Lipids from yeasts and fungi: physiology, production and analytical considerations.

The last years there has been a significant rise in the number of publications in the international literature that deal with the production of lipids by microbial sources (the 'single cell oils; SCOs' that are produced by the so-called 'oleaginous' micro-organisms). In the first part of the present review article, a general overview of the oleaginous micro-organisms (mostly yeasts, algae and fungi) and their potential upon the production of SCOs is presented. Thereafter, physiological and kinetic events related with the production of, mostly, yeast and fungal lipids when sugars and related substrates like polysaccharides, glycerol, etc. (the de novo lipid accumulation process) or hydrophobic substrates like oils and fats (the ex novo lipid accumulation process) were employed as microbial carbon sources, are presented and critically discussed. Considerations related with the degradation of storage lipid that had been previously accumulated inside the cells, are also presented. The interplay of the synthesis of yeast and fungal lipids with other intracellular (i.e. endopolysaccharides) or extracellular (i.e. citric acid) secondary metabolites synthesized is also presented. Finally, aspects related with the lipid extraction and lipidome analysis of the oleaginous micro-organisms are presented and critically discussed.

Biotechnological conversion of waste cooking olive oil into lipid-rich biomass using Aspergillus and Penicillium strains.

AIMS: In this study, we have investigated the biochemical behaviour of Aspergillus sp. (five strains) and Penicillium expansum (one strain) fungi cultivated on waste cooking olive oil. The production of lipid-rich biomass was the main target of the work. In parallel, the biosynthesis of other extracellular metabolites (organic acids) and enzyme (lipase) and the substrate fatty acid specificity of the strains were studied. METHODS AND RESULTS: Carbon-limited cultures were performed on waste oil, added in the growth medium at 15g l(-1) , and high biomass quantities were produced (up to c.18g l(-1) , conversion yield of c. 1·0 g of dry biomass formed per g of fat consumed or higher). Cellular lipids were accumulated in notable quantities in almost all cultures. Aspergillus sp. ATHUM 3482 accumulated lipid up to 64·0% (w/w) in dry fungal mass. In parallel, extracellular lipase activity was quantified, and it was revealed to be strain and fermentation time dependent, with a maximum quantity of 645 U ml(-1) being obtained by Aspergillus niger NRRL 363. Storage lipid content significantly decreased at the stationary growth phase. Some differences in the fatty acid composition of both cellular and residual lipids when compared with the initial substrate fat used were observed; in various cases, cellular lipids more saturated and enriched with arachidic acid were produced. Aspergillus strains produced oxalic acid up to 5·0 g l(-1) . CONCLUSIONS: Aspergillus and Penicillium strains are able to convert waste cooking olive oil into high-added-value products. SIGNIFICANCE AND IMPACT OF THE STUDY: Increasing fatty wastes amounts are annually produced. The current study provided an alternative way of biovalourization of these materials, by using them as substrates, to produce added-value compounds.

Late onset metastasis from renal cell carcinoma masquerading as a gallbladder polyp.

Renal cell carcinoma (RCC) accounts for approximately 3% of all adult malignancies. A third of people with RCC have metastatic lesions when diagnosed, and another third develop metachronous metastasis during follow-up or after surgical treatment. We report a case of gallbladder metastasis from clear-cell RCC in a 71-year-old woman 13 years after RCC of her right kidney. Preoperative imaging studies showed a suspicious, progressively enlarged gallbladder polyp. The patient underwent open cholecystectomy and lymph node dissection along the hepatoduodenal ligament. The pathology report was compatible with metastatic disease from the kidney that was previously resected. Gallbladder metastasis can occur from RCC several years after initial management. Physicians should be aware of this rare pathology, and intensive follow-up is essential after surgery for RCC.

Kearns-Sayre syndrome: presenting with vocal fold palsy.

We present the first documented case of Kearns-Sayre syndrome presenting with a vocal fold palsy.

Mycelium growth kinetics and optimal temperature conditions for the cultivation of edible mushroom species on lignocellulosic substrates.

The influence of environmental parameters on mycelial linear growth of Pleurotus ostreatus, P. eryngii, P. pulmonarius, Agrocybe aegerita, Lentinula edodes, Volvariella volvacea and Auricularia auricula-judae was determined in two different nutrient media in a wide range of temperature, forming the basis for the assessment of their temperature optima. V. volvacea grew faster at 35 degrees C, P. eryngii at 25 degrees C, P. ostreatus and P. pulmonarius at 30 degrees C, A. aegerita at 25 or 30 degrees C and A. auricula-judae at 20 or 25 degrees C depending on the nutrient medium used and L. edodes at 20 or 30 degrees C depending on the strain examined. The mycelium extension rates were evaluated on seven mushroom cultivation substrates: wheat straw, cotton gin-trash, peanut shells, poplar sawdust, oak sawdust, corn cobs and olive press-cake. The mycelium extension rates (linear growth and colonization rates) were determined by the 'race-tube' technique, and were found to be the highest on cotton gin-trash, peanut shells and poplar sawdust for Pleurotus spp. and A. aegerita. Wheat straw, peanut shells and particularly cotton gin-trash supported fast growth of V. volvacea, whereas wheat straw was the most suitable substrate for L. edodes and A. auricula-judae. Supplemented oak sawdust and olive press-cake were poor substrates for most species examined, while almost all strains performed adequately on corn cobs.

Topographic relationship between the cochlea and the middle fossa floor: the anatomical basis for an alternative approach to the cochlear turns.

The cochlea has attained extreme surgical interest since cochlear implantation has been recognized as an established method for the management of certain types of bilateral profound hearing loss. Traditionally access to the cochlear turns is achieved through the middle ear. Extremely limited references exist in the literature regarding alternative surgical approaches to the cochlea. In the present study we tried to highlight the anatomic relationships of the superior aspect of the bony cochlea to the adjacent superficial structures of the petrous bone, as there have been suggestions that the cochlea is surgically accessible through the floor of the middle cranial fossa (MCF). A total of 58 dry human adult skulls (116 temporal bones) were studied. The groove for the greater superficial petrosal nerve (GGSPN) and the facial hiatus were used as landmarks in order to expose the superior aspect of the cochlea. Measurements were made of the following distances: a) between the MCF floor and the superficial part of the basal turn (SPBT), b) between the MCF floor and the apex of the cochlea, c) between the SPBT and the GGSPN and d) between the SPBT medially and the first genu of the facial canal laterally. Our results indicate that adequate and reliable surgical access to the bony cochlea could be achieved through the MCF floor.

Towards a universal newborn hearing screening.

Hearing loss is a common problem which, if remaining undetected during early childhood, could affect the patient's linguistic and mental abilities permanently. Although recommended, mass hearing screening has so far been problematic or even impossible due to several reasons. The available otoacoustic emission devices appear to be effective tools for universal hearing screening. The aim of this study is to evaluate the reliability and practicability of a new device for recording click-evoked otoacoustic emissions (cEOEs) on a pediatric population. Sixty children aged between 6 days and 14 years were evaluated audiologically both by auditory brainstem responses (ABR) and otoacoustic emissions. The latter were obtained by using the well-known ILO88v3.92 otoacoustic analyser and a new, portable device ('Echocheck', Otodynamics Ltd, UK). Sensitivity and specificity of cEOEs recorded by 'Echocheck'was found to be 93% and 91%, respectively, when compared to ABR results. Additionally, 'Echocheck' recordings were proved to be much easier to perform, needing considerably less time in comparison with those of the ILO88 system. In our opinion, 'Echocheck' as well as all similar portable devices--screeners--may represent a much-desired solution for implementing universal hearing screening programmes.