Integrated perspective on microbe-based production of itaconic acid: from metabolic and strain engineering to upstream and downstream strategies

ABSTRACT: The discovery of itaconic acid as a product of citric acid pyrolytic distillation in 1837 opened the possibility of using it as a polymer building block. Itaconic acid, featuring two carboxylic acids and an unsaturated group, can potentially be used as a building block in several chemical syntheses, with a particular emphasis on polymer manufacture. The elucidation of biochemical pathways originating from itaconic acid, first in Aspergillus terreus and, recently, in several species of the Ustilago genus, has intensified and diversified research focused on microbe-based itaconic acid production, including at an industrial scale. These efforts include the engineering of naturally producing species/strains along with the exploration of other species that do not naturally produce itaconic acid but may offer potential benefits. The use of renewable wastes or sugar-enriched residues as substrates to produce itaconic acid, from a circular bioeconomy perspective, is another important aspect of the advancements in microbial itaconic acid production. This review provides an overview of the achievements as well as the challenges concerning the engineering of the producing strains/species, substrate selection, optimisation of bioreactor operation, and downstream itaconic acid purification methods.info:eu-repo/semantics/publishedVersio

Ingredientes para alimentos funcionais: uma área de futuro?

Os prebióticos são ingredientes alimentares não digeríveis, geralmente oligossacarídeos, que exercem um efeito benéfico no indivíduo estimulando selectivamente o crescimento e/ou actividade de espécies bacterianas existentes no cólon, melhorando a saúde do hospedeiro. O mercado mundial deste tipo de produtos tem vindo a crescer a taxas bastante elevadas, apesar de os seus preços de venda serem ainda bastante elevados. Neste sentido, é de acreditar que o desenvolvimento de novos processos de produção biotecnológicos com menores custos associados impulsione ainda mais o mercado. O projecto “BIOLIFE – Ingredientes para alimentos funcionais” visa o desenvolvimento de processos alternativos de produção de prebióticos

Moesziomyces spp. cultivation using cheese whey: new yeast extract-free media, beta-galactosidase biosynthesis and mannosylerythritol lipids production

ABSTRACT: Mannosylerythritol lipids (MELs) are biosurfactants with excellent biochemical properties and a wide range of potential applications. However, high production costs, low productivity and unsatisfactory scale-up production have hampered commercial adoption. Herein, we report for the first time the beta-galactosidase production by Moesziomyces spp. from different sugars (D-galactose, D-glucose and D-lactose), with D-galactose being the best beta-galactosidase inducer, with 11.2 and 63.1 IU/mg(biomass), for Moesziomyces aphidis 5535(T) and Moesziomyces antarcticus 5048(T), respectively. The production of this enzyme allows to break down D-lactose and thus to produce MEL directly from D-lactose or cheese whey (a cheese industry by-product). Remarkably, when CW was used as sole media component (carbon and mineral source), in combination with waste frying oil, MEL productivities were very close (1.40 and 1.31 g(MEL)/L/day) to the ones obtained with optimized medium containing yeast extract (1.92 and 1.50 g(MEL)/g(susbtrate)), both for M. antarcticus and M. aphidis. The low-cost, facile and efficient process which generates large amounts of MELs potentiates its industrialization.info:eu-repo/semantics/publishedVersio

High cellulase-free xylanases production by Moesziomyces aphidis using low-cost carbon and nitrogen sources

ABSTRACT: Background Enzymes involved in xylan hydrolysis have several industrial applications. Selection of efficient microbial hosts and scalable bioreaction operations can lower enzyme production costs and contribute to their commercial deployment. This work aims at investigating the Moesziomyces aphidis yeast cultivation conditions that deliver maximal xylanase titres, yields and productivities using low-cost nitrogen (N) and carbon (C) sources. Results NaNO3 and KNO3 supplementation improved xylanase production 2.9- and 2.7-fold (against 67.2 U mL(-1)), respectively, using xylan as C source. Interestingly, the use of KNO3, instead of NaNO3, results in 2- to 3-fold higher specific activity, highlighting the potassium ion role. In addition, this study investigates synergetic effects on using ionic and organic N sources. A 4.9-fold increase in xylanase production, with high specific activity, is attained combining KNO3 and corn steep liquor (CSL). Exploring the previous findings, this study reports one of the highest extracellular xylanase production titres (864.7 U mL(-1)) by yeasts, using a media formulation containing dilute-acid pre-treated brewery spent grains (BSG), as C source and inducer, supplemented with KNO3 and CSL. Replacement of dilute-acid pre-treatmed BSG by untreated BSG had low impact on xylanase production, of only 6%. Conclusion Efficient production of M. aphidis xylanolytic enzymes, using low-cost N and C sources, is attractive for deployment of on-site enzyme production targeting different biotechnological applications under circular economy and biorefinery concepts. Potential xylanases end-users include industries such as brewing (using BSG as substrate for enzyme production), pulp and paper (benefiting from the cellulase-free xylanase activity) or lignocellulosic ethanol (for cellulase supplementation).info:eu-repo/semantics/publishedVersio

