Book reviews

Nanoencapsulation technologies for the food and nutraceutical industries S.M. JAFARI (Ed.) Academic Press, Elsevier Science Publishing Co Inc., 2016, 125 London Wall, London EC2Y 5AS, United Kingdom, ISBN 978-0-12-809436-5, 610 pages | Food safety in the 21st century: Public health perspective (1st ed.) R. K. GUPTA, B. P. DUDEJA and A. S. MINHAS (Eds) Academic Press is an imprint of Elsevier, 125 London Wall, London EC2Y 5AS, United Kingdom ISBN: 978-0128017739, 624 pages | Molecular methods for the detection and characterization of foodborne and environmental pathogens R.K. GUPTA, B. P. DUDEJA and A. S. MINHAS (Eds) DEStech Publications, Inc. 439 North Duke Street, Lancaster, Pennsylvania 17602 U.S.A. ISBN No. 978-1-60595-079-2, 156 pages | Foodborne diseases 3rd edition C.E.R. DODD, T. ALDSWORTH, R.A. STEIN, D.O. CLIVER and H.P. RIEMANN (Eds) Academic Press is an imprint of Elsevier, London, UK, San Diego, USA, Cambridge, USA, Oxford, UK, 2016, ISBN: 978-0-12-385007-2 (print), 576 pages | The vitamins: Fundamental aspects in nutrition and health 5th edition G.F. COMBS and J.P. MCCLUNG (Eds) Academic Press is an imprint of Elsevier, London, UK, San Diego, USA, Cambridge, USA, Oxford, UK, 2016, ISBN: 978-0-12-802965-7, 628 page

Plant polysaccharide degrading enzyme system of Thermobifida cellulosilytica TB100^T revealed by de novo genome project data

Thermobifidas are thermophilic, aerobic, lignocellulose decomposing actinomycetes. The Thermobifida genus includes four species: T. fusca, T. alba, T. cellulosilytica, and T. halotolerans. T. fusca YX is the far best characterized strain of this taxon and several cellulases and hemicellulases have been cloned from it for industrial purposes targeting paper industry, biofuel, and feed applications. Unfortunately, sequence data of such enzymes are almost exclusively restricted to this single species; however, we demonstrated earlier by zymography that other T. alba and T. cellulosilytica strains encode the same enzyme sets. Recently, the advances in whole genome sequencing by the use of next generation genomics platforms accelerated the selection process of valuable hydrolases from uncharacterized bacterial species for cloning purposes. For this purpose T. cellulosilytica TB100T type strain was chosen for de novo genome sequencing. We have assembled the genome of T. cellulosilytica strain TB100T into 168 contigs and 19 scaffolds, with reference length of 4 327 869 bps, 3 589 putative coding sequences, 53 tRNAs, and 4 rRNAs. The analysis of the annotated genome revealed the existence of 27 putative hydrolases belonging to 14 different glycoside hydrolase (GH) families. The investigation of identified, cloned, and heterologously multiple cellulases, mannanases, xylanases, and amylases may result in industrial applications beside gaining useful basic research related information

Microbiology of plant foods and related aspects

Vegetables and fruits are staple food for the human mankind, and they are also considered as the symbol of healthy nutrition. They are consumed fresh and cooked, in salad mixes, freshly pressed, fermented, minimally processed form, stored under different conditions, etc. Since they are in close contact with the environment, natural or artificial, and have a natural microbiota on their surface highly variable as a function of the surrounding, they are prone to get contaminated with human pathogens, too. More attention is paid to the food-borne outbreaks in the last 10 years related to the consumption of contaminated plant foods, and it is also in the focus of our interest. The main activities of the Unit cover the following areas: microbial contamination of fruits and vegetables, also in relation to the soil, the methods of cell count reduction using also non-thermal methods, the biofilm formation and the response of Bacillus cereus to the technological stresses

Epiphytic microbiota of sour cherry (Prunus cerasus L.) in integrated and organic growing

The surface microbial contamination is of great interest, since these microbes can be potential sources of food-borne diseases. The purpose of this study was to determine and compare the microbial surface contamination of sour cherry (Prunus cerasus L.) produced by integrated and organic cultivation methods in Hungary. The effects of the growing area, year, and cultivar were studied on 62 samples. According to the results, the average microbial contamination of sour cherry is within a certain range, independently from the cultivar, growing area, and year. The frequency distribution of the surface bacterial, mould and yeast counts also did not show significant differences between the growing methods or cultivars. Principal component analysis ranked the sour cherry samples into seven groups on the basis of the level of microbial contamination. The discriminant analysis proved the correctness of the grouping. The grouping was independent from cultivars, growing methods, and years. No examined food-borne pathogen Salmonella spp. or Listeria spp. were found on the surfaces of sour cherry

Effects of environmental conditions on growth of Aspergillus niger and Penicillium expansum

The effect of water activity (0.85–0.99 aw) and temperature (20–35 °C) on growth of two potentially toxigenic moulds, Aspergillus niger and Penicillium expansum, were studied. On the basis of the measured colony diameter ComBase DMFit program was used to estimate the lag phase and growth rate. Similar results may provide basis for the risk assessment of fungal growth (and also for the possible mycotoxin contamination) in food and feed plants in the vegetation season due to the climate change (global warming), and also during unfavourable storage conditions

Isolation and Detailed Characterisation of the First Sterigmatocystin Hyperproducer Mould Strain in Hungary

Aspergillus strains were isolated from Hungarian mills in order to get information on the appearance of sterigmatocystin (ST) producing moulds, whose presence has never been demonstrated in Hungary. Fungal isolates were classified into nine morphotypes, sections Nigri, Nidulantes, Versicolores (two morphotypes), Circumdati, Flavi (two morphotypes), Clavati and Terrei by classical mycological assays. ST producing strains could be classified into section Versicolores. ST production of the isolates was assessed by liquid and solid phase growth experiments and compared to ST producing reference strains: Aspergillus pepii SzMC 22332, Aspergillus versicolor SzMC 22333, Aspergillus griseoaurantiacus SzMC 22334 and Aspergillus nidulans RDIT9.32. Four of our isolates marked as Km11, Km14, Km26 and Km31 showed ST production in liquid medium. ST production on solid phase corn grit substrate was measured after three weeks of incubation, and Km26 isolate proved to be the most prominent with a toxin concentration of 277.1 μg g−1, surpassing all reference strains. The toxin-producing ability of Km26 isolate was also tested in a field experiment, where corn was infected. By the end of the experiment, ST level of 19.56 μg kg−1 was measured in infected corn. Molecular taxonomic identification of the Km26 strain was performed using internal transcribed spacer (ITS), calmodulin and tubulin sequence analyses. Based on these studies, strain Km26 was identified as Aspergillus creber. Here we report that an ST-producing A. creber strain has appeared in Hungary, and the Km26 strain is the first known extreme ST-producing mould in this country. As a result of climate change, aflatoxin B1 producing Aspergillus flavus strains have appeared in Hungary in the last decade. As strain Km26 is the only A. creber isolate in Hungary so far, there is no sign of mass prevalence, and due to the lower temperature optimum of the species compared to A. flavus, its appearance is probably not related to climate change