Integrated biorefinery development using winery waste streams for the production of bacterial cellulose, succinic acid and value-added fractions

Succinic acid (SA) is one of the top candidate value-added chemicals that can be produced from biomass via microbial fermentation. A considerable number of cell factories have been proposed in the past two decades as native as well as non-native SA producers. Actinobacillus succinogenes is among the best and earliest known natural SA producers. However, its industrial application has not yet been realized due to various underlying challenges. Previous studies revealed that the optimization of environmental conditions alone could not entirely resolve these critical problems. On the other hand, microbial in silico metabolic modeling approaches have lately been the center of attention and have been applied for the efficient production of valuable commodities including SA. Then again, literature survey results indicated the absence of up-to-date reviews assessing this issue, specifically concerning SA production. Hence, this review was designed to discuss accomplishments and future perspectives of in silico studies on the metabolic capabilities of SA producers. Herein, research progress on SA and A. succinogenes, pathways involved in SA production, metabolic models of SA-producing microorganisms, and status, limitations and prospects on in silico studies of A. succinogenes were elaborated. All in all, this review is believed to provide insights to understand the current scenario and to develop efficient mathematical models for designing robust SA-producing microbial strains.

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VALORIZATION AND TREATMENT OF OILY WASTEWATERSFROM AGRO-INDUSTRIESUSING LIPASES: AN OVERVIEW

CIÊNCIA, TECNOLOGIA E INOVAÇÃO: DO CAMPO À MESA ◽

10.31692/978-65-88970-00-3.v.2.199-219 ◽

2020 ◽

pp. 199-219

Author(s):

Mulinari Jéssica ◽

Júnior Afonso Henrique da Silva ◽

Oliveira Carlos Rafael Silva de ◽

Júnior Francisco Wilson Reichert

Keyword(s):

Public Health ◽

Removal Efficiency ◽

Circular Economy ◽

Value Added ◽

Relevant Information ◽

Waste Streams ◽

Environmental Liabilities ◽

General Overview ◽

Oil Fraction ◽

Antioxidant Agents

Oily wastewater from agro-industries can cause severe environmental and public health damages if unproperly treated. The conventional methods have several limitations for the treatment of oily wastewaters since the oil fraction can cause pipe clogging and biomass washout during the biological step. Based on this, the use of lipases can increase the oil removal efficiency of the treatments, minimizing operational problems,and improving the performance of the biological process. Lipases can also be used for the valorization of the oily wastewaters, transforming these waste streams intovaluable compounds, such as biodiesel, lubricants, antioxidant agents, etc. The use of wastes for the production of value-added compounds followsthe circular economy approach, minimizing the generation of residues and potential environmental liabilities. Thus, this study aims to give a general overview of themain topics related to thetreatment and valorization of oily wastewaters using lipases. The main characteristics of oily wastewaters from agro-industries areaddressed, as well as the most used conventional techniques for their treatment. Some relevant information about the enzyme lipaseisalso discussed to give the reader a background about how these enzymes can be applied for the treatment and transformation of oily wastes.

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Bioproduction of succinic acid from xylose by engineered Yarrowia lipolytica without pH control

10.21203/rs.3.rs-19834/v1 ◽

2020 ◽

Author(s):

Ashish Prabhu ◽

Rodrigo Ledesma- Amaro ◽

Carol Sze Ki Lin ◽

Frederic Coulon ◽

Vijay kumar Thakur ◽

...

Keyword(s):

Cell Growth ◽

Carbon Source ◽

Succinic Acid ◽

Yarrowia Lipolytica ◽

Recombinant Strain ◽

Sole Carbon Source ◽

Substrate Inhibition ◽

Biomass Concentration ◽

Value Added ◽

Green Economy

Abstract Background Xylose is a most prevalent sugar available in hemicellulose fraction of lignocellulosic biomass (LCB) and of great interest for the green economy. Unfortunately, most of the cell factories cannot inherently metabolize xylose as sole carbon source. Yarrowia lipolytica is a non-conventional yeast to produce industrially important metabolites, and it is able to metabolize a large variety of substrates including both hydrophilic and hydrophobic carbon sources. However, Y. lipolytica lacks effective metabolic pathway for xylose uptake and only scarce information is available on utilization of xylose. For the economically feasible of LCB-based biorefineries, effective utilization of both pentose and hexose sugars is obligatory. Results In the present study, succinic acid (SA) production from xylose by Y. lipolytica was examined. To this end, Y. lipolytica PSA02004 strain was engineered by overexpressing pentose pathway cassette comprising of xylose reductase ( XR ), xylitol dehydrogenase ( XDH ) and xylulose kinase ( XK ) gene. The recombinant strain exhibited a robust growth on xylose as sole carbon source and accumulated SA (3.8 g/L) with a yield of 0.19 g/g in shake flask studies. Substrate inhibition studies revealed a marked negative impact on cell growth and product formation above 60 g/L xylose concentration. The modelling based on inhibition kinetics revealed that Aiba model showed better fit with experimental data, which resulted the correlation coefficient (R 2 ) of 0.82 and inhibition constant (K I ) 88.9 g/L. The batch cultivation of recombinant strain in bioreactor resulted in a maximum biomass concentration of 7.3 g/L and SA titer of 11.2 g/L with the yield of 0.18 g/g. Similar results in term of cell growth and SA production were obtained with xylose-rich hydrolysate derived from sugarcane bagasse. The fed-batch fermentation yielded biomass concentration of 11.8 g/L (OD 600 : 56.1) and SA titer of 22.3 g/L with a gradual decrease in pH below 4.0. Acetic acid was obtained as a main byproduct in all the fermentations. Conclusion The recombinant strain displayed potential bioconversion of xylose to succinic acid. Further this study provided a new insight on conversion of LCB into value-added products. To the best of our knowledge, this is the first study on SA production by Y. lipolytica using xylose as a sole carbon source.

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Integrated Biorefinery: High Value-Added Products from Agro-Industrial Residues

Journal of Biomedical Research & Environmental Sciences ◽

10.37871/jbres1226 ◽

2021 ◽

Vol 2 (4) ◽

pp. 286-287

Author(s):

Alessandra Morana

Keyword(s):

Environmental Impact ◽

Value Added ◽

Thermal Treatments ◽

Integrated Biorefinery ◽

Industrial Residues ◽

Sustainable Technologies ◽

Value Added Products

Every year, the anthropic activities generate thousands of tonnes of agro-industrial residues, which create serious disposal problems and have a very important economic and environmental impact. At this time, the most popular way of their disposing is degradation by biological and/or biochemical and/or thermal treatments; however, they often contain significant percentages of useful compounds that can be extracted and used in several sectors, thus representing an opportunity to be exploited through the development of eco-compatible/sustainable technologies with low environmental impact.

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