Production of flavor compounds from olive mill waste by Rhizopus oryzae and Candida tropicalis

AbstractThe purpose of this study was to investigate the production of flavor compounds from olive mill waste by microbial fermentation of Rhizopus oryzae and Candida tropicalis. Olive mill waste fermentations were performed in shake and bioreactor cultures. Production of flavor compounds from olive mill waste was followed by Gas Chromatography–Mass spectrometry, Gas chromatography- olfactometry and Spectrum Sensory Analysis®. As a result, 1.73-log and 3.23-log cfu/mL increases were observed in the microbial populations of R. oryzae and C. tropicalis during shake cultures, respectively. C. tropicalis can produce a higher concentration of d-limonene from olive mill waste than R. oryzae in shake cultures. The concentration of d-limonene was determined as 185.56 and 249.54μg/kg in the fermented olive mill waste by R. oryzae and C. tropicalis in shake cultures respectively. In contrast, R. oryzae can produce a higher concentration of d-limonene (87.73μg/kg) d-limonene than C. tropicalis (11.95μg/kg) in bioreactor cultures. Based on sensory analysis, unripe olive, wet towel, sweet aromatic, fermented aromas were determined at high intensity in olive mill waste fermented with R. oryzae meanwhile olive mill waste fermented with C. tropicalis had only a high intensity of unripe olive and oily aroma

PTPA variants and impaired PP2A activity in early-onset parkinsonism with intellectual disability

The protein phosphatase 2A complex (PP2A), the major Ser/Thr phosphatase in the brain, is involved in a number of signalling pathways and functions, including the regulation of crucial proteins for neurodegeneration, such as alpha-synuclein, tau and LRRK2. Here, we report the identification of variants in the PTPA/PPP2R4 gene, encoding a major PP2A activator, in two families with early-onset parkinsonism and intellectual disability. We carried out clinical studies and genetic analyses, including genome-wide linkage analysis, whole-exome sequencing, and Sanger sequencing of candidate variants. We next performed functional studies on the disease-associated variants in cultured cells and knock-down of ptpa in Drosophila melanogaster. We first identified a homozygous PTPA variant, c.893T&gt;G (p.Met298Arg), in patients from a South African family with early-onset parkinsonism and intellectual disability. Screening of a large series of additional families yielded a second homozygous variant, c.512C&gt;A (p.Ala171Asp), in a Libyan family with a similar phenotype. Both variants co-segregate with disease in the respective families. The affected subjects display juvenile-onset parkinsonism and intellectual disability. The motor symptoms were responsive to treatment with levodopa and deep brain stimulation of the subthalamic nucleus. In overexpression studies, both the PTPA p.Ala171Asp and p.Met298Arg variants were associated with decreased PTPA RNA stability and decreased PTPA protein levels; the p.Ala171Asp variant additionally displayed decreased PTPA protein stability. Crucially, expression of both variants was associated with decreased PP2A complex levels and impaired PP2A phosphatase activation. PTPA orthologue knock-down in Drosophila neurons induced a significant impairment of locomotion in the climbing test. This defect was age-dependent and fully reversed by L-DOPA treatment. We conclude that bi-allelic missense PTPA variants associated with impaired activation of the PP2A phosphatase cause autosomal recessive early-onset parkinsonism with intellectual disability. Our findings might also provide new insights for understanding the role of the PP2A complex in the pathogenesis of more common forms of neurodegeneration.</p

Peyniraltı Suyu ve Mısır Islatma Şurubunun Heterotrofik Mikroalg Crypthecodinium cohnii ile Biyokütle ve Yağ Üretimi Amacıyla Biyolojik Olarak Değerlendirilmesi

