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This study aimed at the exploitation of lignocellulosic wastes for the evaluation of the newly isolated white-rot fungal strains enzymatic potential for bioethanol production. The isolates belonging to Basidiomycetes, Fomes fomentarius TMF2, Schizophyllum commune TMF3, and Bjerkandera adusta TMF1, could synthesize extracellular laccase and various hydrolase while growing on lignocellulosic waste materials. More specifically, for the first time, F. fomentarius TMF2 synthesized laccase using sunflower meal as a substrate. This substrate could stimulate B. adusta TMF1 for carboxymethyl cellulase and Avicelase production. The isolate B. adusta TMF1 was able to produce amylase during its growth on brewerʼs spent grain, which is up to now the best result reported for this activity of any B. adusta strain. Soybean meal was the most potent substrate for stimulating pectinase production by B. adusta TMF1 and S. commune TMF3. While growing on brewerʼs spent grain, B. adusta TMF1 and S. commune TMF3 produced high levels of xylanase. Spent coffee residues were for the first time tested as a substrate for hydrolase production by selected fungal species. Also, this is the first attempt where the produced enzymes by isolate B. adusta TMF1 were used for lignocellulose hydrolysis of brewerʼs spent grain and corn stover for bioethanol production, where under non- optimized conditions 0.94 g/L and 0.86 g/L of bioethanol could be produced, respectively. This study showed that novel white-rot fungal isolates, especially B. adusta TMF1, could grow on unexploited, low-cost lignocellulosic substrates and to produce biotechnological value-added products within environmental and economical accepted processes.

Purpose This study aimed in exploitation of lignocellulosic wastes for the evaluation of the newly isolated white-rot fungal strains enzymatic potential, covered by the circular economy frame.Methods A standard microbiological methods for the isolation of the white-rot fungal mycelia were used, followed by DNA extraction, PCR amplification, and the API ZYM test. The determination of laccase activity was based on the oxidation of guaiacol while the DNS method was used for the hydrolase determination.Results The isolates, belonged to Basidiomycetes, Fomes fomentraius TMF2, Schizophyllum commune TMF3, and Bjerkandera adusta TMF1, could synthesize extracellular laccase and various hydrolase while growing on lignocellulosic waste materials. More specifically, for the first time, F. fomentarius TMF2 synthesized laccase using sunflower meal as a substrate. This substrate could stimulate B. adusta TMF1 for Carboxymethyl cellulase and Avicelase production. The strain TMF1 was able to produce amylase during its growth on brewerʼs spent grain, which is up to now the best result reported for this activity of any B. adusta strain. Soybean meal was the most potent substrate for stimulating pectinase production by TMF1 and S. commune TMF3. While growing on brewerʼs spent grain, TMF1 and TMF3 strains produced high levels of xylanase. Spent coffee residues were for the first time tested as a substrate for hydrolase production by selected fungal species.Conclusion The obtained results showed that newly isolates of white-rot fungi can grow on unexploited lignocellulosic waste materials to produce different enzymes as a value-added products suitable for various biotechnological applications.

BACKGROUND Biodiesel is an alternative to conventional fossil diesel fuel. Currently, it is mainly produced from vegetable oils and consequently it has an adverse impact on food price. Lipids from oleaginous microorganisms (e.g. microalgae, bacteria, fungi and yeasts) could be an alternative feedstock for biodiesel production and therefore the growth and lipid accumulation of Trichosporon oleaginosus was studied under different conditions. RESULTS The growth of T. oleaginosus on the xylose containing media enhanced the lipid accumulation and reduced cell growth, while on the glucose-containing media the opposite effect was observed. Trichosporon oleaginosus can accumulate above 50% of total lipids in dry cell mass during continuous and batch culture in the nitrogen-limited conditions. In the continuous culture relatively high productivity of total lipid accumulation (0.67 g dm−3 h−1) was observed on the glucose containing media. The type of substrate limitation has considerable impact on the fatty acid composition of yeast cell lipids. The predicted biodiesel properties (based on the fatty acids composition of lipids) were found to meet the CEN quality standards. CONCLUSION The results obtained show that T. oleaginosus has great potential for feasible biodiesel production, especially when sugars from industrial and agricultural waste are used as a substrate. © 2016 Society of Chemical Industry

The current industrial production of the biodiesel relies mainly on vegetable oils that could result in the shortage of edible oils in food markets and increase in their prices. Microbial lipids produced by oleaginous microorganism have attracted a lot of attention in the recent years as a source of high-value polyunsaturated acids as well as alternative feedstock for the production of biodiesel. However, the production of microbial oils faces a number of problems concerning the costs of lipid extraction, carbon source and operational cost for microbial cultivation in conventional stirred tank bioreactor which makes production economically unfeasible. Non-food feedstocks, lignocellulose biomass and different waste streams containing lignocellulose, are low-cost sources of renewable carbon that could significantly reduce the production cost of microbial lipids. This review analyses the current production of microbial lipids from lignocellulose feedstocks and gives an overview of the main stages in the process of lipid production, pretreatment and hydrolysis of the feedstock and microbial cultivation. Cultivation of oleaginous microorganisms has been conducted by submerged cultivation and solid state fermentation. Three process configurations have been used in the lipid production including, separate hydrolysis and lipid production (SHLP), simultaneous saccharification and lipid production (SSLP) and consolidate bioprocessing (CBP). Implementing the biorefinery concept that includes co-production of different value-added products (polyunsaturated fatty acids, amino acids, lignin and pigments) could improve the feasibility of lipid production bioprocess.

Fossil fuels are still major energy sources, but the search for renewable energy sources has been encouraged. Bioethanol has been recognized as an alternative to fossil fuels and nowadays it represents more than 90% of the global biofuel production. Bioethanol production from raw sugar beet cossettes as a semi-solid substrate was studied. The study was carried out in the horizontal rotating tubular bioreactor (HRTB) with Saccharomyces cerevisiae as a microbial production strain. The impact of different combinations of HRTB operational parameters such as, rotation speed (5-15 min(-1)), rotation type [constant or interval (3-15 min h(-1))] and working volume (ratio V (W)/V (T) = 0.2-0.7) on the bioethanol production was examined. In this study, the highest bioprocess efficiency parameters ( = 0.47 g g(-1), E = 87.36% and Pr = 0.618 g L-1 h(-1)) were observed at 0.20 V (W)/V (T), interval rotation of 12 min h(-1) and rotation speed of 15 min(-1). It has to be pointed out that bioethanol production efficiency in the HRTB was on the similar level as observed by bioethanol production from the raw sugar beet juice. Naturally present microorganisms of sugar beet could have a significant impact on bioethanol production. Higher yeast inoculation rate could reduce contaminant activities and, consequently, the bioethanol production efficiency would be improved.