Nanopartículas magnéticas como catalisadores no tratamento de águas utilizando o processo de foto-Fenton

O interesse nas aplicações de nanopartículas magnéticas tem crescido em quase todos os campos, destacando-se mais recentemente a utilização de nanopartículas de óxidos de ferro para tratamento de águas. De entre os óxidos de ferro existentes na natureza, destacam-se o a-Fe2O3, o g-Fe2O3 e o Fe3O4, que podem ser preparados laboratorialmente por métodos de co-precipitação [1], decomposição térmica [2] e síntese hidrotérmica [3]. As nanopartículas superparamagnéticas de óxido de ferro, também conhecidas como SPIONs - superparamagnetic iron oxide nanoparticles, são um caso particular devido à relação entre a distribuição de tamanhos das partículas e a carga superficial. A implementação destes materiais como catalisadores no tratamento de águas e águas residuais pode revolucionar o conceito das tecnologias catalíticas de tratamento porque quando estas nanopartículas, com propriedades magnéticas, são utilizadas em suspensão (i) proporcionam uma maior área de contacto entre a fase ativa e o meio aquoso e (ii) podem ser rapidamente (e facilmente) separadas do meio líquido por efeito de um campo magnético, ficando retidas no reator catalítico. Desta forma são ultrapassadas, tanto a principal limitação encontrada quando são utilizados catalisadores sem propriedades magnéticas em suspensão (difícil separação por processos de filtração), como a limitação associada à deposição de nanopartículas em substratos fixos (típica diminuição da atividade catalítica). Por outro lado, os compostos farmacêuticos são poluentes de maior relevância devido aos efeitos nefastos que podem causar na saúde pública, nos ecossistemas e no ambiente em geral, onde aparecem como resultado do seu consumo crescente e da sua difícil degradação em estações de tratamento de águas residuais. Estes compostos têm sido encontrados em águas subterrâneas, águas de superfície e inclusivamente em águas utilizadas para consumo, sendo esta última uma situação mais alarmante. Em particular, a difenidramina constituí o princípio ativo de diversos produtos farmacêutico, como o Benadryl®, e é classificada como anti-histamínico de primeira geração para formulações farmacêuticas utilizadas no tratamento de rinite, conjuntivite, insónia, picadas de insetos, enjoos/ansiedade, entre outros. Aparece nas águas devido à sua baixa biodegradabilidade e tem demonstrado efeitos tóxicos, cancerígenos e mutagénicos [4]. Por este motivo, no presente trabalho, foram preparados e caracterizados materiais à base de óxido de ferro com propriedades magnéticas para serem testados na degradação de difenidramina pelo processo de foto-Fenton, onde é utilizada uma mistura catalítica fortemente oxidante de um agente contendo ferro e peróxido de hidrogénio (H2O2)

Production of mannosylerythritol lipids using oils from oleaginous microalgae: two sequential microorganism culture approach

