Food Microbiology: Application of Microorganisms in Food Industry

Industrial microbiology is one branch of applied microbiology where microbes are used to produce important products such as metabolic manufacture, biotransformation, manufacture of energy (bio-fuels), management of organic and industrial wastes, manufacture of microbial biomass (microbial protein) for food and feed, manufacture of bio-control agents (antibiotics) and fermentation of food products. Microbial food processing is used to transform simple food into a value-added form with the assistance of microbes. In addition, it involves converting low-value, often inedible, perishable natural resources into high-value, safe food products. Since antiquity, mankind have used microbes to produce a variety of food products such as dairy products, bread, vinegar, wine and beer, as well as fermented seafood, meat and vegetables. There are many useful applications of microbes in the food processing industry, which have a strong influence on the quality and quantity of food. Recently, microbial approaches of food processing have garnered global attention as a workable method to food conservation and a good source of vital nutrients. Microbial contamination of food commodities typically occurs between the field and the processing plant or during processing, storage, transportation and distribution or prior to consumption. Consequently, microbes are being considered as very significant elements in food manufacturing, food quality maintenance and food safety. In this chapter, we focus on the beneficial roles of microorganisms, the applications of microorganisms in the food industry and the risks of microbial contamination

Sensitivity of Four Various Candida Species to Photodynamic Therapy Mediated by Indocyanine Green, an in vitro Study

Statement of the Problem: Various species of candida contribute to oral candidiasis. It is the time to shift from conventional rigid antimicrobial therapies to more patient specific and safer ones. Purpose: The present study aimed to investigate antifungal effects of photodynamic therapy (PDT) using Indocyanine green as photosensitizer and low-power laser irradiation on the viability of candida albicans, candida tropicalis, candida glabrata and candida krusei, and to compare it with Nystatin as the conventional treatment. Materials and Method: In this in vitro study, 0.5 McFarland suspensions of candida's species were prepared (n=50, each). Each strain was then divided into five groups of 10 samples each, according to the following experimental interventions: (1) Nystatin, (2) photodynamic therapy: laser irradiation (wavelength= 808 nm, power= 100 mW, energy density= 10 J/cm2, exposure duration= 100 s) in the presence of the photosensitizer, (3) laser irradiation alone, (4) treatment with the PS alone and (5-control: no exposure to laser light or photosensitizer. Next, serial dilutions were prepared and seeded onto Sabouraud dextrose agar. The colonies were counted, and the values of log (CFU/ml) were analyzed by variance and the Tamhan test (p< 0.05). Results: Photodynamic therapy mediated indocyanine green is significantly effective in reducing the number of CFU/ml of all species of candida tested, compared to control group (p< .001). Nystatin, laser irradiation and photodynamic therapy, with respectively decreasing potency, have considerably reduced the number of candida's colonies in all four bacterial strains (p<. 05). Photosensitizer alone, showed impressive antimicrobial potency against all species of candida except candida albicans, in comparison to control group. Conclusion: It seems that laser therapy alone is more powerful than photodynamic therapy mediated indocyanine green; however, conventional treatment has still the top antimicrobial efficacy towards all candida species

Identification of the main allergen sensitizers in an Iran asthmatic population by molecular diagnosis

