
Author(s):  
Han Ryul Choi ◽  
Min Jae Jeong ◽  
Min Woo Baek ◽  
Jong Hang Choi ◽  
Hee Cheol Lee ◽  
...  

Cold storage of peach fruit at low temperatures may induce chilling injury (CI). Pre-storage 1-MCP and high CO2 treatments were reported among the methods to ameliorate CI and reduce softening of peach fruit. However, molecular data indicating the changes associated with pre-storage 1-MCP and high CO2 treatments during cold storage of peach fruit are insufficient. In this study, a comparative analysis of the difference in gene expression and physico-chemical properties of fruit at commercial harvest vs. stored fruit for 12 days at 0 °C (cold-stored (CS), pre-storage 1-MCP+CS, and pre-storage high CO2+CS) were used to evaluate the variation among treatments. Several genes were differentially expressed in 1-MCP+CS- and CO2+CS-treated fruits as compared to CS. Moreover, the physico-chemical and sensory data indicated that 1-MCP+CS and CO2+CS suppressed CI and delayed ripening than the CS, which could lead to a longer storage period. We also identified the list of genes that were expressed commonly and exclusively in the fruit treated by 1-MCP+CS and CO2+CS and compared them to the fruit quality parameters. An attempt was also made to identify and categorize genes related to softening, physiological changes, and other ripening-related changes. Furthermore, the transcript levels of 12 selected representative genes from the differentially expressed genes (DEGs) in the transcriptome analysis were confirmed via quantitative real-time PCR (qRT-PCR). These results add information on the molecular mechanisms of the pre-storage treatments during cold storage of peach fruit. Understanding the genetic response of susceptible cultivars such as ‘Madoka’ to CI-reducing pre-storage treatments would help breeders release CI-resistant cultivars and could help postharvest technologists to develop more CI-reducing technologies.


Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 910
Author(s):  
María I. Sáez ◽  
María D. Suárez ◽  
Francisco J. Alarcón ◽  
Tomás F. Martínez

This study evaluates the potential of different algae extracts (Crassiphycus corneus, Cc; Ulva ohnoi, Uo; Arthrospira platensis, Ap; Haematococcus pluvialis, Hp) as additives for the preservation of rainbow trout fillets. The extracts were prepared with different water to ethanol ratios from the four algae species. The highest ferric reducing antioxidant power (FRAP) was observed in Uo extracted in 80% ethanol. Ap aqueous extract also had considerable FRAP activity, in agreement with a high total phenolic content. Radical scavenging activity (DPPH) was higher in Cc 80% ethanol extract, in agreement with a high total carotenoid content. In fact, when the algae aqueous extracts were assayed on the fish fillets, their antioxidant activity exceeded that of ascorbic acid (ASC). All algae extracts delayed microbial growth and lipid oxidation processes in trout fillets throughout the cold storage period compared to controls, and also improved textural parameters, these effects being more evident for Ap and Hp. With respect to the color parameters, the Hp extract prevented the a* values (redness) from decreasing throughout cold storage, a key point when it comes to colored species, not least salmonids. On the other hand, the Ap extract was not as effective as the rest of treatments in avoiding a* and b* decrease throughout the storage period, and thereby the color parameters were impaired. The results obtained, together with the natural origin and the viability for large-scale cultivation, make algae extracts interesting fish preservative agents for the food industry.


Author(s):  
Mohsina Abed ◽  
Sara Yousuf

Meropenem is a new Carbapenem antibacterial agent with wide spectrum of activity for intravenous administration. It is synthetic derivative of Thienamycin. Three analogues of Meropenem are evaluated and active against 18 bacterial strains. Meropenem causes rapid bacterial cell death by covalently binding to penicillin binding proteins (PBS). Structural modification at C-2 position, produced double promoiety prodrug of Meropenem and increases bioavailability of oral administration. Other forms of drug such as liposome and nanoparticles are also available with enhanced absorption. 14C labelled Meropenem prepared from 14C Dimethylamine hydrochloride is used for the analysis of M. tuberculosis transpeptidase. ICI213,689 is the only metabolite of Meropenem and it is inactive. Meropenem penetrates well into the body fluids and tissues including cerebrospinal fluid. Its bioavailability is 100% on intravenous administration. Hence it is used in the treatment of meningitis, febrile neutropenia, anthrax and various other skin and skin structure infections. Dosage reduction is required in patient with reduced renal function but not in hepatic impairment. Seizures, gastrointestinal haemorrhage are observed in patients. Vabmoere is the combination of Meropenem and Vaborbactam which is active against the Carbapenem resistant Enterobacteriacea. Meropenem is an effective broad-spectrum antibacterial drug for the treatment of wide range of infection including polymicrobial infection in both children and adult.


2001 ◽  
Vol 64 (10) ◽  
pp. 1584-1591 ◽  
Author(s):  
A. GELMAN ◽  
L. GLATMAN ◽  
V. DRABKIN ◽  
S. HARPAZ

Sensory and microbiological characteristics of pond-raised freshwater silver perch (Bidyanus bidyanus) fish, during cold storage over a period of 25 days were evaluated. Whole fish (averaging 400 g each) were stored in cold storage rooms at either 0 to 2°C, 5°C, or 5°C + potassium sorbate as a preservative. The organoleptic and hypoxanthine test results show that the treatment of potassium sorbate can slow the process of spoilage by about 5 days. Yet, the most important factor affecting the shelf life of these fish is the storage temperature. Keeping the fish at 0 to 2°C can prolong the storage prior to spoilage by 10 days compared with those kept at 5°C. These results obtained through organoleptic tests are corroborated by both the chemical (hypoxanthine and total volatile basic nitrogen) and to some extent by the physical (cosmos) tests. The initial total bacteriological counts were 5 × 102 CFU/cm2 for fish surface and <102 CFU/g for fish flesh, and these counts rose continuously, reaching about 106 CFU/g (0 to 2°C) and 107 CFU/g (5°C) in flesh and 107 to 108 CFU/cm2 on the surface by the end of the storage period. The addition of potassium sorbate led to a smaller increase in bacterial numbers, especially during the first 15 days. Bacterial composition fluctuated during storage. The initial load on the fish surface was predominantly mesophilic and gram positive and consisted mostly (80%) of Micrococci, Bacillus, and Corynebacterium. During the next 10 days, these bacteria were practically replaced by gram-negative flora comprised mostly of Pseudomonas fluorescens that rapidly increased with storage time and accounted for 95% after 15 days.


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