Production of Added-Value Metabolites Through Microbial Fermentation

Dear Colleagues,

There is continuously rising interest in replacing numerous chemical industrial processes with biotechnological ones, as the latter can enable the synthesis of significantly higher-specificity compounds, milder operating conditions, and the production of higher-complexity of molecules. Related to this, due to the progressive changes in global lifestyles in developed societies and the emergence of constantly worsening environmental/economic/ethical problems (i.e., the increasing accumulation of greenhouse gas emissions, progressive non-renewable resource depletion, the increasing insufficiency of various types of edible commodities, etc.) over the last 20–25 years, it has become mandatory to reconsider the linear disposal of various kinds of waste and residues and view several types of abundant (low-, zero-, or even negative-cost) agro-industrial/food processing/food-originated residues as resources containing important and interesting compounds, rather than waste that should be disposed of.

Under this framework, in recent years, biotechnological (mostly enzymatic and microbial) processes and operations have significantly contributed to the eco-friendly production of numerous added-value compounds, foods, and platform chemicals under mild operating conditions. In several cases, as well as the production of microbial metabolites, the conversion/valorization/depollution of agro-industrial and agro-food processing by-products and residues has been carried out. More specifically, attention has been paid to compounds synthesized during the fermentation processes of both autotrophic and heterotrophic microorganisms, such as organic acids, diols, polyols, enzymes, microbial lipids (convertible into second- or third-generation biofuels and/or containing functional polyunsaturated fatty acids), single-cell proteins, mushroom carposomes, high-value myco-products, microbial polysaccharides, etc. Yeasts, fungi, and bacteria cultivated heterotrophically, as well as microalgae and cyanobacteria cultivated autotrophically, mixotrophically, or heterotrophically, represent potential candidates for the production of microbial metabolites. Potential microbial substrates for this process include low-cost solid or liquid materials like starch-rich water; low-cost solid simple sugars or sugar syrups; wastewaters containing high sugar concentrations (i.e., cheese whey), derived from fish farms, or derived from fermentation, or contaminated wastewaters derived from agricultural processes (i.e., greenhouse wastewaters); liquid residues containing low-molecular-weight organic acids; solid and liquid waste from olive oil production; glycerol; lignocellulosic biomass; etc.

This SI, “Production of Added-Value Metabolites Through Microbial Fermentation”, aims to explore the above-mentioned approaches and the use of heterotrophic and/or autotrophic prokaryotic and eukaryotic microorganisms as microbial cell factories to produce various added-value metabolites during growth on several types of substrates in different fermentation modes and configurations.

All submitted papers will be subjected to independent peer-review, implemented as standard by Fermentation. Authors should specify the details of their research in their cover letter. Enquiries from the prospective authors of Mini Reviews are also welcome.

Prof. Dr. Seraphim Papanikolaou
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Fermentation is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2100 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• microbial fermentation
• value added
• metabolic
• waste
• microbial cell factories