Many different wastewater and by-products derived from industrial activities potentially support microalgal growth by providing a cost-effective and sustainable solutions. In this present study, it was aimed to biologically utilize cheese whey (CW) and corn steep liquor (CSL) for microalgal biomass and lipid production by using these wastes in culture media for heterotrophic microalga Crypthecodinium cohnii cultivation. To determine nutrient requirements for C. cohnii growing in a medium prepared with CSL and in CW, statistical screening tools were used. CSL significantly enhanced microalgal growth and it could be an alternative to yeast extract as the primary nutrient source. As for CW, it served as a good culture medium for C. cohnii with the supplement of some of nutrients and eliminated the need for fresh water. Thus, a new culture medium was developed by combining undiluted CW and CSL and optimized for the growth of C. cohnii. Lastly, in a scale-up attempt by using this new medium, microalgal production was performed in a 3 L stirred tank bioreactor. C. cohnii yielded relatively high biomass productivity (2.28 g/L.d) and lipid content (28.7% dry weight) in the optimized medium. Although C. cohnii was known for its ability to accumulate high amounts of docosahexaenoic acid (DHA), it transformed its fatty acid composition to an increased proportion of saturated and monounsaturated fatty acids (C16:0-C18:1) that comprise ~70% of total fatty acids (TFA) when it was cultivated in CW mainly supplemented with CSL. Thus, C. cohnii seemed to be more feasible for biodiesel production than any other purposes when it was cultivated in this new medium.Endüstriyel faaliyetlerden elde edilen birçok farklı atık su ve yan ürünler maliyet-etkin ve sürdürülebilir mikroalg kültüvasyonu için potansiyel kaynaklardır. Mevcut çalışmada, heterotrofik mikroalg Crypthecodinium cohnii kültüvasyonu için kültür besiyerinde peynir altı suyu (CW) ve mısır ıslatma şurubu (CSL) kullanılarak, bu atıkların mikroalgal biyokütle ve yağ üretimi amacıyla biyolojik olarak değerlendirilmesi hedeflenmiştir. Organizmanın, her iki ortamdaki (CW ve CSL) besin ihtiyaçlarını belirlemek amacıyla istatistiksel tarama metodları kullanılmıştır. CSL'nin C. cohnii biyokütle gelişimini olumlu yönde desteklediği ve organizmanın kültür ortamında kullanılan maya ekstraktının alternatifi olarak kullanılabileceği belirlenmiştir. Peyniraltı suyunun ise, organizma için gerekli mineraller açısından önemli bir kaynak olduğu ve CW'in doğrudan kullanımıyla kültür ortamındaki su ihtiyacını karşılama avantajına sahip olduğu kültür ortamı seyreltilmemiş CW ve CSL'nin birlikte kullanımı ile geliştirilmiştir ve optimizasyonu yapılmıştır. Son olarak, yapılan ölçek büyütme çalışmalarında yeni kültür ortamı kullanılarak 3 L'lik karıştırmalı tank biyoreaktörde üretimler gerçekleştirilmiştir. Optimizasyonu yapılan kültür ortamında kısmen yüksek biyokütle verimliliği (2.28 g/L.gün) ve yağ oranı (% 28.7 kuru ağırlık) sağlanmıştır.C. cohnii biyokütlede son derece yüksek oranlarda dokozahekzanoik asit (DHA) üreticisi bir tür olarak bilinmesine rağmen, CSL ile zenginleştirilmiş CW ortamında biyokütlesindeki yağ asidi kompozisyonunu değiştirerek, daha çok tekli doymuş ve tekli doymamış yağ asitlerince (C16:0-C18:1) zengin bir yağ profiline (toplam yağ asidi kompozisyonunun ~70%'i) sahip olduğu saptanmıştır. Buna göre, endüstriyel atıkların değerlendirildiği bu kültür ortamında yetiştirilen C. cohnii'nin biyodizel üretimi için uygun bir kaynak olabileceği sonucuna varılmıştır

Improvement of medium composition and cultivation conditions for growth and lipid production by Crypthecodinium cohnii

WOS: 000423282700009In this study, glycerol was used as an alternative carbon supply in the growth medium of Crypthecodinium cohnii. Concentration of other nutrients was optimized by using response surface methodology (RSM) for the growth and lipid production by microalgae. As a result, when using yeast extract, there was no need using glutamic acid and sodium beta-glycerophosphate in the growth medium. Additionally, it was revealed that there was a reduced growth by C. cohnii with a certain yeast extract concentration. The optimum sea salt concentration in the medium was determined as 16 g L-1. In the optimized medium, the highest biomass productivity and total lipid content achieved were 1.0 g L(-1)d(-1) and 30 % of dry weight basis, respectively. The yield coefficient of YX/S on glycerol obtained in this study was between 0.30-0.48 (w w(-1)). The effect of mechanical agitation on the growth and lipid production by C. cohnii was investigated in a 2 L stirred tank bioreactor. Nile red based flourescence intensity measurements during bioreactor productions revealed that lipid production by C. cohnii continued even after cells entered the stationary phase. The docosahexaenoic acid proportion increased until the beginning of stationary phase (5rd day) at 150 rpm agitation rate in bioreactor