Mannosylerythritol lipids (MELs) are biosurfactants with excellent biochemical properties and a wide range of potential applications. However, most of the studies focusing on MELs high titre production have been relying in the use of vegetable oils with impact on the sustainability and process economy. Herein, we report for the first time MELs production using oils produced from microalgae. The bio-oil was extracted from Neochloris oleoabundans and evaluated for their use as sole carbon source or in a co-substrate strategy, using as an additional carbon source D-glucose, on Moesziomyces spp. cultures to support cell growth and induce the production of MELs. Both Moesziomyces antarcticus and M. aphidis were able to grow and produce MELs using algae-derived bio-oils as a carbon source. Using a medium containing as carbon sources 40 g/L of D-glucose and 20 g/L of bio-oils, Moesziomyces antarcticus and M. aphidis produced 12.47 +/- 0.28 and 5.72 +/- 2.32 g/L of MELs, respectively. Interestingly, there are no significant differences in productivity when using oils from microalgae or vegetable oils as carbon sources. The MELs productivities achieved were 1.78 +/- 0.04 and 1.99 +/- 0.12 g/L/h, respectively, for M. antarcticus fed with algae-derived or vegetable oils. These results open new perspectives for the production of MELs in systems combining different microorganisms.info:eu-repo/semantics/publishedVersio

Conversion of cellulosic materials into glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma spp. under SHF and SSF processes

Background: Mannosylerythritol lipids (MEL) are glycolipids with unique biosurfactant properties and are produced by Pseudozyma spp. from different substrates, preferably vegetable oils, but also sugars, glycerol or hydrocarbons. However, solvent intensive downstream processing and the relatively high prices of raw materials currently used for MEL production are drawbacks in its sustainable commercial deployment. The present work aims to demonstrate MEL production from cellulosic materials and investigate the requirements and consequences of combining commercial cellulolytic enzymes and Pseudozyma spp. under separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes. Results: MEL was produced from cellulosic substrates, Avicel® as reference (>99% cellulose) and hydrothermally pretreated wheat straw, using commercial cellulolytic enzymes (Celluclast 1.5 L® and Novozyme 188®) and Pseudozyma antarctica PYCC 5048T or Pseudozyma aphidis PYCC 5535T. The strategies included SHF, SSF and fed-batch SSF with pre-hydrolysis. While SSF was isothermal at 28°C, in SHF and fed-batch SSF, yeast fermentation was preceded by an enzymatic (pre-)hydrolysis step at 50°C for 48 h. Pseudozyma antarctica showed the highest MEL yields from both cellulosic substrates, reaching titres of 4.0 and 1.4 g/l by SHF of Avicel® and wheat straw (40 g/l glucan), respectively, using enzymes at low dosage (3.6 and 8.5 FPU/gglucan at 28°C and 50°C, respectively) with prior dialysis. Higher MEL titres were obtained by fed-batch SSF with pre-hydrolysis, reaching 4.5 and 2.5 g/l from Avicel® and wheat straw (80 g/l glucan), respectively. Conclusions: This work reports for the first time MEL production from cellulosic materials. The process was successfully performed through SHF, SSF or Fed-batch SSF, requiring, for maximal performance, dialysed commercial cellulolytic enzymes. The use of inexpensive lignocellulosic substrates associated to straightforward downstream processing from sugary broths is expected to have a great impact in the economy of MEL production for the biosurfactant market, inasmuch as low enzyme dosage is sufficient for good systems performance

Production of Mannosylerythritol Lipids Using Oils from Oleaginous Microalgae: Two Sequential Microorganism Culture Approach

ABSTRACT: Mannosylerythritol lipids (MELs) are biosurfactants with excellent biochemical properties and a wide range of potential applications. However, most of the studies focusing on MELs high titre production have been relying in the use of vegetable oils with impact on the sustainability and process economy. Herein, we report for the first time MELs production using oils produced from microalgae. The bio-oil was extracted from Neochloris oleoabundans and evaluated for their use as sole carbon source or in a co-substrate strategy, using as an additional carbon source D-glucose, on Moesziomyces spp. cultures to support cell growth and induce the production of MELs. Both Moesziomyces antarcticus and M. aphidis were able to grow and produce MELs using algae-derived bio-oils as a carbon source. Using a medium containing as carbon sources 40 g/L of D-glucose and 20 g/L of bio-oils, Moesziomyces antarcticus and M. aphidis produced 12.47 +/- 0.28 and 5.72 +/- 2.32 g/L of MELs, respectively. Interestingly, there are no significant differences in productivity when using oils from microalgae or vegetable oils as carbon sources. The MELs productivities achieved were 1.78 +/- 0.04 and 1.99 +/- 0.12 g/L/h, respectively, for M. antarcticus fed with algae-derived or vegetable oils. These results open new perspectives for the production of MELs in systems combining different microorganisms.info:eu-repo/semantics/publishedVersio