Solid-state fermentation

About: Solid-state fermentation is a research topic. Over the lifetime, 5311 publications have been published within this topic receiving 113337 citations.

Coproduction of protease and amylase by thermophilic Bacillus sp. BBXS-2 using open solid-state fermentation of lignocellulosic biomass

Abstract: •Untreated lignocellulosic biomass is fermented to produce bacterial enzymes.•An open (nonaseptic) solid-state fermentation is used to minimize costs.•Thermophilic/alkalophilic fermentation conditions could control contamination.•Much higher titers of enzymes were produced compared to the literature.•Enzymes added to laundry detergents improved stain removal by ∼2.5-fold.

Protein enrichment of brewery spent grain from Rhizopus oligosporus by solid-state fermentation

Abstract: Brewery spent grain represents approximately 85 % of total by-products generated in a brewery. Consisting of carbohydrates, fiber, minerals and low amounts of protein, the use of brewery spent grain is limited to the feeding of ruminants; however, its potential use should be investigated. The reuse of this by-product using microorganisms by solid-state fermentation process as the case of protein enrichment by single-cell protein incorporation is an alternative to ensure sustainability and generate commercially interesting products. In this context, the aim of this study was to grow Rhizopus oligosporus in brewery spent grain under different initial moisture contents and nitrogen sources to increase the protein content of the fermented material. After 7 days of fermentation, increase of 2–4 times in the crude protein and soluble protein content was verified, respectively, compared to unfermented brewery spent grain. The kinetics of protein enrichment demonstrated the possibility of application of this technique, which can be a great alternative for use in diets for animals.

Xylanase production by Aspergillus awamori in solid-state fermentation and influence of different nitrogen sources.

Abstract: The use of purified xylan as a substrate for bioconversion into xyianases increases the cost of enzyme production. Consequently, there have been attempts to develop a bioprocess to produce such enzymes using different lignocellulosic residues. Filamentous fungi have been widely used to produce hydrolytic enzymes for industrial applications, including xyianases, whose levels in fungi are generally much higher than those in yeast and bacteria. Considering the industrial importance of xyianases, the present study evaluated the use of milled sugarcane bagasse, without any pretreat-ment, as a carbon source. Also, the effect of different nitrogen sources and the C:N ratio on xylanase production by Aspergillus awamori were investigated, in experiments carried out in solid-state fermentation. High extracellular xylanolytic activity was observed on cultivation of A. awamori on milled sugarcane bagasse and organic nitrogen sources (45 IU/mL for endoxylanase and 3.5 IU/mL for β-xylosidase). Endoxylanase and β-xylosidase activities were higher when sodium nitrate was used as the nitrogen source, when compared with peptone, urea, and ammonium sulfate at the optimized C:N ratio of 10:1. The use of yeast extract as a supplement to the these nitrogen sources resulted in considerable improvement in the production of xyianases, showing the importance of this organic nitrogen source on A. awamori metabolism.

Production and biochemical properties of proteases secreted by Aspergillus niger under solid state fermentation in response to different agroindustrial substrates

Abstract: This study reports the proteases production by Aspergillus niger LBA02 under solid state fermentation (SSF) using different agroindustrial by-products as substrates and the correlation between the protease production and some physical–chemical parameters. The biochemical properties of the proteases produced in each substrate were further investigated. The highest protease production was obtained using wheat bran as the substrate at 96 h fermentation. The results for chemical composition showed that the substrates with higher protein content induced the protease production at the first 48 h of fermentation. The crude extracts of proteases from A. niger LBA02 produced in wheat bran (PWB), soybean meal (PSM) and cottonseed meal (PCM) showed different biochemical properties when produced in different agroindustrial by-products. The biochemical characterization showed that the enzymes were most active over the pH range 3.0–4.0 and was stable from pH 2.5–4.5. The optimum temperature for activity was approximately 50.0 °C, and the enzymes were stable at 40.0–50.0 °C. In the study of the substrate specificity, the best substrate was hemoglobin from bovine blood with the highest relative activities of 183.84, 147.06 and 186.81% for PWB, PSM and PCM, respectively. The PWB showed higher ratio milk-clotting/protease activities (15.24) compared to PSM (0.38) and PCM (6.28).