Production of oils and fats by oleaginous microorganisms with an emphasis given to the potential of the nonconventional yeast Yarrowia lipolytica

PubMedID: 29764205Recently, there has been a great upsurge of interest in studies related to several aspects of microbial lipid production, which is one of the top topics in relevant research fields due to the high demand of these fatty materials in food, medical, oleochemical and biofuel industries. Lipid accumulation by the so-called “oleaginous microorganisms” can generate more than 20% w/w of oil in dry biomass and is governed by a plethora of parameters, such as medium pH, incubation temperature, nutrient limitation and C/N (carbon/nitrogen) ratio, which drastically affect the lipid production bioprocess. Until now, considerable work has been undertaken to find the cheapest substrate to enable lipid fermentation by oleaginous microorganisms. This review principally details information regarding microbial lipids, suitable production conditions and focuses attention on using the yeast Yarrowia lipolytica to achieve these objectives. Lipid production by this yeast is discussed and the necessary conditions and suitable substrates are reviewed. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group

Lipids by yarrowia lipolytica strains cultivated on glucose in batch cultures

Oleaginous microorganisms, such as Yarrowia lipolytica, accumulate lipids that can have interesting applications in food biotechnology or the synthesis of biodiesel. Y. lipolytica yeast can have many advantages such as wide substrate range usage and robustness to extreme conditions, while under several culture conditions it can produce high lipid productivity. Based on this assumption, in this study, 12 different Yarrowia lipolytica strains were used to investigate microbial lipid production using a glucose-based medium under nitrogen-limited conditions in shake-flask cultivations. Twelve wild-type or mutant strains of Yarrowia lipolytica which were newly isolated or belonged to official culture collections were tested, and moderate lipid quantities (up to 1.30 g/L) were produced; in many instances, nitrogen limitation led to citric acid production in the medium. Lipids were mainly composed of C16 and C18 fatty acids. Most of the fatty acids of the microbial lipid were unsaturated and corresponded mainly to oleic, palmitic and linoleic acids. Linolenic acid (C18:3) was produced in significant quantities (between 10% and 20%, wt/wt of dry cell weight (DCW)) by strains H917 and Po1dL. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.FDK-2014-315

“In principio era il diritto all’acqua”: la dimensione morale come motore dell’azione collettiva per l’acqua pubblica

Il contributo di Davide Mazzoni e Elvira Cicognani, a partire da un approccio di psicologia sociale, riflette sulla dimensione morale della protesta, illustrando uno dei motori del successo della campagna referendaria. Dopo aver introdotto brevemente la letteratura sui processi di azione collettiva, il capitolo approfondisce le ragioni dell’identificazione con il movimento e della partecipazione alla campagna referendaria da parte di molti cittadini. In particolare, il saggio evidenzia che tale partecipazione è stata favorita dalla vasta percezione dell’acqua come un diritto, che le norme oggetto del referendum stavano in qualche modo violando. Il capitolo si basa sui risultati di un pool di studi recenti, condotti attraverso diverse metodologie (sia di tipo qualitativo, come le interviste, che quantitativo, come le inchieste campionarie)

Citric acid production by yarrowia lipolytica

peer reviewedRecently, with an increasing annual demand of more than two million tons, citric acid (CA) has become the main additive and functional component in the food, pharmaceutical, and chemical industries. This rising demand has induced research to search for alternative and cheap ways to fulfil CA requirements in industry. Lately, Yarrowia lipolytica has been considered as a promising microorganism in the production of CA since it has many advantages over moulds: mainly high productivity, easier cultivation (convenient for continuous process), and the capability to use a wide range of agricultural or industrial by-products and wastes as cheap carbon sources. CA production by this yeast depends on certain factors such as medium composition (type and concentrations of carbon, nitrogen, and trace elements) and the type of strain used (wild, mutant, or genetically engineered), as well as cultivation conditions (pH, temperature, dissolved oxygen, etc.). This review principally details recent studies concerning CA production by Y. lipolytica with an emphasis on techniques to increase productivity and yield to meet the expanding demand for this organic acid. Suitable substrates and production factors for high and cost-efficient CA production are discussed. Downstream processes and production systems are also reviewed. © Springer Nature Switzerland AG 2019

Influence of geographic origin on agronomic traits and phenolic content of cv. Gemlik olive fruits

In this work olive samples of Gemlik variety originated from Turkish regions Serinyol, Bahçe, Sariçam, Tarsus and Mudanya were harvested at five different times during fruit maturation. The results showed an important effect of environmental factors on the ripening progression based on the agronomic fruit traits and phenolic fraction. Differences in the technological use of olive fruits were observed among samples of different origins. The phenolic compounds of 25 olive samples were analyzed by HPLC-DAD-ESI-MS/MS, and 9 phenolics belonging to different families of phenols were identified and quantified. The harvest time and the geographical location were observed to interact and quantitatively govern the phenolic compounds production during maturation of olive fruits. Gemlik olive phenolic compounds can be used as a marker of each growing area and as a predictor of the optimal harvesting date, to optimize the organoleptic and nutritional value of the end product. © 2018 Elsevier Inc.The authors are grateful for financial support from The Scientific and Technological Research Council of Turkey (Grant No. TUBITAK-TOVAG 112O164 ). Appendix