Microbiological

The distributions of the times to turbidity for wells inoculated with single cells of Listeria innocua were determined in different environmental conditions (pH 4.5 to 7 and with 0.5% to 8% of NaCl at 30 degrees C). It was established by statistical analysis that the main source of the variability of the detection times, T, is the variability of individual lag times. A linear relation dev(T) approximately T was observed between the detection times and their standard deviation. At slow growth, other sources of variability became increasingly significant.

Polyhydroxyalkanoate (PHA) is a family of biopolymers produced by some bacteria and is accumulated intracellularly as carbon and energy storage material. Fifteen PHA-producing bacterial strains were identified from bacteria isolated from Antarctic soils collected around Casey Station (66°17′S, 110°32′E) and Signy Island (60°45′S, 45°36′W). Screening for PHA production was carried out by incubating the isolates in PHA production medium supplemented with 0.5% (w/v) sodium octanoate or glucose. 16S rRNA gene sequence analysis revealed that the isolated PHA-producing strains were mainly Pseudomonas spp. and a few were Janthinobacterium spp. All the isolated Pseudomonas strains were able to produce medium-chain-length (mcl) PHA using fatty acids as carbon source, while some could also produce mcl-PHA by using glucose. The Janthinobacterium strains could only utilize glucose to produce polyhydroxybutyrate (PHB). A Pseudomonas isolate, UMAB-40, accumulated PHA up to 48% cell dry mass when utilizing fatty acids as carbon source. This high accumulation occurred at between 5 °C and 20 °C, then decreased with increasing temperatures. Highly unsaturated mcl-PHA was produced by UMAB-40 from glucose. Such characteristics may be associated with the ability of UMAB-40 to survive in the cold.

The purpose of this study was to analyze microbial life and to address
safety issues of milk shakes locally available in road side shops and
carts of Peshawar city, Pakistan. Total of 144 samples of different
flavors were examined for the presence of microbial content as total
bacterial load, total coliform count, fecal coliform count and total
staphylococcal count. Majority of samples have higher bacterial load
(10
2
-10
9
cfu/ml) and total coliform count (10
3
-10
6
cfu/ml).
Escherichia Coli, Citrobacter, Klebsiella and Salmonella  species
were detected using different biochemical tests. 26 samples revealed
the presence of fecal coliform contamination  (10
4
cfu/ml) while 120
samples harbored staphylococci (10
6
cfu/ml).High percentage of drug
resistance among biochemical isolates was found against commonly
used antibiotics like Imipenem, Nalidixic acid, Piperaciline,
Ceftriaxone, Vancomycine, Ampicillin, Amoxicilline,
Ciprofloxacine, and Erythromycine.  Furthermore,  66%  Escherichia
Coli,  60% Klebsiella,  51% Citrobacter  and  25% salmonella  were
found to be ESBL positive. In general the analysis indicates
unsatisfactory quality of milk shakes and need to be
microbiologically controlled by regulatory authorities to ensure
public health safety

Tamamen doğal, yenilikçi, sürdürülebilir gıda üretim tekniklerini bünyesinde barındıran bütünleşik yaşam alanı projesi BostanKent...
MultiPonik tekniklerle tarım, hayvancılık, mikrobiyolojik organik kimyasallar ve protein üretim çiftlikleri.

Microbiology, through regulatory requirements and advances in technology, has become a more exacting science. This is despite the relatively high variation with many methods, especially the culture based ones, when compared with analytical methods designed to recover chemical substances.

In a new paper, Tim Sandle presents an overview of the validation of microbiological methods, considering some of the limitations and outlining the key criteria that may be applicable for assessment.

We report on the development of a Standard Operating Procedure (SOP) for extraction and handling of intra- and extracellular protein fractions of Clostridium acetobutylicum ATCC 824 for reproducible high quality two-dimensional gel electrophoresis (2-DE) analyses. Standardized cells from a phosphate-limited chemostat were used to evaluate different protein preparation methods. For the preparation of the secretome, a dialysis/ultrafiltration procedure resulted in higher protein yields and proved to be more reliable compared to different precipitation methods using TCA, DOC-TCA, acetone, and PEG 6000. Sonication was found to be the most efficient method among different tested techniques of cell disruption for the analysis of the intracellular proteome. Furthermore, the effect of protease inhibitors and sample storage conditions were tested for both intra- and extracellular protein samples. Significant changes in the protein pattern were observed depending on the addition of protease inhibitors. 2-DE gels with a pH gradient from 4 to 7 prepared according to the developed SOP contained at least 736 intracellular and 324 extracellular protein spots.

Pleurotus ostreatus is one of the most extensively cultivated mushrooms in the world; however, the success of cultivation often depends on the proliferation of different bacterial pathogens. Pseudomonas tolaasii is thought as the major cause of brown blotch disease of Agaricus bisporus and yellowing of Pleurotus ostreatus. In this study we examined the pathogenicity and assessed the industrial damage causing effect of 41 Pseudomonas strains isolated from deformed, yellowing oyster mushroom (P. ostreatus) sporocarps. Identification of the isolates at species level by the partial sequence analysis of the hypervariable region of the rpoB gene revealed nine Pseudomonas sps. We analyzed the presence of the tolaasin gene-cluster, the production of fluorescent pigments, the oxidase- and nitrite reductase activities, the growth at restrictive temperatures and the carbon source utilizing abilities of each strain. Complex lipopeptide production (including tolaasin) was examined with thin layer chromatography and a novel in vitro necrosis-test was developed and evaluated for the investigation of the pathogenic effect of Pseudomonas strains. Our results underline the importance of extracellular enzyme production in the sporocarp decaying process. Strong correlations were found between the secretion of trypsin-like proteases and lipases and the necrotic effect of these bacteria. All the results clearly established that besides Ps. tolaasii, Ps. fluorescens biovar V strains were pathogenic to P. ostreatus and cause serious losses during mushroom production. Our results underline the importance of extracellular enzyme production in the sporocarp decaying process, especially the trypsin-like proteases and lipases.

... ISSN 1680-5194 © Asian Network for Scientific Information, 2010 Isolation and Identification of Lactic Acid Bacteria from Raw Cow Milk, White Cheese and Rob in Sudan Sawsan Abdelaziz Abdullah ... REFERENCES Abdelgadir, WS, HS Hamad, PL Moller and M. Jakobsen, 2001 ...

The present paper describes the chemical composition and antimicrobial activity of the essential oils of Gentiana asclepiadea L., collected in Serbia. The essential oils were obtained from the underground part (root and rhizome) and aerial part (stem, leaves and flowers) of the plant by hydrodistillation and analyzed by GC and GC-MS. The major compounds in the oil from the underground