Background: There has been a significant growth in the prevalence of allergy, mainly associated to IgE-mediated disorders such as asthma and rhinitis. The identification of atopy in asthmatic patients through the measurement of specific IgE can help to identify risk factors that cause asthmatic symptoms in patients. The development and use of individualized allergen-based tests by the Component Resolved Diagnosis has been a crucial advance in the accurate diagnosis and control of allergic patients. The objective of this work was to assess the usefulness of molecular diagnosis to identify environmental allergens as possible factors influencing the development and manifestation of asthma in a group of asthmatic patients from Iran. Methods: Studied population: 202 adult asthmatic patients treated at the Loghman Hakim Hospital and Pasteur Institute of Teheran (Iran) from 2011 to 2012. Specific IgE determined by the ImmunoCAP system were used to both evaluate the patients' atopic condition and the molecules involved in the allergic sensitization. SDS-PAGE IgE-immunoblotting associated with mass spectrometry was carried out to study the cockroach IgE-binding sensitizing proteins. Results: Forty-five percent of all patients could be considered atopic individuals. Eighty-two percent of atopic patients were sensitized to pollen allergens. The Salsola kali (Sal k 1) and the Phleum pratense (rPhl p 1 and/or rPhl p 5) major allergens were the most common sensitizers among pollens (71% and 18%, respectively). Thirty-five percent of the atopic population was sensitized to cockroach. Four different allergens, including a previously unknown alpha-amylase, were identified in the cockroach extract. No significant associations could be demonstrated between the severity of asthma and the specific IgE levels in the atopic population. Statistical analysis identified the Sal k 1 as the main protein allergen influencing the development and expression of asthma in the studied population. Conclusions: Pollen and cockroach were the most relevant allergen sources in the asthmatic population. The Salsola kali major allergen was the main cause for sensitization in the atopic patients suffering asthma. Using the Component Resolved Diagnosis, it was possible to identify a new Blattella germanica cockroach allergen (Blattella alpha amylase 53 kDa) that could sensitize a relevant percentage of this population.This study has been founded by the Government of The Basque Country, Project IT787-13

Role of nanotechnology in the management of indoor fungi

Fungi are ubiquitous in the environment and seek to colonize and grow on diverse materials as part of their life cycle. They constitute complex biofilms on surfaces and deteriorate the indoor air quality even under adverse conditions. They adapt well to changing humidity and temperature conditions, resuming their growth in minutes. Their vital activity generates a large number of pollutants that contribute to bioaerosols, which generate major health problems. The reports published in last few decades pointed out that contaminated environments play an important role in the transmission of infections, especially in hospitals. Advances in the field of nanotechnology have resulted in different and diverse applications. Antimicrobial nanomaterials have been found to be eco‐friendly alternatives to be applied in functional paint and coatings. These ?smart? surfaces could face at nanoscale level the approaching of propagules to avoid their attachment, which is the first stage in biofilm development. In this sense, several nanomaterials, including metal, non‐metal, and hybrids, have been discussed in relation to their antifungal activity in this chapter.Centro de Investigación y Desarrollo en Tecnología de PinturasFacultad de Ciencias Naturales y Muse

Aflatoxins - Recent Advances and Future Prospects

This book is broadly divided into five sections and 17 chapters, highlighting recent advances in aflatoxin research from epidemiology to molecular genomics and control measures, biocontrol approaches, modern analytical techniques, economic concerns and underlying mechanisms of contamination processes. This book will update readers on several cutting-edge aspects of aflatoxins research with useful up-to-date information for mycologists, toxicologists, microbiologists, agriculture scientists, plant pathologists and pharmacologists, who may be interest to understanding of the impact, significance and recent advances within the field of of aflatoxins with a focus on control strategy

Distribution and diversity of Alt a 1 gene in Alternaria species isolated from outdoor air of Tehran

Background and Aim: In the present study, distribution pattern and phylogeny of Alternaria species isolated from Tehran air was determine based on the homology of Alt a1 gene. Materials and Methods: A number of 48 Alternaria isolates belonging to  A. alternata (33.4%), A. solani (23%), A. tenuissima (23%), A. porri (16.6%), and  A. brassicicola (4%) obtained from Tehran air were cultured on Sabouraud dextrose agar. Genomic DNA was extracted from the isolates and amplified with forward and reverse specific primers of Alt a1 gene. The resultant fragments of 500 to 600 bp of genomic DNA were sequenced and compared with genomic data of NCBI gene bank to evaluate phylogenetic relationship of Alternaria species. Results: Based on the resulting dendrogram, isolates belonging to A. alternata and A. solani were distributed in 4 clusters and those of A. brassicicola, A. porri, and A. tenuissima each in 2 clusters. Approximately, 81% of A. alternata isolates, 73% of A. solani isolates, 45.5% of A. tenuissima isolates and 12.5% of A. porri isolates showed a similarity of 99% and resided in clusters I, II, IV and VII, respectively. Conclusions: Our results indicated that Alt a1 gene was present in all examined species and differences of sequence similarities of this gene shows the importance of species and strains of Alternaria in induction of allergenic reactions in suspected patients especially those with allergic asthma